EF Lenses on R Mount (f/1.2 portrait primes)

Marco Nero wrote:

CESA wrote:

Thanks for your comprehensive response. I have a canon 6D. Will do as you suggest in here. Will setup different targets at different distances and will also do the trick with the batteries.

I have an EOS 6D as well. The test that I posted pictures of was made with that camera so I know you have a Micro Focus Adjustment option on your camera. Something to consider it that after you have calibrated your camera for a specific lens is that if you change lenses several times, you may find that the AF needs a very slight re-calibration with the MFA setting. It happened to me and it has also happened to another member here. No idea how or why.

I think that you should be able to focus at any distance right? From minimum or say 1m up to whatever. I normally shoot at 1.5m up to 7m but sometimes like to do some at 1m.

At longer distances, the region that is in focus increased. So if you do your test at around 5 or 6 feet from the camera to the AF targets, your eventual focus lock with the MFA ought to be fine with longer distances. Don't be tempted to try the MFA adjustment without the camera resting securely on a tripod. I tried making an adjustment in a shopping center one day and ended up making my focus worse. I did it again when visiting family. I just felt that the lens wasn't always hitting the focus all the time, even though I believe it was a very good copy. This was the reason I gave it up to buy the RF version but a part of me does miss my EF lens. Your 6D can remember and store your MFA settings for up to 40 lenses and even 4 variants of the same lens.

I will take the time to do some assessment and follow your advice. Will come back with more.

If you own any f/1.2 (and possibly any f/1.4 lenses) that you use on your EOS 6D, you will probably need to do an MFA adjustment, even if you have a good copy of the lens. Still, do the test with the Live View AF and the OVF AF and compare the results before you're tempted to touch anything. The process is very easy to do should you require a calibration. The MFA process stores the changes to your camera and has no effect on the lens itself (unlike the Sigma Lens Docks). So if you sell your camera or lens later down the track, just erase the stored lens settings.

Hi Nero, thanks for your valuable comments. Understood everything you said here in this post and also on the previous.

So I have printed that chart from FoCal just to test the thing out and have concluded some things.

Notes:

1. The tripod has been used on a carpet - don't know if this influences the test.

2. The tripod has 3 sections. Have used only two of them and to compensate the rest have extended the top bit till the target was on sight through the viewfinder. This was due to lack of space.

3. Artificial lighting from the ceiling and small lamps have been used.to illuminate the space

4. Mirror lock was used plus the timer but only 2 sec. Otherwise would have taken a lot of time.

5. Every shot I would defocus to infinity on purpose, manually.

6. Did the test at 1.35m and 3m from the target.

Started out with 0 on the adjustment. Went all the way up to 20 in steps of 5. Then fine tune it a bit.

Conclusions:

The lens needs something around 17/18 to produce images in focus. I think from 15 to 18 I could noticed a difference. I think 20 is out of focus probably back-focusing by the setting and also at 19.

I will redo the test tomorrow again if possible or the day after tomorrow using natural light, 10sec timer and on a more stable surface, in this case in the kitchen.

You can clearly see a difference when adjusting the lens to 17/18. Not sure which one to use though. I will probably get the FoCal to calibrate.the lens more precisely and do AF consistency check. Will also take advantage of this to calibrate all the other lenses.

When the setting was < 15 I tested it using live view and all of them were in focus at both 1.35m and 3m.

Questions now:

A. Having to adjust the lens this bad, meaning to such a high value is a bad sign?

B. Would be prudent to return the lens?

C. Do you think I should test at another distance? Like 4m or 5m?

Thanks in advance.