[Leica] M8 & Depth of Field

[henningw at archiphoto.com (Henning Wulff)]

Hi Didier,


At 9:57 AM +0100 11/1/06, Didier Ludwig wrote:
>Hi Wai Leong
>
>I'm not shure about that. Yes, the DOF marks on the lenses are no 
>longer correct when used with a M8 - but the other way round. I 
>don't make any calculations - am not really interested in the 
>mathematical aspects of photography - but a few months ago I did 
>just a few empiric tests with the same 50mm/1.2 lens wide open on a 
>M6 and a R-D1 (with it's crop factor of 1,5). It seems to be the 
>opposite - on the R-D1 shots there was visibly more DOF. Same 
>lens/smaller format = MORE DOF.

Not sure how you tested, but if you tested with both cameras at the 
same distance and same aperture, the RD-1 would have exhibited less 
depth of field. If you tested with the two cameras imaging the same 
area, the film M6 would have exhibited more depth of field.

When testing make sure of your parameters.

>It is my general experience that the bigger the formats get, the 
>narrower the DOF is with the same focal length/aperture. On 6x6 
>negatives with 100/f2.8, I have a DOF about as narrow as with 
>50/f1.4 on small format.

You're talking about two completely different things. In the first 
part, you're talking about same focal length/aperture, in the second 
about the same (approximate) angle of view. With the larger negative, 
at the same focal length/aperture you have more depth of field, with 
the same angle of view (longer focal lengths for the larger format) 
which will result in less depth of field.

>But as said, these are no academic calculations, just estimations 
>out of my modest experiences.
>
>Didier
>

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    *            Henning J. Wulff
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