Imaging the ISS

Lads, as you may be aware, the ISS is making passes over Ireland for the next 10 days or so. Some nice high altitude passes in the mix. For instance, tomorrow nights pass at 9.06pm is 55° alt. Well worth trying to image.

Anyway, I tried the last time and ended up with mostly streaks and/or over exposed shots with my SPC900 webcam. Can I run this by you guys. Only got the ISS in small batches of 3 or 4 frames as it crossed the FOV last time. I guess this means I should up the frame rate from the 10fps I used the last time. Buty how much? Does the 15FPS max rule to minimise compression artifacts when planetary imaging still apply when imaging the ISS or are compression artifacts not a worry in this case and I should up the FPS to 30, meaning each time the ISS crosses the FOV I should get it in more frames.

Next question. Last time when I did manage to get a few frames containing the ISS, all bar 1 or 2 frames during the whole pass were streaked. I guess this means I should use a much shorter exposure time. Should I just set K3ccdtools to the shortest time possible?

Lastly. in the one or two frames I got were the ISS did not seem to be streaked, the station was over exposed and a bright white blur. I was thinking. With Jupiter visible in my gap in the trees early enough to use it to adjust settings for this pass and seeing as jupiter is at mag -2 about the same as the ISS at zenith in this pass. Could I use jupiter to set my gamma and gain to get a non over exposed image of jupiter on screen with the eq bands nicely visible. Would these settings then ensure that the similar -2 mag ISS would not be over exposed.

Oh yeah. The SPC900 equates to a 6mm EP in my scope. Would I lose any chance of getting it in the FOV if I 2x barlowed my webcam? Its just that other ISS images I have seen have a much larger image scale. Did they barlow their camera or just crop and resize non barlowed images in photoshop?

Hi,
Image artefacts caused by jpeg compression are the least of your problems while imaging the ISS, how are you tracking the it ?
Like you say, using Jupiter is not a bad starting point when trying to get a the exposure right, I'd then increase the frame rate to help try reduce smearing and also decrease its brightness as its usually brighter the Jupiter.
My scopes image scale is quite big, then again its a 20" so it would do, I wouldn't touch a barlow if you are having trouble tracking without one in the first place.
Have fun.

Here is a screen grab of the settings I used
when I imaged the ISS & Shuttle
www.frankryanjr.com/ISS__STS117_resized_copy.jpg

farm2.static.flickr.com/1059/540548853_f701cde5e0_o.jpg
I used Venus that time to get the exposure roughly right
(But dimmed it down considerably to compensate for
movement of the ISS)

The ap. of the scope will have an effect on the settings.
Go as high a frame rate as you can.
Think high speed camera trying to capture a flying bullet.

Your telrad will have to be bang on also.
I adjusted the red dot finder on my ETX to be 'a fraction'
off center so i could place it in front of the bright dot of the
ISS, you are able to see both that way and so you wont be constantly
trying to keep the red dot on top of the white dot (if that makes sense)

Good luck!



Best of luck!

Nice work Frank! It is not easy at all trying to catch and pursue a moving target.

I hope to do something similar using my AP1200GTO where, hopefully, I will be able to track the ISS across the sky and thereby try and get a higher resolution result.

Got my days mixed up. The high Altitude pass over Ireland is Wednesday night.

Well,
you got me in the mood for this craic so I've dusted off the
ETX and I'm gonna give it a go again tonight for the laugh.