Difference between RAW and TIFF files?

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Whats the difference? Any advantage in using one or the other for saving
pictures at top quality and processing? Frankly after a scan I cannot tell
the diference between JPEG and TIFF looking at them on a monitor (even
zooming in), only the file size of the TIFF is huge, so whats the point
anyway?
 
Whats the difference? Any advantage in using one or the other for saving
pictures at top quality and processing? Frankly after a scan I cannot tell
the diference between JPEG and TIFF looking at them on a monitor (even
zooming in), only the file size of the TIFF is huge, so whats the point
anyway?
Click to expand...

I don't know the answer to the RAW vs. TIFF question except that my
camera seems to want RAW for its highest resolution, and I usually use
TIFF for saving film and slides I have scanned on a dedicated scanner.

I what I have observed is that you will notice the resolution
difference when you make large blowups. TIFF files can be blown up to
very sizeable proportions with no real loss of clarity and resolution.
If I try to blow up a JPEG with moderate compression you will start to
see the pixels at some point. In general, I do use JPEGs for my
"snapshots" and I use TIFF (and RAW when shooting with my digital)
when I flatter myself with pretentions of "fine" photography.

Jon Teske
 
[What's] the difference [between RAW and TIFF]?
Click to expand...
Click to expand...

TIFF ("Tagged Image File Format") is a standard image format that's been
in use for many years. Every non-toy graphics program out there
understands TIFF, and the various tags defined in the TIFF standard
allow people to store things like DPI, colorspace info, profiles, text
comments, and random crud in the file as well as the image data.

RAW is not nearly as well-defined, but some cameras or scanners may be
able to store more data in RAW format (10 bits/channel instead of 8,
etcetera) than in TIFF. (TIFF can do 8 bits/channel or 16 bits/channel,
but not 10.)
Frankly after a scan I cannot tell the diference between JPEG and TIFF
looking at them on a monitor (even zooming in), only the file size of
the TIFF is huge, so [what's] the point anyway?
Click to expand...
What I have observed is that you will notice the resolution difference
when you make large blowups. TIFF files can be blown up to very
sizeable proportions with no real loss of clarity and resolution. If
I try to blow up a JPEG with moderate compression you will start to
see the pixels at some point.
Click to expand...

JPEGs have artifacts because they're compressed in a lossy manner.
TIFFs are usually compressed losslessly (Group4 for black-n-white, LZW
for grayscale/color) so they don't show nearly as many artifacts.

Whatever you do, archive your images in a standard, Open format like
TIFF. That way, you'll always be able to read them. HTH,
 
Whats the difference? Any advantage in using one or the other for saving
pictures at top quality and processing? Frankly after a scan I cannot tell
the diference between JPEG and TIFF looking at them on a monitor (even
zooming in), only the file size of the TIFF is huge, so whats the point
anyway?
Click to expand...

A raw file saves all the information the scanner can recover without
any post processing. JPG compresses a lot of data in a "lossy" way
i.e. you can't get it back.

The reasons you can't see any difference between JPG and TIF are many
Here's two:
- your eyes are only 8-bit (some say even 6-bit)
- your monitor is only 8-bit

The points of raw are many but how important or relevant they are
depends on your requirements.

For example, you're *not* locked into editing decisions you make when
you scan. Editing in scanner software is a bad idea anyway. You can't
really make good editing decision based on a tiny preview image and
with a very limited set of tools. After all scanner software has been
designed to *scan* not to edit.

But more importantly, once you've scanned raw you can archive this as
your "digital negative" and then do all you editing on a copy. If
you're unhappy how that turns out you can always trash it and start
from scratch with your saved digital negative without having to run
the scanner again! Easier on the scanner and much faster too!

And that brings us to the key question. What quality are you after?

If you're just casually scanning your family photos to be shown on a
web page then there's no point in scanning raw.

On the other hand, if you wish to freeze the film's deterioration for
posterity by saving scans as your digital negatives or, you're after
maximum quality and added flexibility then raw is the way to go.

Don.
 
SS said:
Whats the difference? Any advantage in using one or the other for saving
pictures at top quality and processing? Frankly after a scan I cannot tell
the diference between JPEG and TIFF looking at them on a monitor (even
zooming in), only the file size of the TIFF is huge, so whats the point
anyway?
Click to expand...
I can only talk about RAW from my D70. As far as I know, a RAW file
contains information direct from the sensors. That means that the data has
not be converted from the Bayer mosaic to pixels. In essence, without
conversion, the data in a RAW file is completely unsuitable for printing.
There is no provision for saving an image in memory to RAW because the
software would need to convert the image back to the Bayer representation.

Of course, you can't see the difference between an image from a TIFF file
and an image from a JPEG because the monitor is such a poor place to obtain
such judgements. One makes judgements based on prints not monitors. In
addition, it takes many saves to make a significant degradation in a JPEG
file. I save important images in TIFF format because I want to leave
nothing to chance.
Jim
 
Well as for 'quality' I am scanning lots of old slides and negatives from
60's-70's which have been shut away for years. I am using Canon FS4000US
scanner at 4000 dpi saving TIFF and minimum compression JPEGS. I have
several over and under exposed frames that I would like to draw detail out
of as well as 'zooming in' to details such as faces etc, though I find
grainyness takes over before I can get too far 'in'. I have to say I will be
looking at the pictures on the TV as a slideshow, on the computer and also
printing a few at 6x4 or 7x5". Its the crops/blow ups that will be critical
and thus far I see no difference nbetween TIFF and JPEG on that count - loss
of detail and grainyness are exactly the same. Any difference must be very
subtle and hence as I am looking at these pictures to enjoy not in
microscopic detail there seems little point in the different file types over
JPEG - or anyway that is the point for discussion here!
 
That's right, you should see no difference between a tif and a level 10
jpeg and only minor jpeg artifacts at higher compression levels. Level
6 is normal for web work.
 
JPEG - Joint Photographic Experts Group - A storage format standard, with
defined degrees of lossy compression in use.
TIFF - Tagged Image File Format - A storage format standard with defined
degrees of lossless compression in use.
RAW - Manufacturer specific storage format without any compression.
 
SS said:
Whats the difference? Any advantage in using one or the other for saving
pictures at top quality and processing? Frankly after a scan I cannot tell
the diference between JPEG and TIFF looking at them on a monitor (even
zooming in), only the file size of the TIFF is huge, so whats the point
anyway?
Click to expand...

You're question is very confusing. Between your title and the content,
you mention 3 disparate file formats.

That out of the way, I think you're comparing jpeg and tiff. If so,
other responders have nailed it: jpeg is a lossy, finished product, not
meant for editting, file format. Tiff, otoh, can be cloned and touched
up without degradation. And paricularly with the 16 bit tiffs, will
take a bit of histogram strecthing and curve application without
becoming to posterized. It's best when doing the latter to save as a
copy, and leave the original untouched.

16 bit linear tiffs are one step closer to the original, as-scanned
data, and useful with Vuescan scan-from-disk. They can also be worked
in Photshop or other editors.

Raw files are the generic descriptive of digital camera raw output.
 
Well as for 'quality' I am scanning lots of old slides and negatives from
60's-70's which have been shut away for years. I am using Canon FS4000US
scanner at 4000 dpi saving TIFF and minimum compression JPEGS. I have
several over and under exposed frames that I would like to draw detail out
of as well as 'zooming in' to details such as faces etc, though I find
grainyness takes over before I can get too far 'in'.
Click to expand...

This is exactly the reason for scanning raw and using maximum
bit-depth your scanner offers.

The key here is that even though you do not see it directly on a
monitor a raw file contains a lot of data. The reason this is
important is because it allows you to make radical changes (like boost
underexposed frames a lot) without noticing any artifacts.

For example, if you take an underexposed JPG scan and boost it you
will likely see so-called "banding" i.e. gradients will stop being
smooth. On the other hand if you scan raw in, say, 14-bit color you
will be able to easily boost such a scan without any major distortion.
I have to say I will be
looking at the pictures on the TV as a slideshow, on the computer and also
printing a few at 6x4 or 7x5". Its the crops/blow ups that will be critical
and thus far I see no difference nbetween TIFF and JPEG on that count - loss
of detail and grainyness are exactly the same. Any difference must be very
subtle and hence as I am looking at these pictures to enjoy not in
microscopic detail there seems little point in the different file types over
JPEG - or anyway that is the point for discussion here!
Click to expand...

If your goal is to scan for TV or computer (and don't wish to archive
your "digital negatives") then, yes, JPG is sufficient.

I would still scan, at least the difficult images, in full resolution
(you already do that) and in TIFF so they can be edited. After that
reduce resolution and convert to JPG throwing away the TIFF.

Don.
 
Don said:
This is exactly the reason for scanning raw and using maximum
bit-depth your scanner offers.

The key here is that even though you do not see it directly on a
monitor a raw file contains a lot of data. The reason this is
important is because it allows you to make radical changes (like boost
underexposed frames a lot) without noticing any artifacts.

For example, if you take an underexposed JPG scan and boost it you
will likely see so-called "banding" i.e. gradients will stop being
smooth. On the other hand if you scan raw in, say, 14-bit color you
will be able to easily boost such a scan without any major distortion.


If your goal is to scan for TV or computer (and don't wish to archive
your "digital negatives") then, yes, JPG is sufficient.

I would still scan, at least the difficult images, in full resolution
(you already do that) and in TIFF so they can be edited. After that
reduce resolution and convert to JPG throwing away the TIFF.

Don.
Click to expand...

Only problem is, Don, on my Canon G5, the RAW files are HUGE!

Eddie
 
Only problem is, Don, on my Canon G5, the RAW files are HUGE!
Click to expand...

Yes they are, but that's why raw files are so good. It takes a lot of
space to store all that valuable information. Like I said, you can't
make an omelet without braking eggs...

Depending on your requirements you may be able to get away with
decreased resolution but definitely stick with maximum bit-depth
because decreasing that would be false economy.

Of course, a lot depends on the scanner's/camera's capabilities but if
possible, decrease resolution. Do that using integer downscaling only.
For example if native resolution is, say, 1000 use 500 or 250, do not
use 578 or some such because you'll end up with "imaginary" pixels.

Depending on the method the camera/scanner uses to generate low
resolution images you may still end up with some interpolation, but by
using integer divisions these will be minimal.

Don.
 
Only problem is, Don, on my Canon G5, the RAW files are HUGE!
Click to expand...
Then even for AUD$, some Yahoo and eBay stores offer IDE hard drives at
less than AUD$0.75 per gigabyte! That's per GIGABYTE!! That's after
shipping! Almost all IDE desktop mainboards since 1989 have 2 channels,
with 2 devices each, recognized by the BIOS, so there is probably room on
your IDE ribbons and the racks inside your computer case for another hard
drive as a slave device to dedicate to the RAW/TIFF/JPG/PNG (my favorite)
formats.
Regards,
Theo d Crow
 
Only problem is, Don, on my Canon G5, the RAW files are HUGE!
Click to expand...
That would be huge as 6-8Mb? That would make my 220Mb files..... ;-)

--

Hecate - The Real One
(e-mail address removed)
Fashion: Buying things you don't need, with money
you don't have, to impress people you don't like...
 
Eddie said:
Much, much larger. I think more like 44 Mb!
Click to expand...

Your RAW files are 5MB plus or minus a bit, since Canon compresses their RAW
files.

http://www.dpreview.com/reviews/canong5/page10.asp

Since it's a 5MP camera, a 16-bit TIFF file produced by a RAW converter from
a RAW file would be 5 x 6 = 30MB. (I'm not convinced creating 16-bit files
makes any sense from consumer dcams, but that's another rant.)

David J. Littleboy
Tokyo, Japan
 
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