Wildly varying microadjustment on 70-200 II

V

Vertigo1

Messages
2,065
Edit My Images
No
Well I've just subjected my new 70-200 f/2.8 II to the FoCal microadjustment test. Here are the results:

70mm: +3
135mm: 0
200mm: -10

Basically it looks like the lens isn't calibrated very well :(

I'm using a 7D so only have one MA setting to use, not one for each end of the focal length as the 1DX and 5D3 provide.

Don't know what to do here. If it was only a few points difference between the two extremes then I'd just average it but a difference of 13 is quite marked so I can't get it anywhere near accurate at both ends.

Is it worth getting it calibrated? How would I go about this (never sent a lens to Canon)? Am a basic CPS member if that helps at all. Going away in a month and need it for then so don't know what the turnaround is like.

Any advice appreciated.
 
CPS turnaround is usually less than a week

I would advise sending it off - it sounds like something is not right somewhere. I presume you can't get it focusing accurately in practice. Usually when the ends behave differently something is out of alignment, and shame on Canon to suggest that MA can fix everything.
 
How does sending a lens in via CPS work - do I have to send it off to whatever service centre they choose? Do I have the option of taking it somewhere of my choosing or even waiting for it to be done rather than sending off?
 
Ah ok, presume I don't have the option of waiting for it to be done if I elect to take it there myself?
 
At present just FoCal - not used it enough to actually form an opinion really.

Going to do some more tests, both with FoCal and in the real world, before I decide what to do, if anything.
 
I wouldn't rely on Focal and I would query the need to adjust it as in my experience it is one of Nikon's most reliable lenses.
I would reset to 0 and use the lens to take photographs - if you find problems then you might want to think about adjustments/service, not without seeing results as is.
 
gramps said:
I wouldn't rely on Focal and I would query the need to adjust it as in my experience it is one of Nikon's most reliable lenses.
I would reset to 0 and use the lens to take photographs - if you find problems then you might want to think about adjustments/service, not without seeing results as is.
Click to expand...

It's a Canon...
 
Yeah, it's a Canon :)

Well it seems I may have jumped the gun a bit. Did a load more tests and various focal lengths and it's settled down a lot, ranging from around -3 to -7 which is far more sensible. Getting perfectly acceptable results at -6 across the range.

Will see how I get on with in the real world but hopefully all is well. Panic over! :)
 
That's a big difference end to end.

Lens could be faulty, but these kinds of test are prone to user error. What target are you using, test distance, camera/tripod etc?
 
Using the FoCal software with their test target. Everything set up correctly, tripod, recommended test distances etc. I must have screwed something up in the initial run though as, like I said, it settled down a lot with further tests.

Will see how I get on with it for a bit I think.
 
Just how much difference is there with the final image at the different focal lengths is you just keep the value at -3?

People seem to forget that this is a micro adjustment - i.e., it's very small. Here's 100% crops from my 11-16mm lens at various MFA values -

AFMA.jpg


There really is very little difference. Are you sure you're not worried about infinitesimal variations that just aren't noticeable in real-world images.
 
You must log in or register to reply here.
Back
Top