Canon lenses calibration

Started 5 months ago | Discussions thread
OP CESA Regular Member • Posts: 477
Re: Canon lenses calibration

Zeee wrote:

J A C S wrote:

Why are you doing this? Do you see AF problems?

One of the mistakes people make is to do the calibration with the target too close. This would create more problems than it would solve - been there, done that.

This is very true. That is why I called that PDF link the most comprehensive document. I had lots of links to various Canon information. Some said 50X, others said at location, etc. Even the manuals say best to MFA at location. Then add all the home made versions, etc. There were just too many options which was one reason I never liked MFA. FoCal which follows the sensor parallel to target method made my life easier. I followed it's minimal distance recommendations.

Just use the lenses you normally would and inspect the shots carefully for AF errors. Do MA only if you see consistent front or back focus.

Hi both.

I have purchased the FoCal software to perform the AFMA to my lenses specially the 85mm f1.2.

I have done several tests including at different distances or in this case at 2.7m and 3.1m.

The AFMA returned AFMA value of +5. Nothing like the +17 that I was talking about. But there is a catch.

After performing this calibration, I went out to take some close shots or in this full body and some half chest shoots (what's that, 1m and 1.5m or so) and pictures were not perfectly sharp.

Changed the AFMA to +17 and bang on at those distances (half-chest and full body).

Followed everything they recommend with exception of using their target, the ones they sell which I am still waiting for delivery. to repeat the tests. I have printed the target at the local supermarket so it is what it is and don't know if it is suitable. But have repeated the test several times and it was more or less consistent in the sense that the AFMA that returned were pretty close +5 and one time said between +4 and +6 but then ended up in +5 after continuing the test.

Actually, before performing the tests I went out and had the AFMA set to +5 and pictures taken at say 2m or 2.5m were not 100% in focus/sharp f1.2 and f2.

Now, next time I am gonna take a walk will change the AFMA to +17 and will do some tests.

Will also perform the test at 1.5m and see if the camera will show the same AFMA that I got by doing real life tests.

That being said I question the efficacy of this software.

Well known Dustin Abbott has mentioned in one of his videos showing how to calibrate lenses that some of the setting FoCal came out after the test he didn't agree.

The testing conditions, lighting specially probably influence a lot the outcome as well.

I am wondering at which extend this software usefull or not. But had to get it to see by myself. Dustin teaches how to perform the test manually using their targets and the LIVE VIEW shot as starting point.

Additionally did the best aperture and also the AF consistency and they were not consistent as well. That is the best aperture for the sharpest aperture, it gave me different values test at different distances from the target (see above) and the AF consistency gave me slight differences but I was expecting to be the same.

Any comments?

Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow