Started Feb 11, 2013 | Discussions thread
Vlad S Veteran Member • Posts: 3,749
I did it with the 100-300!

bgalb wrote:

The passes that NASA has been alerting me by email are always shortly after sunset and shortly before sunrise when the station is brightly illuminated by the sun. I guess it would be really difficult to track with a telescope of sufficient magnification to show details.

The NASA web site did not work for me. The web page could not be found, although Google had a cashed copy. I used http://www.heavens-above.com/ to look up the ISS passes, and there was one yesterday over San Francisco between 18:56 and 19:01 with the magnitude of -1.2. The maximum altitude was 20 degrees, so standing on a dark hill it was just above the glare of the city. The crescent moon was setting and I used it to estimate the exposure. I started at the "sunny 16"+ 1 stop, but it was a bit too dark, so I added another 1/2 stop or so. I adjusted ISO so I would get 1/800s shutter (fast enough for handheld) and f/6.3 aperture (tradeoff between sharpness and ISO). The ISO came to 800.

Tracking was incredibly difficult. The field of view is small, there were no other bright objects to help tracking, and ISS moves fast - it crosses the field of view as fast as a jet airplane at about 7mi/10km distance. I had the digital teleconverter enabled, which in hind side was a mistake. It only narrowed my FOV, and at 100mm I had a 200mm FOV, but no extra resolution.

I used high speed burst and moved the camera about - the spray and pray method. Got a few shots with ISS in sight, but only at 100mm FL. At longer FL there were only blanks. Not much detail of course, but at 100% magnification it is possible to discern the two banks of the solar panels.

My next good viewing conditions are on Feb 22 and Feb 24. ISS will be higher and brighter. I hope to get to at least 200mm - see if there will be any more detail visible.


 Vlad S's gear list:Vlad S's gear list
Olympus OM-D E-M5 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Olympus M.Zuiko Digital ED 9-18mm F4.0-5.6 Panasonic Lumix G 20mm F1.7 ASPH Panasonic Lumix G Vario 100-300mm F4-5.6 OIS +2 more
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