Always shoot at highest megapixel setting?

Hello,

Does a typical digital camera, regardless of user setting for target
MP, capture all the data required to produce its highest MP image and
then interpret the result to produce the smaller MP?

Or does the camera turn off sensors to directly produce an image with
the targeted MP?

To put this in a practical light, only with regard to displaying
images on a computer screen, I want to state authoritatively that it
is better to set any given digital camera to produce an image closest
in size to that at which it will ultimately be displayed.

My logic is that shooting at the highest setting available would
increase the amount of interpretation necessary by software to
accomplish the reduction. That would be invalid though if the camera
is itself using interpretation to produce the smaller size. In which
case the greater flexiblity in choosing filters/algorithms by use of a
good photo editor would likely outperform the reduction done by the
camera.

Thanks for your help,

Rob

Rob wrote:
Does a typical digital camera, regardless of user setting for target
MP, capture all the data required to produce its highest MP image and
then interpret the result to produce the smaller MP?

Pretty much.

Or does the camera turn off sensors to directly produce an image with
the targeted MP?

That would produce decidedly odd results.

To put this in a practical light, only with regard to displaying
images on a computer screen, I want to state authoritatively that it
is better to set any given digital camera to produce an image closest
in size to that at which it will ultimately be displayed.

"Better" by what standard? Sharpest? Sure. But at the cost of speed
and memory space.

My logic is that shooting at the highest setting available would
increase the amount of interpretation necessary by software to
accomplish the reduction. That would be invalid though if the camera
is itself using interpretation to produce the smaller size.

Software, whether in camera or in computer, reduces image size by
_combining_ pixels and not by discarding them. Further, in-camera
tends to be best (if only by a tiny amount) because the camera makers
know the characteristics of their electronics.

--
Ray Fischer

Rob wrote:
[]
My logic is that shooting at the highest setting available would
increase the amount of interpretation necessary by software to
accomplish the reduction. That would be invalid though if the camera
is itself using interpretation to produce the smaller size. In which
case the greater flexiblity in choosing filters/algorithms by use of a
good photo editor would likely outperform the reduction done by the
camera.

Thanks for your help,

Rob

Rob,

Yes, always record at the highest resolution. The camera uses
interpolation to reduce resolution, and that may be better left to
external software either in the PC (which can use better algorithms), or
in the display device itself (especially for a printer, which may know
more about the best interpolation for its particular physical
characteristics).

If you are considering file size (although that's much less of an issue
today), you may want to use a lower quality level to reduce file size.
Try it with your camera - results may vary - but I found that using
"normal" compression with the highest resolution image size, produced
better results than "fine" compression with the lower resolution, when
viewing images on the computer screen.

By the way: some cameras have a 6MP sensor and claim "interpolated" 12MP
results. I haven't tested such cameras, and the results above may be
completely invalid.

Cheers,
David

On Tue, 12 Feb 2008 21:36:15 -0800 (PST), Rob wrote
in :

Does a typical digital camera, regardless of user setting for target
MP, capture all the data required to produce its highest MP image and
then interpret the result to produce the smaller MP?

In most cases the camera downsamples the image.

Or does the camera turn off sensors to directly produce an image with
the targeted MP?

Not in most cases. One exception is a kind of zoom where the sensor
output is cropped.

To put this in a practical light, only with regard to displaying
images on a computer screen, I want to state authoritatively that it
is better to set any given digital camera to produce an image closest
in size to that at which it will ultimately be displayed.

Not in my experience.

My logic is that shooting at the highest setting available would
increase the amount of interpretation necessary by software to
accomplish the reduction. That would be invalid though if the camera
is itself using interpretation to produce the smaller size. In which
case the greater flexiblity in choosing filters/algorithms by use of a
good photo editor would likely outperform the reduction done by the
camera.

Only when post-processing in RAW. Otherwise the digital camera will
probably do a better job.

--
Best regards,
John Navas
Panasonic DMC-FZ8 (and several others)

On Feb 13, 2:14*am, "David J Taylor" -
this-bit.nor-this-bit.co.uk wrote:

Try it with your camera - results may vary - but I found that using
"normal" compression with the highest resolution image size, produced
better results than "fine" compression with the lower resolution, when
viewing images on the computer screen.

Thank you David! I did not realize digital cameras provide control
over the level of compression applied as well as the resolution.

I understand your statement that sometimes using higher resolutions
with greater compression could produce a clearer "native" result, but
assuming a production environment of photos for display in web pages
it is usally practical to perform at least some post-processing
reduction. Under those circumstances the level of compression applied
by the camera seems might be more important than the resolution at
which the photos were shot. In other words, I may have asked the
wrong question to begin with.

For example, my camera (upon further investigation) provides only for
what Fuji describes as "Normal" compression at the lowest resolution
setting. At the next higher resolution, "Fine" and "Normal" are
provided. I'm thinking, as a rule of thumb with any digital camera
and knowing in advance that I'll invariably need to perform post-
process reduction, I should choose the smallest resolution providing
the "Fine" setting for compression (and use that Fine setting).

Does that make sense?

Thanks,

Rob

Rob wrote:
On Feb 13, 2:14 am, "David J Taylor" -
this-bit.nor-this-bit.co.uk wrote:

Try it with your camera - results may vary - but I found that using
"normal" compression with the highest resolution image size, produced
better results than "fine" compression with the lower resolution,
when viewing images on the computer screen.

Thank you David! I did not realize digital cameras provide control
over the level of compression applied as well as the resolution.

OK, glad you've learned something.

I understand your statement that sometimes using higher resolutions
with greater compression could produce a clearer "native" result, but
assuming a production environment of photos for display in web pages
it is usally practical to perform at least some post-processing
reduction. Under those circumstances the level of compression applied
by the camera seems might be more important than the resolution at
which the photos were shot. In other words, I may have asked the
wrong question to begin with.

For example, my camera (upon further investigation) provides only for
what Fuji describes as "Normal" compression at the lowest resolution
setting. At the next higher resolution, "Fine" and "Normal" are
provided. I'm thinking, as a rule of thumb with any digital camera
and knowing in advance that I'll invariably need to perform post-
process reduction, I should choose the smallest resolution providing
the "Fine" setting for compression (and use that Fine setting).

Does that make sense?

Thanks,

Rob

Rob,

To be honest, as soon as you said "web pages" I immediately thought "shoot
at the lowest resolution and lowest quality setting (i.e. smallest file
size). Depending on your exact needs, that may be more than adequate.
Generally, for Web use, it's better to produce the fastest loading (i.e.
smallest file size) you can, even if a few JPEG artefacts are visible. If
these is any chance you will want to do something else with the photos,
that's different.

Cheers,
David

David J Taylor wrote:
Rob wrote:
On Feb 13, 2:14 am, "David J Taylor" -
this-bit.nor-this-bit.co.uk wrote:

Try it with your camera - results may vary - but I found that using
"normal" compression with the highest resolution image size, produced
better results than "fine" compression with the lower resolution,
when viewing images on the computer screen.
Thank you David! I did not realize digital cameras provide control
over the level of compression applied as well as the resolution.

OK, glad you've learned something.

I understand your statement that sometimes using higher resolutions
with greater compression could produce a clearer "native" result, but
assuming a production environment of photos for display in web pages
it is usally practical to perform at least some post-processing
reduction. Under those circumstances the level of compression applied
by the camera seems might be more important than the resolution at
which the photos were shot. In other words, I may have asked the
wrong question to begin with.

For example, my camera (upon further investigation) provides only for
what Fuji describes as "Normal" compression at the lowest resolution
setting. At the next higher resolution, "Fine" and "Normal" are
provided. I'm thinking, as a rule of thumb with any digital camera
and knowing in advance that I'll invariably need to perform post-
process reduction, I should choose the smallest resolution providing
the "Fine" setting for compression (and use that Fine setting).

Does that make sense?

Thanks,

Rob

Rob,

To be honest, as soon as you said "web pages" I immediately thought "shoot
at the lowest resolution and lowest quality setting (i.e. smallest file
size). Depending on your exact needs, that may be more than adequate.
Generally, for Web use, it's better to produce the fastest loading (i.e.
smallest file size) you can, even if a few JPEG artefacts are visible. If
these is any chance you will want to do something else with the photos,
that's different.

Cheers,
David


This is from a less than informed source, but it has always been my
practice to take the pictures at the best resolution the came can put
out, and maintain that in my photo archives. As new technologies come
out, what is now considered high resolution now will be low resolution
in the future.

If you need a lower resolution now you can always save a copy at the
lower resolution using software like Irfanview.


--
Keith Nuttle

On Wed, 13 Feb 2008 11:41:06 -0800 (PST), Rob wrote
in :

I understand your statement that sometimes using higher resolutions
with greater compression could produce a clearer "native" result, but
assuming a production environment of photos for display in web pages
it is usally practical to perform at least some post-processing
reduction. Under those circumstances the level of compression applied
by the camera seems might be more important than the resolution at
which the photos were shot. In other words, I may have asked the
wrong question to begin with.

The level of compression and the amount of downsampling are two entirely
different things. The former is best down in post-processing, but the
latter is usually done better in camera, because the camera is working
from the RAW sensor output, not a converted image.

For example, my camera (upon further investigation) provides only for
what Fuji describes as "Normal" compression at the lowest resolution
setting. At the next higher resolution, "Fine" and "Normal" are
provided. I'm thinking, as a rule of thumb with any digital camera
and knowing in advance that I'll invariably need to perform post-
process reduction, I should choose the smallest resolution providing
the "Fine" setting for compression (and use that Fine setting).

Does that make sense?

Yes.

--
Best regards,
John Navas
Panasonic DMC-FZ8 (and several others)

[A complimentary Cc of this posting was sent to
Rob
], who wrote in article :

To add to what other people say:

Does a typical digital camera, regardless of user setting for target
MP, capture all the data required to produce its highest MP image and
then interpret the result to produce the smaller MP?

Smart cameras have a "limited digital zoom". If you store 5MP of
10MP sensor, it would allow digital zoom of up to 1.4x.

One should also keep in mind that of 10MP dSLR shot, only about 5MP
are "live"; the rest is "dead" - they do not carry any information.
Doing a smart downsampling to 5MP would not use any information.
(With compacts, the ratio goes down to about 40%.)

It is another question whether you trust your camera's software do to
the "smart" downsampling...

Hope this helps,
Ilya

In article , Ilya Zakharevich
wrote:

One should also keep in mind that of 10MP dSLR shot, only about 5MP
are "live"; the rest is "dead" - they do not carry any information.
Doing a smart downsampling to 5MP would not use any information.
(With compacts, the ratio goes down to about 40%.)

that's absolute nonsense.