Originally posted by reh321 So you go "old school" with an RF link? I don't mean to sound disparaging - I am quite familiar thru experience with those methods - but a lot of people here seem to really like the automation provided by P-TTL.
So... I actually don't know how to use a TTL flash since I don't own one.
---------- Post added 04-28-15 at 05:49 PM ----------
Originally posted by Sagitta while deep sky / long focal lengths may not be doable
I used my O-GPS this weekend for the first time. I found two factors to be important in image success -- focal length and lens size. The wider the better, obviously, just like an exposure with a 200mm has to be a lot shorter than with a 10mm due to magnification and all that jazz that everyone understands.
What surprised me was that my astrotracking images with my 31mm FA Limited worked better than with my 10mm Samyang. I figured out that the reason was lens size. Even though there was NO wind and not even a breeze the one clear night we had, the Samyang's weight and size affected the astrotracker's ability to track accurately. So two rules for lenses: wider and smaller.