Digital Photos (was: Reno Suite...)

"C J Campbell" wrote in message
...
[...] Any of the professional-grade digital SLRs should have an option
for
saving the data in a "raw" format (which typically is actually just a
proprietary, non-lossy compressed format).

Actually, most RAW files are compressed somewhat, too. Read the
instruction
manual.

I said they were compressed. You even quoted the part of my post where I
said that. Something wrong with your hearing aid?

"G.R. Patterson III" wrote in message
...
Jpeg is the preferred format for photos that are going to be displayed for
view
(for example, the shots we submit to Jay of our aircraft should be jpegs).
Gifs
are preferred for shots that people are likly to just glance at (for
example,
thumbnails) because they typically are smaller than jpegs and consequently
load
faster.

IMHO, you have this exactly backwards.

Generally, a GIF (or PNG or compressed TIF, for that matter) file will be
larger than a JPEG file, for the same image. GIF is a non-lossy compression
format, and doesn't have the luxury that JPEG has of throwing information
away to make the file smaller.

In the case of computer-generated images or natural images that have few
variations (scanned B&W document that has been "posterized", for example),
GIF can come out ahead with a smaller size and more importantly, will not
lose any detail the way a JPEG will. But this is the exception to the rule,
and doesn't apply to photographic images.

Generally speaking, if you have a GIF image and a JPEG image the same size
(in pixels) and the GIF image is smaller, it's either because the JPEG
compression was set to the minimum value, or because the JPEG version has
24-bit color while the GIF has only 8-bit color (which obviously results in
a 2/3 reduction in file size even before any compression has taken place).
The color-depth difference is, in particular, a very common reason one might
be fooled into thinking JPEG is not as efficient as GIF, since when
compression a color photographic image, that difference will almost always
exist.

Pete

"Jay Beckman" wrote in message
news:qW3vd.3841$2r.1754@fed1read02...
I just got a Canon EOS 20D. Both .jpg and .raw can be saved to one CF
card.

Thanks...I haven't been paying as much attention to that segment of the
market, so didn't realize they had added that feature (nor to the Nikon line
in the same market segment, for that matter). It didn't occur to me that
the high-end features in the 1Ds line might appear in the lower-end cameras.

That said, even with two cards, I have to admit that I find that feature of
limited use to most people. And especially with just one card, for most
people you'll be better off just saving the raw image, and converting to
JPEG later on the computer.

In any case, the information is probably more helpful to the original poster
than to me. At least, one hopes so. Thanks for bringing it up.

"Peter Duniho" wrote in message
...
"Jay Beckman" wrote in message
news:qW3vd.3841$2r.1754@fed1read02...
I just got a Canon EOS 20D. Both .jpg and .raw can be saved to one CF
card.

Thanks...I haven't been paying as much attention to that segment of the
market, so didn't realize they had added that feature (nor to the Nikon
line in the same market segment, for that matter). It didn't occur to me
that the high-end features in the 1Ds line might appear in the lower-end
cameras.

I'm just finally taking the plunge into "prosumer" digital simply because I
had so much $$$ tied up in my film rigs. The 20D is deep, deep, deep in
terms of what it can do, but it also lets me take tons of simple .jpg images
on a snap shot basis.

That said, even with two cards, I have to admit that I find that feature
of limited use to most people. And especially with just one card, for
most people you'll be better off just saving the raw image, and converting
to JPEG later on the computer.

Agreed as the .raw files are huge (20Mb+) and you really can't do much with
them unless you have photo editing software (I just moved up to PSElements
v3) that can handle .raw.

That being said, the data "depth" in the .raw files allows for much more
tweaking before converting to .jpg (although I save everything initially in
..psd which is more or less "lossless.")


In any case, the information is probably more helpful to the original
poster than to me. At least, one hopes so. Thanks for bringing it
up.

De nada,

Jay B

"RST Engineering" wrote in message
...
There was a comment on the "was" thread about .jpg being an inferior
format to a couple of other formats. So if my Kodak 1.3Mp camera only
downloads in .jpg, how do I fool it into downloading in some other
uncompressed format?

According to the camera specifications, the actual file format is listed
as: "Exif version 2.1 (JPEG base).

Suggestions other than borrowing Gail's very expensive Canon for my
magazine shots?

When a magazine editor is really particular, especially for cover
shots, s/he'll send out a staff photographer. On a low-end camera like a 1.3
Mp, you are more than likely stuck with whatever it gives you unless the POH
says different. But don't give up, print out a 4 X 6 inch copy of the
original photo at 300 dpi. If you don't see any serious degredation, chances
are the editor will be happy with them.
If Gail doesn't want to cooperate, ask the photo guru at Sierra C. to
trade the loan of a camera for a hop around the town.
Every time a digital image is saved in JPEG, it loses a smidgen of
quality in resolution and/or color rendition -- even if it was in JPEG to
start with. Kind of like the old Xerox of a Xerox of a Xerox...ad nauseum.
But read on...., preserve the original JPEG files by locking them with a
read-only attribute. Then, save a copy of the original in either .PNG or
..TIFF format to do whatever manipulations you feel like. PNG and TIFF retain
fidelity through a lot more saves than JPEG. If the image manipulation
software in your computer won't save in PNG or TIFF, read on....,
In workshops I teach for writers cum photographers, I recommend
getting a picture processor (software) at least equal to PhotoShop Elements
or Paint Shop Pro. Both inexpensive packages come loaded with more features
than they will ever use and retail for less than $100.

"Peter Duniho" wrote in message
...
"C J Campbell" wrote in message
...
[...] Any of the professional-grade digital SLRs should have an option
for
saving the data in a "raw" format (which typically is actually just a
proprietary, non-lossy compressed format).

Actually, most RAW files are compressed somewhat, too. Read the
instruction
manual.

I said they were compressed. You even quoted the part of my post where I
said that. Something wrong with your hearing aid?

What? Dang. I knew I had to get thing checked.

"Morgans" wrote in message
...

"C J Campbell" wrote


Even so, your Kodak 1.3Mp is wholly inadequate for any form of
publication.
You will need at least 4.0Mp to achieve high enough resolution for
print.

??????????????????????????????????

ANY form of publication? I know lots of forms of publications that a 1.3
would not be an issue.

At what size are you planning to print? 8 X 10 magazine picture? Yes,
for
that size, an amateur could see lose of sharpness. Smaller sizes, printing
at home, the printer will be the limiting factor, for most people.

Broad, sweeping statements like you made are seldom to stand up for all
situations. How about a less authoritarian stance?

Nobody would believe I wrote it otherwise.

Yes, you can get by with incredibly inferior quality in some publications.
And your printer is not the limiting factor in that case; it is the printer
of the publisher. But 1.3 simply does not preserve enough detail or color
for the vast majority of print publications.

"Casey Wilson" wrote in message
news:Ha5vd.3159$Z%1.2468@trnddc03...
[...] Then, save a copy of the original in either .PNG or .TIFF format to
do whatever manipulations you feel like. PNG and TIFF retain fidelity
through a lot more saves than JPEG.

If by "a lot more" you mean "infinitely more"...

Lossless compressions algorithms are, by definition, well...lossless. Every
time you uncompress the data (to view it in a photo editor, for example) and
then recompress it using the same lossless algorithm (or any other lossless
algorithm, for that matter), you will get *exactly* the same data back the
next time you uncompress the data. No matter how many times you do the
exercise, this will be true.

C J Campbell opined

"Peter Duniho" wrote in message
...

For a consumer-grade camera, as long as you set the JPEG format to the
highest resolution, lowest-compression setting, you should fine. You'd be
unlikely to notice any difference between the raw image and the compressed
one. Any of the professional-grade digital SLRs should have an option for
saving the data in a "raw" format (which typically is actually just a
proprietary, non-lossy compressed format).

Actually, most RAW files are compressed somewhat, too. Read the instruction
manual.

But do they do lossey compression? If they don't that compression doesn't
matter.



-ash
Cthulhu in 2005!
Why wait for nature?

JPEG uses a spatial frequency compression algorithm to compress the image.
Many cameras provide the ability to control the quality of the JPEG
compression which affects the resulting file size and image quality. This
is in effect controlling the spatial frequency bandwidth of the compression
algorithm. Allowing higher spatial frequency components in the image
increases the JPEG file size and preserves more of the image detail. You
should check to see if your camera provides this capability.

Dean Wilkinson
http://www.razorsedgesoft.com/airplan/index.htm

"RST Engineering" wrote in message
...
There was a comment on the "was" thread about .jpg being an inferior
format
to a couple of other formats. So if my Kodak 1.3Mp camera only downloads
in
.jpg, how do I fool it into downloading in some other uncompressed format?

According to the camera specifications, the actual file format is listed
as:
"Exif version 2.1 (JPEG base).

Suggestions other than borrowing Gail's very expensive Canon for my
magazine
shots?

Jim