MA for zooms

I know micro adjustments have been discussed a lot but I can't really find a definitive answer on the best way to adjust zoom lenses...

Canon recommends the longest focal length or the one you use most often but on a lens like the 70-200mm I don't have a particular most used length but don't want to adjust for 200mm at the expense of 70mm.

What are peoples experiences of adjusting zooms?

binliner wrote in post #13369743
What are peoples experiences of adjusting zooms?

I don't bother.

I always adjust for the telephoto end.

different distances and zoom numbers yield different results...no consistency

I believe the new 1D X has more than one MF adjustment setting for an individual zoom lens allowing a user to calibrate it at least at the shortest and longest focal length.

Here is B&H's take on it.

http://www.youtube.com …PTnz_mimo&featu​re=related

The long end has the shallowest depth of field and so focus is most critical there. The short end is more forgiving of a small focus error.

So, in general, adjust at the long end. Unless you have a specific focal length that you use all the time.

-js

binliner wrote in post #13369743
What are peoples experiences of adjusting zooms?

When I get a lens that doesn't focus perfectly I send it to Canon and have them fix it.

They don't pay me to fix their stuff, so I don't. Life is too short for the misery of trying to MA a zoom lens for all focal lengths and focus distances.

Note that last part....it isn't just the focal length that can be off. Sometimes a lens will be fine at near distances and off at longer ones. I once had a 135L that was like that.

I think having a situation with a lens that MA can actually fix sounds like a nice thing, but it really only happens occasionally, and then pretty much only with primes.

I feel the same. This is what the manuals states.

I found Chucks tech tips on this. I still can't get over suggesting "if you can do better go for it".

http://digitaljournali​st.org/issue0812/tech-tips.html

I pretty much do my adjustments at the telephoto end; it's been good enough in most cases. If you really don't have a frequently used focal length, you could split the difference and do the MA at the middle range of the lens. Then you'd only be pulling either end off a fraction of whatever difference there might be at either end.

A lot of people do claim success with it. Personally I'm not 100% convinced at this point and I did give it a good try. Even purchased the lens align. Must be handy for third party lens owners. Mind you you can send the lens back to the manufacturer.