06-26-2011, 09:28 AM
[quote name='Sammy' timestamp='1309078734' post='9555']
[quote name='Brightcolours' timestamp='1309074520' post='9553']The Olympus 70-300mm f4.8-6.7 for instance.... It is equivalent to 140-600mm on full frame, yes. But look at that aperture (or rather: f-value): equivalent aperture of f9.6-13.4!
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At some stage these "equivalent aperture" calculations cease to make sense. You easily managed to reach this stage. 600 mm on full frame - wow! - that´s costly and you need a truck to move it. Anyhow, for tele shooting achieving sufficient DOF poses typically more of a problem than the other way around. Hence, in practical terms, in addition to the massive size and weight advantage, a system like mFT is in many situations indeed preferable.
[/quote]
That is of course, not true. Even with the longest teles, the subject will always seem in focus even wide open, even with a 800mm f5.6. And bigger apertures you can not find:
Just to illustrate: 800mm / 5.6 = 142mm aperture!
That is why tele lens users often use their lovely teles wide open. That is also why the big aperture large teles are so popular with professionals, and why amateurs who actually understand optics always lust over these lenses.
It was you who was comparing a super small aperture tele on 4/rds with a moderate aperture full frame 135 format tele... so if you feel that somehow is a wonky comparison, guess who is to blame <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
' />.
Youw ill NOT need a truck to move a 60mm f13.4 lens, by the way. Thing is, those are such toy like figures, that there simply is no market for that on 135 format DSLRs.
And that is exactly my point... you compare a 300mm f6.7 on MFT with a 400mm f5,6 of FF.
MFT: 600mm f13.4 (!!!!!)
APS-C: 640mm f8.9
FF: 400mm f5.6
Yeah, how weird that that f8.9 lens is heavier than that very slow f13.4 lens <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='' />
Those are the actual facts... get an equivalent lens on MFT, and it will NOT be lighter. As my example of the 35mm f2 lens shows. Want me to give more examples?
[quote name='Brightcolours' timestamp='1309074520' post='9553']The Olympus 70-300mm f4.8-6.7 for instance.... It is equivalent to 140-600mm on full frame, yes. But look at that aperture (or rather: f-value): equivalent aperture of f9.6-13.4!
[/quote]
At some stage these "equivalent aperture" calculations cease to make sense. You easily managed to reach this stage. 600 mm on full frame - wow! - that´s costly and you need a truck to move it. Anyhow, for tele shooting achieving sufficient DOF poses typically more of a problem than the other way around. Hence, in practical terms, in addition to the massive size and weight advantage, a system like mFT is in many situations indeed preferable.
[/quote]
That is of course, not true. Even with the longest teles, the subject will always seem in focus even wide open, even with a 800mm f5.6. And bigger apertures you can not find:
Just to illustrate: 800mm / 5.6 = 142mm aperture!
That is why tele lens users often use their lovely teles wide open. That is also why the big aperture large teles are so popular with professionals, and why amateurs who actually understand optics always lust over these lenses.
It was you who was comparing a super small aperture tele on 4/rds with a moderate aperture full frame 135 format tele... so if you feel that somehow is a wonky comparison, guess who is to blame <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
' />.Youw ill NOT need a truck to move a 60mm f13.4 lens, by the way. Thing is, those are such toy like figures, that there simply is no market for that on 135 format DSLRs.
And that is exactly my point... you compare a 300mm f6.7 on MFT with a 400mm f5,6 of FF.
MFT: 600mm f13.4 (!!!!!)
APS-C: 640mm f8.9
FF: 400mm f5.6
Yeah, how weird that that f8.9 lens is heavier than that very slow f13.4 lens <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/wink.gif' class='bbc_emoticon' alt='
' />Those are the actual facts... get an equivalent lens on MFT, and it will NOT be lighter. As my example of the 35mm f2 lens shows. Want me to give more examples?