ccd-newastro : Messages : 22-53 of 72864

#23 From: "Ron Wodaski" <ronw@...>
Date: Wed Jul 5, 2000 5:13 am
Subject: RE: Camera focus with Fastar ronw@...
Send Email

You are correct; the NGF-S is of no help in the Fastar configuration. The only way to focus in Fastar mode is with the moving primary mirror. I experienced all the usual problems trying to do this -- I would see focus change on me if the telescope was moved any significant distance, for example; and if I had to change directions with the focuser while focusing on a small area of the chip, the star I was focusing on would typically jump right off of that small area.

As far as focusing changing when you move the scope, this is something you have to live with on an SCT unless you actually lock the mirror down (which, of course, you cannot do in Fastar mode). As far as dealing with reversing focusing direction, it pays to develop a sense of where best focus is so that you don't have to switch directions. This takes some experience, however. Because of the way the mirror moves, "down" occurs when you are turning the focusing knob counterclockwise, so I try to make my focus changes moving the knob counterclockwise. I will deliberately move far enough out of focus on the clockwise side, so that when I move the knob counterclockwise to adjust focus, I start out slightly out of focus and gradually get closer to focus turning the knob counterclockwise.

The first one or two times I am adjusting focus, I will take the time to go past focus turning counterclockwise to get a sense of how good a peak pixel value of FWHM I can get. I then turn clockwise to back past focus, then I give the focusing knob a small turn counterclockwise again to put my star back on the chip. I then move back to focus, trying to achieve the best focus without going past. If I do go past, I bite the bullet and start over, and approach again using counterclockwise turns. This keeps the star on the chip for focusing, and I arrive at focus with the mirror reasonably settled.

I haven't yet tried the STV on the Fastar. The STV in normal mode is binned 2x2, and when binned 1x1 you only get the central 320x240 of the chip. So I prefer to use the ST-237 on the Fastar setup.

Ron Wodaski
http://www.newastro.com

-----Original Message-----
From: Jack Patterson [mailto:jpatters@...]
Sent: Tuesday, July 04, 2000 8:05 PM
To: ccd-newastro@egroups.com
Subject: [ccd-newastro] Camera focus with Fastar

Ron,

Your book says that short focal ratio scopes require precise focus and more effort to achieve the best focus, and the NGF-S focuser is recommended for fine focusing control on a SCT. It seems like the f2 Fastar would need critical focus and the NGF-S is probably not useable since the central obstruction would probably increase and the 2+" space for the focuser may not be there. How did you focus the Fastar with the ST237 camera for the images at your site or what would you recommend for Fastar fine focus control?
Also, have you used your STV on the Fastar and if you have, how did its imaging compare to your ST237/Fastar results? Do you plan on doing a STV review sometime?

Thanks,

Jack Patterson
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#24 From: "Ron Wodaski" <ronw@...>
Date: Fri Jul 7, 2000 2:05 pm
Subject: Comet LINEAR image showing structure ronw@...
Send Email

I have uploaded an image of Comet LINEAR 1999/S4 to the File section
of ccd-newastro:

http://www.egroups.com/files/ccd-
newastro/CCD+Gallery/Linear_S4_July_6.jpg

The image is a composite of seven separate one-minute images. The
individual images were calibrated, aligned on the comet's nucleus,
and summed in Maxim/DL.

The image shows some nice detail in the vicinity of the nucleus.
There appears to be a leading bulb of ions or dust, as well as a
pronounced "shockwave" of denser dust streaming out from the nucleus.
The tail is shown to be denser (or at least brighter) on the south
side (left side of the image).

The comet is moving fairly quickly, as you can see from the distance
between the star images -- the images are little more than a minute
apart in most cases.

Ron Wodaski

Reply | Messages in this Topic (1)

#25 From: "Jack Patterson" <jpatters@...>
Date: Sat Jul 8, 2000 11:03 pm
Subject: Re: Comet LINEAR image showing structure jpatters@...
Send Email

Ron, I like your comet image with its detail a lot more than others I've
seen which are usually animations.  And it started me thinking about what's
considered "proper" in the world of astro imaging.  I don't really know
since I'm new to this.  What if you removed the duplicate stars to make a
more realistic image?   Would that be proper?  If not, what about the
stacked comet images themselves.  A comet is not static, it changes in
appearance depending on where it's located in relation to heat sources.  So,
stacked images could conceivably show a different image than what was
actually there at any given time, although not likely in a short period.  I
was just wondering what you might think.
Thanks,
Jack Patterson

----- Original Message -----
From: Ron Wodaski <ronw@...>
To: <ccd-newastro@egroups.com>
Sent: Friday, July 07, 2000 9:05 AM
Subject: [ccd-newastro] Comet LINEAR image showing structure


> I have uploaded an image of Comet LINEAR 1999/S4 to the File section
> of ccd-newastro:
>
> http://www.egroups.com/files/ccd-
> newastro/CCD+Gallery/Linear_S4_July_6.jpg
>
> The image is a composite of seven separate one-minute images. The
> individual images were calibrated, aligned on the comet's nucleus,
> and summed in Maxim/DL.
>
> The image shows some nice detail in the vicinity of the nucleus.
> There appears to be a leading bulb of ions or dust, as well as a
> pronounced "shockwave" of denser dust streaming out from the nucleus.
> The tail is shown to be denser (or at least brighter) on the south
> side (left side of the image).
>
> The comet is moving fairly quickly, as you can see from the distance
> between the star images -- the images are little more than a minute
> apart in most cases.
>
> Ron Wodaski
>

#26 From: "Ron Wodaski" <ronw@...>
Date: Sat Jul 8, 2000 11:43 pm
Subject: RE: Comet LINEAR image showing structure ronw@...
Send Email

The neat thing about astrophotography, and CCD imaging in particular, is
that there are usually multiple ways to look at the data. The situation you
mention below is a good example -- there are different ways to present the
information in my collection of comet images. They are all different slices
of the truth, each emphasizing something different. I think it's useful to
think of the images not as images, but as a collection of data that can be
viewed using various approaches or filters.

Here are some examples of what I could do with the data I collected that
night:

* I could post each of the individual images separately, and they could be
examined for differences. I could even mathematically combined them --
subtract one image from the next, for example, leaving behind only what has
changed between the two images. If there were a subtle outgassing, this
should show it to us even if the eye could not pick it up amid all the other
things flying out of the comet. This emphasizes change in the comet.

* I could animate the images, showing the movement of the comet against the
starry background. Alternatively, I could animate the image so that the
comet is stationary, and the stars appear to move! <g> This emphasizes the
dynamic nature of the comet's motion.

* I could combine the seven images by averaging (or taking the median) of
the pixel values. This would nearly eliminate the stars from the images,
leaving just the comet. This emphasizes the comet's appearance averaged over
time.

* I could add the images together, adding all the pixel values, to help
reveal subtle details in the comet. As you point out, this would mask any
subtle changes over time, but would show subtle non-dynamic features more
clearly. This technique emphasizes stable but subtle features.

* I could adjust the brightness, contrast, and gamma settings to show
details at various levels of brightness, using single or combined images as
appropriate. The image I posted emphasizes subtle structural brightness
variations, but I also could crank up the brightness to emphasize any
details in the comet's dimmer tail section.

So it's really a matter of personal preference and interest. Or, one can
play with all of these approaches to see which, at any given time, produce
the most interesting results. In the image I posted, the interesting part
was the structural details. A week from now, the interesting thing might be,
say, the length of the tail, and I would use different techniques to bring
that out.

Part of what you learn doing astrophotography is the relationships between
photographic technique and the underlying data. Each image has it's own
unique set of data in it, and knowing how to use a variety of techniques
makes it possible for the imager to emphasize the most interesting data in a
given image. The average CCD raw image contains much more information than
the human eye can digest in one view, and it often is possible to present
the data in different ways.

Ron Wodaski



Ron Wodaski
http://www.newastro.com



-----Original Message-----
From: Jack Patterson [mailto:jpatters@...]
Sent: Saturday, July 08, 2000 4:03 PM
To: ccd-newastro@egroups.com
Subject: Re: [ccd-newastro] Comet LINEAR image showing structure


Ron, I like your comet image with its detail a lot more than others I've
seen which are usually animations.  And it started me thinking about what's
considered "proper" in the world of astro imaging.  I don't really know
since I'm new to this.  What if you removed the duplicate stars to make a
more realistic image?   Would that be proper?  If not, what about the
stacked comet images themselves.  A comet is not static, it changes in
appearance depending on where it's located in relation to heat sources.  So,
stacked images could conceivably show a different image than what was
actually there at any given time, although not likely in a short period.  I
was just wondering what you might think.
Thanks,
Jack Patterson

----- Original Message -----
From: Ron Wodaski <ronw@...>
To: <ccd-newastro@egroups.com>
Sent: Friday, July 07, 2000 9:05 AM
Subject: [ccd-newastro] Comet LINEAR image showing structure


> I have uploaded an image of Comet LINEAR 1999/S4 to the File section
> of ccd-newastro:
>
> http://www.egroups.com/files/ccd-
> newastro/CCD+Gallery/Linear_S4_July_6.jpg
>
> The image is a composite of seven separate one-minute images. The
> individual images were calibrated, aligned on the comet's nucleus,
> and summed in Maxim/DL.
>
> The image shows some nice detail in the vicinity of the nucleus.
> There appears to be a leading bulb of ions or dust, as well as a
> pronounced "shockwave" of denser dust streaming out from the nucleus.
> The tail is shown to be denser (or at least brighter) on the south
> side (left side of the image).
>
> The comet is moving fairly quickly, as you can see from the distance
> between the star images -- the images are little more than a minute
> apart in most cases.
>
> Ron Wodaski
>



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#27 From: "Jack Patterson" <jpatters@...>
Date: Sun Jul 9, 2000 8:00 pm
Subject: Re: Comet LINEAR image showing structure jpatters@...
Send Email

Excellent response!  It really helped a lot.  I suggest you include
something similar in your book.

Jack Patterson

----- Original Message -----
From: Ron Wodaski <ronw@...>
To: <ccd-newastro@Egroups.com>
Sent: Saturday, July 08, 2000 6:43 PM
Subject: RE: [ccd-newastro] Comet LINEAR image showing structure


> The neat thing about astrophotography, and CCD imaging in particular, is
> that there are usually multiple ways to look at the data. The situation
you
> mention below is a good example -- there are different ways to present the
> information in my collection of comet images. They are all different
slices
> of the truth, each emphasizing something different. I think it's useful to
> think of the images not as images, but as a collection of data that can be
> viewed using various approaches or filters.
>
> Here are some examples of what I could do with the data I collected that
> night:
>
> * I could post each of the individual images separately, and they could be
> examined for differences. I could even mathematically combined them --
> subtract one image from the next, for example, leaving behind only what
has
> changed between the two images. If there were a subtle outgassing, this
> should show it to us even if the eye could not pick it up amid all the
other
> things flying out of the comet. This emphasizes change in the comet.
>
> * I could animate the images, showing the movement of the comet against
the
> starry background. Alternatively, I could animate the image so that the
> comet is stationary, and the stars appear to move! <g> This emphasizes the
> dynamic nature of the comet's motion.
>
> * I could combine the seven images by averaging (or taking the median) of
> the pixel values. This would nearly eliminate the stars from the images,
> leaving just the comet. This emphasizes the comet's appearance averaged
over
> time.
>
> * I could add the images together, adding all the pixel values, to help
> reveal subtle details in the comet. As you point out, this would mask any
> subtle changes over time, but would show subtle non-dynamic features more
> clearly. This technique emphasizes stable but subtle features.
>
> * I could adjust the brightness, contrast, and gamma settings to show
> details at various levels of brightness, using single or combined images
as
> appropriate. The image I posted emphasizes subtle structural brightness
> variations, but I also could crank up the brightness to emphasize any
> details in the comet's dimmer tail section.
>
> So it's really a matter of personal preference and interest. Or, one can
> play with all of these approaches to see which, at any given time, produce
> the most interesting results. In the image I posted, the interesting part
> was the structural details. A week from now, the interesting thing might
be,
> say, the length of the tail, and I would use different techniques to bring
> that out.
>
> Part of what you learn doing astrophotography is the relationships between
> photographic technique and the underlying data. Each image has it's own
> unique set of data in it, and knowing how to use a variety of techniques
> makes it possible for the imager to emphasize the most interesting data in
a
> given image. The average CCD raw image contains much more information than
> the human eye can digest in one view, and it often is possible to present
> the data in different ways.
>
> Ron Wodaski
>
>
>
> Ron Wodaski
> http://www.newastro.com
>
>
>
> -----Original Message-----
> From: Jack Patterson [mailto:jpatters@...]
> Sent: Saturday, July 08, 2000 4:03 PM
> To: ccd-newastro@egroups.com
> Subject: Re: [ccd-newastro] Comet LINEAR image showing structure
>
>
> Ron, I like your comet image with its detail a lot more than others I've
> seen which are usually animations.  And it started me thinking about
what's
> considered "proper" in the world of astro imaging.  I don't really know
> since I'm new to this.  What if you removed the duplicate stars to make a

> more realistic image?   Would that be proper?  If not, what about the
> stacked comet images themselves.  A comet is not static, it changes in
> appearance depending on where it's located in relation to heat sources.
So,
> stacked images could conceivably show a different image than what was
> actually there at any given time, although not likely in a short period.
I
> was just wondering what you might think.
> Thanks,
> Jack Patterson
>
> ----- Original Message -----
> From: Ron Wodaski <ronw@...>
> To: <ccd-newastro@egroups.com>
> Sent: Friday, July 07, 2000 9:05 AM
> Subject: [ccd-newastro] Comet LINEAR image showing structure
>
>
> > I have uploaded an image of Comet LINEAR 1999/S4 to the File section
> > of ccd-newastro:
> >
> > http://www.egroups.com/files/ccd-
> > newastro/CCD+Gallery/Linear_S4_July_6.jpg
> >
> > The image is a composite of seven separate one-minute images. The
> > individual images were calibrated, aligned on the comet's nucleus,
> > and summed in Maxim/DL.
> >
> > The image shows some nice detail in the vicinity of the nucleus.
> > There appears to be a leading bulb of ions or dust, as well as a
> > pronounced "shockwave" of denser dust streaming out from the nucleus.
> > The tail is shown to be denser (or at least brighter) on the south
> > side (left side of the image).
> >
> > The comet is moving fairly quickly, as you can see from the distance
> > between the star images -- the images are little more than a minute
> > apart in most cases.
> >
> > Ron Wodaski
> >

#28 From: "Ron Wodaski" <ronw@...>
Date: Mon Jul 10, 2000 4:37 am
Subject: New content coming ronw@...
Send Email

I made good progress on chapter 6 this weekend. This new chapter covers dark
frames, flat fields, and other techniques for controlling noise in your
images. I'd like to know if anyone is interested in viewing the early
versions/partial versions of chapters, or whether I should wait until the
chapter is done and checked for errors before I post it to the web site. It
normally takes a couple of weeks to finish a chapter, and another few days
to convert it to web format. If I post intermediate sections, I might be
better able to respond to special requests from subscribers, too. What do
you think?

Ron Wodaski
http://www.newastro.com

#29 From: Steve Mandel <smandel@...>
Date: Mon Jul 10, 2000 4:43 am
Subject: Re: New content coming smandel@...
Send Email

Hi Ron:

I think your material is just wonderful and would love to see what is next.
  I have learned so much from the first chapter on focus - I am "hungry" for
more.  Please post what you have!!!

Thank you for writing this book,

Steve




At 09:37 PM 7/9/00 -0700, you wrote:
>I made good progress on chapter 6 this weekend. This new chapter covers dark
>frames, flat fields, and other techniques for controlling noise in your
>images. I'd like to know if anyone is interested in viewing the early
>versions/partial versions of chapters, or whether I should wait until the
>chapter is done and checked for errors before I post it to the web site. It
>normally takes a couple of weeks to finish a chapter, and another few days
>to convert it to web format. If I post intermediate sections, I might be
>better able to respond to special requests from subscribers, too. What do
>you think?
>
>Ron Wodaski
>http://www.newastro.com
>
>
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#30 From: Michael Clary <tricomp1@...>
Date: Mon Jul 10, 2000 6:27 am
Subject: Re: New content coming tricomp1@...
Send Email

Ron,

I don't know exactly who is on your subscriber list, but I do know that
there a lot of experts (plus a large number of wanna be's) out here. If I
were you, I'd try posting partials for a while and see if the feedback is
worth your time. You might get some good input that makes your job easier.
On the other hand, you might stimulate questions that you may or may not
wish to deal with. Either way, it's probably worth a try, but the bottom
line is set it up to your advantage...we'll all benefit in the long run!

press on!
Michael Clary
tricomp1@...

on 7/9/00 9:37 PM, Ron Wodaski at ronw@... wrote:

> I made good progress on chapter 6 this weekend. This new chapter covers dark
> frames, flat fields, and other techniques for controlling noise in your
> images. I'd like to know if anyone is interested in viewing the early
> versions/partial versions of chapters, or whether I should wait until the
> chapter is done and checked for errors before I post it to the web site. It
> normally takes a couple of weeks to finish a chapter, and another few days
> to convert it to web format. If I post intermediate sections, I might be
> better able to respond to special requests from subscribers, too. What do
> you think?
>
> Ron Wodaski
> http://www.newastro.com

#31 From: "Ron Wodaski" <ronw@...>
Date: Tue Jul 11, 2000 4:20 am
Subject: RE: New content coming ronw@...
Send Email

I gave this some thought after reading the replies, and I think what might
work best is to focus on sections, rather than entire chapters. I will
experiment with posting each section as I complete it, following a technical
accuracy check. The next section to be posted will be on dark frames.

Ron Wodaski
http://www.newastro.com



-----Original Message-----
From: Steve Mandel [mailto:smandel@...]
Sent: Sunday, July 09, 2000 9:44 PM
To: ccd-newastro@Egroups.com
Subject: Re: [ccd-newastro] New content coming


Hi Ron:

I think your material is just wonderful and would love to see what is next.
  I have learned so much from the first chapter on focus - I am "hungry" for
more.  Please post what you have!!!

Thank you for writing this book,

Steve




At 09:37 PM 7/9/00 -0700, you wrote:
>I made good progress on chapter 6 this weekend. This new chapter covers
dark
>frames, flat fields, and other techniques for controlling noise in your
>images. I'd like to know if anyone is interested in viewing the early
>versions/partial versions of chapters, or whether I should wait until the
>chapter is done and checked for errors before I post it to the web site. It
>normally takes a couple of weeks to finish a chapter, and another few days
>to convert it to web format. If I post intermediate sections, I might be
>better able to respond to special requests from subscribers, too. What do
>you think?
>
>Ron Wodaski
>http://www.newastro.com
>
>
>------------------------------------------------------------------------
>Missing old school friends? Find them here:
>http://click.egroups.com/1/5534/1/_/_/_/963203854/
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>
>To unsubscribe from this group, send an email to:
>ccd-newastro-unsubscribe@egroups.com
>


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#32 From: "Ron Wodaski" <ronw@...>
Date: Tue Jul 11, 2000 4:22 am
Subject: RE: New content coming ronw@...
Send Email

I am getting some help from folks who are experts in the field, but it is
coming mostly privately. Many folks have the ability to contribute, but are
too busy to take on the commitment of a complete book. So I am looking
forward to including quite a few contributions.

As I mentioned in a separate post, I will experiment with posting one
section at a time, rather than one chapter at a time. It will smooth things
out for me -- no huge deadlines -- and give folks more content at a
reasonable pace.

Ron Wodaski
http://www.newastro.com

-----Original Message-----
From: Michael Clary [mailto:tricomp1@...]
Sent: Sunday, July 09, 2000 11:28 PM
To: ccd-newastro@egroups.com
Subject: Re: [ccd-newastro] New content coming

Ron,

I don't know exactly who is on your subscriber list, but I do know that
there a lot of experts (plus a large number of wanna be's) out here. If I
were you, I'd try posting partials for a while and see if the feedback is
worth your time. You might get some good input that makes your job easier.
On the other hand, you might stimulate questions that you may or may not
wish to deal with. Either way, it's probably worth a try, but the bottom
line is set it up to your advantage...we'll all benefit in the long run!

press on!
Michael Clary
tricomp1@...

on 7/9/00 9:37 PM, Ron Wodaski at ronw@... wrote:

> I made good progress on chapter 6 this weekend. This new chapter covers
dark
> frames, flat fields, and other techniques for controlling noise in your
> images. I'd like to know if anyone is interested in viewing the early
> versions/partial versions of chapters, or whether I should wait until the
> chapter is done and checked for errors before I post it to the web site.
It
> normally takes a couple of weeks to finish a chapter, and another few days
> to convert it to web format. If I post intermediate sections, I might be
> better able to respond to special requests from subscribers, too. What do
> you think?
>
> Ron Wodaski
> http://www.newastro.com

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#33 From: Steve Mandel <smandel@...>
Date: Tue Jul 11, 2000 4:27 am
Subject: RE: New content coming smandel@...
Send Email

Ron:

When will it be posted?

I hope the next thing you post after darks is on flats - there are a lot of
questions out there about that.

Thanks,
Steve




At 09:20 PM 7/10/00 -0700, you wrote:
>I gave this some thought after reading the replies, and I think what might
>work best is to focus on sections, rather than entire chapters. I will
>experiment with posting each section as I complete it, following a technical
>accuracy check. The next section to be posted will be on dark frames.
>
>Ron Wodaski
>http://www.newastro.com
>
>
>
>-----Original Message-----
>From: Steve Mandel [mailto:smandel@...]
>Sent: Sunday, July 09, 2000 9:44 PM
>To: ccd-newastro@Egroups.com
>Subject: Re: [ccd-newastro] New content coming
>
>
>Hi Ron:
>
>I think your material is just wonderful and would love to see what is next.
> I have learned so much from the first chapter on focus - I am "hungry" for
>more.  Please post what you have!!!
>
>Thank you for writing this book,
>
>Steve
>
>
>
>
>At 09:37 PM 7/9/00 -0700, you wrote:
>>I made good progress on chapter 6 this weekend. This new chapter covers
>dark
>>frames, flat fields, and other techniques for controlling noise in your
>>images. I'd like to know if anyone is interested in viewing the early
>>versions/partial versions of chapters, or whether I should wait until the
>>chapter is done and checked for errors before I post it to the web site. It
>>normally takes a couple of weeks to finish a chapter, and another few days
>>to convert it to web format. If I post intermediate sections, I might be
>>better able to respond to special requests from subscribers, too. What do
>>you think?
>>
>>Ron Wodaski
>>http://www.newastro.com
>>
>>
>>------------------------------------------------------------------------
>>Missing old school friends? Find them here:
>>http://click.egroups.com/1/5534/1/_/_/_/963203854/
>>------------------------------------------------------------------------
>>
>>To unsubscribe from this group, send an email to:
>>ccd-newastro-unsubscribe@egroups.com
>>
>
>
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>experiments.
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#34 From: "Ron Wodaski" <ronw@...>
Date: Tue Jul 11, 2000 4:47 am
Subject: RE: New content coming ronw@...
Send Email

Exactly; they are a natural pair. I think you'll like the level of
information I'm providing on these two subjects. I know how I struggled with
the concepts when I was starting out, and I'm trying to address the
questions that naturally come up.

Ron Wodaski
http://www.newastro.com



-----Original Message-----
From: Steve Mandel [mailto:smandel@...]
Sent: Monday, July 10, 2000 9:28 PM
To: ccd-newastro@Egroups.com
Subject: RE: [ccd-newastro] New content coming


Ron:

When will it be posted?

I hope the next thing you post after darks is on flats - there are a lot of
questions out there about that.

Thanks,
Steve




At 09:20 PM 7/10/00 -0700, you wrote:
>I gave this some thought after reading the replies, and I think what might
>work best is to focus on sections, rather than entire chapters. I will
>experiment with posting each section as I complete it, following a
technical
>accuracy check. The next section to be posted will be on dark frames.
>
>Ron Wodaski
>http://www.newastro.com
>
>
>
>-----Original Message-----
>From: Steve Mandel [mailto:smandel@...]
>Sent: Sunday, July 09, 2000 9:44 PM
>To: ccd-newastro@Egroups.com
>Subject: Re: [ccd-newastro] New content coming
>
>
>Hi Ron:
>
>I think your material is just wonderful and would love to see what is next.
> I have learned so much from the first chapter on focus - I am "hungry" for
>more.  Please post what you have!!!
>
>Thank you for writing this book,
>
>Steve
>
>
>
>
>At 09:37 PM 7/9/00 -0700, you wrote:
>>I made good progress on chapter 6 this weekend. This new chapter covers
>dark
>>frames, flat fields, and other techniques for controlling noise in your
>>images. I'd like to know if anyone is interested in viewing the early
>>versions/partial versions of chapters, or whether I should wait until the
>>chapter is done and checked for errors before I post it to the web site.
It
>>normally takes a couple of weeks to finish a chapter, and another few days
>>to convert it to web format. If I post intermediate sections, I might be
>>better able to respond to special requests from subscribers, too. What do
>>you think?
>>
>>Ron Wodaski
>>http://www.newastro.com
>>
>>
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#35 From: "AllenD " <iamal@...>
Date: Thu Jul 13, 2000 2:15 am
Subject: gallery iamal@...
Send Email

Ron your color images are excellent. M81 ...WOW! Tell me how to get
similar result with my equipment.

Reply | Messages in this Topic (3)

#36 From: "Ron Wodaski" <ronw@...>
Date: Thu Jul 13, 2000 3:13 am
Subject: RE: gallery ronw@...
Send Email

For starters, what equipment are you using -- telescope, camera, mount? What
camera control software do you use?

Ron Wodaski
http://www.newastro.com



-----Original Message-----
From: AllenD [mailto:iamal@...]
Sent: Wednesday, July 12, 2000 7:15 PM
To: ccd-newastro@egroups.com
Subject: [ccd-newastro] gallery


Ron your color images are excellent. M81 ...WOW! Tell me how to get
similar result with my equipment.


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Reply | Messages in this Topic (3)

#39 From: "Al " <iamal@...>
Date: Thu Jul 13, 2000 1:51 pm
Subject: Re: gallery iamal@...
Send Email

--- In ccd-newastro@egroups.com, "Ron Wodaski" <ronw@n...> wrote:
> For starters, what equipment are you using -- telescope, camera,
mount? What
> camera control software do you use?
>
> Ron Wodaski
> http://www.newastro.com
>
> I'm currently using a C8/WedgePod and imaging with a ST-237 camera
@ f/1.95 I get a so so alignment and usually have to eyeball my
object with 7x50 finder to center them on the chip due to Fastar
setup and not knowing how to use the setting circles effecently. I
use CCDOPS to acquire and do some processing but I like results from
Photoshop too. The night sky dosen't want to give up it's galaxies to
me. And I'll be dam if I can figure out how to get all that hidden
information out of those pixels. But Im determined. I have posted a
few files in the "feedback" area for posting images here, and am
looking for suggestions for improving technique
Thanks You


>
>
> -----Original Message-----
> From: AllenD [mailto:iamal@q...]
> Sent: Wednesday, July 12, 2000 7:15 PM
> To: ccd-newastro@egroups.com
> Subject: [ccd-newastro] gallery
>
>
> Ron your color images are excellent. M81 ...WOW! Tell me how to get
> similar result with my equipment.
>
>
> --------------------------------------------------------------------
----
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Reply | Messages in this Topic (3)

#40 From: "Kevin Dixon" <ksbtk@...>
Date: Sun Jul 16, 2000 3:05 am
Subject: polar alignment question ksbtk@...
Send Email

Good evening:

First, let me express my thanks to Ron for establishing this e-group
and for making chapters of the new book available on-line.  Chapter 2
looks to be worth its weight in gold.

I have a Celestron C8 Deluxe and an SBIG ST-237 CCD camera.  My
question is, how accurate must the polar alignment be when using this
set-up at f/6.3 (using a focal reducer) and at f/1.9 (using Fastar)?

I look forward to all input.  Thanks.

Clear skies,
Kevin
ksbtk@...

Reply | Messages in this Topic (8)

#41 From: "Kevin Dixon" <ksbtk@...>
Date: Sun Jul 16, 2000 3:07 am
Subject: imaging Jupiter and Saturn ksbtk@...
Send Email

Good evening:

With the return of Jupiter and Saturn, I am interested in imaging
these beauties.  I would be doing this with a C8 Deluxe and an ST-
237.  I have read of using a Barlow lens but am unsure of the
specifics.

All hints and recommendations are most welcome.  Thanks.

Clear skies,
Kevin
ksbtk@...

#42 From: "Dennis Chapman" <dec@...>
Date: Sun Jul 16, 2000 4:06 am
Subject: M31 Color imaging, focus problems? dec@...
Send Email

Greetings,
   I've uploaded a trio of images I took the other night of M31. The
image with the red filter looks decent however the images that were
taken with the green and blue filters look out of focus. When I
combine these with Maxim/DL I get awful color matching (stars with
white cores and blue-green outer rings).

   My question is are there be slight differences in focus needed when
taking images with different color filters? Should I be using one of
the color filters for focusing? I normally use the clear filter.

  Let me add that I'm very new to CCD imaging (these are first light
images on my system).

Equipment:
   Takahashi FSQ-106 with EM200 mount
   SBIG ST8E NABG & CFW8 color wheel
   Each image was taken for 70s with 2x2 binning and auto-dark
   calibration.

Clear Skies!
Dennis

#43 From: Michael Clary <tricomp1@...>
Date: Sun Jul 16, 2000 3:45 pm
Subject: Re: M31 Color imaging, focus problems? tricomp1@...
Send Email

Hi Dennis,

Although I use the ST-7E nabg, I do have the CFW-8. I've noticed that
although the RGB filters on my wheel have a common focus point, that point
is not the same for my clear/IR-blocked filter. If I focus with the clear to
do LRGB, then I need to refocus with the r, g, or b (usually r) before I
start my color sequence.

Why? Custom Scientific provides quality filters for the CFW-8, but....
One obvious reason could be the fact that these are screw-in filters. If one
is tighter than the others, this shifts the focal point. You say that your
red image looks "decent" but the blue and green look out of focus,
indicating that there is a common focal point for your clear and red, but
not for your blue and green. In this case, it makes use of Maxim's rgb
sequence capability difficult if not impossible. You'll need to refocus for
each filter unless you can get all of the color filters set to a common
focus point (through jiggling of the filters...i.e. adjusting how loose or
tight they are screwed in...not really a satisfactory solution).

With respect to your color balance, one reason is the focused and out of
focus images. Focused images tend to yield smaller stars, out of focus
images get you "bloated" stars. When you stack them into an rgb, you get the
blue/green halo caused by your out of focus blue and green filters. One
other possible reason your seeing bad color is unbalanced backgrounds. You
need to equalize your backgrounds (find an area with no stars and use pixel
math to equalize/normalize the r, g, and b images).

Hope this helps
Michael Clary
tricomp1@...

on 7/15/00 9:06 PM, Dennis Chapman at dec@... wrote:

> Greetings,
> I've uploaded a trio of images I took the other night of M31. The
> image with the red filter looks decent however the images that were
> taken with the green and blue filters look out of focus. When I
> combine these with Maxim/DL I get awful color matching (stars with
> white cores and blue-green outer rings).
>
> My question is are there be slight differences in focus needed when
> taking images with different color filters? Should I be using one of
> the color filters for focusing? I normally use the clear filter.
>
> Let me add that I'm very new to CCD imaging (these are first light
> images on my system).
>
> Equipment:
> Takahashi FSQ-106 with EM200 mount
> SBIG ST8E NABG & CFW8 color wheel
> Each image was taken for 70s with 2x2 binning and auto-dark
> calibration.
>
> Clear Skies!
> Dennis
>
>
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#44 From: "Ron Wodaski" <ronw@...>
Date: Sun Jul 16, 2000 5:59 pm
Subject: RE: polar alignment question ronw@...
Send Email

As you probably guessed, the shorter the focal length, the less critical the
need for perfect polar alignment. With the f/6.3 focal reducer, the C8's
focal length is 1260mm. That is moderately long, and you will get best
results with a non-drift polar alignment using a decent polar alignment
scope. You should be able to get 30-60 second unguided exposures in that
configuration, depending on how good your polar alignment winds up being.
Such exposures are too brief for most objects, but you can take 2, 5, 10 or
even more exposures and combine them to get a good image.

At f/1.95, your focal length is way down, to ~400mm. A polar-scope alignment
should give you 1.5-2 minute exposures, time enough to get good results on
many objects. For dimmer objects, you can still take multiple exposures. For
example, if you were imaging a globular, you could get nice results in a
single exposure, or if you were imaging the North American Nebula, you might
want to try 5 100-second exposures, for example.

Once I've done polar alignment, I generally take an exposure that is about
double the length of the exposure I expect to be able to take at a given
focal length, and I analyze it to get a sense for how close the polar
alignment is. For example, if I am using an 800mm scope, I would probably
take a 2- or 3-minute exposure to see how much star trailing occurs. If it
is minor, I know I can probably take 1.5-2 minute exposures. If it is major,
I might only be able to get 45-60 second exposures. You can develop a sense
of what your polar alignment procedure can do for you over a series of
nights. If the polar alignment is very poor, I will simply do it over. If I
have a very dim object to image, a bit of drift alignment might be my
option. I use a pretty crude method of drift alignment -- I take images that
show star trails, and then I make a random adjustment to alt or az, and not
whether it improves, or not. <g> Once I establish the benefit of adjustments
in various directions, I iterate toward whatever length of exposure I have
as my target. If I am imaging something dim like the Cocoon, I might aim for
5 minutes unguided. If I were imaging the North American Nebula, which has
some brighter stars that will bloom, I would settle for say two minutes.

Generally speaking, it's worth learning how to do a good polar alignment; a
good alignment reduces problems across the board. With a good alignment,
guiding corrections are smaller and less frequent; rotation is smaller
during longer or stacked exposures; setting circles will be more accurate.

Ron Wodaski
The New Astronomy Book Site - http://www.newastro.com



-----Original Message-----
From: Kevin Dixon [mailto:ksbtk@...]
Sent: Saturday, July 15, 2000 8:05 PM
To: ccd-newastro@egroups.com
Subject: [ccd-newastro] polar alignment question


Good evening:

First, let me express my thanks to Ron for establishing this e-group
and for making chapters of the new book available on-line.  Chapter 2
looks to be worth its weight in gold.

I have a Celestron C8 Deluxe and an SBIG ST-237 CCD camera.  My
question is, how accurate must the polar alignment be when using this
set-up at f/6.3 (using a focal reducer) and at f/1.9 (using Fastar)?

I look forward to all input.  Thanks.

Clear skies,
Kevin
ksbtk@...



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Reply | Messages in this Topic (8)

#45 From: "Ron Wodaski" <ronw@...>
Date: Sun Jul 16, 2000 6:04 pm
Subject: RE: imaging Jupiter and Saturn ronw@...
Send Email

You can use a Barlow lens for imaging pretty much the same way you would use
it for visual observing. For the C8 and ST-237, simply put the Barlow into
the visual back, and the camera into the Barlow. You will be at f/20, and
have a fairly narrow field of view, so putting objects on the chip becomes
more challenging. If you have a larger finder (perhaps something like a 10x
or 12x finder, with an aperture in the 50-70mm range), you can use the
finder to accurately put Jupiter and Saturn on the chip. Otherwise, you may
have to take images, consult a star chart to see where you are, and then
move the scope toward the planet, image again, figure out your position,
etc.

If you are having trouble putting planets on the chip, you can defocus a
bit, and look for the out-of-focus planetary image, which will now be much
larger. If you are at all close to the planet a long exposure (a few
seconds) may show brightness in the direction of the planet, and you can
move toward that until you get the planet on the chip.

Planets need very short exposures, generally; I've used as short as a couple
of milli-seconds on Jupiter and Venus. You will probably need to really
stretch the Back and Range setting (that's CCDOPS lingo; in Maxim, it would
be Min and Max) to see detail. Use a really high number for Range/Max, and a
really low number for Back/Min.

Working at f/20, mirror shift will be more of a problem than it was at
shorter focal lengths, and this may force you to use a larger focusing area
to keep the planet in view. This increases the amount of time to download
each focus image, and you can take 2-3x longer to focus on planets than on
other objects when imaging with an SCT and its moving primary mirror.

Ron Wodaski
The New Astronomy Book Site - http://www.newastro.com



-----Original Message-----
From: Kevin Dixon [mailto:ksbtk@...]
Sent: Saturday, July 15, 2000 8:08 PM
To: ccd-newastro@egroups.com
Subject: [ccd-newastro] imaging Jupiter and Saturn


Good evening:

With the return of Jupiter and Saturn, I am interested in imaging
these beauties.  I would be doing this with a C8 Deluxe and an ST-
237.  I have read of using a Barlow lens but am unsure of the
specifics.

All hints and recommendations are most welcome.  Thanks.

Clear skies,
Kevin
ksbtk@...



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#46 From: "Ron Wodaski" <ronw@...>
Date: Sun Jul 16, 2000 6:23 pm
Subject: RE: M31 Color imaging, focus problems? ronw@...
Send Email

I have had a problem with color filtered images coming to focus differently
on a few occasions. Some things that come to mind as possible sources:

* A loose piece of glass in one or more of your filters. The filter might
lay at an angle, or be at a different distance from the chip as a result of
its sudden freedom to move.

* Some filters experience changes/degradation in coatings over a period of
years. If you have older filters, this could contribute to the problem.

* Exposure variations can also cause a problem. If the exposure durations
are not set up so that the amount of light received is roughly similar, the
longer exposures will have fatter stars. This is true in white light as
well: the longer your exposure, the larger the star images. If a star has
pronounced color, it will be larger on one color image than another, and
this is in fact how the star's color will show up on the combined image: the
outer edge of one color will show behind the white core, giving color to the
star. If the exposure durations are seriously out of whack, you can get
bloating that can't be corrected by adjusts during the combine -- the star
images are just too big. This is not the case in your images, but I'm being
complete. <g>

* Movement of the camera, as well as bumping of the scope, can also affect
focus, of course.

OK; those are the general cases; let's get down to your images. <g>

Even your red image is slightly out of focus. The FSQ-106 is designed to
bring everything together ONLY at the actual focus point; moving out of
focus, colors vary in the degree to which they are out of focus. This is
part of the design; the scope is optimized for a large flat field for
imaging purposes.

However, the difference between the degree of out-of-focus on the blue and
green, compared to the red, seems a bit large to be caused by this effect.

One obvious thing that shouldn't be overlooked: what is the tension on your
focuser? The FSQ-106 has a pretty beefy focuser, and it is designed to work
with a fairly high degree of tension on it; it should take some effort to
turn the focus knob. It shouldn't be hard to turn, just nice and firm so
that the weight of a camera has no chance of moving the focuser when pointed
at the zenith. Is there any free play at all in the focusing mechanism? Did
you lock down focus position after achieving best focus?

Another possible source of trouble: the way that the camera is mounted in
the focuser. I'm using a very firm setup, and I would recommend it for you,
too. If you are using a 1.25" nosepiece by any chance, those are notorious
for slippage and alignment problems; get rid of it. <g> Even a 2" nosepiece
can have problem. If you are using the stock Takahashi 2" adapter, it has
two lock-down screws, but even so the camera can tilt a bit. If you are
using a 2" adapter with one set screw, these are also notorious for allowing
tipping. As you move around the sky, the camera tilts one way, then the
other way, and gradually works itself downhill. On some 2" adapters, the
camera can tilt suddenly throwing everything badly out of focus.

The method I use to attach my camera uses two parts: a Tak CA-35 (wide mouth
camera adapter, desirable because it will not vignette the steep light cone
of the FSQ), which thread into the back of the large black plate on the back
of the FSQ-106. I then attach a Tak TCD0001, which threads into the CA-35
and presents a standard T-thread for attaching your CCD camera. I find it
pretty easy to simply spin the camera onto the TCD0001. I tighten firmly,
and then use the built-in camera angle adjuster to get the camera orthogonal
with the mount. Then I focus. The camera DOES NOT MOVE, EVER, unless I move
the focuser or the camera angle adjuster. This is THE way to mount a camera
on this scope. <g> Call me at Anacortes Telescope and I'll get you the parts
ordered (360-588-9000), or talk to Herb or Ray if I am not there; I've given
them this same information.

I would definitely eliminate camera movement before digging into color
filter wheel problems. It has been the most common source of focus shift for
me.

Another source of focus shift, but it's fairly subtle, is temperature
change. You will have to adjust focus during the night. The amount of focus
shift due to temperate shift is much smaller than the shift you've
experience. But remember that the FSQ has a steep light cone. This gives you
small, tight stars when well-focused, but it also means critical focus takes
a bit more effort to achieve. Thus, a temperature shift will have more
impact on a steep light cone than on a long one.

Ron Wodaski
The New Astronomy Book Site - http://www.newastro.com



-----Original Message-----
From: Dennis Chapman [mailto:dec@...]
Sent: Saturday, July 15, 2000 9:06 PM
To: ccd-newastro@egroups.com
Subject: [ccd-newastro] M31 Color imaging, focus problems?


Greetings,
   I've uploaded a trio of images I took the other night of M31. The
image with the red filter looks decent however the images that were
taken with the green and blue filters look out of focus. When I
combine these with Maxim/DL I get awful color matching (stars with
white cores and blue-green outer rings).

   My question is are there be slight differences in focus needed when
taking images with different color filters? Should I be using one of
the color filters for focusing? I normally use the clear filter.

  Let me add that I'm very new to CCD imaging (these are first light
images on my system).

Equipment:
   Takahashi FSQ-106 with EM200 mount
   SBIG ST8E NABG & CFW8 color wheel
   Each image was taken for 70s with 2x2 binning and auto-dark
   calibration.

Clear Skies!
Dennis


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#47 From: "Dennis Chapman" <dec@...>
Date: Sun Jul 16, 2000 9:07 pm
Subject: Re: M31 Color imaging, focus problems? dec@...
Send Email

Hi Michael,
   Thanks for the reply.

--- In ccd-newastro@egroups.com, Michael Clary <tricomp1@e...> wrote:

> One obvious reason could be the fact that these are screw-in
filters. If one
> is tighter than the others, this shifts the focal point. You say
that your
> red image looks "decent" but the blue and green look out of focus,
> indicating that there is a common focal point for your clear and
red, but
> not for your blue and green.

   I happened to take the CFW-8 apart yesterday to add a narrow band
transmission filter to the empty slot. A couple of the filters were
a bit loose so I tightened them up. It was cloudy last night so I
couldn't check if this was the problem, however the sky is blue now
so maybe I'll be in luck tonight.

Regards,
Dennis
------<<--->>------
   Dennis Chapman
dec@...
------>>---<<------

#48 From: Dennis Chapman <dec@...>
Date: Sun Jul 16, 2000 10:00 pm
Subject: RE: M31 Color imaging, focus problems? dec@...
Send Email

Ron,
   You bring up a number of good points, let me respond to some of them.

>
> * A loose piece of glass in one or more of your filters. The filter might
> lay at an angle, or be at a different distance from the chip as a result
of
> its sudden freedom to move.
>

   I found a couple of loose filters when I took the CFW8 apart to add
another filter.

>
> * Exposure variations can also cause a problem. If the exposure durations
> are not set up so that the amount of light received is roughly similar,
the
> longer exposures will have fatter stars. This is true in white light as
> well: the longer your exposure, the larger the star images. If a star has
> pronounced color, it will be larger on one color image than another, and
> this is in fact how the star's color will show up on the combined image:
the
> outer edge of one color will show behind the white core, giving color to
the
> star. If the exposure durations are seriously out of whack, you can get
> bloating that can't be corrected by adjusts during the combine -- the star
> images are just too big. This is not the case in your images, but I'm
being
> complete. <g>
>

   I'm not sure on the correct ratio for my camera yet. I have been exposing
equal amounts of time for R G & B. I'm sure this isn't right but I'm still
learning about the camera/filter wheel. I would think the best way to work
this out would be to compare pixel values between the three exposures of a
white star. Is there another trick for getting the balance right for color
wheels?

>
> One obvious thing that shouldn't be overlooked: what is the tension on
your
> focuser? The FSQ-106 has a pretty beefy focuser, and it is designed to
work
> with a fairly high degree of tension on it; it should take some effort to
> turn the focus knob. It shouldn't be hard to turn, just nice and firm so
> that the weight of a camera has no chance of moving the focuser when
pointed
> at the zenith. Is there any free play at all in the focusing mechanism?
Did
> you lock down focus position after achieving best focus?
>

   I did have the focuser locked down finger tight after achieving focus.
However, M31 doesn't climb over the redwoods at my home until about 2 AM.
Since I orginally focused when Arcturus first became visible it was some
time
until I took the M31 shots. I probably need to recheck focus as the night
goes on.

> Another possible source of trouble: the way that the camera is mounted in
> the focuser. I'm using a very firm setup, and I would recommend it for
you,
> too. If you are using a 1.25" nosepiece by any chance, those are notorious
> for slippage and alignment problems; get rid of it. <g> Even a 2"
nosepiece
> can have problem. If you are using the stock Takahashi 2" adapter, it has
> two lock-down screws, but even so the camera can tilt a bit. If you are
> using a 2" adapter with one set screw, these are also notorious for
allowing
> tipping. As you move around the sky, the camera tilts one way, then the
> other way, and gradually works itself downhill. On some 2" adapters, the
> camera can tilt suddenly throwing everything badly out of focus.
>
> The method I use to attach my camera uses two parts: a Tak CA-35 (wide
mouth
> camera adapter, desirable because it will not vignette the steep light
cone
> of the FSQ), which thread into the back of the large black plate on the
back
> of the FSQ-106. I then attach a Tak TCD0001, which threads into the CA-35
> and presents a standard T-thread for attaching your CCD camera. I find it
> pretty easy to simply spin the camera onto the TCD0001. I tighten firmly,
> and then use the built-in camera angle adjuster to get the camera
orthogonal
> with the mount. Then I focus. The camera DOES NOT MOVE, EVER, unless I
move
> the focuser or the camera angle adjuster. This is THE way to mount a
camera
> on this scope. <g> Call me at Anacortes Telescope and I'll get you the
parts
> ordered (360-588-9000), or talk to Herb or Ray if I am not there; I've
given
> them this same information.
>
> I would definitely eliminate camera movement before digging into color
> filter wheel problems. It has been the most common source of focus shift
for
> me.
>

   When I ordered the gear from Herb I asked him about mounting the camera to
the scope. He forwarded an email & jpg from you outlining the above. Paula
tells me that the TCD0001 shipped last Friday. In its place I'm currently
using the stock 2" Tak adapter.

   On an unrelated note, I find myself unable to DEC balance the scope with
the camera & color wheel attached to the scope. It doesn't seem to have
affected the EM200's tracking, but I'd prefer it balanced. I'm thinking of
adding something like an ankle weight that joggers wear near the dew shield.
Any tricks that others have to help balance a camera load?

> Another source of focus shift, but it's fairly subtle, is temperature
> change. You will have to adjust focus during the night. The amount of
focus
> shift due to temperate shift is much smaller than the shift you've
> experience. But remember that the FSQ has a steep light cone. This gives
you
> small, tight stars when well-focused, but it also means critical focus
takes
> a bit more effort to achieve. Thus, a temperature shift will have more
> impact on a steep light cone than on a long one.
>
> Ron Wodaski
> The New Astronomy Book Site - http://www.newastro.com
>
>

   Thanks for taking the time to respond Ron. I and others eagerly await
upcoming chapters of your book.

Regards,
Dennis
------<<--->>------
   Dennis Chapman
dec@...
------>>---<<------

#49 From: "Ron Wodaski" <ronw@...>
Date: Sun Jul 16, 2000 11:21 pm
Subject: RE: M31 Color imaging, focus problems? ronw@...
Send Email

Here are answers to your questions below.

Ron Wodaski
The New Astronomy Book Site - http://www.newastro.com

-----Original Message-----
From: Dennis Chapman [mailto:dec@...]
Sent: Sunday, July 16, 2000 3:00 PM
To: ccd-newastro@egroups.com
Subject: RE: [ccd-newastro] M31 Color imaging, focus problems?

<snip>

   I'm not sure on the correct ratio for my camera yet. I have been exposing
equal amounts of time for R G & B. I'm sure this isn't right but I'm still
learning about the camera/filter wheel. I would think the best way to work
this out would be to compare pixel values between the three exposures of a
white star. Is there another trick for getting the balance right for color
wheels?

--> A good starting point is 1:1:1.5 R:G:B; SBIG recommends 1:1:1.6. I've
found 1:1:1.5 to be about right for my imaging, although I have enough light
pollution that on some nights, 1:0.85:1.5

   I did have the focuser locked down finger tight after achieving focus.
However, M31 doesn't climb over the redwoods at my home until about 2 AM.
Since I orginally focused when Arcturus first became visible it was some
time until I took the M31 shots. I probably need to recheck focus as the
night
goes on.

--> You would almost certainly have two reasons for focus shift in that
situation: you are looking through less atmosphere, which will change the
focus point; the temperature probably shifted, which will also shift the
focus point. Since it can take an hour or more to image an object in color,
with all the exposures and fiddling, I check focus periodically.

   When I ordered the gear from Herb I asked him about mounting the camera to
the scope. He forwarded an email & jpg from you outlining the above. Paula
tells me that the TCD0001 shipped last Friday. In its place I'm currently
using the stock 2" Tak adapter.

--> The TCD0001 should solve your problem; you will need the CA-35 to use
it.

   On an unrelated note, I find myself unable to DEC balance the scope with
the camera & color wheel attached to the scope. It doesn't seem to have
affected the EM200's tracking, but I'd prefer it balanced. I'm thinking of
adding something like an ankle weight that joggers wear near the dew shield.
Any tricks that others have to help balance a camera load?

--> I'm working with Herb to design new methods of putting scopes on the
Takahashi mounts that will give you more positional freedom, which you need
for imaging with the larger cameras. I would think that the best combination
for you would be one of the new saddle plate adapters. These attach to the
mount with the two large metric screws, and then you can attach a Losmandy
G-11 saddle to the adapter. You can then put your FSQ-106 on a Losmandy DUP
(universal dovetail plate) and slide it for balance. I agree that, with the
ST-8E and CFW-8 on the FSQ, you can't move the rings or tube clamp far
enough to get proper balance. Using the adapter, G-11 saddle plate, and DUP,
you can. I offset the rings toward one end of the DUP, which gives me a very
large range of balance points and good stiffness for imaging. This setup has
made my life easier.

   Thanks for taking the time to respond Ron. I and others eagerly await
upcoming chapters of your book.

--> I am putting up portions of chapter 6 today; I have the intro to the
chapter up already, and should have more in a few hours.

Ron Wodaski
http://www.newastro.com

#50 From: "Ron Wodaski" <ronw@...>
Date: Mon Jul 17, 2000 12:56 am
Subject: New content - "New Astronomy" Book ronw@...
Send Email

I have added new material in chapter six of "The New Astronomy" online
version. As requested by several folks, I am putting up sections of chapters
as I write them. You can find the new content by clicking on chapter 6 in
the table of contents:

http://www.newastro.com/newastro/subscriber.asp

Note: If you are not a subscriber to the web version, you will not be able
to access this page. Go instead to this link for information about the
online version of the book:

http://www.newastro.com/newastro/default.asp

As always, if you have any questions, suggestions, or comments, please post
them here!

Ron Wodaski
The New Astronomy Book Site - http://www.newastro.com