Adjusting Lenses To 1D3

I just finished adjusting 3 of my lenses to my 1D3. The 24-70 required +8, the 135 required +11, and the 100mm required +19. I didn't do my widest lenses because they are up for sale. While I'm glad I could correct lens to camera I wonder what, if anything, this should tell me. Ideas?

only found my 100 macro needed an adjustment, rest were spot on. I seem to have a good 1D3 but whether this is related I don't know. Wonder if anyone has collated bad AI servo capability with levels of lens adjustments needed?

could someone explain this please - should lenses be adjusted? why and how?

Thanks.

GentleGiant wrote in post #4129477
could someone explain this please - should lenses be adjusted? why and how?

The 1D Mark III, and the presumibly the 1Ds Mark III, have a focus microadjustment. This is a lens-specific feature available through the menu system that allows you to make subtle adjustments to the front/back focus of each model lens. The idea is that we can use this feature instead of having to send the lenses and bodies to Canon to get calibrated as a matched set.

I've been watching the adjustment threads closely because A) I'm curious because it's a neat new whizbang, and B) I had tremendous difficulty adjusting two of my lenses. Based upon that I'm not satisfied that the process and impact of using this feature is well understood as of yet. However, out of the seven or eight of these threads that I've read, the consensus seems to go like this: 90% of people with a 1D3 never touch it and get great shots. I've yet to see someone who used the microadjustment come back and say that it made such a dramatic difference that it saved shots from being otherwise unusable (though I'm sure someone has). Weather or not you need it is debatable and can really only be answered by your own needs. How to do it for the best effectiveness, to my eye, appears to be much more ambiguous.

So to answer the OP's question, I don't think those number tell you anything. The settings have been hugely different for the same model lens across a number of different people--tuning the camera to the nuances of a particular lens is, after all, what it's there for.

Imaginos wrote in post #4129557
The 1D Mark III, and the presumibly the 1Ds Mark III, have a focus microadjustment. This is a lens-specific feature available through the menu system that allows you to make subtle adjustments to the front/back focus of each model lens. The idea is that we can use this feature instead of having to send the lenses and bodies to Canon to get calibrated as a matched set.

I've been watching the adjustment threads closely because A) I'm curious because it's a neat new whizbang, and B) I had tremendous difficulty adjusting two of my lenses. Based upon that I'm not satisfied that the process and impact of using this feature is well understood as of yet. However, out of the seven or eight of these threads that I've read, the consensus seems to go like this: 90% of people with a 1D3 never touch it and get great shots. I've yet to see someone who used the microadjustment come back and say that it made such a dramatic difference that it saved shots from being otherwise unusable (though I'm sure someone has). Weather or not you need it is debatable and can really only be answered by your own needs. How to do it for the best effectiveness, to my eye, appears to be much more ambiguous.

So to answer the OP's question, I don't think those number tell you anything. The settings have been hugely different for the same model lens across a number of different people--tuning the camera to the nuances of a particular lens is, after all, what it's there for.

I used the 45deg focus chart thing and when I got them all "accurate" using that focus chart, the pictures were all soft when I was using the camera for real. I set it all back to 0 and let it be. I think if youre going to use it, you need to not use that focus chart BS. Just put the camera on a tripod, focus on something using AF and then just check it on live view to see if you can make it any sharper via adjusting it yourself. If you can, time for the CFN adjustment. If you cant, let it be.

AdamLewis wrote in post #4130390
I think if youre going to use it, you need to not use that focus chart BS.

That's more or less in agreement with my experience. About five iterations of different focus charts and all manners of geometric widgetry, which I admit was fun for the mental gymnastics, the results were extremely frustrating. I finally just printed an ISO 12223 chart at 300 dpi and hung it at the end of a hallway. Not rigorous for sure, but it got results.

However, the most interesting revelation I had was that some lenses will consistently have a slightly sharper image at different MAs depending on weather it was coming from OOF at minimum or OOF at infinity. My 100 2.8 Macro was the easiest to adjust because it didn't take a great deal of experimentation to find that one setting was conspicuously sharper than the others. My 70-200 2.8L IS, in stark contrast, was best at a -4 (or something) when it's focusing out from the minimum limit, but a +4 when coming down from infinity. Even worse, what conclusion am I supposed to make when a 50 1.2L focuses sharpest at +5 from the minimum, but then -5 from infinity, and is worse still at +0 from either? It's things like that which make me suspect this one little MA feature is fabulously complex and is not yet well understood. It might be that I just happen to have a kit with three frustrating lenses in it, but I dunno; I like to know as much as I can about such things.

Another example of a good question is, should this be done at the critical aperture? What about IS? Stuff like that. I guess I'm really saying is that Canon should provide a white paper for features this complex.

All that said, I'd bet real money that 99% of all shooters with all manners of lenses will get good results having never touched that function, just as they did for all the years before it was introduced. I believe that my 70-200 is in the remaining 1%.