Lance B
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 p.1 #5 · D800 problems. FocusTune, Nikkor 24-70 f/2.8 :( | |
kazinvan wrote:
Lance B wrote:
A few comments:
The 24-70 is supposed to be sharper at 24mm than at 70mm, but only by a smidgen.
See this on DP Review:
http://forums.dpreview.com/forums/post/42121375
In other words if you need more than -/+20 in AF Fine tune, then use the "Default" AF setting in AF Fine tune, not the "Saved Value" and delete the entry in the list of saved values. The "Default" setting is basically for the camera and is 2.5x coarser than the AF Fine tune setting. So, if you need -25 in AF Fine tune, then you only need -10 in the "Default" fine tune.
Unfortunately, this cannot help with the huge disparity between the 24mm setting and the 70mm settings.
Lance, thanks for the info. I didn't realize that default was more coarse. However, that applies to any lens you mount on the camera, right? I haven't tested my other lenses, so that may not be a good setting for me to go with.
It does apply to any lens you mount on the camera, but this can be circumvented if you enter it into the Lens List of 20 memorised lenses. The point of the Default setting is that it adjusts the camera to a set point if the camera's AF is out by a certain amount. You only use the memorised list of lenses for those lenses that do not fit with the global alteration of the Default (camera) setting.
So, let's assume the camera's AF is out by +5 and affects all your lenses by this amount. You would not enter any of your lenses into the Saved List of Lenses. However, if one or more of your lenses is affected differently than the camera's global Default setting of +5, then you would set your individual lenses to the AF Fine tune that suits that lens best and then save it to the Saved List of Lenses.
Unfortunately, the Default value is not additive to the Saved value. I think it probably should be due to the fact that if the camera is out by +5 (in reality 2.5x that figure due to it's coarse value = +12.5), I think it would stand to reason that all lenses would be affected by the camera being out by this amount as most lenses are probably close to the correct AF fine tune in the first place. You may only then need a small tweaked amount in the Saved Value in order to "fine tune it" or possibly none at all.
The point of the fine tuning adjustment is to adjust for the tolerances of the whole system and is to be expected as tolerances occur. If we assume that Nikon has a +/-5 or +/-10 as their tolerance for both the manufacture of camera and lenses, than even at +/-10 lenses should, and I think mostly do, fall into the +/-20 range of the AF Fine tune as this would allow for a +/-10 for the lens and for the camera being additive as a worst case scenario.
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