bcrawf

Odd problem here: my Canon zoom lens, EF 100-400 f4.5-5.6 L IS II USM, which I was using with sharp results at a Tele calibration setting of +9, reset itself to 0 when I stupidly let the camera battery go flat. I now find that this lens, at Tele length, is best at a calibration setting of +2. It was hard to accept, but I have tested and retested. Anybody have related experience?

mwsilvers Loc: Central New Jersey

If the test parameters were different than the first time around the results can differ, but that does seem to be a significant amount of change. The target you used, the distance, and the lighting, not to mention the camera settings, and your approach to performing calibrations could all influence the results.

TriX Loc: Raleigh, NC

What calibration method?

ggenova64

Did you address Canon support?

dandev Loc: Enumclaw, WA

6 months ago I purchased Reikan FoCal (from B&H) and it was one of the best $150 investment I've made. I have a Canon 5Dlll and a number of L lenses.
Not only does it do a good job of getting the right auto-focus adjust numbers, but it also does a sweep of "sharpness" at different f-stops - and it compares it with "what it should be." It gives you a printed report and graph.

Here's why that's important. I recently purchased the same Canon 100-400 v2 that you mentioned. When I ran it through FoCal, it told me that the quality of the lens at low f-stop numbers ( f5.6) was way off. I returned the lens. In other words - bad lens out of the box. B&H had no issues with the return. At the same time, I compared the output of the Canon 100-400 with my existing Tamron 150-600 v1, and found that the "sharpness" numbers were pretty close. The Canon was better at a few f stops, but the Tamron was better at others. (So much for reading reviews.) I verified that with actual test shots.

I initially bought the software after having issues with my 24-105 v1. Sure enough, at low apatures (f4, f5.6) were way off. I sent to to Canon for repair ($350 - ouch). It now performs better than the "standards."

TriX Loc: Raleigh, NC

Another vote for Reikan’s Focal - I cal all my Canon lenses with it, and being able to adjust the MFA accurately on two of my lenses has moved them from unacceptably (to me) soft to tack sharp. As you mention, it also allows you to accurately profile the resolution of your lenses and identify those that are out of spec.

gray_ghost2 Loc: Antelope, (Sac) Ca.

Does the program recalibrate the lens/camera or do you have to manually make the adjustments once the program identifies the the differences?

mwsilvers Loc: Central New Jersey

Micro focus adjustments on Canon bodies are manual only. The purpose of the software is to help you identify the best settings for each specific lens tested.

dandev Loc: Enumclaw, WA

The program let's you determine the auto-focus settings. (In a Canon - that's a close adjust and far adjust setting for a zoom lens.) The process takes about 15 minutes per lens once you figure it out. You need a test target (comes with the software), a laptop tethered to your camera, a tripod, and a place to set it up. (I used my hallway as some of the measurement were done at 25-30 feet.) Nothing is automatically adjusted in the camera.

The profile just gives you a chart with resolution vs. focal length. Like Trix said above, it let's you know which lenses are out of spec.

imagemeister Loc: mid east Florida

It is possible - especially if there are any flaws in your testing technique .....or if something happened to your lens - I believe that it is suggested that you test once a year or more with heavy use.....

..

TriX Loc: Raleigh, NC

The program instructs you (both visually and audibly) to move the MFA adjustment on some bodies and the process is completely automated on others. There are typically 5-7 adjustments, and it takes me about 5 minutes on a prime and a little longer on a zoom since there is a correction for both the long and short end (or any two FLs you select). BTW, there are several levels of the SW available, the least expensive of which was about $60 when I purchased it. The more expensive version has more options and works beyond 400 mm, but I found the less expensive version to be the best $ I have spent to improve the IQ of my system. You can easily spend 1-2K$ on a lens, so <$100 to get the performance you paid for out of ALL your lenses is a bargain in my opinion. I have tried other systems, but have found FoCal to be by far the most accurate and repeatable with no interpretation of the results required. You can either purchase the target or print it on a decent printer (my Canon 9000 produced an excellent target).

Whether or not to calibrate and whether it should be done at the factory is a regular debate on UHH, but I have posted tests (glad to repost the links) showing both the value of calibration and showing that the correction is consistent across various distances and at infinity.

dandev Loc: Enumclaw, WA

The biggest aha for me was:
1. Poor IQ may be the result of an out of cal lens. I have no idea how long my 24 to 105 was taking soft photos.
2. You can get a bad lens out of the box from Canon. That did not make me happy. For my next lenses, I might buy Canon refurbished as they supposedly go through an additional checkout.

TriX Loc: Raleigh, NC

FYI, I dunno. The worst Canon lens I have purchased in terms of needing calibration (requiring -16) was a Canon refurbished 85mm f1.8, and on sending it to Canon service, they returned it to me without repair, saying it was within spec. Since I was able to cal it, I elected to keep it, but still not sure that was a good decision.

Gibar

I found this method of calibrating a lens to be far more accurate and simple to do than other commercial available alternatives.
And it's free.

http://www.youtube.com/watch?v=7zE50jCUPhM