Canon 85mm 1.2LII vs Sigma 85mm 1.4

[elflord]

I only ever use center point. I dont trust the others. After recomposing I refocus manually.

How do you use manual focus ? I take it you are using phase detect AF and therefore not live view (?) Which focusing screen do you use ?

[sarangiman]

Yeah anyone that can manually focus with an 85mm lens < f/2.0 & still get critical focus with hit rates >50% is a magician to me Unless you have stationary subjects & have a lot of time... in which case I might just use live-view.

A loupe on the viewfinder might be nice...

I guess since focusing & recomposing will always lead to back-focus one could try & compensate by firing off a number of shots while slowly leaning backward (I think I got that right?). Seems a little funny to me though.

[neuroanatomist]

What strikes me about TDP is not just the issues he has with Sigma, but the fact that he never has any trouble with AF on Canon lenses.

Excerpts from some of the TDP reviews:

"That is except in some of the medium-low light situations I encountered when using this lens. I found a couple of situations that the Canon EF 28-200mm f/3.5-5.6 USM Lens would not lock focus. These were situations I felt should have been adequate for the 28-200 (on a Canon 1-Series Digital SLR using the center focus point only) to obtain focus lock."

"The Canon EF 14mm f/2.8 L II USM Lens features a rear focusing system driven by Canon's excellent USM (Ultrasonic Motor). ... I am getting excellent AF hit rates in my real world shots, but strangely had some inconsistencies in my comparison testing."

"The Canon EF 135mm f/2.8 With Softfocus Lens...also proved to be difficult to get accurate focus with. While it nailed autofocus on most of my close portrait shots, other subjects proved to be difficult for it."

I'm never the first to believe internet forum complainers...but when multiple independent reviewers with good track records (TDP, Lensrentals.com, PZ, etc.) make mention of AF issues with Sigma lenses, it becomes reasonably believable. 

[elflord]

Excerpts from some of the TDP reviews:

"That is except in some of the medium-low light situations I encountered when using this lens. I found a couple of situations that the Canon EF 28-200mm f/3.5-5.6 USM Lens would not lock focus. These were situations I felt should have been adequate for the 28-200 (on a Canon 1-Series Digital SLR using the center focus point only) to obtain focus lock."

"The Canon EF 14mm f/2.8 L II USM Lens features a rear focusing system driven by Canon's excellent USM (Ultrasonic Motor). ... I am getting excellent AF hit rates in my real world shots, but strangely had some inconsistencies in my comparison testing."

"The Canon EF 135mm f/2.8 With Softfocus Lens...also proved to be difficult to get accurate focus with. While it nailed autofocus on most of my close portrait shots, other subjects proved to be difficult for it."

I'm never the first to believe internet forum complainers...but when multiple independent reviewers with good track records (TDP, Lensrentals.com, PZ, etc.) make mention of AF issues with Sigma lenses, it becomes reasonably believable.

I hadn't seen all of these before. The complaint about the 135mm is pretty damning. The issue with the 28-200 strikes me as relatively minor (it's not a complaint about AF accuracy) and it's not clear if there are any real world implications for the reported problems with the 14mm.

Regarding the Sigma 85mm, Photozone describe it as "spot on", lensrentals describe it as consistently front or backfocusing (also my experience).  lenstip are unequivocally positive in their review for the 85mm.

Curiously, photozone had a lot of trouble with the Canon 24-70L whereas TDP's review for it reads like an advertisement.

TDP is a great resource but it would not be my first choice of resource for assessing the relative merits of brand vs third party lenses.

[neuroanatomist]

TDP is a great resource but it would not be my first choice of resource for assessing the relative merits of brand vs third party lenses.

I don't disagree with that.  But then, I don't use 3rd party lenses. They certainly fill an important niche - mostly, that of cheaper alternatives to brand lenses.  Nothing is free, so often the reduced cost results in quality tradeoffs I'm unwilling to make.  Granted, there are 3rd party lenses for which no brand alternative exists, and the competition is certainly good for all of us!

[sarangiman]

Yeah competition is good & I hope Sigma's 9-blade much-more-circular aperture forces Canon to rethink their 85/1.2 II. This is one aspect in which the Sigma lens is not only as good as, but, better than the Canon 85L. As one of the previously posted reviews itself states.

[alipaulphotography]

I only ever use center point. I dont trust the others. After recomposing I refocus manually.

How do you use manual focus ? I take it you are using phase detect AF and therefore not live view (?) Which focusing screen do you use ?

Focus as you would with the center point, recompose with the finger still on the shutter, twist the focus ring on the lens so focus is on the eyes.

I use the super precision matte focusing screen. EE-S maybe?

I have a 5D - so no live view. Ideally I'd use back button focus if I owned a 5D mk II.

[wickidwombat]

I only ever use center point. I dont trust the others. After recomposing I refocus manually.

How do you use manual focus ? I take it you are using phase detect AF and therefore not live view (?) Which focusing screen do you use ?

Focus as you would with the center point, recompose with the finger still on the shutter, twist the focus ring on the lens so focus is on the eyes.

I use the super precision matte focusing screen. EE-S maybe?

I have a 5D - so no live view. Ideally I'd use back button focus if I owned a 5D mk II.

doesnt the 5D let you reconfigure the * to be back button focus? i'm pretty sure it should

[Ryusui]

I have a 5D - so no live view. Ideally I'd use back button focus if I owned a 5D mk II.

doesnt the 5D let you reconfigure the * to be back button focus? i'm pretty sure it should

Yup.  C.Fn-04.

[skitron]

I have found my "hit rate" with f/1.4- f/2 lenses (50 f/1.4 and 135 f/2) improves radically if I shoot using AI focus and shot at 8 fps on the MkIV, particularly when shooting people handheld. Just that tiny rocking on your feet is enough to shift focus from the eyes to somewhere useless.

I think it's more than just front/back movement, though that's an important point. I get the feeling that one shot AF quits a split second too soon with fast primes, or at least with Sigma fast primes. AI Servo keeps trying even if you and the subject are stationary. I get a higher hit rate if I use AI Servo and wait to fire until the AF has settled.

Interesting, i will definitely try this. Thanks for the info!

[brando72]

I only ever use center point. I dont trust the others. After recomposing I refocus manually.

How do you use manual focus ? I take it you are using phase detect AF and therefore not live view (?) Which focusing screen do you use ?

Focus as you would with the center point, recompose with the finger still on the shutter, twist the focus ring on the lens so focus is on the eyes.

Is there a problem using the center point, recomposing and then taking shot? Why do you need to focus again after you recompose assuming shutter is still 1/2 pressed?

[brando72]

sorry,

Is there a problem using the center point, recomposing and then taking shot? Why do you need to focus again after you recompose assuming shutter is still 1/2 pressed?

[neuroanatomist]

Is there a problem using the center point, recomposing and then taking shot?

With fast lenses shot wide open with a reasonably close subject, you're guaranteeing a back-focused shot.  See this article.  It's enough of a problem that some Hasselblad cameras use a gyro sensor to detect the degree of angular motion when you recompose, and adjust the focus to compensate...

[brando72]

Thanks Neuro. I will read up on this.

[wickidwombat]

Is there a problem using the center point, recomposing and then taking shot?

With fast lenses shot wide open with a reasonably close subject, you're guaranteeing a back-focused shot.  See this article.  It's enough of a problem that some Hasselblad cameras use a gyro sensor to detect the degree of angular motion when you recompose, and adjust the focus to compensate...

you can focus on their nose and recompose then the eyes are pretty sharp... unless they have a gigantic honker that is....