MFA tweak...How much is acceptable?

[M_Six]

Got an MFA question. How far off is too far? My brand new 85 f1.8 was simply not hitting the focus point. Last night at an awards ceremony I had to switch to the 135L and stand in the back of the room. The images from the 85 weren't even looking sharp on the LCD, so I knew they'd be crap on the laptop. Today I set up a jerry-rigged MFA session in our hotel room and managed to dial in the 85 to what seems to be a sharp focus. But it's an adjustment of -6. Is that acceptable (assuming it really is now hitting focus)? Or should I send it in to Canon for calibration?

[HDNitehawk]

You have 14 more places before you get to -20. I don't think -6 is so bad. If it is brand new like you say, return it and get another.

[Sean Setters]

Read this, it's very informative. An MFA of -6 on your camera might be a +2 or 0 on mine. There are certain tolerances, and being able to adjust the focus via MFA was meant to address the variation in those tolerances. If it works at -6, keep it and use it at -6.

I did send back a third-party lens (two copies, in fact) because of focus issues, though. In that case, the lens required a [rather extreme] MFA with relatively close subjects, and a completely different MFA with farther away subjects. There was no way to reconcile the two, and I decided it wasn't worth the hassle.

Recently, though, I dialed in a -4 MFA on a lens I purchased used off of Ebay and it works absolutely perfectly for me. I couldn't be happier. This particular 28-70 f/2.8 L may be 10 years old, but I wouldn't trade it for anything, MFA and all.


Kailey Sue Fan 2 by budrowilson, on Flickr

[clemmb]

Or should I send it in to Canon for calibration?

I have older models that do not have MFA. Anyone have an idea of cost to send canon a body and lens for calibration?

[thekingb]

Great results with -6 mfa....I wouldn't hesitate to keep the lens.

[M_Six]

Thanks, All. I'll run a proper MFA drill this weekend. I might even buy Reikan Focal and give that shot. My 50mm f1.4 could use some tweaking as well.

[neuroanatomist]

FoCal is wonderful - equivalent results to what I get with the LensAligh Pro, not all that much faster...but the automation (which I think requires above the base version, I have the Pro) means I can walk away and let the work be done for me...

A 6-unit adjustment is no biggie...I'd be concerned if a new lens needed >15 units, and would likely exchange it.

[clemmb]

I have older models that do not have MFA. Anyone have an idea of cost to send canon a body and lens for calibration?

So, anyone have an idea on cost for Canon to calibrate my lens and camera? 24-105 and 1DmkIIN

[andnowimbroke]

Last I heard, you'll spend close to two hundred dollars. If you buy the $100 CPN package, you'll save 30% and get a couple cleanings out of the deal... Or you can buy a 5d3 and not worry about it. Come on. You know you want to

[clemmb]

Or you can buy a 5d3 and not worry about it. Come on. You know you want to

No, actually I love my 1DmkIIN. I really want the 1DmkIV but now that it has been removed the used prices will probably go up
I would really like the 1DX but $6,799, OUCH