Re: Blood moon
Thank you for the lesson in lens design, Scott.
I'm well familiar with thermal design issues.
If you'll note, I did not use the phrase "infinity stop".
- Leigh
I am sorry that you felt I was talking down to you, but "setting the lens to infinity" was not so easy. My m5vII refused to autofocus on the moon when it was still bright, and the depth of field is not enough to prevent going well out of focus when I left the camera set up outside, switched off, to keep it cold. The focus scale on my 40-150 has an infinity sign that is about 4 mm wide. The best focus was found off center, and the actual setting moved around a bit during the evening. My M-1 does better at AF (the M-5vII may have suffered some moisture damage to its viewfinder), but focus bracketing with magnification improves the results noticeably with it as well.
The sharpest long lens that I have access to is a Leica R 280/4.0 APO (manual focus only), so I tried that tonight, while the moon is still full and "super." I first focused on a building a mile or so away, to determine "infinity." I then bracketed focus on the moon and found a slight additional shift gave the best result:
P9280041i by
scott kirkpatrick, on Flickr
This is from a single frame. The 8-frame HR mode didn't do better, perhaps because the atmosphere introduces jitter in the image during the time it takes to make multiple exposures.
scott