6D Mark II - Can't figure out Micro Adjustments!!

[Undercovernerd]

Hello everybody! I am here because I can't seem to figure out micro adjustments for the life of me! I believe my new 6D Mark II is front focusing with my Sigma 50mm Art lens but it's really hit or miss so it's hard to tell.

I've tried to do numerous techniques. I've tried using 5 batteries at a 45 degree angle evenly spaced apart, I've tried a printable chart, I've been low to some grass and even on the carpet. I've stood super upclose as well as 8 feet back. You name it.

All in all the resultts are so inconsistsnt I can't really tell what to adjust. I can adjust so the focus is farther back and still get front focus, it's weird.

Any ideas?

[Waddizzle]

If you are getting inconsistent results, that should be red flag warning that your technique is flawed.  You should be using a fairly robust tripod.  You should use a test target situated at 50x the focal length of the lens under test.  You should use just the center AF point, too.

Finally, the type of light that you use can adversely impact the results.  Indoor lighting has caused me problems in the past.  I have been able to get far more consistent results using the broad spectrum light from the Sun.  Do a web search for a YouTube video about the " Dot Tune " auto focus micro adjustment, AFMA, method.

Does the camera recognize the Sigma lens?  If are using an Art lens, then you should make any adjustments with Sigma Dock. It allows for a far more extensive and accurate set of adjustments.

If you cannot get consistent results doing your tests, then you should take a step back and reconsider your conclusion that your  lens is back or front focusing.

[spell checkers]

[ScottyP]

Get a box. Put it on the floor. Tape a sheet of printer paper with printed text onto the side facing you.  Stab a pencil into the side of the box. Place a ruler so it is resting on the pencil on a 45 degree incline, like a ramp facing you on the side of the box, snug against the box. Put the camera on a couple of books facing the box. You should be 6-10 feet away.   It should be straight on facing the box; not at an angle and not higher or lower.  Focus on the printed paper over near the ramp. Use the 2 second delay and shoot a picture focused on the paper.  You should be shooting WIDE OPEN aperture so the DOF is shallow so you can see better where focus is.   

You can can also put the box and ruler on a table if you have a good tripod to raise the camera up even with the box. 

Then look at the photo to see what part of the ruler is in focus.  If the focus is right, the marks on the ruler in focus will be the ones right even with the plane of the front of the box. If not you can see if it is front or back focusing by looking at what part of the ruler is in focus.  

[Waddizzle]

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@ScottyP wrote:

Get a box. Put it on the floor. Tape a sheet of printer paper with printed text onto the side facing you.  Stab a pencil into the side of the box. Place a ruler so it is resting on the pencil on a 45 degree incline, like a ramp facing you on the side of the box, snug against the box. Put the camera on a couple of books facing the box. You should be 6-10 feet away.   It should be straight on facing the box; not at an angle and not higher or lower.  Focus on the printed paper over near the ramp. Use the 2 second delay and shoot a picture focused on the paper.  You should be shooting WIDE OPEN aperture so the DOF is shallow so you can see better where focus is.   

You can can also put the box and ruler on a table if you have a good tripod to raise the camera up even with the box. 

Then look at the photo to see what part of the ruler is in focus.  If the focus is right, the marks on the ruler in focus will be the ones right even with the plane of the front of the box. If not you can see if it is front or back focusing by looking at what part of the ruler is in focus.  

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You really need a tripod to make accurate test photos.  A distance of 6-10 feet is probably too far away for a 50mm lens, too.

Several test shots need to taken, and an average needs to computed.  If there really is a back/front focusing issue, it is best to make the adjustment in the Art lens, not in the camera.  

The OP should check if the lens has the latest firmware, too.  The camera is so new, that there could be a firmware issue.

[TTMartin]

Canon AF Microadjustment Guidebook (2016)

[Undercovernerd]

This is really good info thank you! I was using indoor lighting, albeit bright it probably wasn't good enough as you had exclaimed. I'll try outdoors.. If something was front/back focused would I see consultant real-world results when shooting? Not every shot is somewhat out of focus but a lot of them are. The focus seems to be mostly in front. I have way more throw aways than I did with my original 6D.

[Undercovernerd]

I'll probably just purchase the dock then. It really seems like the best option when I've researched into it. Will that still require me to manually adjust or does it do testing on its own?

[Waddizzle]

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@Undercovernerd wrote:
I'll probably just purchase the dock then. It really seems like the best option when I've researched into it. Will that still require me to manually adjust or does it do testing on its own?

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Yes, it is better to make adjustments in a lens, if it is capable to do it.  It requires that you go though the extra step of removing the lens from the camera and connecting the dock on the lens mount to communicate with the lens and make adjustments.  

I do not know how many AFMA setpoints the 6D Mark II has, but the 6D has two for a zoom, and one for a prime.  The Sigma dock offers 16 points of adjustment with my. 150-600mm "C" lens.  Instead of settings at the wide end and the low end, you are able to make settings at intermediate focal lengths.  In addition to those for settings, there are four different distances at each focal length.

The adjustment process was not a one day, or one weekend project.  Being able to take good and consistent test photos is critical.   I took hundreds test shots, just trying to get seemingly consistent results, whether they are good or bad.  I wanted to take 10 photos and get fairly consistent results.  Don't forget to refocus between shots, too.

It took me several months before I made any actual AFMA to the Sigma lens.  With 16 available test points, and i only took shots mostly at the "corners", which means the shortest and longest distances, at the wide and at the short end.

[Undercovernerd]

Okay this makes me feel much better! I spent about 4 hours across 3 days trying to figure things out. I would get very inconsistant results. Without changing any settings, I'd get what appears as perfect focus then in the next few shots I'd get, say, front focus. Then it would back focus. So on and so forth to the point where I didn't have enough concrete evidence to make an accurate adjustment.

My best results came when I printed a focus chart on a standard piece of copy paper. I was getting consistent results with +6 adjustment in the camera (as I don't have the dock). However, once I thought I had things dialed in and tried shooting at a different distance than the testing, it was like I was having issues all over again!

Is this normal for a prime? Should I expect to have out of focus shots every time I shoot on a tripod? I understand a few here and there but ever other shot isn't what I want it to be. Perhaps I'm being too picky lol idk

[Waddizzle]

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@Undercovernerd wrote:

Okay this makes me feel much better! I spent about 4 hours across 3 days trying to figure things out. I would get very inconsistant results. Without changing any settings, I'd get what appears as perfect focus then in the next few shots I'd get, say, front focus. Then it would back focus. So on and so forth to the point where I didn't have enough concrete evidence to make an accurate adjustment.

My best results came when I printed a focus chart on a standard piece of copy paper. I was getting consistent results with +6 adjustment in the camera (as I don't have the dock). However, once I thought I had things dialed in and tried shooting at a different distance than the testing, it was like I was having issues all over again!

Is this normal for a prime? Should I expect to have out of focus shots every time I shoot on a tripod? I understand a few here and there but ever other shot isn't what I want it to be. Perhaps I'm being too picky lol idk

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Distance can make a difference.  I would expect the Sigma Art lenses to offer AFMA at more than one distance for a prime, quite likely four distances.  

I would set everything back to zero AFMA, and either try to be more careful with how you take test shots, or throw in the towel. What aperture setting are you using?  Are you using a remote shutter, or the internal shutter delay?  MIrror lockup?  Try to do a web search for the " DOT TUNE " video on YouTube.  You want your test target at 50x the focal length, if you have only one AFMA adjustment point for your prime.