Good lens, high MP camera = superior combination

"RichA" wrote in message
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For all those thinking 12-15 megapixels is just "fine" take a look at
the resolution differences of this lens on a 24 megapixel FF and an
APS sensored camera with fewer MP. Despite the inevitable softening
at the edge of the FF, overall the resolution is hugely better in the
FF 24MP camera. $2000 for the FF camera (850) and about $1000 for the
APS. All that seems to be happening with the APS is that you are
short-changing the Zeiss lens.

http://dpreview.com/lensreviews/sony_24_2_m15/

"All that seems to be happening with the APS" is that you are buying an
over-specified lens for your camera, and paying the size, weight, and cost
penalties.

David

"RichA" wrote in message
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Over-specified implies the APS is incapable of showing what the lens
is capable of resolving. Fair enough. But has anyone ever seen an
APS sensor image that didn't benefit from a better lens? In other
words, if Sony made one of their generic lenses in the same focal
length, and you compared it with the Zeiss lens on an APS, we should
see no difference in resolving power, provided the Sony lens met a
minimum spec?

No. In this case "over-specified" means using a lens with a nominal image
circle of ~43mm, whereas an image circle of ~28mm would suffice. Such a
lens would be lighter, smaller and cheaper.

Whatever the sensor size, provided it is correctly fitted with an
anti-alias low-pass filter, there will be no point in providing the sensor
with information beyond the cut-off point of the filter and sensor
combination. What may matter more is having a good MTF up to that cut-off
frequency. Of course, the cut-off isn't sharp, so there won't be a
precise numerical answer to the requirement. I could also see a lens as
being "over-specified" in such circumstances.

David

"John A." wrote in message
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I say if you're the sort who periodically upgrades your camera body,
go ahead and get at least somewhat "over-specified" lenses if you can
afford it. If you alternate between buying lenses over-specified for
your body and bodies over-specified for your lenses you'll always see
an improvement with every purchase.

Yes, that makes sense, but carried to extreme, it means you should always
buy full-frame lenses, just in case your next upgrade is to a full-frame
camera. I, for one, don't want the cost, size or weight penalty that
would incur! G

David

"RichA" wrote in message
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I don't think any company has really matched bodies to lenses in a
major way except at the pro level or Leica.

... and in all the fixed-lens cameras, of course.

You can buy a Nikon D300s
with weather sealing, but you can't buy too many DX lenses with that,
you have to go to the FX level, as far as I know. The cost to have
what might amount to five or six sets of lenses would be prohibitive
for the company.

David