[Aavso-photometry] DSI Pro CCD Cameras $129

[Jeff Hopkins]

Hello Bob,

The $129 for the monochrome CCD camera is a great buy and they will 
ll be gone soon. If you are interested in getting your feet wet 
withCCD photometry you will not find another opportunity this cheap.

I have been doing single channel UBV photon counting since the early 
1980s. A couple of years ago I got an Optec SSP-4 to do JH band 
infrared work. I use an old (1970 era) Celestron C-8 for the UBV work 
and a new Meade 12" LX200GPS for the SSP-4.

Also a couple of years ago I started getting involved with CCD BVRI 
photometry using a DSI Pro. I modified it, added a cooler, filter 
wheel and F3.3 FR. I use it with my 12" and it works very well. The 
DSI Pro with F/3.3 FR should work fine for you too. My 12" is an F10 
also.

I use the Astrodon filters and imaged M67 back in February to 
determine my transformation coefficient. So far all seems fine with 
these filters.

As for software, there are three parts:

1. Image acquisition
2. Image processing
3. Data Reduction

The Meade software can do the first two and give you instrumental 
counts or magnitudes. You will then need something to take those data 
and reduce to standard magnitudes. I have a FIleMaker Pro Database 
program I developed and use. You could also use a spreadsheet 
program, but not as efficient. I have also been experimenting with 
AIP4Win. While this costs $99 you get a very nice book with it that 
has a lot of CCD information. Both the Meade and AIP4WIN software do 
the image processing fine (similar, but different). Since the Meade 
software is included for the $129, try it before investing in other 
software.

The Meade software is actually very good, if not confusing. The 
software is know as the AutoStar Suite. When you open the program you 
are taken to a very nice planetarium program which can be connected 
to your telescope and control it. If the scope is aligned to the 
stars the planetarium program will show where it is pointing and with 
a click move the scope to where the cursor is. From within this 
program you can select Imaging and DSI and it will open another 
window with a program called Envisage. This is the imaging 
program.The saved images can then be opened with the AutoStar Image 
Processing part. Now you can draw a box around a star and get its 
magnitude ADUs (the sum of the pixels counts in an aperture minus the 
sky analog to digital counts). There are lots of things you can do at 
this point.

What you will need for the DSI Pro to do Filter photometry us a 
different nose piece to replace what comes with it (to handle a large 
filter slide). You can get one of these from ScopesStuff along with a 
dark slide/shutter (very handy for taking dark frames) for $72 @ 
http://www.scopestuff.com/ss_dsib.htm

For just V work the filter will screw into the nose piece of the 
camera. When you are ready for BVRI photometry, get the ATIK filter 
wheel ($199 also from ScopeStuff).

To help people get started with CCD photometry (particularly with a 
DSI Pro) I have written a book with a friend (Gene Lucas). You can 
find out more at http://www.hposoft.com/ASCCD.html

I have a few copies left. If interested you can send payment via 
PayPal and have the book in a couple of days.

Let me know if you have any other questions.

Good luck.

Jeff


At 14:16 -0700 07/30/2007, Bob Crumrine wrote:
>I'm thinking of making the plunge into this area, but am trying to 
>think it through, first, to see what else I might be getting into! 
>I have a Meade 8" LX200 classic F/10 that I currently use for PEP 
>with an Optec SSP-3 Photometer monitoring small amplitude variables. 
>This setup works very well and I enjoy using it, and I'd want CCD 
>observing to augment, not replace the SSP-3 work.
>According to the pixel size calculation chart in the AAVSO CCD 
>manual, this will give me an image scale of about 0.88 arc seconds 
>per pixel and I remember reading that 2 seconds is acceptable.  I'm 
>considering purchasing an F3.3 focal reducer, or perhaps a 6.3, but 
>would prefer the 3.3 due to the wider field of view.  The F/3.3 
>reducer would give me 2.7 seconds.  The skies aren't too great here 
>so if 2 sec is typical in good skies, I wouldn't think we'd be any 
>better than 3 or 4 here most of the time near the Great Lakes.  Any 
>recommendations for focal reducer?  I read a negative comment about 
>them in the CCD manual.
>
>I read in the CCD manual that different CCD chips produce different 
>spectral response and I would expect different CCDs to require 
>different V filters to match the desired V response, but it seems 
>that V filters from Astrodon and Optec will work equally will with 
>any CCD chip; what am I missing?  Or is this what the transformation 
>coefficients take care of?  I'm familiar with PEP transformations 
>measuring red and blue stars.
>
>I've also been reading about software programs; what's really 
>required here?  What do I need for differential V-band photometry in 
>addition to the Meade drivers?  I've read about CCDSoft, MaxImDL and 
>others, and also Mira.  The first two seem pretty $$$ but Mira seems 
>affordable.
>
>Also, one thing to consider is that I don't have a permanent 
>observatory and usually roll or carry things out from the garage.  I 
>do have access to a modern laptop computer running XP Pro.
>
>Thanks!
>Bob Crumrine (CRR)
>Fairport, NY, near Rochester

-- 
Jeff Hopkins
HPO SOFT
Counting Photons
http://www.hposoft.com/Astro/astro.html
Hopkins Phoenix Observatory
7812 West Clayton Drive
Phoenix, Arizona 85033-2439 U.S.A.
(623)849-5889
(623) 247-1190 (Fax)
www.hposoft.com