03-14-2011, 07:50 PM
[quote name='Brightcolours' timestamp='1299978866' post='6701']
... it does not matter whether a lens is tested on a D200 or something else. If it is a good lens on a D200, it is a good lens on a D7000.
[/quote]
Thanks BC
I understand now that the lens test results are largely transferable... certainly lenses are not going to perform better on a higher resolution sensor, where they've shown poor resolution at lower MP, so those are ones to avoid.
[quote name='PuxaVida' timestamp='1300005205' post='6706']
Regarding the resolution of lenses vs. sensors (APS-C or FF), you can stick to the statement that the resolution of the system is limited by the sensor not by the lens. Of course (at least in theory) there can be exceptions but very rarely:
A tack-sharp lens with 200lp/mm resolution (24mm) mounted on a D700 will give more system resolution than D3x and a 80lp/mm lens combo (if we simply ignore the AA filter and NEF handling differences).
If you have a DX body and you think that you will possibly upgrade to FX in someday, then better collect FF compatible lenses. Yes they might be heavier/bulkier than DX versions but among other arguable advantages, at least one thing is for sure that you almost get no visible vignetting/light falloff (the image circles of FX lenses are larger than the DX sensor requires). And of course, it's a good investment for the future FX body.
Serkan
[/quote]
Thanks Serkan.
I'm still puzzling / trying to work out, in a not very well-informed but technically enquiring way, about the impact of sensor size, if any - as opposed to pixel count - on resolution.
I got this from DP Review (on Resolution, [url="http://www.dpreview.com/learn/?/key=resolution"]here[/url]):
"Limitations of the optics required to create an incredibly sharp image on the small sensor area can also affect the image resolution."
It seems to make sense - and I think I've read Markus' and others' comments to this effect - that packing more pixels into the same sensor area (increasing pixel density) makes more demands both on the lens and on the user.
So, to resolve detail into an image which is 4928 x 3264 pixels on a sensor which is 23.6mm x 15.6mm (~209 pixels/mm or 43690 pixels/mm2) [D7000] is going to require higher resolution from the lens than an image which is 6048 x 4032 pixels on a sensor which is 35.9mm x 24.0mm (~168 pixels/mm or 28302 pixels/mm2) [D3x].
And the former is going to be (more) sensitive to small(er) movements in the lens, even though the latter has more pixels. I think. If I've got this right..?!
On the other hand, the DX sensor is using a more central part of the image produced by FF lenses, hence better border and corner performance - because it's not really using true border and corner parts of the image produced by the lens..?
[size="2"]This bit's probably 'too much information'..!
So, yes, if that's right FF lenses do make sense (when they're affordable!), but I won't rule out DX-specific lenses completely... One of the main reasons I chose the D7000 was size and weight. When I started looking at getting a DSLR I was looking at the Canon EOS 500/550 series. I looked at this and the D5000 and they seemed a bit small and flimsy, compared them with 7D and D300S, both of which seemed too big, and much too heavy, though I much preferred their viewfinders. So I was really pleased when I found the D90 which seemed just right - then heard the D7000 was on the way... so waited..!! <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' />
I did a 5-mile hilly walk with the camera, plus 16-85mm and Tamron 70-300 lenses on Saturday. That's just over 2kg of gear... and I really felt it by the end! D700 body alone starts at 1kg... so I don't really anticipate going there, but one day... who knows...!
[/size]Ian
... it does not matter whether a lens is tested on a D200 or something else. If it is a good lens on a D200, it is a good lens on a D7000.
[/quote]
Thanks BC
I understand now that the lens test results are largely transferable... certainly lenses are not going to perform better on a higher resolution sensor, where they've shown poor resolution at lower MP, so those are ones to avoid.
[quote name='PuxaVida' timestamp='1300005205' post='6706']
Regarding the resolution of lenses vs. sensors (APS-C or FF), you can stick to the statement that the resolution of the system is limited by the sensor not by the lens. Of course (at least in theory) there can be exceptions but very rarely:
A tack-sharp lens with 200lp/mm resolution (24mm) mounted on a D700 will give more system resolution than D3x and a 80lp/mm lens combo (if we simply ignore the AA filter and NEF handling differences).
If you have a DX body and you think that you will possibly upgrade to FX in someday, then better collect FF compatible lenses. Yes they might be heavier/bulkier than DX versions but among other arguable advantages, at least one thing is for sure that you almost get no visible vignetting/light falloff (the image circles of FX lenses are larger than the DX sensor requires). And of course, it's a good investment for the future FX body.
Serkan
[/quote]
Thanks Serkan.
I'm still puzzling / trying to work out, in a not very well-informed but technically enquiring way, about the impact of sensor size, if any - as opposed to pixel count - on resolution.
I got this from DP Review (on Resolution, [url="http://www.dpreview.com/learn/?/key=resolution"]here[/url]):
"Limitations of the optics required to create an incredibly sharp image on the small sensor area can also affect the image resolution."
It seems to make sense - and I think I've read Markus' and others' comments to this effect - that packing more pixels into the same sensor area (increasing pixel density) makes more demands both on the lens and on the user.
So, to resolve detail into an image which is 4928 x 3264 pixels on a sensor which is 23.6mm x 15.6mm (~209 pixels/mm or 43690 pixels/mm2) [D7000] is going to require higher resolution from the lens than an image which is 6048 x 4032 pixels on a sensor which is 35.9mm x 24.0mm (~168 pixels/mm or 28302 pixels/mm2) [D3x].
And the former is going to be (more) sensitive to small(er) movements in the lens, even though the latter has more pixels. I think. If I've got this right..?!
On the other hand, the DX sensor is using a more central part of the image produced by FF lenses, hence better border and corner performance - because it's not really using true border and corner parts of the image produced by the lens..?
[size="2"]This bit's probably 'too much information'..!
So, yes, if that's right FF lenses do make sense (when they're affordable!), but I won't rule out DX-specific lenses completely... One of the main reasons I chose the D7000 was size and weight. When I started looking at getting a DSLR I was looking at the Canon EOS 500/550 series. I looked at this and the D5000 and they seemed a bit small and flimsy, compared them with 7D and D300S, both of which seemed too big, and much too heavy, though I much preferred their viewfinders. So I was really pleased when I found the D90 which seemed just right - then heard the D7000 was on the way... so waited..!! <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' /> I did a 5-mile hilly walk with the camera, plus 16-85mm and Tamron 70-300 lenses on Saturday. That's just over 2kg of gear... and I really felt it by the end! D700 body alone starts at 1kg... so I don't really anticipate going there, but one day... who knows...!
[/size]Ian