Here's a shot I took at about 11:40PM Pacific Time
I used my new lens!
I used my new lens!
and because this all would increase the shutter open time to some 5 seconds.
Great one Dembadon, would you care to post also a live size crop of the moon?
One more thing, Dembadon,
A hint for the exposure, Dembadon. You have been using the extremes of the lens: f 300mm and Aperture 5.6. Now you can see here that lens performance degrades slightly at the extremes, (play with the slides). From 200mm to 300mm you see the blur increase sharply from ~1.5 to ~2.5 units, meaning that you get actually more resolution at 200mm than at 300mm, assuming that you have ample pixels like the EOS 550D. Also stopping down slightly (f8) increases the resolution again.
So what I would have done for the sharpest result is using maybe 250-280mm, just slightly before the zoom hits the stop, because that stop could also decentre the lenses ever so slightly. And I would stop down a bit, like f7 or f8.
I'd also would have select manually ISO 100, for minimizing the noise, and then put the combination on the tripod, and because this all would increase the shutter open time to some 5 seconds.
Very nice shot Dembadon! Clouded in here with snow falling.
Congrats on the new lens - it covers some very handy focal range(s).
I'll try to keep the focal range around 250-280mm, as you suggest, from now on.
In this case it is not the motion - both pictures were taken for times short enough so that the motion can be neglected. It is more about atmospheric effect.
Could be that the resolution of the lens is too low for the effect to be seen - we are talking about 300 mm vs 1000 mm or even 1500 mm if memory serves me well.
That's correct- atmospheric turbulence can be modeled as a slowly-varying (in time & space) phase-only object, over the timescales and length scales of most imaging systems (thin screen model). Long exposures tend to show uniform blurring, while shorter exposures become sharper.
As explained earlier - it doesn't have to be camera motion.
It won't hurt to check how the lens performs in good light and with short times - at 300 mm rule of thumb says to use time 1/300 sec. Make it 1/500 (300 mm * 1.6 = 480 mm) and try to shot some distant object. Take a look at 1:1 crop then.