05-18-2011, 11:49 PM
[quote name='Lomskij' timestamp='1305761174' post='8567']
Mmm, not really - it's easier to think of it as of narrower field of view instead. You have 1.5x narrower FOV - it means you have to step back to get the same framing - DOF increases correspondingly. Being a bit of nit-picker I have to point out that it's slightly more than one stop (~1.08 stop for Nikon and ~1.14 for Canon) but the difference is rather marginal, so let's say it's one stop.
Actually, 85mm f/1.8 performs exactly as 135mm f/2.8 on Canon <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='B)' />
Edit: I see that Brightcolours already calculated that <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/laugh.gif' class='bbc_emoticon' alt=':lol:' />
[/quote]
So that makes it closer to 1 1/3rd stop... not 1.08 or 1.14 <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
' />.
A tad over 1 1/3rd stop for Canon APS-C, a tad under 1 1/3rd stop for "Sony" (Pentax, Sony, most Nikon APS-C).
Mmm, not really - it's easier to think of it as of narrower field of view instead. You have 1.5x narrower FOV - it means you have to step back to get the same framing - DOF increases correspondingly. Being a bit of nit-picker I have to point out that it's slightly more than one stop (~1.08 stop for Nikon and ~1.14 for Canon) but the difference is rather marginal, so let's say it's one stop.
Actually, 85mm f/1.8 performs exactly as 135mm f/2.8 on Canon <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/cool.gif' class='bbc_emoticon' alt='B)' />
Edit: I see that Brightcolours already calculated that <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/laugh.gif' class='bbc_emoticon' alt=':lol:' />
[/quote]
So that makes it closer to 1 1/3rd stop... not 1.08 or 1.14 <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
' />.A tad over 1 1/3rd stop for Canon APS-C, a tad under 1 1/3rd stop for "Sony" (Pentax, Sony, most Nikon APS-C).