ISS photo's 27/07/08

Boy this ISS imaging lark isn't easy!! Very hard to hand track my unwieldy dob.

Things seemed to be working out great for me I thought. Thought there was only one pass at 9.38pm (Which I missed) but discovered there was another pass at 10.48 or thereabouts when I checked Heavens above just in the door from work. I had just enough time to set the scope up and collimate. I am even sure I got focus spot on. I had auto settings on K3cccd tools and was able to get sharp diffraction spikes on Arcturus. I then turned off auto settings and manually set gain. K3CCD preview windo go very dark.

So anyway, along comes the ISS and I start tracking by hand. Out of the corner of my eye I can see flashes on the laptop screen which is the ISS bouncing through the FOV. I knew right then I was over exposed. The flashes were too bright.

I didn't bother trying to align or stack any frames in Registax with over exposed frames and instead I will just post the best unprocessed frames I managed to grab.

Maybe next time I'll get something better!

Very good Keith,

I've been waiting for a gap in the weather to try as well.

Last night was perfect but I was too tired .

Michael.

Nicely done Keith, tracking is a bit off though...

:laugh:

Tracking isn't off as much as I thought though!!

Had a look at a good few ISS imaging threads over on CN and it seems I did quite well in comparison in terms of the number of frames where the ISS was in the FOV. I captured 2500 frames in total. Have the ISS in about 40 or 50. The average seems to about about 10 or 15.

My problem I believe was shutter speed. Too slow a shutter speed led to over exposure and too slow a shutter speed led to most of my 40 or 50 frames being absolutley unusable due to streaking.

Those images above were the best non streaky frames pretty muched evenly spaced throughout the pass. ie. first frame was high WSW, next frame high S, next high SE, next low ESE.

So the big question is. What gain and shutter speed do I use and wrt shutter speed, there doesn't seem to be a numerical indication of shutter speed in K3ccdtools. Its just a slider bar for gain and shutter speed. Which is a faster shutter speed? Slider to the left or to the right??

Oh and how many FPS should I capture at. I used 15fps. Is it like imaging planets where using a usb 1.1 webcam means anything over 15fps uses too much video compression or is that not an issue when imaging the ISS and one can push the FPS much higher?

ANyway, dunno if the weather will co-operate tonight, but there are another 2 decent passes tonight. If the weather is good I'll be leaving work early to get home for the 9.38pm pass. Might the sky be a bit too bright for that 60 degree alt pass though. There is another 40 degree pass at about 11.15pm

So whats everyone elses settings for K3ccdtools then??