OK, thanks John. I was curious if the front corrector lens of that scope
introduces any chromatic aberrations. I know
for my AP160 that there is a measurable difference between R, G, and B.

-Ray

> -----Original Message-----
> From: TAC-imaging@yahoogroups.com [mailto:TAC-imaging@yahoogroups.com] On
Behalf Of John
> Sent: Friday, November 27, 2009 12:30 PM
> To: TAC-imaging@yahoogroups.com
> Subject: [TAC-imaging] Re: Orion Ritchey f/8?
>
>
>
> Hi Ray,
>
> I'm using the 2" Astronomics RGB filters.
> I've got the RGB filter offsets to zero since I wasn't able to measure any
repeatable offset above the seeing noise
floor over sets of
> 5 runs each of Focusmax.
>
> It may be that I could get some better readings on a night of better seeing
and with more runs to average - it's on
the TODO list.
>
> John
>
> --- In TAC-imaging@yahoogroups.com <mailto:TAC-imaging%40yahoogroups.com> ,
"Ray Gralak \(Yahoo Groups\)" <yahoo@...>
> wrote:
> >
> > Hi John,
> >
> > OK, thanks. That's good to know.
> >
> > Is there much focus shift between color filters?
> >
> > -Ray
> >
> > > -----Original Message-----
> > > From: TAC-imaging@yahoogroups.com <mailto:TAC-imaging%40yahoogroups.com> 
[mailto:TAC-imaging@yahoogroups.com
> <mailto:TAC-imaging%40yahoogroups.com> ] On Behalf Of John
> > > Sent: Thursday, November 26, 2009 11:43 AM
> > > To: TAC-imaging@yahoogroups.com <mailto:TAC-imaging%40yahoogroups.com>
> > > Subject: [TAC-imaging] Re: Orion Ritchey f/8?
> > >
> > >
> > >
> > > I've got the 10" LX200R (before they were forced to change the name to
ACF) and it works well with my 35mm ccd
camera
> > (Kodak
> > > 11002 chip).
> > >
> > > It illuminates the whole chip well enough for flats to finish the job and
the star shapes are good out to the
edges,
> > as long as you get
> > > the camera at the correct distance from the scope back.
> > >
> > > John
> > >
> > > --- In TAC-imaging@yahoogroups.com <mailto:TAC-imaging%40yahoogroups.com> 
<mailto:TAC-
> imaging%40yahoogroups.com> , "Ray Gralak \(Yahoo Groups\)" <yahoo@>
> > > wrote:
> > > >
> > > > Iver wrote:
> > > > > > How do you like your ACF?
> > > > >
> > > > >
> > > > > The ACF works well with my H-9 but I'm skeptical it will give good
results with a larger CCD, I think even the
> > 8300
> > > > would be pushing
> > > > > it!
> > > >
> > > > OK, thanks Iver. The only thing I find distracting about that RC is that
I think the diffraction spikes around
the
> > stars
> > > > look bad.
> > > >
> > > > -Ray
> > > >
> > >
> > >
> > >
> > >
> >
>
>
>
>

Hi Keith,

Ok, maybe I'm being too picky about the diffraction spikes. Does Floyd have a
site with images I could look at?

-Ray

> -----Original Message-----
> From: TAC-imaging@yahoogroups.com [mailto:TAC-imaging@yahoogroups.com] On
Behalf Of Keith
> Sent: Thursday, November 26, 2009 8:18 PM
> To: TAC-imaging@yahoogroups.com
> Subject: [TAC-imaging] Re: Orion Ritchey f/8?
>
>
>
> Ray, a good friend by the name of Floyd Blue had one of the Astronomics
versions of the 8" at the last star party I
attended. I got a
> chance to ask him a lot of questions about it and to look at the images and
subframes he was getting with it and the
ST-2K. I didn't
> see anything objectionable with the images. It seemed to collimate and hold
collimations well. It also didn't exhibit
excessive focus
> shift because of the carbon fiber tube. I think that the Astronomics versions
of these R-C's is going to go down in
the history books
> as a repeat of the Orion ED-80 refractor reputation. Simply one of the best
bang-for-the-buck deals in recent history
in the
> astrophotography hardware category. I believe the mirrors are Pyrex and the
coatings are metal vapor deposition. Quite
a nice OTA
> in my opinion.
>
> Keith
>
> --- In TAC-imaging@yahoogroups.com <mailto:TAC-imaging%40yahoogroups.com> ,
"Ray Gralak \(Yahoo Groups\)" <yahoo@...>
> wrote:
> >
> > Here's another question I've been meaning to ask... Has anyone seen or tried
out one of Orion's new Ritchey-Cretien
8"
> > f/8? I wonder if the price ($1195) too good to be true. The mirror is
probably pyrex so I'm guessing it would
require a
> > lot of refocusing as the temperature drops during the night.
> >
> >
http://www.telescope.com/control/product/~category_id=FreeShip0409/~pcategory=te\
lescopes/~product_id=08958
>
<http://www.telescope.com/control/product/~category_id=FreeShip0409/~pcategory=t\
elescopes/~product_id=08958>
> >
> > (And BTW I don't work for Orion! I'm just intrigued by the low cost of some
of their gear.)
> >
> > -Ray
> >
>
>
>
>

Hi Ray,

I'm using the 2" Astronomics RGB filters.
I've got the RGB filter offsets to zero since I wasn't able to measure any
repeatable offset above the seeing noise floor over sets of 5 runs each of
Focusmax.

It may be that I could get some better readings on a night of better seeing and
with more runs to average - it's on the TODO list.

John


--- In TAC-imaging@yahoogroups.com, "Ray Gralak \(Yahoo Groups\)" <yahoo@...>
wrote:
>
> Hi John,
>
> OK, thanks. That's good to know.
>
> Is there much focus shift between color filters?
>
> -Ray
>
> > -----Original Message-----
> > From: TAC-imaging@yahoogroups.com [mailto:TAC-imaging@yahoogroups.com] On
Behalf Of John
> > Sent: Thursday, November 26, 2009 11:43 AM
> > To: TAC-imaging@yahoogroups.com
> > Subject: [TAC-imaging] Re: Orion Ritchey f/8?
> >
> >
> >
> > I've got the 10" LX200R (before they were forced to change the name to ACF)
and it works well with my 35mm ccd camera
> (Kodak
> > 11002 chip).
> >
> > It illuminates the whole chip well enough for flats to finish the job and
the star shapes are good out to the edges,
> as long as you get
> > the camera at the correct distance from the scope back.
> >
> > John
> >
> > --- In TAC-imaging@yahoogroups.com <mailto:TAC-imaging%40yahoogroups.com> ,
"Ray Gralak \(Yahoo Groups\)" <yahoo@>
> > wrote:
> > >
> > > Iver wrote:
> > > > > How do you like your ACF?
> > > >
> > > >
> > > > The ACF works well with my H-9 but I'm skeptical it will give good
results with a larger CCD, I think even the
> 8300
> > > would be pushing
> > > > it!
> > >
> > > OK, thanks Iver. The only thing I find distracting about that RC is that I
think the diffraction spikes around the
> stars
> > > look bad.
> > >
> > > -Ray
> > >
> >
> >
> >
> >
>

--- In TAC-imaging@yahoogroups.com, "John" <winfij@...> wrote:
>
> I've got the 10" LX200R (before they were forced to change the name to ACF)
and it works well with my 35mm ccd camera (Kodak 11002 chip).
>
> It illuminates the whole chip well enough for flats to finish the job and the
star shapes are good out to the edges, as long as you get the camera at the
correct distance from the scope back.
>
> John


John, I'm glad to hear that! With my camera I always use the scope with a
reducer/corrector and the issues that come with one! I wasn't even thinking
about using the scope without an R/C. So unbinned you get round stars in the
corners? Have you tried CCDI to see how flat the field is?

-Iver

Ray, a good friend by the name of Floyd Blue had one of the Astronomics versions
of the 8" at the last star party I attended.  I got a chance to ask him a lot of
questions about it and to look at the images and subframes he was getting with
it and the ST-2K.  I didn't see anything objectionable with the images. It
seemed to collimate and hold collimations well.  It also didn't exhibit
excessive focus shift because of the carbon fiber tube.  I think that the
Astronomics versions of these R-C's is going to go down in the history books as
a repeat of the Orion ED-80 refractor reputation.  Simply one of the best
bang-for-the-buck deals in recent history in the astrophotography hardware
category.  I believe the mirrors are Pyrex and the coatings are metal vapor
deposition.  Quite a nice OTA in my opinion.

Keith


--- In TAC-imaging@yahoogroups.com, "Ray Gralak \(Yahoo Groups\)" <yahoo@...>
wrote:
>
> Here's another question I've been meaning to ask...  Has anyone seen or tried
out one of Orion's new Ritchey-Cretien 8"
> f/8?  I wonder if the price ($1195) too good to be true. The mirror is
probably pyrex so I'm guessing it would require a
> lot of refocusing as the temperature drops during the night.
>
>
http://www.telescope.com/control/product/~category_id=FreeShip0409/~pcategory=te\
lescopes/~product_id=08958
>
> (And BTW I don't work for Orion! I'm just intrigued by the low cost of some of
their gear.)
>
> -Ray
>

Hi John,

OK, thanks. That's good to know.

Is there much focus shift between color filters?

-Ray

> -----Original Message-----
> From: TAC-imaging@yahoogroups.com [mailto:TAC-imaging@yahoogroups.com] On
Behalf Of John
> Sent: Thursday, November 26, 2009 11:43 AM
> To: TAC-imaging@yahoogroups.com
> Subject: [TAC-imaging] Re: Orion Ritchey f/8?
>
>
>
> I've got the 10" LX200R (before they were forced to change the name to ACF)
and it works well with my 35mm ccd camera
(Kodak
> 11002 chip).
>
> It illuminates the whole chip well enough for flats to finish the job and the
star shapes are good out to the edges,
as long as you get
> the camera at the correct distance from the scope back.
>
> John
>
> --- In TAC-imaging@yahoogroups.com <mailto:TAC-imaging%40yahoogroups.com> ,
"Ray Gralak \(Yahoo Groups\)" <yahoo@...>
> wrote:
> >
> > Iver wrote:
> > > > How do you like your ACF?
> > >
> > >
> > > The ACF works well with my H-9 but I'm skeptical it will give good results
with a larger CCD, I think even the
8300
> > would be pushing
> > > it!
> >
> > OK, thanks Iver. The only thing I find distracting about that RC is that I
think the diffraction spikes around the
stars
> > look bad.
> >
> > -Ray
> >
>
>
>
>

I've got the 10" LX200R (before they were forced to change the name to ACF) and
it works well with my 35mm ccd camera (Kodak 11002 chip).

It illuminates the whole chip well enough for flats to finish the job and the
star shapes are good out to the edges, as long as you get the camera at the
correct distance from the scope back.

John



--- In TAC-imaging@yahoogroups.com, "Ray Gralak \(Yahoo Groups\)" <yahoo@...>
wrote:
>
> Iver wrote:
> > > How do you like your ACF?
> >
> >
> > The ACF works well with my H-9 but I'm skeptical it will give good results
with a larger CCD, I think even the 8300
> would be pushing
> > it!
>
> OK, thanks Iver. The only thing I find distracting about that RC is that I
think the diffraction spikes around the stars
> look bad.
>
> -Ray
>

Iver wrote:
> > How do you like your ACF?
>
>
> The ACF works well with my H-9 but I'm skeptical it will give good results
with a larger CCD, I think even the 8300
would be pushing
> it!

OK, thanks Iver. The only thing I find distracting about that RC is that I think
the diffraction spikes around the stars
look bad.

-Ray

> How do you like your ACF?


The ACF works well with my H-9 but I'm skeptical it will give good results with
a larger CCD, I think even the 8300 would be pushing it!

-Iver

Hi Iver,

Thanks for the heads-up on the Astronomics version. It seems much better overall
than the Orion. And as for the camera I
suppose it might find its way on that scope.

How do you like your ACF?

-Ray

> -----Original Message-----
> From: TAC-imaging@yahoogroups.com [mailto:TAC-imaging@yahoogroups.com] On
Behalf Of IVER
> Sent: Wednesday, November 25, 2009 8:22 PM
> To: TAC-imaging@yahoogroups.com
> Subject: [TAC-imaging] Re: Orion Ritchey f/8?
>
>
>
>
> Ray, are you thinking of getting one for the new camera? Astronomics sells a
slightly different version that S&T
reviewed, they said
> it held focus very well!
>
http://www.astronomics.com/main/product.asp/catalog_name/Astronomics/category_na\
me/U5QNWB3RKWWL8N3EL99F9DX9A0/pr
> oduct_id/AT8RC
>
<http://www.astronomics.com/main/product.asp/catalog_name/Astronomics/category_n\
ame/U5QNWB3RKWWL8N3EL99F9DX9A0/p
> roduct_id/AT8RC>
>
> I've thought about getting one for a while now but it might not be much of a
step up from my 8" ACF. What I really
want is a FSQ
> 106 but that's not likely for some time!
>
> -Iver
>
>
>
>

Ray, are you thinking of getting one for the new camera? Astronomics sells a
slightly different version that S&T reviewed, they said it held focus very well!
http://www.astronomics.com/main/product.asp/catalog_name/Astronomics/category_na\
me/U5QNWB3RKWWL8N3EL99F9DX9A0/product_id/AT8RC

I've thought about getting one for a while now but it might not be much of a
step up from my 8" ACF. What I really want is a FSQ 106 but that's not likely
for some time!

-Iver

Here's another question I've been meaning to ask...  Has anyone seen or tried
out one of Orion's new Ritchey-Cretien 8"
f/8?  I wonder if the price ($1195) too good to be true. The mirror is probably
pyrex so I'm guessing it would require a
lot of refocusing as the temperature drops during the night.

http://www.telescope.com/control/product/~category_id=FreeShip0409/~pcategory=te\
lescopes/~product_id=08958

(And BTW I don't work for Orion! I'm just intrigued by the low cost of some of
their gear.)

-Ray

Hi Keith,

Those are good points. My plan is to try it with the inexpensive Orion Deluxe
Axis autoguider using maybe a web cam or
one of my Meade DSI cameras for the autoguider.
http://www.telescope.com/control/astrophotography/astrophotography-accessories/o\
rion-deluxe-off-axis-guider

One project I've always wanted to do was a complete Herschel-list Galaxy survey
(2500 galaxies) with a CCD. I should be
able to get most of them from my backyard .

> I feel like I might regret it not having an internal filter wheel

I think there will also be available at least a couple choices for a filter
wheel but I'm going to wait and see on that.


Once I get the camera I'll take a few test shots and post them here. SBIG says
they'll be shipping next month (December)
but they are notorious for launching products late.

-Ray

> -----Original Message-----
> From: TAC-imaging@yahoogroups.com [mailto:TAC-imaging@yahoogroups.com] On
Behalf Of Keith
> Sent: Wednesday, November 25, 2009 10:06 AM
> To: TAC-imaging@yahoogroups.com
> Subject: [TAC-imaging] Re: SBIG ST-8300M?
>
>
>
> Hi Ray, I'm not thinking of getting one. It's a great price point but I feel
like I might regret it not having an
internal filter wheel or the
> onboard guider and RGH electronics port. I do feel that this chip is the
perfect match for refractors with their short
or medium long
> focal lenghths. It produces a very nice image and pixel scale as you stated. I
first learned of this chip from Tony
Hallas at GSSP
> who said he wanted one. Its also a full frame chip compared to interline with
a better QE than what's been out there
previously.
>
> Keith
>
> --- In TAC-imaging@yahoogroups.com <mailto:TAC-imaging%40yahoogroups.com> ,
"Ray Gralak \(Yahoo Groups\)" <yahoo@...>
> wrote:
> >
> > Hi Jeff,
> >
> > Yes, they are 5.4 microns or about 60% that of a 9 micron CCD. But you can
also bin 2x2 if you want.
> >
> > That said I think would be a great CCD for most high-quality refractors. I
have an AP Traveler that I plan to use it
with. With the ST-
> 2000M I now have on that scope the image scale is about 2.7 arc-secs per
pixel, but with the ST8300 it would be about
1.6 arc-
> secs/pixel. I could also use the 0.75x reducer to get more FOV if I want. The
ST-8300 has about 2.3x the area of the
St2000.
> >
> > -Ray
> >
> > > Aren't the pixels kinda small? Like 5-somethimg?
> > >
> > > jeff
> > >
> > > On Nov 25, 2009, at 7:54 AM, "Ray Gralak \(Yahoo Groups\)" <yahoo@...
<mailto:yahoo%40gralak.com> > wrote:
> > >
> > > I was pretty surprised to see that SBIG announced the ST-8300M and
ST-8300C for $1995 at AIC. I placed an order
for one
> > > yesterday. Anyone else thinking of getting one of these? The biggest thing
missing is the second guide chip but
for the
> > > price the rest of the features look really good.
> > >
> > > -Ray
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> > >
> > >
> >
>
>
>
>

Hi Ray, I'm not thinking of getting one.  It's a great price point but I feel
like I might regret it not having an internal filter wheel or the onboard guider
and  RGH electronics port.  I do feel that this chip is the perfect match for
refractors with their short or medium long focal lenghths.  It produces a very
nice image and pixel scale as you stated.  I first learned of this chip from
Tony Hallas at GSSP who said he wanted one.  Its also a full frame chip compared
to interline with a better QE than what's been out there previously.

Keith


--- In TAC-imaging@yahoogroups.com, "Ray Gralak \(Yahoo Groups\)" <yahoo@...>
wrote:
>
> Hi Jeff,
>
> Yes, they are 5.4 microns or about 60% that of a 9 micron CCD. But you can
also bin 2x2 if you want.
>
> That said I think would be a great CCD for most high-quality refractors. I
have an AP Traveler that I plan to use it with. With the ST-2000M I now have on
that scope the image scale is about 2.7 arc-secs per pixel, but with the ST8300
it would be about 1.6 arc-secs/pixel. I could also use the 0.75x reducer to get
more FOV if I want. The ST-8300 has about 2.3x the area of the St2000.
>
> -Ray
>
> > Aren't the pixels kinda small? Like 5-somethimg?
> >
> > jeff
> >
> > On Nov 25, 2009, at 7:54 AM, "Ray Gralak \(Yahoo Groups\)" <yahoo@...
<mailto:yahoo%40gralak.com> > wrote:
> >
> > I was pretty surprised to see that SBIG announced the ST-8300M and ST-8300C
for $1995 at AIC. I placed an order for one
> > yesterday. Anyone else thinking of getting one of these? The biggest thing
missing is the second guide chip but for the
> > price the rest of the features look really good.
> >
> > -Ray
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> >
>

Hi Jeff,

Yes, they are 5.4 microns or about 60% that of a 9 micron CCD. But you can also
bin 2x2 if you want.

That said I think would be a great CCD for most high-quality refractors. I have
an AP Traveler that I plan to use it with. With the ST-2000M I now have on that
scope the image scale is about 2.7 arc-secs per pixel, but with the ST8300 it
would be about 1.6 arc-secs/pixel. I could also use the 0.75x reducer to get
more FOV if I want. The ST-8300 has about 2.3x the area of the St2000.

-Ray

> Aren't the pixels kinda small? Like 5-somethimg?
>
> jeff
>
> On Nov 25, 2009, at 7:54 AM, "Ray Gralak \(Yahoo Groups\)" <yahoo@...
<mailto:yahoo%40gralak.com> > wrote:
>
> I was pretty surprised to see that SBIG announced the ST-8300M and ST-8300C
for $1995 at AIC. I placed an order for one
> yesterday. Anyone else thinking of getting one of these? The biggest thing
missing is the second guide chip but for the
> price the rest of the features look really good.
>
> -Ray
>
> [Non-text portions of this message have been removed]
>
>
>
>

Aren't the pixels kinda small?   Like 5-somethimg?

jeff

On Nov 25, 2009, at 7:54 AM, "Ray Gralak \(Yahoo Groups\)" <yahoo@...>
wrote:

I was pretty surprised to see that SBIG announced the ST-8300M and ST-8300C for
$1995 at AIC. I placed an order for one
yesterday. Anyone else thinking of getting one of these? The biggest thing
missing is the second guide chip but for the
price the rest of the features look really good.

-Ray




[Non-text portions of this message have been removed]

I was pretty surprised to see that SBIG announced the ST-8300M and ST-8300C for
$1995 at AIC. I placed an order for one
yesterday. Anyone else thinking of getting one of these? The biggest thing
missing is the second guide chip but for the
price the rest of the features look really good.

-Ray

In case anyone else is interested follow the link and check out the ST8300 8
megapixels $1995-

http://www.astrophotoinsight.com/blog

> I hope this link works!

Thanks, but the link did not work.

A friend helped me to experiment some more with my 20Da to see how far I
could push it.  Using internal darks we were doing 20 minute exposures in H
Alpha using a camera lens.  My friend says that once I did flats I could
have some decent pictures.

I am going to try some more experiments this week, but in the short term it
looks like I am going to stick with narrowband and the 20Da.


Rob Hawley
________________________________________

Rob, here is something you might be interested in! Sounds like a great deal.
http://files.posterous.com/astrophoto/vujJvuEx69cXiQwvFhhS3ZVqI3GAw9OrHVTlXjiM4M\
z06kRPpy4AOqUTeRsv/photo_3.jpg?AWSAccessKeyId=1C9REJR1EMRZ83Q7QRG2&Expires=12570\
45889&Signature=nO9COUx4tOVaFlkuUHFMWPBHtyQ%3D

I hope this link works!

-Iver

Another piece of equipment that I am planning to replace is my DSLR.  I love
the Canon 20Da and will still be using it for eclipses and anytime I need to
do more serious daytime astronomy.  It seems that more than 5 minute
exposures is pushing its envelope.  I need to look at something that is
cooled.

What should I be looking at for a dedicated camera capable of doing
narrowband work?  I am considering the Orion StarShoot Deep Space Monochrome
Imager III using either a DSI or another camera as an autoguider.

Would it make more sense to buy a combined camera such as ST-7XME?  That
would seem to eliminate the need for the complexity of a second guide scope.


Rob Hawley

It is likely that the previous offer saturated this market, but I also have
one that I am willing to sell for $400.

I used the astrotrac for my wide field images.

http://www.robhawley.net/sg09/index.html
http://www.robhawley.net/bw/summer/#Section_2


I really like it, but the other equipment in my setup was (generously)
called duct tape on top of bailing wire.  Since the wide field was always a
proxy for what I really wanted to do (narrow band from my backyard) I have
decided to sell this and take the plunge to more serious equipment.


Rob Hawley

If you take pictures alone the galactic equator with a minimum (>25mm?) focal
length, you won't see much rotation, but towards the pole you will.  This
assuming you use a EQ mount.  Rotation will depend on your number of pixels and
pixel size (therefore distance from center of camera), and amount of time your
shutter is open.  One can calculate this, but beyond my ability at this point.

Without an EQ, you only need focal length, exposure time, and pixel distance to
figure out streak's length.

The major problems with gears and motors is how smooth they are. Most mounts I
have played with have mechanical wobbles in the minutes range.  Even the newer
Vixen SXD Sphinx mount couldn't do a 500mm photo for 300 seconds without 2
wobbles, before I got the new Orion standalone autoguider locked on Jupiter, and
did a PEC (periodic error correction).. I have yet to verify that 300 seconds
now works smoother and PEC was successful.  Same kind of wobble with the Meade
LX200 telescope, used as a tripod.  PEC helped, but not enough.
Guiding gets rid of the wobble, despite PEC being successful, or newly messed up
because of a mechanical issue (loose screw, etc).
I had some trouble with the original Orion autoguider on LX200, not yet
completely debugged, and that needs a laptop whose hard disk boot sector got
tangled by an improper uninstall of Ubuntu Unix.
Now that I have two mounts and two guiders I will figure it out.
The camera "40D" is a Canon DSLR, 2 years old, 10Mpixel.
The ED80 is a refractor, yes. FL=800mm.
Guiding is still a pain for me to practice here in Fremont, as the standalone
guider can't find stars unless they are bright enough, and I use 4" or more
guide scope, or really long exposures (5-10 seconds) which makes corrections not
as smooth.

You could always use something expensive like a Paramount ME that claims you
might not need a guider due to it's accuracy...

80mm is a decent size for guiding as it catches more light; 500mm FL gets you
enough sky to find a brighter star.  Ask around what others are using for
guiding tubes vs their main tube.  I read that 2:1 FL to FL is a good idea. 
Orion recommends their Shorttube 80.

I have done lots of successful 30 seconds exposures, but have not had many
chances to do 300+ seconds successfully yet due to technical problems.  30
seconds only really works at high ISO's which adds too much noise.

Hopefully at CalStar I will have darkness + technical success.
Sent via BlackBerry from T-Mobile

-----Original Message-----
From: Orrin Winton <orrin.winton@...>

Date: Wed, 16 Sep 2009 18:49:36
To: tac-imaging@yahoogroups.com<tac-imaging@yahoogroups.com>
Subject: [TAC-imaging] piggybacking: Hans


Hans thanks for your response Sept 4.

One other response I got, on tac-sac, suggested (if I understood
correctly) that e.g. an auto-guider might not be a requirement for a 5-
minute piggyback exposure, with the camera lens at around 24-70mm.
Just a polar-aligned eq motorized mount. I saw the pic he took; it was
good. Any comments about needing (or not needing) an auto-guider for
piggybacking?

"Orion ED 80 500mm" you mention -- that's an 80mm aperture refractor?
And the "Vixen SXD" is a camera? I don't know much. ... And with that
setup, do you use an auto-guider?

Thanks
Orrin in Susanville



I did some stuff with 40D on top of LX200 at 28mm FL with std EFS
lens, and got good results. I didn't try much at that len's 85mm limit.
I did try a Sigma 500mm ED and found an unusable amount of color
aberration at anything above 300mm.
I haven't tried a Canon lens at 300 yet.
I get better results at 1/3 the cost with an Orion ED 80 500mm, which
I am now playing/experimenting with on a new Vixen SXD.
Unfortunately on a recent trip to a dark spot in the Caribbean, I
didn't take the above with me. Pictures straight up with a 10-24mm at
10 (equiv 33/25*10 mm) are so wide that I get counter-rotation in
opposite edges of the image. So I don't recommend going down that far
unless you like a few star trails on the edges.




[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

Hans thanks for your response Sept 4.

One other response I got, on tac-sac, suggested (if I understood
correctly) that e.g. an auto-guider might not be a requirement for a 5-
minute piggyback exposure, with the camera lens at around 24-70mm.
Just a polar-aligned eq motorized mount. I saw the pic he took; it was
good. Any comments about needing (or not needing) an auto-guider for
piggybacking?

"Orion ED 80 500mm" you mention -- that's an 80mm aperture refractor?
And the "Vixen SXD" is a camera? I don't know much. ... And with that
setup, do you use an auto-guider?

Thanks
Orrin in Susanville



I did some stuff with 40D on top of LX200 at 28mm FL with std EFS
lens, and got good results. I didn't try much at that len's 85mm limit.
I did try a Sigma 500mm ED and found an unusable amount of color
aberration at anything above 300mm.
I haven't tried a Canon lens at 300 yet.
I get better results at 1/3 the cost with an Orion ED 80 500mm, which
I am now playing/experimenting with on a new Vixen SXD.
Unfortunately on a recent trip to a dark spot in the Caribbean, I
didn't take the above with me. Pictures straight up with a 10-24mm at
10 (equiv 33/25*10 mm) are so wide that I get counter-rotation in
opposite edges of the image. So I don't recommend going down that far
unless you like a few star trails on the edges.




[Non-text portions of this message have been removed]

I did some stuff with 40D on top of LX200 at 28mm FL with std EFS lens, and got
good results.  I didn't try much at that len's 85mm limit.
I did try a Sigma 500mm ED and found an unusable amount of color aberration at
anything above 300mm.
I haven't tried a Canon lens at 300 yet.
I get better results at 1/3 the cost with an Orion ED 80 500mm, which I am now
playing/experimenting with on a new Vixen SXD.
Unfortunately on a recent trip to a dark spot in the Caribbean, I didn't take
the above with me.  Pictures straight up with a 10-24mm at 10 (equiv 33/25*10
mm) are so wide that I get counter-rotation in opposite edges of the image.  So
I don't recommend going down that far unless you like a few star trails on the
edges.

Sent via BlackBerry from T-Mobile

-----Original Message-----
From: Orrin Winton <orrin.winton@...>

Date: Fri, 4 Sep 2009 17:38:58
To: tac-imaging@yahoogroups.com<tac-imaging@yahoogroups.com>
Subject: [TAC-imaging] Canon 50D piggyback


Hi folks, I posted on tac-sac and then someone suggested I post here.

As a piggyback camera, what do people think of the Canon 50D with EF-S
18-200mm zoom IS lens?

Then there's a slightly more costly version with an 18-200mm OS lens.
IS versus OS?

And is the performance of, say, the 50D going to be a bit better than
a 450D?

Thanks for any comments. I have other  questions but I thought I'd
break them up, and ask one at a time.

Orrin in Susanville









[Non-text portions of this message have been removed]

Hi folks, I posted on tac-sac and then someone suggested I post here.

As a piggyback camera, what do people think of the Canon 50D with EF-S
18-200mm zoom IS lens?

Then there's a slightly more costly version with an 18-200mm OS lens.
IS versus OS?

And is the performance of, say, the 50D going to be a bit better than
a 450D?

Thanks for any comments. I have other  questions but I thought I'd
break them up, and ask one at a time.

Orrin in Susanville

Seeing was still mushy, but turbulence was down and there were brief periods of
better transparency.  Best I've done thus far with the C9.

http://www.lafterhall.com/dmk_c9_jupiter_color_grn_blu_30aug09_001.jpg

Cheers
Jim

Been getting some fair lunar and planetary images with the C9, but a couple
nights ago the seeing was so mushy that I gave up with the big scope and tried
imaging with the 4 inch ED.  Image scale is pretty small, but at least I got a
couple decent images....all things considered.

http://www.lafterhall.com/dmk_dbk_sv102ed_jupiter_001.jpg

Bigger isn't always better.
Jim
Livermore

Hi Jim, nice image, especially considering the conditions. I've been imaging
about 7 yrs. now and this has been by far the longest stretch of bad weather
I've experienced! I think I've only had a few good nights since last fall! In
addition to the poor seeing I've had fog to contend with and that has been
especially bad this year. I think I'll have to pack up and head inland if I want
to do any imaging.
Oh well,enough complaining!
Thanks for sharing,
Iver

Seeing conditions the last couple months continue to be disappointing with
Jupiter so large.  Seeing was mushy last night, but one of the avi's I shot with
a color DBK video camera had some good frames off and on.  Shot with a C9 @
f/25, UV/IR block filter.  Processed in RegiStax and Photo Shop.

http://www.lafterhall.com/dbk_925_jupiter_color-mono_21aug09_001.jpg

Sort of having a good time now.....
Jim
Livermore