What am I doing wrong? Is the lens back/front focusing?

stevelee said:

My camera won‘t shoot at 1/160,000 second anyway.

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How come? Have it checked by Canon

stevelee said:

With the 100-400L II, I recently shot the moon and Jupiter. With IS on at 400mm, handheld shots I took at 1/320 second looked good enough to post one of them, as I did in the moon section. I cropped it and posted a 100% pixel peep. I didn’t add any extra sharpening, and just did a bit of highlight recovery in ACR. My camera won‘t shoot at 1/160,000 second anyway.

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I sometimes take acceptable shots at 1/20s hand held, frequently at 1/100s, and use 1/250s in Tv in dark conditions at 400mm. But, shake leads to a softening, which you don't see as movement but as a slight blurring, and you do see when cropping high resolution sensors. This is nicely illustrated in shots of a $ bill in http://arihazeghiphotography.com/blog/focus-micro-adjustment-is-it-always-needed/
I like to be above 1/400s, and preferably above 1/1000s to get that real sharpness.

AlanF said:

I sometimes take acceptable shots at 1/20s hand held, frequently at 1/100s, and use 1/250s in Tv in dark conditions at 400mm. But, shake leads to a softening, which you don't see as movement but as a slight blurring, and you do see when cropping high resolution sensors. This is nicely illustrated in shots of a $ bill in http://arihazeghiphotography.com/blog/focus-micro-adjustment-is-it-always-needed/
I like to be above 1/400s, and preferably above 1/1000s to get that real sharpness.

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Interesting. While it illustrates your point, I see less difference between the two than I would have expected.

Obviously one needs to balance concerns of shake, high ISO noise, DOF, etc. I was surprised that the best compromise I found for the moon shots were the ones taken at 1/320.

stevelee said:

Interesting. While it illustrates your point, I see less difference between the two than I would have expected.

Obviously one needs to balance concerns of shake, high ISO noise, DOF, etc. I was surprised that the best compromise I found for the moon shots were the ones taken at 1/320.

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True. High iso will lead to noise that leads to loss of sharpness. So, there is always a balance. I find a shutter speed of about 1/300 good for moon shots, but they are not cropped nearly as much as many bird shots and there is less lunar fine structure and sharp edges than in feathers. Fortunately, DOF is not too much of a problem in moon shots.

AlanF said:

True. High iso will lead to noise that leads to loss of sharpness. So, there is always a balance. I find a shutter speed of about 1/300 good for moon shots, but they are not cropped nearly as much as many bird shots and there is less lunar fine structure and sharp edges than in feathers. Fortunately, DOF is not too much of a problem in moon shots.

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Focusing is an issue for me. Autofocus might work, or it might fish around looking at a mostly black sky. I can’t focus visually while holding a long lens over my head. So I set it to what looks like infinity on the scale and try to remember what the line means. So I feel like I need to stop down a bit to give me margin of error and maybe hit a good spot for the lens.

The exposure issue was that I needed to get Jupiter to show up but not blow the sunny side of the moon out too bad. Fortunately, they weren’t flying by too fast, so I could do a lot of bracketing manually. While I can enjoy other people’s shots, I don’t have any interest in shooting BIF myself.