A little note about microadjustment.

I know people have varied opinions on certain brands of lenses and even canon lenses in relation to their need for micro adjustment. Well, here are some odd facts. I own two camera bodies, a 5DII and a T1i. I also own 3 lenses, a sigma 50 1.4, Canon 85 1.8 and a Canon 70-200L IS II.

On my T1i, there is no micro adjustment. The Sigma is really far off to the point that it is unusable. The Canon 85 is dead on accurate, even at 1.8 and the 70-200 is ok, but seems just a bit off.

Now, on my 5DII, the Sigma needs +20 micro adjustment, the Canon 85 needs +12 micro adjustment and the 70-200 is dead on at 0.

So I guess the moral of the story is, dont judge lens performance of another's lens based on its performance on their camera bodies.

This could be interesting. I have had some really strange MA experiences myself.

A few of my lenses, the 50L and 85L especially have needed a lot of MA to work on my 1D4. I'll use the 85L as an example.

Focusing from 15 feet away, the 85L will actually backfocus by roughy two feet when the MA is set to zero on the 1D4. An MA of -17 solves the issue.

But here is the part I really do not understand. The 85L (MA = -17) and the 50L (MA = -15) both focus perfectly on my 5D classic which is not even capable of MA.

What does that mean?

Oh, BTW I do have other lenses that focus on the 1D4 with either zero or a bit of positive MA, so the disconnect is not just that my 1D4 body needs tons of negative MA with every lens. It does not.

IMO the lesson is....well, I don't know what the lesson is other than do not be afraid if you need a lot of MA to make a lens work. It might be fine on other bodies.

JeffreyG wrote in post #14088265
What does that mean?

It means that complex systems function is a sum of the component tolerances.

JeffreyG wrote in post #14088265
Oh, BTW I do have other lenses that focus on the 1D4 with either zero or a bit of positive MA, so the disconnect is not just that my 1D4 body needs tons of negative MA with every lens. It does not.

This is the weirdness that flies in the face of what we would think is going on. (I assume that the lenses that have 0 MA on the 1DIV are also OK on the 5D?)

My opinion: Its partly the manufacturing tolerances, but also has to do with exactly how the AF and each lens communicate, so that each combination of lens and body can be potentially different.

I wonder if you's get the same weirdness with two 1DIV's and a set of lenses? Most of what i have seen reported is between different lenses and different bodies not behaving in any consistent manner.

Man... Y'all scaring me. Now I'll have to go home after work and test my 85L II that I got a week ago. I only used it on one 5DII.
Now that you brought this up, I'll have to test it out on my SECOND 5DII.

District_History_Fan wrote in post #14088483
It means that complex systems function is a sum of the component tolerances.

This pretty much sums it up. I've definitely had lenses that worked fine on one body and were off on others. Also a good reason to not buy any new bodies without the MA function.

Cesium wrote in post #14088814
This pretty much sums it up. I've definitely had lenses that worked fine on one body and were off on others. Also a good reason to not buy any new bodies without the MA function.

On the other hand, I ran over a dozen lenses on a 30D and 5D before MA was invented and only one of them had a focus problem (135L). And even that lens was probably not correctable by MA because it focused fine at near distances and then progressively backfocused at longer ranges.

I guess that's the part I struggle with. The bodies I have owned that allow for MA also really need MA. The bodies I owned that didn't have MA also didn't need it.

I know I'm practically alluding to some kind of conspiracy theory here, but it does sometimes feel like the inclusion of MA into bodies gave Canon license to relax tolerances. I hate adjusting lenses to bodies, and now I see on the 1Dx/5d3 that the MA adjustability is going to be even 'better' which means it is also going to be even more work. MA is kind of a mixed blessing. When you have a lens that is off, MA is easier than sending everything in for adjustment. But actually adjusting everything at home is a pain.

Hi!

Just last night I made a bunch of MA tests on a pair of new primes I bought.
MA'ing is a pain, but for those who might not know of it, FoCal makes the job quite a bit easier (read this thread).

Using the Fully Automatic MA mode of the software and repeating the procedure a few times gave me some pretty consistent results, as long as you do the tests in the right conditions (CFL lighting screws things up, found out the hard way!!:oops

MA'ing like this at home takes a bit of time, but it also lets you be more in control and really see how your particular copies behave. I tested several different apertures and one or two distances. You can then by yourself pick a value that best suits your needs.

Like this I found out that my copy of the 50 1.4 isn't particularly sharp, even from f2 to f8, and that @50mm f2.8, my 24-70L is much much sharper.

What I am thankful for is having two bodies - 7D,5DII - with MFA.

Dude, just tested my 85L II on both of 5DII's **GASP!!** and it's CRAZY SHARP. No MA needed. I guess 85L II really holds its rep. And I brag about it too much on this forum haha.

JeffreyG wrote in post #14089718
I know I'm practically alluding to some kind of conspiracy theory here, but it does sometimes feel like the inclusion of MA into bodies gave Canon license to relax tolerances.

So, you're saying that my 60D is manufactured to higher tolerances than my 7D?

I'm at a total loss to figure out why Canon called this feature Micro adjustement when it obviously has a mega influence on many people's setup.. From my own experiences with the 50D 'micro' adjustment made sense; the difference before and after MA was pretty small. And the same happened with a friend's 1D and my 7D. Any improvements were only really visible if pixels were peeked.

On all three cameras, if MA hadn't been available then I wouldn't have noticed. And I don't notice any problems with my 60D - but of course, that's because it's manufactured to higher tolerances than the 1Dx.

I have a 7D and a 5D2 and so far I've only had to MA the 7D for 2 out of 6 lenses and none for the 5D2. At short distances (less than 1 metre) my 50 1.8 needed +10 IIRC and my Sigma 150-500 OS needed +5 to get it spot on. All my other lenses are fine with both bodies, although I will re check the 100-400 when I get a chance to do it properly. Last time I was out shooting with it I missed focus on a few photos at long distance, but that might of been a slow shutter/user combo as the cause.

hollis_f wrote in post #14089838
And the same happened with a friend's 1D and my 7D. Any improvements were only really visible if pixels were peeked.

Hollis, on my 5DII using the 85 1.8 I can see that the focus is off through the viewfinder and Im not even using a manual focus screen.

District_History_Fan wrote in post #14088483
It means that complex systems function is a sum of the component tolerances.

This

JakAHearts wrote in post #14090097
Hollis, on my 5DII using the 85 1.8 I can see that the focus is off through the viewfinder and Im not even using a manual focus screen.

And this is fixable by micro adjustment?

Hollis, I'll shoot you some saamples later today showing show MA on my 1D4 moves the plane of focus a couple feet. And I'll show how the 5D is spot on with the same lens. There is nothing micro about it.