syriusz wrote:
> John Smith wrote:
>> Nie uzyskasz jednak GO jak z hipotetycznego obiektywu 75/1.8 przypiętego
>> do cropa.
>
> Błąd. Nie do cropa tylko do FF. Może mnie nie zrozumiałeś.
> 50/1.8 na cropie uzyskasz TAKĄ SAMĄ GO jak _75/1.8_na_FF_ przy
> zachowaniu _tego samego kadru_.
> Podobnie: 50/1.8 na cropie uzyskasz TAKĄ SAMĄ GO jak _80/1.8_na_FF_ przy
> zachowaniu _tego samego kadru_ (o czym była mowa pierwotnie).

Nie zachowasz niestety:

Depth of Field Using 35mm SLR with 50mm Lens and Subject Distance of 10
Feet,
and DSLR with 33mm Lens and Subject Distance of 10 feet

There may be times when you want to change lenses to keep the same
subject size in the photograph. In this example, you could use a 50mm
lens on the 35mm SLR, and a 33mm (50/1.5) lens on the DSLR. At a focus
distance of 10 feet, you would get similar photographs as shown in
Figure 13. As shown in Figures 11 and 12 below, the DSLR photographs
will exhibit more depth of field when the focal length for the DSLR is
adjusted so the framing is identical for the two cameras (Figure 13.)
The total DOF at f/5.6 for the 35mm SLR is about 4.25 feet, from about
8.25 feet to 12.5 feet. The total DOF at f/5.6 for the DSLR is about 7.5
feet, from about 7.5 feet to 15 feet. So, the DOF is about 3.25 feet
longer, at f/5.6, with the 33mm lens focused at 10 feet on the DSLR.

http://www.dofmaster.com/dof_dslr.html

--
pozdrawiam,
Marcin 'Yans' Bazarnik