The Problem With The Focus-Recompose Method

[Sonny]

We all do it but does that make it right?

The Problem With The Focus-Recompose Method

[groovyone]

This topic seems to come up a lot. I do try to at least select the focus point closest to the final framing, but sometimes you just have to go with the fastest center point and do what you can. I have seen focus shift with some of my 1.4 lenses and longer focal length 2.8s.

[kenw]

Being an engineer and dealing with Pythagoreum stuff almost daily, I am amused at one of the commenters on the linked who clearly doesn't get it.....My early days were full of F-R (focus-recompose) but shooting macro will quickly ween you from that. Then you realize that sometimes, the only composing you can do is after the fact. Weak composition/framing I can sometimes fix with cropping. OOF, not so much....

[auddii]

I found it an interesting read considering how often we argue about it on the forum.

[brad]

Originally Posted by kenw

Being an engineer and dealing with Pythagoreum stuff almost daily, I am amused at one of the commenters on the linked who clearly doesn't get it.....My early days were full of F-R (focus-recompose) but shooting macro will quickly ween you from that. Then you realize that sometimes, the only composing you can do is after the fact. Weak composition/framing I can sometimes fix with cropping. OOF, not so much....

You can get away with small errors while doing it when there is some distance to your subject, but with macro photography, there is just not enough distance to give you that slight margin for error.

F-R is a bad habit picked up when you're shooting people or landscapes at deeper DOFs... at least its a bad habit the way we tend to do it.. pivoting on point.

It works *slightly* better if you slow down and move the entire camera position so that the plane of focus is the same when you focus as when you recompose.. but that takes practice, work, and a steady hand. There are still errors, especially if you get in a hurry, but they are lessened.

(I've talked about the problems with Focus-Recompose and shallow depths of field for years in my basic camera class -- it goes hand in hand with teaching about depth of field -- I even draw triangles and comparisons.)

[kenw]

i think there is a point in quantifying the OOF part even if only a technical exercise, as the issue is made worse by the shallow DoF used in portraiture and some macro work. As the aperture moves to the bigger #s, the in-focus depth increases to the point of pixel peeping and beyond before the real world (ie, viewer/customer) sees an issue. And then you will have some get wrapped around the CoC axle, and it dissolves into a geek fest. Never mind the common preference is not often for bleedingly sharp portraiture anyway; perfectly focused nose pores are rarely flattering. But that's the art part, not the science. But in macro the difference is much more noticeable and of major impact.

In some cases it is just a technical exercise, others it can be real. The angle determines the length difference, and the aperture and focus distance determines how much the length difference matters. The important part is to be aware that it is real and understand the impact and how to minimize or avoid it. As an engineer who also has to teach things at times, I think I would have explained it a little differently and perhaps used more diagrams, but the article is quite good as is. And technically correct.

[Photogdude]

it's just another tool/technique to know when to use and not to use

pretty simple

[Some Idiot]

Originally Posted by photogdude

it's just another tool/technique to know when to use and not to use

pretty simple

bingo !

[brad]

Originally Posted by Photogdude

it's just another tool/technique to know when to use and not to use

pretty simple

Exactly.. but having an understanding of *why* it happens is important to use to figure out when to use/not use it.

[kenw]

Originally Posted by brad

Exactly.. but having an understanding of *why* it happens is important to use to figure out when to use/not use it.

Or you could say it is a matter of knowing when it matters and when it doesn't.