Image sizes for [SI]

On 10 Sep 2011 23:40:47 GMT, Andrew Reilly wrote:
: On Sun, 11 Sep 2011 09:53:05 +1200, Eric Stevens wrote:
:
: You have picked an example which is ideal for JPG compression:
: large plain surfaces of almost constant colour. You should try
: something more complex in which detail and texture is important.
:
: Not really. Complex detail and texture (especially "natural"
: textures) are the images that typically work best with JPEG
: compression. It's hard edges and in smooth gradations of tone
: that JPEG blocking and ringing shows up most clearly.

That has not been my experience.

: Don't forget that photos for the SI aren't intended for printing,
: but for comparison of style and "art" on screen.

I don't disagree, but I've seen SI pictures lose enough detail in JPEG
conversion to make their artistic merit, and certainly their technical merit,
harder to see.

Bob

On 10 Sep 2011 23:40:47 GMT, Andrew Reilly wrote:
: On Sun, 11 Sep 2011 09:53:05 +1200, Eric Stevens wrote:
:
: You have picked an example which is ideal for JPG compression:
: large plain surfaces of almost constant colour. You should try
: something more complex in which detail and texture is important.
:
: Not really. Complex detail and texture (especially "natural"
: textures) are the images that typically work best with JPEG
: compression. It's hard edges and in smooth gradations of tone
: that JPEG blocking and ringing shows up most clearly.

That has not been my experience.

: Don't forget that photos for the SI aren't intended for printing,
: but for comparison of style and "art" on screen.

I don't disagree, but I've seen SI pictures lose enough detail in JPEG
conversion to make their artistic merit, and certainly their technical merit,
harder to see.

Bob

On Sun, 11 Sep 2011 08:42:13 -0400, Alan Browne
wrote:
: On 2011-09-10 05:59 , Eric Stevens wrote:
: I've cross-posted this as I don't really know what is the
: home-newsgroup for Shoot In [SI].
:
: The RULZ have for some time specified an image file size of 300KB and
: I am wondering if this is still an appropriate size limit.
:
: Most JPG files translate to an image size of 4 to 5 times the
: compressed file size. 300KB translates to a 1.2MB ~ 1.5MB image. On a
: 3:2 frame ratio this translates to less than a 866 x 577 image. These
: days you are hard placed to buy a laptop of less than 1280 x 800 and
: desk tops come with screens about 1920 x 1200.
:
: At some point in the not very distant past, 1200xwhatever (usually 800)
: (landcape) was proposed as the limit, as well as 300 kB which usually
: means a JPG quality of 60 - 80 ( / 100). Rarely a discernible loss of
: quality in what is shown on the display.

Maybe in your pictures, but often not in mine. I always shoot in RAW, and I
can almost always see some degradation, even in fairly high-resolution JPEGs.
And I usually can't maintain 60-80/100; it's not unusual for me to have to get
down to 3-4/10 to meet the size limit.

Bob

On Sun, 11 Sep 2011 08:42:13 -0400, Alan Browne
wrote:
: On 2011-09-10 05:59 , Eric Stevens wrote:
: I've cross-posted this as I don't really know what is the
: home-newsgroup for Shoot In [SI].
:
: The RULZ have for some time specified an image file size of 300KB and
: I am wondering if this is still an appropriate size limit.
:
: Most JPG files translate to an image size of 4 to 5 times the
: compressed file size. 300KB translates to a 1.2MB ~ 1.5MB image. On a
: 3:2 frame ratio this translates to less than a 866 x 577 image. These
: days you are hard placed to buy a laptop of less than 1280 x 800 and
: desk tops come with screens about 1920 x 1200.
:
: At some point in the not very distant past, 1200xwhatever (usually 800)
: (landcape) was proposed as the limit, as well as 300 kB which usually
: means a JPG quality of 60 - 80 ( / 100). Rarely a discernible loss of
: quality in what is shown on the display.

Maybe in your pictures, but often not in mine. I always shoot in RAW, and I
can almost always see some degradation, even in fairly high-resolution JPEGs.
And I usually can't maintain 60-80/100; it's not unusual for me to have to get
down to 3-4/10 to meet the size limit.

Bob

On 9/11/2011 12:30 AM, Eric Stevens wrote:
..

Here is one (almost picked at random) which helps illustrate the
point: http://dl.dropbox.com/u/31088803/DSC_1683-2.jpg is really a
photograph of a man fishing from a small red boat. This is the
original (taken with a D70) with a JPG of 3.98 MB (2000 x 3008 MB).

http://dl.dropbox.com/u/31088803/DSC_1683-2a.jpg is the same
photograph reduced to 450 x 676 and 302kB.

In my opinion the loss of detail in the smaller photograph causes it
lose the impact present in the larger photograph. I'm not advocating a
4MB file size but I do want to make the point that reducing the file
size does take something away from the original image.

Regards,

Eric Stevens


PS. The boat is actually plain weather-beaten aluminium. In
post-processing I painted it red to make it stand out more in the
photograph.

Regards,

Eric Stevens

In some ways I tend to agree. You do lose some detail when
downsizing. No way to escape it..
But.. I think you could get a little more bang for the buck
as far as your downsizing. For that small second shot, it's
a pretty large file size for what you get out of it.
And a good bit of detail has been lost. I bet you did no
sharpening to the downsized image for one thing.
I've found adding a little sharpening goes a long way to
retaining a crisp look when using a smaller file size.
Sure, it causes some artifacts, but when looking at the
whole image and not pixel peeping, it's usually not a
major problem. With the way I downsize, I can get a good
bit larger image for the same file size, than the example
you've shown.
It's lost some detail vs the original, but not massively
so.
As an example..
Which would you rather look at.
Yours at that pretty small 450 x 676 size..
http://dl.dropbox.com/u/31088803/DSC_1683-2a.jpg

Or this one which is 837x1260, and actually using a
slightly smaller file "283k" than the one you posted..
http://home.comcast.net/~disk200/boat50-4.jpg

Sure, it's not perfect, but I think a tad more efficient
at keeping the impact of the original. Yes, I did sharpen it
just a tad, and also bumped the saturation a tad, as the
conversion using my program took a bit of color out for some
reason.
When I load a large image into the browser and then click the
"-" to make it fit full screen, it tends to sharpen the image
almost like using a sharpener in an edit program.
With my smaller version, you see less of that, so not quite as
sharp as the original in that view. But.. I think it looks sharper
than the small image you converted to.
I think you could probably use a bit more jpg compression than
you presently are, and still keep a pretty decent, but larger
downsized image.

On 9/11/2011 12:30 AM, Eric Stevens wrote:
..

Here is one (almost picked at random) which helps illustrate the
point: http://dl.dropbox.com/u/31088803/DSC_1683-2.jpg is really a
photograph of a man fishing from a small red boat. This is the
original (taken with a D70) with a JPG of 3.98 MB (2000 x 3008 MB).

http://dl.dropbox.com/u/31088803/DSC_1683-2a.jpg is the same
photograph reduced to 450 x 676 and 302kB.

In my opinion the loss of detail in the smaller photograph causes it
lose the impact present in the larger photograph. I'm not advocating a
4MB file size but I do want to make the point that reducing the file
size does take something away from the original image.

Regards,

Eric Stevens


PS. The boat is actually plain weather-beaten aluminium. In
post-processing I painted it red to make it stand out more in the
photograph.

Regards,

Eric Stevens

In some ways I tend to agree. You do lose some detail when
downsizing. No way to escape it..
But.. I think you could get a little more bang for the buck
as far as your downsizing. For that small second shot, it's
a pretty large file size for what you get out of it.
And a good bit of detail has been lost. I bet you did no
sharpening to the downsized image for one thing.
I've found adding a little sharpening goes a long way to
retaining a crisp look when using a smaller file size.
Sure, it causes some artifacts, but when looking at the
whole image and not pixel peeping, it's usually not a
major problem. With the way I downsize, I can get a good
bit larger image for the same file size, than the example
you've shown.
It's lost some detail vs the original, but not massively
so.
As an example..
Which would you rather look at.
Yours at that pretty small 450 x 676 size..
http://dl.dropbox.com/u/31088803/DSC_1683-2a.jpg

Or this one which is 837x1260, and actually using a
slightly smaller file "283k" than the one you posted..
http://home.comcast.net/~disk200/boat50-4.jpg

Sure, it's not perfect, but I think a tad more efficient
at keeping the impact of the original. Yes, I did sharpen it
just a tad, and also bumped the saturation a tad, as the
conversion using my program took a bit of color out for some
reason.
When I load a large image into the browser and then click the
"-" to make it fit full screen, it tends to sharpen the image
almost like using a sharpener in an edit program.
With my smaller version, you see less of that, so not quite as
sharp as the original in that view. But.. I think it looks sharper
than the small image you converted to.
I think you could probably use a bit more jpg compression than
you presently are, and still keep a pretty decent, but larger
downsized image.

On Sun, 11 Sep 2011 09:13:01 -0500, NM5K wrote:
: On 9/11/2011 12:30 AM, Eric Stevens wrote:
: .
:
: Here is one (almost picked at random) which helps illustrate the
: point: http://dl.dropbox.com/u/31088803/DSC_1683-2.jpg is really a
: photograph of a man fishing from a small red boat. This is the
: original (taken with a D70) with a JPG of 3.98 MB (2000 x 3008 MB).
:
: http://dl.dropbox.com/u/31088803/DSC_1683-2a.jpg is the same
: photograph reduced to 450 x 676 and 302kB.
:
: In my opinion the loss of detail in the smaller photograph causes it
: lose the impact present in the larger photograph. I'm not advocating a
: 4MB file size but I do want to make the point that reducing the file
: size does take something away from the original image.
:
: Regards,
:
: Eric Stevens
:
:
: PS. The boat is actually plain weather-beaten aluminium. In
: post-processing I painted it red to make it stand out more in the
: photograph.
:
: Regards,
:
: Eric Stevens
:
: In some ways I tend to agree. You do lose some detail when
: downsizing. No way to escape it..
: But.. I think you could get a little more bang for the buck
: as far as your downsizing. For that small second shot, it's
: a pretty large file size for what you get out of it.
: And a good bit of detail has been lost. I bet you did no
: sharpening to the downsized image for one thing.
: I've found adding a little sharpening goes a long way to
: retaining a crisp look when using a smaller file size.
: Sure, it causes some artifacts, but when looking at the
: whole image and not pixel peeping, it's usually not a
: major problem. With the way I downsize, I can get a good
: bit larger image for the same file size, than the example
: you've shown.
: It's lost some detail vs the original, but not massively
: so.
: As an example..
: Which would you rather look at.
: Yours at that pretty small 450 x 676 size..
: http://dl.dropbox.com/u/31088803/DSC_1683-2a.jpg
:
: Or this one which is 837x1260, and actually using a
: slightly smaller file "283k" than the one you posted..
: http://home.comcast.net/~disk200/boat50-4.jpg

I think I prefer the original. The sharpening in the doctored picture makes
the bare twigs on the trees far more luminous than they would be in real life,
and I find that distracting. Remember, you're supposed to notice the boat.

Bob

On Sun, 11 Sep 2011 09:13:01 -0500, NM5K wrote:
: On 9/11/2011 12:30 AM, Eric Stevens wrote:
: .
:
: Here is one (almost picked at random) which helps illustrate the
: point: http://dl.dropbox.com/u/31088803/DSC_1683-2.jpg is really a
: photograph of a man fishing from a small red boat. This is the
: original (taken with a D70) with a JPG of 3.98 MB (2000 x 3008 MB).
:
: http://dl.dropbox.com/u/31088803/DSC_1683-2a.jpg is the same
: photograph reduced to 450 x 676 and 302kB.
:
: In my opinion the loss of detail in the smaller photograph causes it
: lose the impact present in the larger photograph. I'm not advocating a
: 4MB file size but I do want to make the point that reducing the file
: size does take something away from the original image.
:
: Regards,
:
: Eric Stevens
:
:
: PS. The boat is actually plain weather-beaten aluminium. In
: post-processing I painted it red to make it stand out more in the
: photograph.
:
: Regards,
:
: Eric Stevens
:
: In some ways I tend to agree. You do lose some detail when
: downsizing. No way to escape it..
: But.. I think you could get a little more bang for the buck
: as far as your downsizing. For that small second shot, it's
: a pretty large file size for what you get out of it.
: And a good bit of detail has been lost. I bet you did no
: sharpening to the downsized image for one thing.
: I've found adding a little sharpening goes a long way to
: retaining a crisp look when using a smaller file size.
: Sure, it causes some artifacts, but when looking at the
: whole image and not pixel peeping, it's usually not a
: major problem. With the way I downsize, I can get a good
: bit larger image for the same file size, than the example
: you've shown.
: It's lost some detail vs the original, but not massively
: so.
: As an example..
: Which would you rather look at.
: Yours at that pretty small 450 x 676 size..
: http://dl.dropbox.com/u/31088803/DSC_1683-2a.jpg
:
: Or this one which is 837x1260, and actually using a
: slightly smaller file "283k" than the one you posted..
: http://home.comcast.net/~disk200/boat50-4.jpg

I think I prefer the original. The sharpening in the doctored picture makes
the bare twigs on the trees far more luminous than they would be in real life,
and I find that distracting. Remember, you're supposed to notice the boat.

Bob

On 9/11/2011 1:30 AM, Eric Stevens wrote:

snip

PS. The boat is actually plain weather-beaten aluminium. In
post-processing I painted it red to make it stand out more in the
photograph.


Sorry Eric, I pixel peeked. You did a nice job on the boat, but The
reflection is still gray. ;-)

--
Peter

On 9/11/2011 1:30 AM, Eric Stevens wrote:

snip

PS. The boat is actually plain weather-beaten aluminium. In
post-processing I painted it red to make it stand out more in the
photograph.


Sorry Eric, I pixel peeked. You did a nice job on the boat, but The
reflection is still gray. ;-)

--
Peter