Hi folks
Like to say `Hi` just joined the group and wondered if any members
happen to have used the DMK type firewire cameras with their star
analyser and if so was a spacer or two needed?.
Cheers
Steve

Hi Steve and welcome to the group :-)

I think your problem is more likely to be getting the star analyser
close enough to the CCD rather than needing spacers. The DMK21AF04
camera you have has the mono version of the CCD which is used in the
Philips Toucam webcams so the ideal distance is around 35-40mm with a
maximum of 55mm to fit the spectrum on the chip. The back focus of the
C mount is 17.5mm
http://www.ptgrey.com/support/kb/data/lens_flange.gif
so you ideally need a nosepiece adapter about 15-20mm long, which is
quite short, up to 37mm maximum. If your current adapter is too long,
Modern Astronomy do a low profile C adapter which might fit the bill
http://www.modernastronomy.com/watec.html  (look under accessories)

Robin



--- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@...> wrote:
>
> Hi folks
> Like to say `Hi` just joined the group and wondered if any members
> happen to have used the DMK type firewire cameras with their star
> analyser and if so was a spacer or two needed?.
> Cheers
> Steve
>

Hi again Steve,

You may find that your camera has a CS mount, which has the same
thread as the C mount but needs 5mm less back focus, giving you an
additional 5mm to play with.
http://www.schneideroptics.com/info/faq/industrial.htm#qu5

Robin

  --- In staranalyser@yahoogroups.com, "staranalyser"
<staranalyser@...> wrote:
>
> Hi Steve and welcome to the group :-)
>
> I think your problem is more likely to be getting the star
analyser
> close enough to the CCD rather than needing spacers. The DMK21AF04
> camera you have has the mono version of the CCD which is used in
the
> Philips Toucam webcams so the ideal distance is around 35-40mm
with a
> maximum of 55mm to fit the spectrum on the chip. The back focus of
the
> C mount is 17.5mm
> http://www.ptgrey.com/support/kb/data/lens_flange.gif
> so you ideally need a nosepiece adapter about 15-20mm long, which
is
> quite short, up to 37mm maximum. If your current adapter is too
long,
> Modern Astronomy do a low profile C adapter which might fit the
bill
> http://www.modernastronomy.com/watec.html  (look under accessories)
>
> Robin
>
>
>
> --- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@> wrote:
> >
> > Hi folks
> > Like to say `Hi` just joined the group and wondered if any
members
> > happen to have used the DMK type firewire cameras with their star
> > analyser and if so was a spacer or two needed?.
> > Cheers
> > Steve
> >
>

Yes thanks for the info Robin.
I did get a small spacer that came with the camera which should help.
I have contacted Imaging solutions for the back focus distance you
asked me to give you but still waiting for a reply from them.
Looks like it might be a case of just trying the star analyser first
and see if a spacer is needed.
Steve

Hi Steve,

It sounds like it is a CS mount then and using the (5mm ?) spacer
makes it compatible with a C mount. so...

The back focus of a CS mount camera is 12.5mm which means the
nosepiece needs to be 22-28mm ideally. I checked with Bern at Modern
Astronomy and his low profile C adapter is 15mm. If you used that with
your spacer which came with the camera, that would bring the total
distance to 12.5 + 5 + 15 = 32.5mm which should work fine. How long is
the nosepiece you have?

Robin

--- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@...> wrote:
>
> Yes thanks for the info Robin.
> I did get a small spacer that came with the camera which should help.
> I have contacted Imaging solutions for the back focus distance you
> asked me to give you but still waiting for a reply from them.
> Looks like it might be a case of just trying the star analyser first
> and see if a spacer is needed.
> Steve
>

staranalyser wrote:
>
> The back focus of a CS mount camera is 12.5mm which means the
> nosepiece needs to be 22-28mm ideally. I checked with Bern at Modern
> Astronomy and his low profile C adapter is 15mm. If you used that with
> your spacer which came with the camera, that would bring the total
> distance to 12.5 + 5 + 15 = 32.5mm which should work fine. How long is
> the nosepiece you have?
>

Hi again Robin
The cs to 1.25" adaptor I have at present seems to fit the bill with a
nosepiece (I assume you mean the 1.25" bit that fits in the holder) is
about 13mm long but it doesn`t have a filter thread as it was made for
me by a friend. I am expecting another adaptor coming tomorrow which has
the filter thread and if its cut all the way through I should be able to
put it in my little lathe and cut it off to the correct length or cut a
filter thread in my present one. Just a wee bit confused with the
measurement - from the measurements above am I looking for a grating to
chip distance of between 34.5mm to 40.5mm (ie 12.5+22 and 12.5+28)?.
Thanks
Steve

--- In staranalyser@yahoogroups.com, Steve <steve@...> wrote:
>
> staranalyser wrote:
> >
> > The back focus of a CS mount camera is 12.5mm which means the
> > nosepiece needs to be 22-28mm ideally. I checked with Bern at
Modern
> > Astronomy and his low profile C adapter is 15mm. If you used
that with
> > your spacer which came with the camera, that would bring the
total
> > distance to 12.5 + 5 + 15 = 32.5mm which should work fine. How
long is
> > the nosepiece you have?
> >
>
> Hi again Robin
> The cs to 1.25" adaptor I have at present seems to fit the bill
with a
> nosepiece (I assume you mean the 1.25" bit that fits in the
holder) is
> about 13mm long but it doesn`t have a filter thread as it was made
for
> me by a friend. I am expecting another adaptor coming tomorrow
which has
> the filter thread and if its cut all the way through I should be
able to
> put it in my little lathe and cut it off to the correct length or
cut a
> filter thread in my present one. Just a wee bit confused with the
> measurement - from the measurements above am I looking for a
grating to
> chip distance of between 34.5mm to 40.5mm (ie 12.5+22 and
12.5+28)?.
> Thanks
> Steve
>

It sounds like you have everything you need. A man with a lathe has
many friends ;-)

Yes, an adapter length of around 22-28mm will make good use of the
the width of the CCD while still allowing the zero order star image
to be seen. There is a bit of a trade off between sensitivity and
resolution. I sometimes vary the distance depending on the
brightness of the object. Closer in means you can go fainter but at
the expense of resolution.
Your 13mm adapter would give you about 19A/pixel
13mm adapter + your 5mm spacer ~ 16A/pixel
25mm adapter ~ 13.5A/pixel
25mm adapter = 5mm spacer ~ 12A/pixel

To give you an idea of the scale of what you will get, the Gamma Cas
spectrum on my website here was taken at 18.7A/pixel using the same
size chip as yours.
http://mysite.wanadoo-members.co.uk/astro2/spectra_12.htm
Cooler stars have longer spectra which stretch further into the IR
and just about fit diagonally at 12.7A/pixel
http://mysite.wanadoo-members.co.uk/astro2/spectra_14.htm

Robin


Robin

Hi Robin
Re my C mount to grating spacing again. I`ve acquired another C to
1.25" nylon type adaptor with filter thread. When screwed into my DMK
camera adaptor the star analyser would be 35mm from the camera body
which with the C mount distance of 12.5mm gives me a chip to grating
distance of about 47.5mm. Would this distance be ok with my ccd chip?.
Cheers
Steve

--- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@...> wrote:
>
> Hi Robin
> Re my C mount to grating spacing again. I`ve acquired another C to
> 1.25" nylon type adaptor with filter thread. When screwed into my DMK
> camera adaptor the star analyser would be 35mm from the camera body
> which with the C mount distance of 12.5mm gives me a chip to grating
> distance of about 47.5mm. Would this distance be ok with my ccd chip?.
> Cheers
> Steve
>
Sorry that should be CS to 1.25" adaptor so its a CS mount. I have a
5mm spacer to make it to a C mount.
Steve

Hi Ashley,

That should be ok but it is very much on the top limit. You will
need to put the star image in one of the corners of the frame and
orientate the grating so the spectrum runs diagonally across the
frame. That way you will be able to squeeze the star and spectrum up
to about ~800nm into the image.

Robin

--- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@...>
wrote:
>
> --- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@> wrote:
> >
> > Hi Robin
> > Re my C mount to grating spacing again. I`ve acquired another C
to
> > 1.25" nylon type adaptor with filter thread. When screwed into
my DMK
> > camera adaptor the star analyser would be 35mm from the camera
body
> > which with the C mount distance of 12.5mm gives me a chip to
grating
> > distance of about 47.5mm. Would this distance be ok with my ccd
chip?.
> > Cheers
> > Steve
> >
> Sorry that should be CS to 1.25" adaptor so its a CS mount. I have
a
> 5mm spacer to make it to a C mount.
> Steve
>

staranalyser wrote:
> Hi Ashley,
>
> That should be ok but it is very much on the top limit. You will
> need to put the star image in one of the corners of the frame and
> orientate the grating so the spectrum runs diagonally across the
> frame. That way you will be able to squeeze the star and spectrum up
> to about ~800nm into the image.

Hi Robin
Thanks for that info. I assume using my f6.3 reducer is very much reqd
to get a smaller image on my f10 scope?.
Regards
Steve

--- In staranalyser@yahoogroups.com, Steve <steve@...> wrote:

> I assume using my f6.3 reducer is very much reqd
> to get a smaller image on my f10 scope?.

That will certainly help. A small star image with your large spacing
should give you excellent resolution.


Robin

Congratulations. A nice first spectrum. Those wide TiO lines show up
really well.

Robin

--- In staranalyser@yahoogroups.com, Marcelo Rios <clarion2010@...>
wrote:
>
> Hello everybody
>   I leave a Link Them where they can see my first spect.
>   http://www.espacioprofundo.com.ar/foros/about1178.html
>   greetings
>
>
>
>
> ---------------------------------
>  Preguntá. Respondé. Descubrí.
>  Todo lo que querías saber, y lo que ni imaginabas,
> está en Yahoo! Respuestas (Beta).
>  ¡Probalo ya!
>

I have frend he nead to see the spectrum directly whit his years

it is possible i thing whit a staranalyser but he only see something
look like a dot of color or so

is it possible to expend the spectrum by putting the starnanalyser at
more distance maybe

or another way to

h
jack 47'N 71'O

--- In staranalyser@yahoogroups.com, "Jacques Savard"
<jacquessavard@...> wrote:
>
> I have frend he nead to see the spectrum directly whit his years
>
> it is possible i thing whit a staranalyser but he only see something
> look like a dot of color or so
>
> is it possible to expend the spectrum by putting the starnanalyser at
> more distance maybe
>
> or another way to
>
> h
> jack 47'N 71'O
>

One suggestion. Visual work was my whole concern for years and
with others I faced the same problem. Pick Vega or some bright
star for demonstration. Turn the eyepiece inside or outside of
focus to make a nice bright - vertically stretched - line. That
is a larger objekt for older eyes to see and sometimes is seen.

You can also screw the SA onto an 18-14mm eyepiece then with
bright Vega it shows a larger bright spectral target.

You could also hookup your webcam and show on a monitor!

Hope this helps -
Jerry

The Star Analyser produces a rather short spectrum if you just screw
it onto an eyepiece. One way to lengthen the spectrum is to increase
the distance from the SA to the eyepiece eg by using an extension
tube (eg an old Barlow lens tube with  the lens removed or screwing
it onto the incoming side of a star diagonal.

Robin

--- In staranalyser@yahoogroups.com, "jwarnerr" <jwarner1@...> wrote:
>
> --- In staranalyser@yahoogroups.com, "Jacques Savard"
> <jacquessavard@> wrote:
> >
> > I have frend he nead to see the spectrum directly whit his years
> >
> > it is possible i thing whit a staranalyser but he only see
something
> > look like a dot of color or so
> >
> > is it possible to expend the spectrum by putting the
starnanalyser at
> > more distance maybe
> >
> > or another way to
> >
> > h
> > jack 47'N 71'O
> >
>
> One suggestion. Visual work was my whole concern for years and
> with others I faced the same problem. Pick Vega or some bright
> star for demonstration. Turn the eyepiece inside or outside of
> focus to make a nice bright - vertically stretched - line. That
> is a larger objekt for older eyes to see and sometimes is seen.
>
> You can also screw the SA onto an 18-14mm eyepiece then with
> bright Vega it shows a larger bright spectral target.
>
> You could also hookup your webcam and show on a monitor!
>
> Hope this helps -
> Jerry
>

do not know how to said in english

at the club observatory we have a 14 inch casgrain

if I am able to fit a starnalyser to this
--1- what is the best target?
--2- what is the fatest target I could espect?
--3- could I see by directly the spectrum easyly ?
--4- is it possible to make a kind of projection on frosted glass ?

jack 47'N 71'O

Hi Jaques

Yes you can use the Star analyser with a 14 inch casegrain but use a focal
reducer to keep the star image size small.

1. The Star Analyser instructions have suggested targets (a copy ofthe
instructions is in the group files) but  to start with try bright A type
stars which show H Balmer lines (good for calibration and
focus practice)  and M class stars which show good molecular absorption
lines.

2. Do you mean faintest?  The star needs to be about 5-6 magnitudes brighter
than for a normal image. I have recorded QSO down to mag 15 with a long
exposure CCD camera on a 200mm aperture. The absolute minimum depends on
your light pollution.

3. You can see spectra of bright stars visually (Use an extension tube or
star diagonal to increase the spacing of the Star Analyser from the eyepiece
to make the spectrum longer) You will see much more though, even with a
simple webcam.

4. I have never tried this. I am sure a webcam and computer screen will show
spectra to a large audience much better though

HTH
Robin




>From: "Jacques Savard" <jacquessavard@...>
>Reply-To: staranalyser@yahoogroups.com
>To: staranalyser@yahoogroups.com
>Subject: [staranalyser] the biggest or the fatest
>Date: Sun, 20 May 2007 02:14:35 -0000
>
>do not know how to said in english
>
>at the club observatory we have a 14 inch casgrain
>
>if I am able to fit a starnalyser to this
>--1- what is the best target?
>--2- what is the fatest target I could espect?
>--3- could I see by directly the spectrum easyly ?
>--4- is it possible to make a kind of projection on frosted glass ?
>
>jack 47'N 71'O
>
>

_________________________________________________________________
The next generation of Hotmail is here! http://www.newhotmail.co.uk

Hi Folks
Got my Star Analyser and very pleased with it and taken a first shot
of Vega but unsure what to do next?. The various web sites with
tutorials describing `Vspec` don`t seem to match the current version
of it??.
Could anyone point me to an upto date site please.The shot is in
`Steves file` folder.
Thanks for your help
Cheers
Steve

Hello,

This email message is a notification to let you know that
a file has been uploaded to the Files area of the staranalyser
group.

   File        : /Producing and calibrating a graph using visual spec.pdf
   Uploaded by : staranalyser <staranalyser@...>
   Description : Method for producing a calibrated graph using Visual Spec

You can access this file at the URL:
http://groups.yahoo.com/group/staranalyser/files/Producing%20and%20calibrating%2\
0a%20graph%20using%20visual%20spec.pdf

To learn more about file sharing for your group, please visit:
http://help.yahoo.com/help/us/groups/files

Regards,

staranalyser <staranalyser@...>

Hi Steve,

Nice first spectrum :-)  The Hydrogen Balmer lines are showing up
clearly.

I have finally done something I should have done ages ago. In the
files section you will find some simple instructions to produce a
graph and wavelength calibrate it using Visual Spec (also copied
below) This should get you started.

Robin

-------------------------------------------------------------------

Simple graph making and  wavelength calibration using Visual Spec
software

Importing the image

  You need to convert your image to black and white and rotate to get
the spectrum horizontal using your favourite image processing
software.
  You also need a fits image for vspec. Note. Not all Fits image
formats are the same and some do not work with Vspec.  I use
K3CCDTools to generate mine (16bit unsigned) Fits generated by IRIS
software work ok too
  Adjust the image using the upper and lower threshold icons until the
profile is visible

Making the graph

Make sure your spectrum is orientated with the red end on the right.
If not reverse it by clicking on the "mirror X" icon
  Click the "display  reference binning zone" icon to put a window on
the image.
  Adjust the window so it just includes the spectrum (drag down from
bottom, narrow from top)
  Click the "object binning" icon (NOT "reference binning") and a graph
of the spectrum should appear

Calibration

Once you have the raw graph up, select the "calibation 2 lines" icon

Confirm you want to use the current series as reference

Enter the two wavelengths into the boxes (the first one could be
zero, the second 6563 (Ha) for example)

Sweep the cursor over the peak at the first line (eg zero)while holding
down the left mouse button. You should see two dotted lines defining
the peak and the wavelength next to it (It might need a few tries
starting and ending at different points, Vspec will only calculate
the line if it is distinct enough to be valid)

Click on the number to turn it red and press enter. The pixel number
should appear next to the first wavelength box on the toolbar.

Repeat for the second calibration line. When you press enter, the
calibration should be done and you will be able to read of the
scale in Angstroms.


Alternatively


To calibrate using one line, drag the cursor with the left mouse
button pressed over the line (usually the zero order) to highlight it
and then press
the "calibration 1 line" icon.

You will then see a box where you can enter the wavelength of the
line and the sampling (dispersion in A/pixel)

Press apply and the calibration will be done.

Adjust the wavelength and sampling numbers entered  to get the best
fit to other lines in your spectrum


--- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@...> wrote:
>
> Hi Folks
> Got my Star Analyser and very pleased with it and taken a first shot
> of Vega but unsure what to do next?. The various web sites with
> tutorials describing `Vspec` don`t seem to match the current version
> of it??.
> Could anyone point me to an upto date site please.The shot is in
> `Steves file` folder.
> Thanks for your help
> Cheers
> Steve
>

Hi Robin
Many thanks for the instructions. I was a bit confused with the other
web sites as the tutorial commands didn`t match what was on screen!. :-)
Cheers
Steve

Hi again Robin
According to the Star analyser manual I crop the image until I just
have the spectrum (ie no star) but I think Vspec requires the star for
the first calibration line ie zero? or have I got that wrong?.
Thanks
Steve

Hi Steve,

Unfortunately Valerie's update of the tutorials is not as frequent
as the updates to the program. It is a very powerful program once
you get used to its quirks though. It might be hard to believe but
is actually much more user friendly than the ones the professionals
use ;-)

Robin
--- In staranalyser@yahoogroups.com, Steve <steve@...> wrote:
>
> Hi Robin
> Many thanks for the instructions. I was a bit confused with the
other
> web sites as the tutorial commands didn`t match what was on
screen!. :-)
> Cheers
> Steve
>

Hi Steve,

It is a good idea to include the zero order as that gives you a
pretty good zero calibration point for free as you say. If you can
identify two lines in your spectrum eg Halpha, Hbeta, then you can
use them instead and you might get a better calibration as the
dispersion is not precisely linear (in fact Vspec can fit a
ploynomial to several lines but that is probably best left for
another day ;-)

I will check the SA manual wording, thanks for pointing it out

Robin

-- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@...> wrote:
>
> Hi again Robin
> According to the Star analyser manual I crop the image until I just
> have the spectrum (ie no star) but I think Vspec requires the star
for
> the first calibration line ie zero? or have I got that wrong?.
> Thanks
> Steve
>

Hi all
I have been taking a few spectra with the SA and a thought occurred to
me. As the star to spectrum distance remains the same regardless of
the star chosen if I use the same optical configuration each time ,
would it be possible for me to devise a reference spectrum unique to
my set up which I could simply compare with any other spectra I take?.
I have successfully taken Vega`s spectrum and was only able to
calibrate it by comparing it with other spectra found online. Other
spectra I have taken I can`t seem to identify the lines as I have no
reference.
Hope its not off topic but does anyone know a way with Photoshop to
darken absorption lines and brighten emission ones?.
Regards
Steve

Hi Steve,

Yes you can use Vega as a standard to calibrate for wavelength using
the Hydrogen Balmer series lines

H alpha 6563A
H beta  4861A
H gamma 4340A
H delta 4102A
etc

which show up well in A class stars. You can then use the same
calibration on other spectra where the lines are not obvious. Just
make a note of the dispersion (A/pixel) you get from Vspec when you
calibrate your Vega spectrum and use the same figure when doing a
single point calibration using the zero order on your new spectrum.

Vega can also be used to calibrate the spectral response of the
instrument (SA grating plus camera) so you can plot the correct
intensity of the spectrum across the wavelength range. If you want
to try it, the Vspec tutorials take you through it  but if you get
stuck let me know and I can help.

You can see the instrument response I got for my setup here
http://mysite.wanadoo-members.co.uk/astro2/spectroscopy_5.htm
I just divide any spectrum I produce by this response curve to
calibrate the relative intensity correctly.

Robin

--- In staranalyser@yahoogroups.com, "ashleyparkuk" <steve@...>
wrote:
>
> Hi all
> I have been taking a few spectra with the SA and a thought
occurred to
> me. As the star to spectrum distance remains the same regardless of
> the star chosen if I use the same optical configuration each time ,
> would it be possible for me to devise a reference spectrum unique
to
> my set up which I could simply compare with any other spectra I
take?.
> I have successfully taken Vega`s spectrum and was only able to
> calibrate it by comparing it with other spectra found online. Other
> spectra I have taken I can`t seem to identify the lines as I have
no
> reference.
> Hope its not off topic but does anyone know a way with Photoshop to
> darken absorption lines and brighten emission ones?.
> Regards
> Steve
>

Hi Folks
Just taken and processed a spectrum of Delta Vir (in Steve`s folder)
last night and have some Hydrogen lines superimposed on it. A few
peaks show between the first order star and the spectrum (due I think
to some over enthusiastic Photoshop processing:-^). My question - is
the `Y` axis just a measure of intensity and if so how come it starts
at 900 sometimes with Vspec?.
Cheers
Steve

Has anyone tried using a slit with the SA?  Any examples?

We would be very interested in the technique(s) used if anyone
has done it.

Thanks,
Jerry