1st DSLR pic through scope

[Demonperformer]

Not totally sure this is the right section to post this, but as this quite obviously "needs improvement" ....

This morning was my first attempt at connecting my new Canon 1000D to the 102SLT ... as much as anything, to see if I could get the equipment/software to work before taking it to the SCAG meeting on Saturday. So, was surrounded by my usual streetlights, which were responsible for much of the background glow.

I took pics at a series of exposures, but this one was 20sec (single exposure, no calibration frames). This provided a nice compromise between getting fainter stars and not blotting everything out with longer exposures. On an alt-az mount, so one of the things I wanted to explore was how long I could take without trailing becoming an issue. I have cut down the image to the left hand side, as there was a lot of blank space with no stars further right. The bright one is Antares.

And yes, before anyone says it, I know my pictures would improve considerably if I remembered to remove the focussing mask BEFORE taking them:iamwithstupid: - but I'm sure I can't be the first person to have made that error!

Any suggestions on other things that would improve my pics (based on this rather limited sample size:D) gratefully received.

Thanks for looking.

[Psychobilly]

Your definitely not the first person and certainly wont be the last to do it.. I left one on for 4 hours of subs one night

There would probably haev been a fair few more stars in the image with it off as well...

I wouldnt worry too much about calibration frames with 20s exposures.

It's hard to tell what you need to do because of the "distortion" caused by the mask

Peter..

[jgs001]

Off to a good start... better try again without the focusing mask. Your sub length is limited by where in the sky you are aiming for. If you aim low in the east or west, 90 seconds to 120seconds are possible. This time comes down, the higher up or further North/South you go, dramatically so I found. You may also want to look at the balance point on the scope, if it's the standard scope, you may find, that your far too tail heavy with an SLR on the back. The other thing, an LP filter. The SW LPR filter is very good value for money and will work nicely.

[dph1nm]

I have tried the Canon 1000D on an Nexstar SLT102. Couldn't get more that 30secs tracking out of the Alt-Az mount without trailing, double images etc (and I lost quite a few at 30secs), so image rotation wasn't really a problem!

I did discover that if you included all the trailed frames then they tended to average out so the stars still looked quite round (but rather bloated). Binning the final result 2x2 also helps.

One thing - for DSOs, with so many short frames I definitely needed to subtract bias frames (I use 1/4000 sec in the dark with the lens cap on), otherwise the structure in the bias on my 1000D rapidly becomes visible. I have never used darks. I would also think that you will either need flats or to use some gradeint removal tool, as I certainly get vignetting, even with a 2" adapter.

NigelM