70-200 2.8 IS II vs. 85 1.2 II for Portraits?

candleJack wrote:

Press Correspondent wrote:

DOF (the amount of blur) is the same: 2.8*85/200=1.19 with the same subject framing (different dustance).

Dof and perceived background blur is not the same thing. Dof calculators assume certain "ideal" lens features. The 85 gives more perceived background blur, plus it gives it with an "intimate" 85mm perspective, which is basically the whole reason this lens exists.

You go into much more details here than just a simple rule of thumb that I meant. My point was, is it gonna be like 2.8 or like 2.0 or like 1.4? The formula gives 1.2, so the amount of blur will be similar. Other properties like perspective or DOF will depend on the distance of course.

Bokeh (the quality of blur) is better on the prime.

Agree with that.. at least up to half body shots. Anything wider than that the prime deteriorates pretty badly as well.

85/1.2 focuses very slow. I have decided against investing in it, but waiting for the upgrade instead. If you are in a rush, get 85/1.8 until the new 85/1.2 is released.

Also note that f/1.2 is not for regular portraits, but for taking photos of person's eye with the rest of the face blurred. F/1.2 doesn't blur the backgroung, it completely destroys it beyond recognition and as such makes the image look flat, since there is no depth in the background anymore.

I disagree with this. It's not for taking pictures with a single eye in focus but for achieving a lot of background separation with a wider framing. And a destroyed background does anything but make the picture flat. It might make it look like you used a backdrop, but that only happens in extreme cases.

Well, I hope you at least see what I meant. I have seen portraits at f/5.6 where the background was blurred enough to not focus attention on it, yet retained the three-dimentionality of the real environment. I also have seen some wide open shots that were like the subject is cut out by scissors and glued to some cloudy mess completely losing the feel of volume in the photo.

I think there are two factors at play here. One is bokeh. When bokeh is pleasant, you don't need much blur. When bokeh is bad, you want to blur it more. The other is the the overly shallow DOF obscession among amateurs. They take pictures of an eye on a blurry face and they enjoy it, because they paid so much for the lens, poor souls

Of course this is a wonderful lens if used properly and differently, but a sharp eye on a blurry face is what I see posted the most

It will be impossible to capture moving subjects (kids) with 85/1.2 due to the slow focus and shallow DOF. The static subject must be on the focusing point (forget focus and recompose at f/1.2). It is OK with 5D3 and such, but does not work so well for the bodies with 9 or 19 focusing points.

I'm having better success with manual focus on static subjects so I have to agree with you here, it's not for moving stuff.. not at f/1.2 at least.

It is a great lens, but very specialized. If you are in doubt, it would probably not be a wise investment yet.

I second this, if after understanding what it can give you you're still in doubt, don't get it.

Best regards,

Alex