Auto Focus MicroAdjust--Why the Stigma?

[YuengLinger]

Lately I've seen more posts than ever here, and on retailers' review sections, stating that a lens was sent back because it needed AFMA.

Personally, I have several L lenses and a Sigma 35mm Art. Each one benefitted from some Microadjustment, from +/- 3 all the way up to +/- 13, and all these lenses perform great on my 5DIII, phenomenally better, in fact, than on my old 60D which I bought before knowing about AFMA.

I've thought that AFMA is one of the great features of bodies that have it.

So why the increasing shunning of a lens that needs fine-tuning to work its best with a body?

Seriously, look at some of the recent threads about newer lenses and the claims that just the need for AFMA meant the lens got shipped back.

 

[AcutancePhotography]

Are people really saying they are returning lenses that needed a simple micro adjust? Or are people saying they are sending lenses back because AFMA does not fix the problem.

The two are quite different.

 

[Mt Spokane Photography]

A lot of people don't understand AFMA, and return a lens when its the camera that is also a part of the issue.

However, if A lens shows excessive error, needing 17 or higher to correct it, I'll return it, because the next camera I buy might need even more, and I'd be required to pay to have the lens adjusted.

That happened with my 35mm f/1.4, it needed about 7 AFMA on my 5D MK II, but required +17 when I bought a 1D MK IV, likely due to additive errors in the MK IV. I sent the lens in for adjustment under warranty, and it was right-on for both cameras after that.

 

[YuengLinger]

Are people really saying they are returning lenses that needed a simple micro adjust? Or are people saying they are sending lenses back because AFMA does not fix the problem.

The two are quite different.

I would not have thought it bizarre for somebody to return a lens that couldn't be tuned up with a little AFMA. I'm amazed that somebody with a camera that can AFMA thinks a lens is "bad" when a little fine tuning is needed. I can see from your reply you are as surprised as I am!

A quick look through this and other forums backs up what I'm saying...I didn't see a need to quote and embarrass somebody specifically, or start something personal with such a person.

Mt Spokane, good point about AFMA to the limits, but I see people saying even with +/- 6 they sent the lens back.

 

[Mt Spokane Photography]

Are people really saying they are returning lenses that needed a simple micro adjust? Or are people saying they are sending lenses back because AFMA does not fix the problem.

The two are quite different.

I would not have thought it bizarre for somebody to return a lens that couldn't be tuned up with a little AFMA. I'm amazed that somebody with a camera that can AFMA thinks a lens is "bad" when a little fine tuning is needed. I can see from your reply you are as surprised as I am!

A quick look through this and other forums backs up what I'm saying...I didn't see a need to quote and embarrass somebody specifically, or start something personal with such a person.

Mt Spokane, good point about AFMA to the limits, but I see people saying even with +/- 6 they sent the lens back.

I've seen the posts, I think they are a minority, after all, its like those returning cameras that don't autofocus accurately, a few are definitely camera issues, and a few are operator issues.

The same with AFMA, its not easy to do it correctly, and its easy to come up with results that are far off.

 

[chrysoberyl]

Frankly, AFMA scares me a bit. Is there a thread that discusses the right way to do it? Thanks.

 

[Don Haines]

I work in a research lab. When we get a piece of equipment, the first thing we do is calibrate it. Same thing with a camera or a lens... calibrate before use (AFMA)

 

[Don Haines]

Frankly, AFMA scares me a bit. Is there a thread that discusses the right way to do it? Thanks.

The easiest way I know of is Reikan Focal, and run it in automatic mode... very easy!

 

[Eldar]

I believe the main discussion around AFMA and returned lenses came with the Sigma 50mm Art. And we had it for at least two reasons. The first was due to the lens being inconsistent and unstable, the other because of the USB-dock.

The discussion around the first was to debate whether AFMA could solve the problem or not (it certainly did not on my (several) copies of neither the 50 Art, nor the 35 Art, so I have returned both). The other was how to use the dock and why it seemed like we were doing Sigma´s job. That basic calibration should have been done by them prior to shipping the lens.

My experience is that all lenses, in particular the faster ones, need AFMA. I use FoCal and it is a fairly quick job to get good lenses, like the majority of L-lenses, calibrated. Slower lenses may be a bit more difficult, but at the same time less critical. I simply gave up on Sigma, since the AF could not be trusted. An out of focus image is out of focus, no matter how good the optical quality of the lens is ...

 

[Slyham]

Frankly, AFMA scares me a bit. Is there a thread that discusses the right way to do it? Thanks.

The easiest way I know of is Reikan Focal, and run it in automatic mode... very easy!

It scares me too. :-[ I have had my 70D for a couple of months now and I haven't tried it.

Don - Do you recommend the pro version or would the plus version be sufficient?

 

[Eldar]

Frankly, AFMA scares me a bit. Is there a thread that discusses the right way to do it? Thanks.

The easiest way I know of is Reikan Focal, and run it in automatic mode... very easy!

It scares me too. :-[ I have had my 70D for a couple of months now and I haven't tried it.

Don - Do you recommend the pro version or would the plus version be sufficient?

AFMA is rather simple and if you only have one body and a couple of lenses, you may just as well do it manually. In addition to FoCal I use LensAlign. There are lots of videos on youtube, like this: https://www.youtube.com/watch?v=k642WWzMcCI You can easily make one that´ll work by your self. Be also aware that you can always go back to zero, so whatever adjustments you make can easily be reversed back to start.

 

[Don Haines]

Frankly, AFMA scares me a bit. Is there a thread that discusses the right way to do it? Thanks.

The easiest way I know of is Reikan Focal, and run it in automatic mode... very easy!

It scares me too. :-[ I have had my 70D for a couple of months now and I haven't tried it.

Don - Do you recommend the pro version or would the plus version be sufficient?

unless you have a really long lens (the threshold is 400mm) or you really like running lots of tests, the plus version would probably do. I ended up with the pro version because I needed it to calibrate the Tamron 150-600.

 

[Slyham]

Frankly, AFMA scares me a bit. Is there a thread that discusses the right way to do it? Thanks.

The easiest way I know of is Reikan Focal, and run it in automatic mode... very easy!

It scares me too. :-[ I have had my 70D for a couple of months now and I haven't tried it.

Don - Do you recommend the pro version or would the plus version be sufficient?

AFMA is rather simple and if you only have one body and a couple of lenses, you may just as well do it manually. In addition to FoCal I use LensAlign. There are lots of videos on youtube, like this: https://www.youtube.com/watch?v=k642WWzMcCI You can easily make one that´ll work by your self. Be also aware that you can always go back to zero, so whatever adjustments you make can easily be reversed back to start.

Good info. I think I will give it a try knowing I can reverse it back the the original state.

 

[Slyham]

Frankly, AFMA scares me a bit. Is there a thread that discusses the right way to do it? Thanks.

The easiest way I know of is Reikan Focal, and run it in automatic mode... very easy!

It scares me too. :-[ I have had my 70D for a couple of months now and I haven't tried it.

Don - Do you recommend the pro version or would the plus version be sufficient?

unless you have a really long lens (the threshold is 400mm) or you really like running lots of tests, the plus version would probably do. I ended up with the pro version because I needed it to calibrate the Tamron 150-600.

Thanks. I'm going to try it on my own and if that doesn't work I will look into automatic options. Thanks for sharing.

 

[AcutancePhotography]

Just remember that with AFMA you are changing the way the lens will focus on your camera.

If you do it properly, it will improve things
If you do it improperly, it will make things worse.

So if your first attempt at AFMA does not work, don't think your lens is bad. Just go through the AFMA process again and make sure you are careful.

There is nothing to be afraid of. You will not do any permanent damage to your lens... you just may make the problem worse if you are not careful.

If at first you don't succeed, AFMA again. ;D

 

[Mt Spokane Photography]

The issue that makes AFMA difficult is understanding the limitations and issues with phase detect autofocus. The concept is simple, just adjust your camera body so that it focuses either closer or further away. You can adjust it in small steps.

However, there are some pitfalls.

1. The Target. In order to adjust the AF accurately, you must be certain of the point the camera focused on, and that can be a challenge, since the camera AF system does not always focus where the little red square indicates. Targets specifically designed to assure that the camera grabs focus at the right spot will eliminate the issue.

2. Light Levels. The AF system has a lot more variability in low light. In very bright light, it will not have as much, but its always there, so take several shots and ignore the outliers.

3. Detail in the target can affect the Focus, the AF system generally prefers horizontal lines and will grab those rather than vertical ones.

4. Light color also affects AF. I don't know why, but perhaps its due to the lens.

5. Vibration. You can't detect the best focus if vibration is present.

6. Lens variability. Always start your autofocus at either the mfd or infinity. This will help with lens variability, but some lenses like the 50mm f/1.8 never quite focus at the exact same point.

Software like FoCal takes those things and more into account, even so, its not perfect.

That's not to say that adjusting the AFMAS by trial and error or dot tune is bad, it is going to improve things in most cases, but may not provide a optimal setting.

The final thing to consider is that a error of +/- 3 points is probably not going to make much of a difference. That's because AF does not change much.


Here is a curve from Focal that shows this. The curve is pretty flat near the center. You can see that just keeping the lens set to "0" is not going to make a big difference, even though -2 might be best.

Here is the curve for my 85mm f/1.8. A adjustment of -9 or -10 was definitely a improvement.

 

[Ryan708]

Does anyone know if there is a firmware-type hack for the 60D to alow AFMA? I really wish canon didnt dumb down the 60D

 

[YuengLinger]

Does anyone know if there is a firmware-type hack for the 60D to alow AFMA? I really wish canon didnt dumb down the 60D

I believe you put your 60D down by any wireless tablet, then enter the following into a search engine: 7-0-D

Choose a suitable retailer and order. Update complete. :

 

[jd7]

A lot of people don't understand AFMA, and return a lens when its the camera that is also a part of the issue.

However, if A lens shows excessive error, needing 17 or higher to correct it, I'll return it, because the next camera I buy might need even more, and I'd be required to pay to have the lens adjusted.

That happened with my 35mm f/1.4, it needed about 7 AFMA on my 5D MK II, but required +17 when I bought a 1D MK IV, likely due to additive errors in the MK IV. I sent the lens in for adjustment under warranty, and it was right-on for both cameras after that.

The issue raised by the OP does seem to come up (disappointingly) frequently enough on the internet, and I can only assume the answer is as above - a lot of people don't understand AFMA. With a fast lens, I would be far more surprised if it didn't need AFMA than if it did! And that is not a criticism of either lens or camera.

 

[infared]

Oh..oh...oh..I misunderstood the topic..I thought it said:

Re: Auto Focus MicroAdjust--Why the Sigma?



(Couldn't resist, it was just too tempting! I am actually a fan of, and own the Sigma 50mm and 35mm Arts).

Yes ...mine are both adjusted via the Stigma Dock. 8)

I am a fan of AFMA ...it's just another tool to get us where we need to be. It's all good. Take it or leave it.
WARNING: Yes...it can get complicated and take untold amounts of time out of your life AND sometimes not provide a complete solution to to the problem.
Good luck with your journey.