A pixel by any other name...

On 2013-04-11 20:55:13 -0700, Savageduck said:

On 2013-04-11 20:28:05 -0700, Jennifer Murphy said:

On Thu, 11 Apr 2013 17:14:13 -0700, Savageduck
wrote:

On 2013-04-11 16:18:33 -0700, Jennifer Murphy said:

I think digital photography is beyond my mental capacities (sigh).

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be? I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.

Here are a couple of examples:



Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)
Print Size: 21.1 x 14.1 cm; 8.3 x 5.5 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 12.92 MB (13,550,637 Bytes)

Filetype: JPG
Pixels: 3156 x 2678 Pixels (8.45 MPixels) (1.18)
Print Size: 26.7 x 22.7 cm; 10.5 x 8.9 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 7.07 MB (7,418,412 Bytes)

The JPG also has a quite different aspect ratio (1.18 vs 1.5).

In the above case you have two different dimension sizes; the CR2 is
2496 x 1664 p giving you 4.15MP and the jpeg is 3156 x 2678 p at 8.9MP,
an almost 50% difference due to the dimensional difference. These are
MPixels which deal only with physical dimensions.
Note the actual file (disk size) sizes are 12.92 MB for the CR2 and
7.07 MB for the JPEG. There is still more data contained in the RAW CR2.
I suspect you have an adjusted and size extrapolated JPEG there, not a
JPEG immediately converted from the CR2. The 16-bit CR2 is unadjusted
and not altered in any way.

Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)
Print Size: 16.3 x 12.2 cm; 6.4 x 4.8 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 13.99 MB (14,665,216 Bytes)

Filetype: JPG
Pixels: 2816 x 2112 Pixels (5.95 MPixels) (4:3)
Print Size: 23.8 x 17.9 cm; 9.4 x 7.0 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 2.61 MB (2,736,853 Bytes)

This is a similar scenario to the Canon example. the dimensional size
of the jpeg has been enlarged, while the true size of the files, the
RW2 and the compressed jpeg reflect the truth of the data contained in
each.
Also in this case the 16-bit RW2 is unadjusted

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 81.14 MB (85,081,048 Bytes)

Filetype: JPG
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 4.25 MB (4,455,756 Bytes)

For this pair, the number of pixels and the aspect ratio are the same,
but the size of the file shrank by almost 20:1.

This is a different situation. First PSD is not the native RAW format,
for that it should be an NEF. PSD is an Adobe file type, as sub-type of
TIFF which preserves layer and adjustments made with Photoshop and some
other editing software.
Note that the dimensions of both the PSD and the JPEG are identical,
and so both have the same total pixels, 7.09MP.

The disk or file size tells the other side of the story. The
adjustments and edits were probably made to the converted RAW NEF file
and then saved to the hard drive. It will not be saved as a NEF, but as
a 16-bit, uncompressed PSD, retaining all the data of the adjustments.
Then to save it as a compressed JPEG it will be saved as an 8-bit
compressed JPEG

You make similar points to nospam. Thanks.

To keep things simple, here is the data for a CR2 and corresponding
matched jpeg, shot in a Canon G11 capturing RAW+JPEG (Fine Large).

Filetype: CR2
Pixels: 2736x3648 or 9.98 MP for a 10MP camera.
File/disk size: 14.2MB

Filetype: JPEG (ex-camera, fine, large)
Pixels: 2736x3648 or 9.98 MP for a 10MP camera.
File/disk size: 4.2MB

Out of the camera the dimensional size and megapixels for both the RAW
CR2 and the JPEG will always be the same provided you select the
largest possible in-camera JPEG setting.

The initial file/disk size is going to be dependent on the the content
of the image, with the addition that the JPEG's size will depend on the
in-camera compression, in this case an approximately 7:1 compression
ratio.

....er, make that an approximately 7:2 compression ratio.

--
Regards,

Savageduck

In article , Jennifer
Murphy wrote:

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be?

i don't know where you're getting the raw files but they're not
straight from the cameras. the numbers are wrong.

I have a couple of friends with cameras that are better than mine. I
asked them for the "raw" files and that's what I got.

they are raw files. the problem is the numbers don't match the camera
specs, but i found the reason. more on that below.

also keep in mind that a jpeg can be resized to anything you want.

And once resized, the number of pixels as reported by IrfanView could be
anything, right?

an image can be whatever you resize it to.

in photoshop, pick image size... and you get this dialog:
http://pe-images.s3.amazonaws.com/es...ng/new/image-s
ize-command.gif

you can then type in any pixel dimensions you want. there are some
options for what happens when you enter numbers, such as constraining
the aspect ratio, but the point is it can be pretty much any size.

you can also resize based on percentage rather than pixels. enter a
percentage and have the computer do the math and calculate the exact
number of pixels for you. it's a lot easier to type 300% instead of
multiplying 1952 * 3 and entering the result.
http://pe-images.s3.amazonaws.com/es...ng/new/choosin
g-percent.gif

if you are going to compare raw versus jpeg, they must be unmodified
out of the camera, with the settings set to maximum resolution.

I'm starting to think that my friends may not know as much about how
their cameras work as I thought they did.

could be. just because they bought an expensive camera doesn't mean
they know how to use it.

however, that doesn't seem to be the issue here.

Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)

i don't know where you got that raw file but it's not from a canon 5d.
a canon 5d (mark i) has 4368 x 2912 pixels, for 12.7 megapixels, not 4
megapixels. the aspect ratio on a 5d is 3:2, so the jpeg was cropped.

I was told by the owner that it was the raw camera file. (sigh)

it is.

i just downloaded a sample canon 5d raw file from he
http://www.rawsamples.ch/

after dumping all of the tags in the file, there are actually several
image dimensions in the

Image Width : 2496
Image Height : 1664
....
Zoom Source Width : 0
Zoom Target Width : 0
....
Canon Image Width : 4368
Canon Image Height : 2912
....
AF Image Width : 4992
AF Image Height : 3328
....
AF Area Width : 119
AF Area Height : 119
....
Sensor Width : 4476
Sensor Height : 2954
Sensor Left Border : 100
Sensor Top Border : 39
Sensor Right Border : 4467
Sensor Bottom Border : 2950
....
Exif Image Width : 4368
Exif Image Height : 2912

the smaller size is probably for an embedded jpeg image inside the raw,
which lets software quickly show a preview image without having to
process the raw data.

that also means that whatever software you're using is telling you the
wrong information. it's broken. find another app.

Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)

something is wrong there too. the dmc-g1 has 12 megapixels, not 2.76 mp.

Again, I asked for the raw camera file and that's what I was given.

and that's what you have.

i downloaded a sample g1 image from the same site and it also has
multiple image sizes in the exif data.

Sensor Width : 4060
Sensor Height : 3016
Sensor Top Border : 4
Sensor Left Border : 8
Sensor Bottom Border : 3004
Sensor Right Border : 4008
....
Panasonic Image Width : 4000
Panasonic Image Height : 3000
....
Exif Image Width : 1920
Exif Image Height : 1440
....
Image Height : 3000
Image Width : 4000

as above, there's an embedded jpeg and its dimensions are probably
1920x1440. the dimensions of the raw file is 3000x4000.

the software you're using is looking at the wrong data. it's broken.

there's a lot of info in the exif tags. one tag that i haven't seen
before is this one:
Baby Age : (not set)

apparently, it can be used for pets too ( tag #51):
http://www.exiv2.org/tags-panasonic.html

i'm not sure how that gets set. maybe face detection is a lot more
sophisticated than it used to be.

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)

psd is photoshop, not raw, and a nikon d700 has 12 megapixels, not 7.

This is very disappointing. I am reluctant to go back to my friends and
suggest that they con't know what the heck they are doing.

they probably do know what they're doing.

although a psd is often created from a raw, it's not a raw file and
calling it raw is wrong.

further evidence the software you're using is buggy and you should find
a different app.

is that the one your friend adjusted the perspective? if so, that
explains why it's 7 mp and why it's a photoshop file. it was resized
and cropped in photoshop to fix the perspective distortion.

There is one that she cropped in PS, but the one that is 130MB (.psd)
was supposed to be a raw camera file.

the original started a raw camera file, which she opened in photoshop
(using camera raw, a part of photoshop). given its size, it likely has
additional layers and is also probably 16 bits/pixel.

Maybe I need to hire a professional photographer to do it right. I've
spent sop much time trying to get a good shoot, what I could have paid
for it several times over.

that's always an option, but isn't a guarantee either. it also depends
how much you value time versus money.

Thanks for the patient instruction.

anytime.

On 12/04/2013 00:18, Jennifer Murphy wrote:
I think digital photography is beyond my mental capacities (sigh).

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be? I thought a jpg file was a compressed
version of the raw image file. So the number of pixels should be at most
the same, and I would have thought somewhat lower.

If you take a given JPG file and save it as a BMP you will get a file
with the *SAME* number of pixels as 24bit RGB but no compression at all.

If as an experiment you then add say 50% random shot noise to the image
and then resave it as a JPEG file with a different name you will get
something close to the upper size limit for a JPEG at that quality. Blur
it slightly with a 0.7 pixel width Gaussian blur and save again and you
should get something broadly comparable with a photo image.

Equally if you take a BMP file and save it as JPEG then the number of
pixels will not change at all. The new representation inside the saved
file is completely different and highly compressed.

What you are experiencing below is characteristic of changing settings
in the camera without understanding what you are doing. RTFM.

Here are a couple of examples:



Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)
Print Size: 21.1 x 14.1 cm; 8.3 x 5.5 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 12.92 MB (13,550,637 Bytes)

Filetype: JPG
Pixels: 3156 x 2678 Pixels (8.45 MPixels) (1.18)
Print Size: 26.7 x 22.7 cm; 10.5 x 8.9 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 7.07 MB (7,418,412 Bytes)

The JPG also has a quite different aspect ratio (1.18 vs 1.5).

You are not comparing like with like here! The Canon EOS 5D Mk I camera
native sensor resolution is about 12.8Mp as 4368 x 2912 max.


Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)
Print Size: 16.3 x 12.2 cm; 6.4 x 4.8 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 13.99 MB (14,665,216 Bytes)

Filetype: JPG
Pixels: 2816 x 2112 Pixels (5.95 MPixels) (4:3)
Print Size: 23.8 x 17.9 cm; 9.4 x 7.0 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 2.61 MB (2,736,853 Bytes)

Again you are not comparing like with like. The Panasonic DMC-G1 native
sensor resolution is about 12Mp as 4000x3000 max.

You are always free to throw away image data but I don't recommend it!

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 81.14 MB (85,081,048 Bytes)

Filetype: JPG
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)
Print Size: 24.6 x 20.6 cm; 9.7 x 8.1 inches (at 300 dpi)
Colors: 16,7 Millions (24 BitsPerPixel)
Disk Size: 4.25 MB (4,455,756 Bytes)

For this pair, the number of pixels and the aspect ratio are the same,
but the size of the file shrank by almost 20:1.

20:1 compression is a bit brutal. Are you sure that your camera is set
to save JPEGs at the highest available quality setting. NB makers tend
to give their quality settings names that are shifted upwards by one
step. So "good" = "rubbish", "very good" = "good", etc.

Obviously you can tell the camera to throw away data and save a smaller
image than was actually captured. Several ways to do it as well. Some
systems will average adjacent pixels to improve signal to noise when
appropriate linear scaling factors are chosen (eg 50%). The other common
variant is digital zoom where only the centre part of an image is saved
and crudely interpolated up (not recommended).

Unless you are in danger of running out of media space or know for
certain that you will never want high resolution images of the subject
it is usually worth using the camera in highest quality and resolution
mode. You can resize later but if you never captured the data in the
first place no amount of prayer afterwards will bring it back.

Raw is worthwhile if you know that the subject will contain extreme
contrast with important highlights and shadow detail - eg. weddings.

Increasingly with still digital cameras offering video modes that don't
flatten the battery in a matter of minutes you now see them offering
multiple aspect ratios to cater for TV shapes 4:3 (3:2) and 16:9.

--
Regards,
Martin Brown

In article , Martin Brown
wrote:

Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)

You are not comparing like with like here! The Canon EOS 5D Mk I camera
native sensor resolution is about 12.8Mp as 4368 x 2912 max.

i thought that too, but it turns out she is.

the problem is the software she's using is buggy and is reporting the
wrong data. see my other post for more detail.

Jennifer Murphy wrote:
I think digital photography is beyond my mental capacities (sigh).


You have a fairly simple choice.

You can either "just" use the cameras. Modern cameras
work very well.

Or you can fully understand them.

Anywhere between these two extremes
will probably make you unhappy
and confused.

BugBear

On Fri, 12 Apr 2013 02:04:33 -0400, nospam
wrote:

In article , Jennifer
Murphy wrote:

I have several photos that were saved both as raw image files and as
jpgs. For many of them, the jpg file reports more pixels than the raw
image file. How can that be?

i don't know where you're getting the raw files but they're not
straight from the cameras. the numbers are wrong.

I have a couple of friends with cameras that are better than mine. I
asked them for the "raw" files and that's what I got.

they are raw files. the problem is the numbers don't match the camera
specs, but i found the reason. more on that below.

also keep in mind that a jpeg can be resized to anything you want.

And once resized, the number of pixels as reported by IrfanView could be
anything, right?

an image can be whatever you resize it to.

in photoshop, pick image size... and you get this dialog:
http://pe-images.s3.amazonaws.com/es...ng/new/image-s
ize-command.gif

you can then type in any pixel dimensions you want. there are some
options for what happens when you enter numbers, such as constraining
the aspect ratio, but the point is it can be pretty much any size.

you can also resize based on percentage rather than pixels. enter a
percentage and have the computer do the math and calculate the exact
number of pixels for you. it's a lot easier to type 300% instead of
multiplying 1952 * 3 and entering the result.
http://pe-images.s3.amazonaws.com/es...ng/new/choosin
g-percent.gif

if you are going to compare raw versus jpeg, they must be unmodified
out of the camera, with the settings set to maximum resolution.

I'm starting to think that my friends may not know as much about how
their cameras work as I thought they did.

could be. just because they bought an expensive camera doesn't mean
they know how to use it.

however, that doesn't seem to be the issue here.

Camera: Canon 5D Mark I with Canon EF 24-70mm f/2.8L lens

Filetype: CR2 (raw file)
Pixels: 2496 x 1664 Pixels (4.15 MPixels) (3:2)

i don't know where you got that raw file but it's not from a canon 5d.
a canon 5d (mark i) has 4368 x 2912 pixels, for 12.7 megapixels, not 4
megapixels. the aspect ratio on a 5d is 3:2, so the jpeg was cropped.

I was told by the owner that it was the raw camera file. (sigh)

it is.

i just downloaded a sample canon 5d raw file from he
http://www.rawsamples.ch/

after dumping all of the tags in the file, there are actually several
image dimensions in the

Image Width : 2496
Image Height : 1664
...
Zoom Source Width : 0
Zoom Target Width : 0
...
Canon Image Width : 4368
Canon Image Height : 2912
...
AF Image Width : 4992
AF Image Height : 3328
...
AF Area Width : 119
AF Area Height : 119
...
Sensor Width : 4476
Sensor Height : 2954
Sensor Left Border : 100
Sensor Top Border : 39
Sensor Right Border : 4467
Sensor Bottom Border : 2950
...
Exif Image Width : 4368
Exif Image Height : 2912

the smaller size is probably for an embedded jpeg image inside the raw,
which lets software quickly show a preview image without having to
process the raw data.

that also means that whatever software you're using is telling you the
wrong information. it's broken. find another app.

Camera: Panasonic DMC-G1 with a 14-45 zoom lens

Filetype: RW2 (raw file)
Pixels: 1920 x 1440 Pixels (2.76 MPixels) (4:3)

something is wrong there too. the dmc-g1 has 12 megapixels, not 2.76 mp.

Again, I asked for the raw camera file and that's what I was given.

and that's what you have.

i downloaded a sample g1 image from the same site and it also has
multiple image sizes in the exif data.

Sensor Width : 4060
Sensor Height : 3016
Sensor Top Border : 4
Sensor Left Border : 8
Sensor Bottom Border : 3004
Sensor Right Border : 4008
...
Panasonic Image Width : 4000
Panasonic Image Height : 3000
...
Exif Image Width : 1920
Exif Image Height : 1440
...
Image Height : 3000
Image Width : 4000

as above, there's an embedded jpeg and its dimensions are probably
1920x1440. the dimensions of the raw file is 3000x4000.

the software you're using is looking at the wrong data. it's broken.

there's a lot of info in the exif tags. one tag that i haven't seen
before is this one:
Baby Age : (not set)

apparently, it can be used for pets too ( tag #51):
http://www.exiv2.org/tags-panasonic.html

i'm not sure how that gets set. maybe face detection is a lot more
sophisticated than it used to be.

Camera: Nikon D700 with a 24-120 mm zoom lens

Filetype: PSD (raw file)
Pixels: 2910 x 2435 Pixels (7.09 MPixels) (1.20)

psd is photoshop, not raw, and a nikon d700 has 12 megapixels, not 7.

This is very disappointing. I am reluctant to go back to my friends and
suggest that they con't know what the heck they are doing.

they probably do know what they're doing.

although a psd is often created from a raw, it's not a raw file and
calling it raw is wrong.

further evidence the software you're using is buggy and you should find
a different app.

is that the one your friend adjusted the perspective? if so, that
explains why it's 7 mp and why it's a photoshop file. it was resized
and cropped in photoshop to fix the perspective distortion.

There is one that she cropped in PS, but the one that is 130MB (.psd)
was supposed to be a raw camera file.

the original started a raw camera file, which she opened in photoshop
(using camera raw, a part of photoshop). given its size, it likely has
additional layers and is also probably 16 bits/pixel.

Maybe I need to hire a professional photographer to do it right. I've
spent sop much time trying to get a good shoot, what I could have paid
for it several times over.

that's always an option, but isn't a guarantee either. it also depends
how much you value time versus money.

Thanks for the patient instruction.

anytime.

All very helpful. Thanks so much.

The data I am reporting comes from IrfanView (IV). I just open the file
in IV and press the "I" key for "Info". I get an Image Properties dialog
box. For some images, there might be one or two other informational
buttons: one is "Exif info*" and another one is "IPTC Info". Sometimes I
get one or both or neither.

Can you recommend another program for examining these images? It needn't
be free.

In article , Jennifer
Murphy wrote:

The data I am reporting comes from IrfanView (IV). I just open the file
in IV and press the "I" key for "Info". I get an Image Properties dialog
box. For some images, there might be one or two other informational
buttons: one is "Exif info*" and another one is "IPTC Info". Sometimes I
get one or both or neither.

there's definitely exif info in all of the images, which is what i
dumped in the previous post. if it's not showing that there is exif
info, it's even buggier than i thought.

Can you recommend another program for examining these images? It needn't
be free.

if you just want to know the number of pixels, open the image in a
browser and it should show the pixel dimensions in the title bar next
to the file name. however, this won't work for raw files, but the raw
files are whatever the camera's native resolution is so you can look up
that information.

for viewing, adjusting, cropping, retouching, printing, etc., then you
want photoshop or lightroom, but either is overkill for just looking at
the number of pixels.

as long as the camera is set to the highest quality or you get the raw
file, you can be assured you have the best the camera can do. the rest
is up to the photographer.

On 04/11/2013 06:44 PM, nospam wrote:
In article , philo
wrote:

You may want to read this article:


http://www.kenrockwell.com/tech/raw.htm

actually, you *don't* want to read that article.

that person makes stuff up and intentionally misleads people, thinking
it's some sort of game (he admits this on his about page).



Since you cannot cite an example I'm going to have to assume you are
trolling. (Others may make their own judgment.)

The writer states quite clearly that what he writes is simply his own
opinion.
--
https://www.createspace.com/3707686

In article , philo*
wrote:

You may want to read this article:

http://www.kenrockwell.com/tech/raw.htm

actually, you *don't* want to read that article.

that person makes stuff up and intentionally misleads people, thinking
it's some sort of game (he admits this on his about page).

Since you cannot cite an example I'm going to have to assume you are
trolling. (Others may make their own judgment.)

an example of what? do you mean errors in the above link? there are
*numerous* problems with that page. here's a few:

Raw requires dedicated software to read.

completely wrong. mac os x has raw support built in, which means most
mac software can read raw directly. even just tapping the spacebar will
open an image.

photoshop and lightroom open both raw and jpeg and make no distinction
between them, including being able to use camera raw on jpeg (but you
don't get the full benefit that way, obviously). in other words, the
workflow is *identical* for raw and jpeg, with the *same* software.

If you use Photoshop and Adobe Camera Raw, you just might have to buy
the newest version of Photoshop, since Adobe doesn't update older
versions to read the files from new cameras.

nope. convert to dng and use your existing photoshop.

If you're shooting action, raw doesn't work. You'll fill an 8 gig
card faster than you can imagine.

more nonsense. it works just fine.

I never shoot raw. Why would I? Raw is a waste of time and space, and
doesn't look any better than JPG even when you can open the files.

disk space is cheap and raw can easily look better than jpeg.

all of that was just from the first section!

more idiocy:
Many people who shoot raw, which I consider to be a big waste of
time, don't realize that white balance can be adjusted in Photoshop
even from JPGs

it can, but the results are nowhere near as good as with raw.

one of the key advantages of raw is being able to set white balance
*after* you shoot. there is no downside because raw doesn't actually
have a white balance until it's processed.

Raw is NOT a digital negative. Unlike a real negative, it still has
restricted resolution and dynamic range, and most importantly, cannot
be read or seen except with very special software. JPGs are far more
universally read, and closer to a negative in terms of being visible
to everyone over time. Raw is like a color negative since each piece
of software you might use to open it yields different colors!

raw *is* a digital negative. that's the whole point.

in fact, some cameras save raw in dng format, which stands for digital
negative!

real negatives have restricted resolution and dynamic range. nothing is
unlimited. jpegs are closer to a print, not a negative.

a negative has to be held up to the light (or on a lightbox), and even
then, it's almost impossible to tell what it is because there's a deep
orange mask and colours are reversed.

3.) Because it's not standardized, you can't send these files to
clients or anyone and expect them to open.

of course you can. raw support is built into modern operating systems.
anyone who expects to receive raw files probably has photoshop or
lightroom or similar and can open them that way too.

The writer states quite clearly that what he writes is simply his own
opinion.

what he says is that he makes stuff up for fun and that some of what's
on the site is actually a hoax.

http://www.kenrockwell.com/about.htm
I have a big sense of humor, and do this site to entertain you (and
myself), as well as to inform and to educate. I occasionally weave
fiction and satire into my stories to keep them interesting. I love a
good hoax. Read The Museum of Hoaxes, or see their site. A hoax, like
some of the things I do on this website, is done as a goof simply for
the heck of it by overactive minds as a practical joke. Even Ansel
Adams kidded around when he was just a pup in the 1920s by selling
his photos as "Parmelian Prints." I have the energy and sense of
humor of a three-year old, so remember, this is a personal website,
and never presented as fact. I enjoy making things up for fun, as
does The Onion, and I publish them here ‹ even on this page.

read it for entertainment, not for learning.

On 04/13/2013 03:42 PM, nospam wrote:
In article , philo
wrote:

You may want to read this article:

http://www.kenrockwell.com/tech/raw.htm

actually, you *don't* want to read that article.

that person makes stuff up and intentionally misleads people, thinking
it's some sort of game (he admits this on his about page).

Since you cannot cite an example I'm going to have to assume you are
trolling. (Others may make their own judgment.)

an example of what? do you mean errors in the above link? there are
*numerous* problems with that page. here's a few:

Raw requires dedicated software to read.

completely wrong. mac os x has raw support built in, which means most
mac software can read raw directly. even just tapping the spacebar will
open an image.



snip


Ok I guess everyone is entitled to their own opinion