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DSLR photometry

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#1 Hubert

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Posted 21 July 2013 - 05:55 AM

Hi guys, I'm starting a new thread instead of responding to my previous thread about the AGB camera.

I'm still thinking about photometry and a can do it with the ST402 ( still haven't bought it ) and my C9.25 but now I'm considering something else.

I have done in the past photometry with my DSLR especially on Eps Aur ( for Jeff Hopkins). Actually I like to do measurements of variables which are currently in the picture. For now the SN in Lac, R CrB, Z UMi etc...

Instead of always doing timings ( which I have done in the past ) I think that I better concentrate on the previous mentioned stars. I think there is no need to buy a CCD en V-filter because I have a Canon 40D and it's perfect for V-measurements via the green channel.

I also going to sell my C9.25 and buy a 8 or 10" f/4 photonewton. With the DSLR and a shorter focal length there is no need for a laptop and guiding.

Any thoughts on this?

#2 Ed Wiley

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Posted 21 July 2013 - 10:25 AM

Hi Hubert:
Since you have already participated in the Eps Aur campaign and have explored DSLR photometry you already know the potential for this sort of photometery better than I do. Having read a bit about it and having seen AAVSO interest growing in DSLR photometic potential, I think you should "go for it."

Re scopes: No advice from me either way.

Good photon collecting!

Ed

#3 jgraham

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Posted 21 July 2013 - 11:33 AM

I have done a fair amount of DSLR photometry with good results, not quite up to par as with my monochrome CCD and V filter, but getting there. A fast Newtonian would be effective, but not necessary. I use whatever scope I happen to have mounted inlcuding my 8" f/10 SCT. The field of view with this scope is a good match for AAVSO E charts.

#4 StarDusty

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Posted 02 September 2013 - 07:09 PM

I have tried DSLR photometry with a stock XS Canon and a homemade 6" f/5.6 telescope. I used the tutorials found online via AAVSO and IRIS software to pull the Green out of the RGB image. Here is a plate of the result.

Only after defocusing the image during capture did my result fall within expected limits.

Attached Files



#5 jgraham

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Posted 06 September 2013 - 07:42 AM

Coolness! I struggled a bit with results that varied from excellent to a tad rough. I suspect that the problem the Orion imaging skyglow filter that I was using clipping the green a bit. Since removing it my results have been consistently very good. I've been using an 8" f/4 and while I have been tempted to de-focus a tad I haven't had the need to do that yet.

Neat stuff.

#6 jgraham

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Posted 08 September 2013 - 08:51 PM

One thing that I find interesting about DSLR photometry is that I get a color image for each variable. The long period varables that I typically observe are among the reddest stars I've seen. In sharp contrast are cataclysmic variables which tend to be blue.

Neat stuff.






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