Archived posting to the Leica Users Group, 2003/04/24
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At 10:38 AM +0800 4/25/03, Red Dawn wrote:
>Hi Henning,
>
>> The shot with the 10D/50 will have significantly more DOF than the
>> one with the 80mm on 24x36.
>
>uhmmm.......i don't really agree - at least not from wat i observed when
>shooting. Calculations using DOF calculators also seem to fit my theory. i
>will go and do a test to find out since i have the necessary equipment.
What DOF calculators are you using?
> > Anyone who has shot different formats will attest to this. A 180mm
>> lens has the same angle of view on 4x5 as a 50 has on 24x36. Shoot
>> both of a subject at the same distance and aperture, say f/8, and
>> you'll instantly see that the 24x36mm shot has immensely greater
>> depth of field.
>
>No, we're comparing apples and oranges here. For one, your example uses
>DIFFERENT lenses optimised for their respective formats. There's no cropping
>factor here. the 180mm is made for use on the 4 x 5.
You're using different lenses for different formats as well; 50/1.4
for the 10D and 80/1.4 Summilux for the full frame 35mm. There is a
cropping factor; it's just not as drastic.
BTW, I have a D60 with essentially the same sensor as the 10D, and
various lenses for both the Leicas and the Canon. The results back
the theory.
>Our original debate here is using lenses made for 35mm camera systems on
>different "formats" - the normal 24 x 36mm format and the smaller digital
>sensors of non full frame DSLRs.
So what. Different lenses for different formats. The lens quality is
not an issue, as long as basic quality is assured. We are talking
about lenses that can resolve 30lppm or thereabouts; not an
unreasonable assumption about any better quality 35mm format lenses
at present.
> > Optical theory substantiates this.
>
>Yes it does, but u're comparing different things, as i said above.
No I'm not, as I said above.
>boon hwee
You're comparing different formats. The fact that all lenses have
been formulated to cover the full 24x36mm format changes nothing. In
my comparison with 4x5, I didn't say whether the 180mm lens was
formulated to cover 4x5 or 8x10. It doesn't matter, unless the lens
is truly a dog, in which case this sort of discussion is moot.
I'm assuming that all lenses are capable of covering the formats
required, and are of a reasonable quality, ie. mid to high end
amateur or professional. This should not be an issue.
- --
* Henning J. Wulff
/|\ Wulff Photography & Design
/###\ mailto:henningw@archiphoto.com
|[ ]| http://www.archiphoto.com
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