Do you believe DXO's pronouncement on lenses and high megapixelcameras?

On 22/05/2013 06:56, RichA wrote:
They said you need top-flight lenses for a 24mp APS camera or you will
not match the resolution the sensor is capable of. This is a first,
IMO, as I understood that any moderately decent lens stopped down
would exceed current camera sensor resolutions, at least in the
centre.
So, D7100, D5200, D3200 users...better set aside a few thousand $$$'s
for those FX lenses.

For me, it doesn't work like that in practice. The 24 MP camera is
simply a replacement for an existing one, and the extra pixels mean that
I don't need to worry as much about aliasing. As I'm viewing images on
a 3 MP display at best, I don't need exceptional lens quality, so the
extra cost you suggest can be used for travelling more instead. The
results I'm getting from the D5200 are noticeably better than my D5000,
especially in lower light conditions. The sensitivity gain means I
don't need to lust after wide-aperture lenses either.

You would need to print exceptionally large to see everything which a 24
MP sensor can provide.

I've also been pleasantly surprised by the results from my 18 MP
small-sensor camera - a Sony HX200V. Of course, you can't enlarge as
much, but for a compact bridge camera the images are excellent. 18 MP
in such a small sensor will be over-sampling the lens, just as th 24 MP
in the DSLR will be tending towards over-sampling the lenses I can
afford or wish to use - such as my 18-200 mm Nikon zoom.
--
Cheers,
David
Web: http://www.satsignal.eu

On 5/22/2013 3:11 AM, David Taylor wrote:
On 22/05/2013 06:56, RichA wrote:
They said you need top-flight lenses for a 24mp APS camera or you will
not match the resolution the sensor is capable of. This is a first,
IMO, as I understood that any moderately decent lens stopped down
would exceed current camera sensor resolutions, at least in the
centre.
So, D7100, D5200, D3200 users...better set aside a few thousand $$$'s
for those FX lenses.

For me, it doesn't work like that in practice. The 24 MP camera is
simply a replacement for an existing one, and the extra pixels mean that
I don't need to worry as much about aliasing. As I'm viewing images on
a 3 MP display at best, I don't need exceptional lens quality, so the
extra cost you suggest can be used for travelling more instead. The
results I'm getting from the D5200 are noticeably better than my D5000,
especially in lower light conditions. The sensitivity gain means I
don't need to lust after wide-aperture lenses either.

You would need to print exceptionally large to see everything which a 24
MP sensor can provide.

I've also been pleasantly surprised by the results from my 18 MP
small-sensor camera - a Sony HX200V. Of course, you can't enlarge as
much, but for a compact bridge camera the images are excellent. 18 MP
in such a small sensor will be over-sampling the lens, just as th 24 MP
in the DSLR will be tending towards over-sampling the lenses I can
afford or wish to use - such as my 18-200 mm Nikon zoom.

Whatever works for you. See my comment in the now audiophile thread.

--
PeterN

On 22/05/2013 14:12, PeterN wrote:
[]
Whatever works for you. See my comment in the now audiophile thread.

I would, Peter, except I now delete those threads which have gone
off-topic without being renamed!
--
Cheers,
David
Web: http://www.satsignal.eu

On 5/22/2013 11:11 AM, David Taylor wrote:
On 22/05/2013 14:12, PeterN wrote:
[]
Whatever works for you. See my comment in the now audiophile thread.

I would, Peter, except I now delete those threads which have gone
off-topic without being renamed!

Understood. I sometimes lurk in those.

--
PeterN

David Taylor wrote:
On 22/05/2013 14:12, PeterN wrote:
[]
Whatever works for you. See my comment in the now audiophile thread.

I would, Peter, except I now delete those threads which have gone
off-topic without being renamed!

You can't have much to read here then.

David

On 23/05/2013 01:30, RichA wrote:
[]
The 3MP screen thing only applies if you never look at images except
at screen or near screen size. In other words, you never exceed
around a 20% magnification of the image. Go to 50%, things change
because you are using the whole screen to view just part of an image.
But I agree, it's tough enough discriminating between say 12 and 16mp
on a 16x20 print let alone seeing the detail a 24mp camera produces in
a small print.

It would be unusual for me to use just 50% (linear) of an image,
although it /does/ happen. Even then, 50% (linear) of an 18/24 MP image
is 4.5/6 MP, still in excess of the display resolution. I certainly
would not want to carry around heavy and expensive lenses just for those
situations, although I accept that others might.
--
Cheers,
David
Web: http://www.satsignal.eu

On 23/05/2013 00:54, David Hare-Scott wrote:
David Taylor wrote:
On 22/05/2013 14:12, PeterN wrote:
[]
Whatever works for you. See my comment in the now audiophile thread.

I would, Peter, except I now delete those threads which have gone
off-topic without being renamed!

You can't have much to read here then.

David

Correct. I read the bits related to photography, and not to parochial
politics or software I don't use.

Have you found issues with high-megapixel cameras?
--
Cheers,
David
Web: http://www.satsignal.eu

David Taylor wrote:
On 23/05/2013 00:54, David Hare-Scott wrote:
David Taylor wrote:
On 22/05/2013 14:12, PeterN wrote:
[]
Whatever works for you. See my comment in the now audiophile
thread.

I would, Peter, except I now delete those threads which have gone
off-topic without being renamed!

You can't have much to read here then.

David

Correct. I read the bits related to photography, and not to parochial
politics or software I don't use.

Have you found issues with high-megapixel cameras?

Yes, I have a shiny new Nikon d5200 (24MP). The Main issue at present is
the fingers are not finding the correct button/knob automatically but I am
prepared to give it more time. It's fun futzing about with these things,
there is at least as much entertainment in that as in the finished product.
The last time I didn't have to think about *how* to do something with a
camera was 20 years ago with film. The brain is less supple now and now the
cameras have more knobs! But that has nothing to do with the sensor
resolution.

Keeping in mind that the world of the DSLR is pretty new to me the things
that grab me about the sensor is the MPs provide some extra zoom for
wildlife shots and give you the chance to correct some framing errors, and
the high ISO option allows capture in near darkness. Sure the pics are
somewhat fuzzy but I have a useable image that I would never obtain
otherwise. I have been sitting outside waiting for the fox that visits
about half an hour after sunset. Perhaps if I get him I will make a big
print and call the fuzz 'artistic'.

As for the question raised about whether the lens or the sensor is the
limitation on image quality it is all academic to me. I will start worrying
about such niceties the day that the level of operator competence approaches
the camera's limitations. Until that day which of the components will reach
its limit first is of no concern.

David

On 24/05/2013 01:52, David Hare-Scott wrote:
[]
Yes, I have a shiny new Nikon d5200 (24MP). The Main issue at present
is the fingers are not finding the correct button/knob automatically but
I am prepared to give it more time. It's fun futzing about with these
things, there is at least as much entertainment in that as in the
finished product. The last time I didn't have to think about *how* to do
something with a camera was 20 years ago with film. The brain is less
supple now and now the cameras have more knobs! But that has nothing to
do with the sensor resolution.

Keeping in mind that the world of the DSLR is pretty new to me the
things that grab me about the sensor is the MPs provide some extra zoom
for wildlife shots and give you the chance to correct some framing
errors, and the high ISO option allows capture in near darkness. Sure
the pics are somewhat fuzzy but I have a useable image that I would
never obtain otherwise. I have been sitting outside waiting for the fox
that visits about half an hour after sunset. Perhaps if I get him I
will make a big print and call the fuzz 'artistic'.

As for the question raised about whether the lens or the sensor is the
limitation on image quality it is all academic to me. I will start
worrying about such niceties the day that the level of operator
competence approaches the camera's limitations. Until that day which of
the components will reach its limit first is of no concern.

David

After using my new D5200 for about two weeks solid (and some 4000
photos) the fingers are now finding the right buttons most of the time.
I'm getting to prefer the layout to the D5000 I used to use.

Couldn't agree more about the advantages of that sensor in low-light and
giving a better chance of cropping without losing too much. ISO 6400 is
the highest I've used, and the noise on "web-size" images is almost
unnoticeable - far better than Ektachrome 160 (or was it 400?) produced!

For me, the limitations of the lens(es) are ones I am happy to accept.
--
Cheers,
David
Web: http://www.satsignal.eu

David Hare-Scott wrote:
David Taylor wrote:
On 23/05/2013 00:54, David Hare-Scott wrote:
David Taylor wrote:
On 22/05/2013 14:12, PeterN wrote:

[snip]

Have you found issues with high-megapixel cameras?

[snip]

As for the question raised about whether the lens or the sensor is the
limitation on image quality it is all academic to me. I will start worrying
about such niceties the day that the level of operator competence approaches
the camera's limitations. Until that day which of the components will reach
its limit first is of no concern.

Many talk about lens resolution and camera resolution as though there
were some hard figure of resolution of a lens which meant that when
camera resolution went beyond that there was no point in having the
excess resolution because the lens wouldn't allow the camera to use
it.

That's not how resolution works. The limits aren't hard limits. They
have soft edges. The resolution of a camera sensor is what it could
resolve with a perfect lens. The resolution of a lens is what it could
resolve with a perfect camera sensor (i.e. one so much better than the
lens that its imperfections are for all practical purposes irrelevant).

Put an imperfect lens and camera together and the resulting resolution
is the combination of the two. The camera's sensor performance is
limited by the lens, and the performance of the lens is limited by the
camera. Improve either and the combined resolution will improve. Keep
improving one and the combined resolution will improve less and less
as it becomes more limited in proportion by the greater imperfections
of the other.

There's not a sudden magic border between performance being lens
limited where it switches over to being sensor limited. There's a
large area of gradually changing proportions of limitation.

Where lens and camera are roughly equally matched improving either by
say 50% for example, will cause the same amount of improvement in the
combined resolution of the two, say 25% for example. That's assuming
imperfection is a simple unidimensional linear quantity, which is of
course a simplification.

Here's a practical example. I have a 500m reflex lens (Sony 500mm
f8). It's well known to be rather soft, not up to the detail
resolution of a good 500mm refractor lens. I've compared it with the
resolution of a top class 70-400mm at 400mm and it's easily seen to be
inferior in detail resolution. It's probably the softest of all my
primes, possible exceptions being some rather old film-era lenses I
rarely use.

I can compare this 500mm reflex's detail resolution with a 14MP sensor
and a 24MP sensor. Pixel peeping I clearly get more detail with the
24MP sensor. In other words even a rather soft prime gets more
resolution on a 24MP APS-C sensor.

Resolution calculations which suggest that wouldn't happen are clearly
based on an oversimplified model of system resolution performance.
Camera plus lens combined resolution isn't hard edged between camera
limits and lens limits.

--
Chris Malcolm