Photo settings question

[Analog6]

IF it is fine tonight I thought I'd try for Venus and Jupiter with my Sigma 100-500 on the Canon 60D. Effective focal length will be about 750, the f stop will be 6.7, and I need to know how long can I have for exposure before they start blurring?

Any advice greatly appreciated.

[N1]

Keep it a short as possible, I'd say definitely no longer than a second. But what details you'll record depends a little on the seeing too. Also, I think the biggest challenge is to record stuff like Jupiter's moons and not lose the phase of Venus to overexposure in the same image. The difference in brightness is considerable. If conditions are good, consider an exposure series that could be made into an HDR type composite later.

In any case, take a few test shots & review them on the 60D's monitor by zooming all the way in. That'll give you a pretty good indication of what you are achieving.

[Octane]

Yeah, about 0.6 seconds.

H

[Analog6]

Thanks, I'll get out early and get all set up.