Quote:
Originally Posted by AnakChan
That's a very interesting guideline on focusing. With my FL @ 2500mm/F10 & camera 3.76µm pixel pitch, my CFZ varies 232µm to 317µm depending on colour wavelength which seems quite generous.
Having said that, I do set my triggers to refocus every 5th shot, 2 deg temp changes, or if HFR changes by 10% (whichever comes first) and I find that it refocuses quite often - definitely much more frequently than every 60 mins Paul has recommended. I probably could tone that down a little and not refocus so frequently.
Even though I image almost exclusively at such long focal lengths, with suburban Perth's rather "flat" terrain and highly susceptible jet streams, shorter focal lengths probably makes more sense, as with those conditions, it's almost like lottery to get a night where I maximise the capability of focal lengths. i.e. aside from the right scope for the right target, IMO, it's also the environmental conditions with the right scope.
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Hi Sean
Thank you for your comments.
Your frequent focusing has got me thinking.
We bang out subs like sausages really somewhat taking away the importantce of a good photo graph..like if you were taking a shot, say a portrait, you would be very careful and also for following shots...the need for many subs has at least for me caused me to firget that finally it is about individual captures.... and so having read your approach I am inclided to tell the EAF to focus more often. Certainly I review subs and throw out bad ones and I guess although one must do that it may promote the sausage turn out approach....
I will run at 1000 mm (200 mm ap f5) with my additional new set up and avoid the long F/L experience ..at least until I get it all together..I mean I still don't do dark and flat frames so that's where I need to concentrate...I have been rushing forward and need to tidy up my game.
Thanks again for your input I greatly appreciate you taking your time to do so.
Alex