85L mkii soft at longer distances?

[likwidplastik]

I recently bought a new 85L. I'm using a 5Dmkiii and I did microadjustments at 50x via Focal and FocusTune (both resulted in a -1 adjustment). Headshots and chest up shots are razor sharp. Problem is, if I pull back to do a full body shot the image is soft.

I dropped the lens off at Canon to have it checked (service center is only 30 mins from me). They said "the adjustment of the circuit board was incorrect causing the focus to operate improperly. Electrical adjustments were carried out on the circuit board."

Problem is, I'm still having the same issue...razor sharp up close, soft at longer distances (full body shots)

Any ideas?

 

[danimon]

thats understandable..the 85 L light rendering IMO much closer to 50L than 135L..that left you with some haze if you shot wide open.if you shot up close, you won't notice the haze that much since your object fills a large area of the photo and the haze just fill small part of it..problem comes when you shot with more distant object, that makes the haze would fill quite much of detail of your object since your object now fills smaller area of the photo..i guess this is the main drawback of this lens. this problem could be worse if you get frontfocus or backfocus when shoting. how to avoid it? you can do nothing but stop down a bit or bring back the contrast at postprocessing stage, based on my experience

 

[mackguyver]

Are you shooting wide open? If so, try stopping down to see if you still have the same issues. I've noticed that it's harder to get critical focus at f/1.2 when I standing further away because it's harder to see smaller details. You might try spot focusing if you're using a newer body, too, as that can help. Those are just some ideas, but without seeing some sample shots showing the problem, it's hard to know what you're seeing.

 

[J.R.]

AFMA values are known to change for the subject distance - though the values should start to normalize at the latter end. Have you tried doing AFMA at more than 50x?

I would also agree with mackguyver that it is difficult to get critical focus at f/1.2 at longer subject distance. You would not know what part of the contrast is the AF point locking on to. The AF points are larger than what they appear on the viewfinder so don't be surprised if the AF locks on to the eyebrow instead of the eye resulting in soft photos.

Hope this helps ... J.R.

 

[surapon]

Dear likwidplastik
Here is the link to see the DOF. infor. That you can use calculate the DOF of this Monster / Awesome Lens .

http://www.dofmaster.com/dofjs.html

Enjoy
Surapon