rf focusing - beginners question

[minuteman]

Hi!

Last week i got my Bessa R2M -Set with the 50/2,0 and a 35/2,5 pancake lens. Very happy with it. Coming from the SLR world, one problem i have encountered is when focusing the 35 lens in low light situations (subway, restaurants etc.) with open aperture. How do you focus on objects outside the focusing frame? FWIK tilting the camera is no option because you also move the focus plane behind the object.

cheers,
Chris

 

[wontonny]

You point at it, focus, then recompose. Yes it takes some getting used to from the SLR world.

 

[ferider]

Don't worry about the moving focus plane when focusing and
recomposing. The error introduced for your two lenses is
completely covered by the depth of field.

Enjoy,

Roland.

 

[reub2000]

Focus and compose? Scale focusing?

 

[Bryce]

Chris-
Roland hit it. The error introduced by focusing and recomposing is usually small enough to be hidden by depth of field, even with the lens wide open.
My experience with fast lenses is limited, but I think wide open and very near subjects may be best made with a small compensation. You'll just have to try it out. Maybe with head and shoulders portrait, focus on the eyes, then the tip of the nose, and compare after the pictures have been developed.
I think most people get by without this.

 

[minuteman]

Thanks @all, tomorrow i will try to shoot some portaits with the 50/2 to see if there is any need for correction of focus after recomposing.

cheers,
Chris

 

[payasam]

Many lenses have a slightly curved field, so that objects focussed on can go out of focus when recomposing puts them off centre. This should be negligible with a 50 mm lens, even at near distances, and a 35 mm will have even more depth of field.

 

[ferider]

As an example:

With the 50mm lens, when you move 1/3rd out of center (typical composition), at 1m distance, you make an error of about 1cm. When you move as far as possible to the corner of the picture (untypical), you make a 7cm focusing error.

Best,

Roland.

 

[wyk_penguin]

Thanks @all, tomorrow i will try to shoot some portaits with the 50/2 to see if there is any need for correction of focus after recomposing.

cheers,
Chris

I still manage to sneak by the laws of Physics with the Jupiter 85 at f/2. 😛 Don't worry a bit.

The worry that you don't really see what you are going to capture will fade after more RF use. Now I pick up an SLR and say, "How am I supposed to compose when things are out of focus?"