@skirkersamtian wrote:
That's what I thought too, so I was using the calibration chart to check and my two main lenses were focusing on the 1/2 section. And when I shoot portraits those are never completely in focus. I'm away at work for a few nights, when I get home I'll attach images with the EXIF.
John summarized the facts very well.
Front or back focusing really should not enter into the discussion when using Live View. I always tell people that performing lens calibrations are deceptively difficult. I am not saying it is complicated to do, but it is not quite as simple and straightforward as it might seem.
The process is just as much a test of the photographer as it is the gear, which you seem to have recognized by making use of the shutter delay timer.
But, there are other factors that can come into play. The type of ambient lighting can a play a major role. Calibrating indoors with artificial lighting, and then using the lens outdoors in sunlight is a recipe for soft images. The distance to the focus target is another major factor. When you post your images, try to state the distance to the target, and the focal length being used on the zoom.
Calibrations should be performed under the same shooting conditions for when the gear will be used. If you will be shooting outdoors, then do the calibration outdoors. Place the focus target at distances similar to where your subjects might be.
A generic calibration should be performed in the sunlight, because sunlight contains a full spectrum of light frequencies. The distance to the target should be 25-50x the focal length in use. I like to compensate for crop factor when determining the distance to the target. The focus target needs to be of sufficient size for super telephoto lenses, which you are not using. Most of the off the shelf calibration kits provide a target that is sufficient sized for lenses up to 200mm.
You did not state which focal length that you used when you tested the 70-200mm. The distance to the target should have been checked for the different lenses. The 50mm should not have been tested at the same distance as the 70-200mm when it was set to 200mm.
Please post images with EXIF data, or upload them to Dropbox or somewhere. State the focal lengths for the zoom, and the distance to the targets, too. Thanks.
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