Has anyone calibrated 70-200 mkII with FoCal?

Is anyone having difficulty getting consistent results with the 70-200mkII when using FoCal?

I've calibrated each of my other lens with great success and excellent consistently. I've repeated tests 3-4 times and have come up with the same values for each lens.

However, when trying to do this with my 70-200II, results are all over the place, to the point were the program tells me that I should basically abort the test because it is unreliable. Moreover, I'm able to calibrate at 70mm without any difficulty (getting a value of +1), but at 200mm, I'm getting anywhere between -6 and +10. I suspect that there may be a lens issue because inconsistency in the telephoto range is what prompted me to purchase the software in the first place. I've used real world subjects and LensAlign Pro, but could never settle on MA value, so I decided to take my eyes out of the equation and use the FoCal software. Surprisingly, the FoCal software seems to coincide with my eyes' inability to determine a best value.

I'm thinking of sending the lens to Canon tomorrow since it's still under warranty, but I'm curious to know if others have had problems with this lens, specifically at the telephoto end.

Hmmm....mine calibrated just fine. Although it was almost perfect at both ends om my 5d mkIII and pretty close on the 1d mkIV. Reachout to software creator.

sempaidavid wrote in post #14993590
Hmmm....mine calibrated just fine. Although it was almost perfect at both ends om my 5d mkIII and pretty close on the 1d mkIV. Reachout to software creator.

By any chance, do you remember what target distance you used for the telephoto/200mm calibration? Did you stick to the 50x focal length (about 33ft away)?

I calibrated my 70-200 but it was the most difficult to get right in FoCal. I ended up with great performance on both ends at -3 but my results were all over the place. The 70mm results were fine but I didn't get consistent results at all using the 50x rule at 200mm.

I ended up calibrating the 200mm end at around 80x with a slightly larger target.

It's driving me crazy. Normally I would just leave it alone, but the whole reason I decided to calibrate in the first pace was because I was noticing inconsistencies across real-world images. I tried at least 8-9times tonight, but I think I'll give it one more shot tomorrow morning at a couple different distances. It's discouraging considering f/2.8 @ 200mm is when DOF is most shallow, and this focal length is when I've mostly been noticing less than sharp results.

mannetti21 wrote in post #14993664
It's driving me crazy. Normally I would just leave it alone, but the whole reason I decided to calibrate in the first pace was because I was noticing inconsistencies across real-world images. I tried at least 8-9times tonight, but I think I'll give it one more shot tomorrow morning at a couple different distances. It's discouraging considering f/2.8 @ 200mm is when DOF is most shallow, and this focal length is when I've mostly been noticing less than sharp results.

Keep in mind the 70-200 is sharper at 70mm than it is at 200mm wide open, not a dramatic difference, they're close, but I can easily see a difference in sharpness between the 2 focal lengths.

FoCal is a good piece of software, so I would definitely keep trying. I've gotten my best results calibrating outside in natural light, also, unless you have a rock solid tripod you might want to increase FoCal's mirror lockup delay setting to 2 or 3 seconds instead of the default which is 1s.

mannetti21 wrote in post #14993369
I suspect that there may be a lens issue because inconsistency in the telephoto range is what prompted me to purchase the software in the first place.

Did you buy the Pro version? If so, try the focus consistency test. That'll tell you how bad the shot-to-shot variation is with that lens.

I'll try increasing the MLU delay since my tripod isn't great. Also, I do have the Pro version so ill check the focus consistency as well. Thanks, ill let you know how round 2 goes today.

Yes, mine is a big PITA to adjust with FoCal. I have made posts about this in the past too... I had to basically rely on personal testing to get it perfect. Out in the field, it's perfect. The best results were with large target, outdoors (I do all mine outdoors) at a large distance.

I don't know why it has trouble. Mostly at 200mm for me. 70mm calibrates perfectly though.

I haven't needed to do any adjustment with my 70-200. Actually I haven't needed to do any adjustment with any of my lenses. The only one I had to adjust for was a Sigma that I borrowed to mess around with and a 24-70 that I rented.

Ok, so I ran it twice more this morning. First trial got +6 on the tele-end, second trial got +7 on the tele-end. There were definitely some major outliers in the (-3) to 0 range. Overall, it is a bit more consistent near the peak of the graph.

Focus consistency test showed greater than 97% for 3 trials with 10 points in each trial.

Since I've already adjusted my wide end and settled on a +1 value, should I leave that as-is for the tele test, or should I clear it back to zero? For the first trial this morning (+6), I still had the wide set to (+1), for the second trial (+7), I cleared the wide to 0. Going to run another one with wide at 0 again....(Edit: This time with wide set to 0, results on the tele-end was +6.


Also, anybody know why the software is taking a shot at +2 on the first shot, even though I have it set in camera to 0? Since it can't automatically change the MA value on the 5D3, I know the shot is actually at 0, but it is plotting one of the three MA=0 shots at +2. Seems very odd.

Just avoid the frustration and send it to CPS and be done with it.

Ok, so I have no clue what is different about this morning vs. last night but here are my results today:

W: +1
T: +6

W: +1
T: +7

W: 0
T: +6

W: 0
T: +7

Note that I varied the Wide-end from 0 to the FoCal recommended +1 to see if it had any effect. I'd have to run it probably another 4 or 5 times to be sure, but it doesn't seem to significantly effect the tele-end calibration. However, during the test, it seemed that there were are greater number of outliers when the wide end wasn't set to 0.

Looks like you got your values! I had to run mine a bunch to get consistant values that I use today.

And wow, what a difference...I was impressed when it was off by 6, now I'm in awe.