Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Oct 29, 2005, 5:28 AM   #1
Senior Member
 
kenmck15's Avatar
 
Join Date: Aug 2005
Posts: 2,568
Default

Hey guys
Im looking at some images and everyone seems tolight up and smile as soon as a cam mentions that it can use .raw and .tif file types.

can someone please explain what these are and the benefits of using such file types. I noticed that the image files are huge

thanks
kenmck15 is offline   Reply With Quote
Sponsored Links
Old Oct 29, 2005, 6:53 AM   #2
Senior Member
 
Monza76's Avatar
 
Join Date: Jul 2004
Posts: 4,093
Default

RAW and TIF are uncompressed (or lossless compression) files. They may be 16bit or 12bit files which offers more colour adjustment options. RAW is typically smaller than TIF but since it is the raw data from the sensor it requires processing before it can be used. JPEG is a lossy format which results in small 8bit files which will degrade is successively modified and saved because of compression losses. Great for general photography as long as you leave the originals alone.

This just scratches the surface, someone will come in with even more I am sure.

Ira
Monza76 is offline   Reply With Quote
Old Oct 29, 2005, 10:19 AM   #3
Senior Member
 
hgernhardtjr's Avatar
 
Join Date: Nov 2004
Posts: 516
Default

In additon to what Ira said, RAW is in effect the true digital negative, untouched by any built in pre-decided photograph parameters and firmware enhancements such as sharpness, color balance, etc.

In effect, RAW is the true un modified information off the sensor and that, with the appropriate RAW editor (such a Camera Raw included in PhotoShop CS2, provides the avid photoggrapher or photo-editor the ability to do almost virtually anything we used to do with film negatives, and a whole boatload more!

The RAW file standard varies among manufacturers, but Adobe is working toward standardizing the format with their DNG format. And, as Ira indicated, RAW produces large files ... perhaps 10-15 times the size of a JPG ... but no original data is lost or compressed. Again, ideal for the photo-editor.
hgernhardtjr is offline   Reply With Quote
Old Oct 29, 2005, 10:50 PM   #4
Senior Member
 
Join Date: Dec 2002
Posts: 5,803
Default

Just to throw out some more info/thoughts...
I agree with all the above comments.
If you use JPG or RAW is mostly a personal choice. RAW gives you more flexability, but it is slower to use. Both in the camera and on the computer. They take up more disk space and they can use more ram when processing. They open slower and always require conversion as you can't actually "edit" the RAW file, but you can convert it into a format that you can edit. As was said above, the RAW file is the data directly off the sensor in the camera, with no modifications. It needs to be converted into TIFF, JPG or some other format that is editable before you can do anything with it.

With all those downsides, it does have benefits. I only shoot in RAW.
But you should try it both ways and see which fits you better. There are many people who produce very good results shooting JPGs. They know about RAW, but JPG is good enough for them so they pass on the downsides of RAW because the upsides aren't enough to make it worth it *to them*.

Eric
eric s is offline   Reply With Quote
Old Oct 30, 2005, 2:36 PM   #5
E.T
Senior Member
 
E.T's Avatar
 
Join Date: Jul 2003
Posts: 921
Default

hgernhardtjr wrote:
Quote:
RAW produces large files ... perhaps 10-15 times the size of a JPG
That depends on entirely how crappy compression camera uses.

With KonicaMinolta A2 size of best JPEG is around 4-7MB and RAW ~11MB. Quality of those JPEGs doesn't differ anyway from 22MB sized TIFF so I consider TIFF as quite useless format. (saving it also takes longer and you can take fewer of those to buffer)

RAW is entirely different case, because it's raw data from sensor camera's settings things like wrong white balance doesn't matter because white balance adjusting is done in processing and because you're doing it in computer with way more CPU power results can be considerably better, especially with noisy underexposed shots.
E.T is offline   Reply With Quote
Old Oct 30, 2005, 2:58 PM   #6
Guest
 
Posts: n/a
Default

This article covers the details of each image type:

http://www.popphoto.com/article.asp?...rticle_id=1516
  Reply With Quote
Old Oct 30, 2005, 4:25 PM   #7
Senior Member
 
kenmck15's Avatar
 
Join Date: Aug 2005
Posts: 2,568
Default

thank you for all the responses i will look into everythig u guys have suggested

cheers
kenmck15 is offline   Reply With Quote
Old Oct 31, 2005, 12:04 PM   #8
Senior Member
 
Join Date: Sep 2005
Posts: 1,093
Default

E.T wrote:
Quote:
RAW is entirely different case, because it's raw data from sensor camera's settings things like wrong white balance doesn't matter because white balance adjusting is done in processing and because you're doing it in computer with way more CPU power results can be considerably better, especially with noisy underexposed shots.
I wonder if you can help me understand this point. I find it very difficult to get an image with the white balance that properly captures what I am seeing at the scene. Is this what people mean when they talk about getting the color right later while working with the computer? If so, how do you remember precisely what it looked like? Or is the goal to get a color balance that you like, without regard to whether it is precise, and what counts as "right" is what you find pleasing?

I've seen many expert photographers make the same point that you are making. I don't doubt that it encapsulates a real point. I just don't quite know what that point is.


tclune is offline   Reply With Quote
Old Oct 31, 2005, 12:40 PM   #9
Moderator
 
Join Date: Aug 2004
Posts: 8,529
Default

tclune,

I think most people would say it is always better to get things right in-camera rather than in post processing. However, white balance is one of those things that is just tricky - especially depending on how picky the photographer is. Some camerase do a pretty good job of white balance - for instance I'm very happy with the auto-WB in my camera for 90% of my shots. But, adjusting WB in-camera can take a lot of experience - especially if lighting is not consistant - making custom WB difficult or impossible.

Adjusting WB in RAW conversion is INFINITELY easier to do than trying to adjust via software in JPEG. As to what white balance SHOULD look like in a photo, I think it's a judgement call if you don't really have true white or something close in your image. But, white balance and exposure compensation are probably the two biggest things that you can easily correct in RAW but are very difficult to correct without a lot of time or negative side affects in JPEG.

Just for another viewpoint, I am not at the level of a lot of the people here, but I tend to use JPEG for most uses and RAW for shots that will either have a large dynamic range or tricky whitebalance (some indoor lighting)or portrait work where I know I (or in the case of dynamic range) the camera is not capable of capturing the image as I see it with reliability.
JohnG is offline   Reply With Quote
Old Oct 31, 2005, 1:49 PM   #10
Senior Member
 
Join Date: Sep 2005
Posts: 1,093
Default

JohnG wrote:
Quote:
As to what white balance SHOULD look like in a photo, I think it's a judgement call if you don't really have true white or something close in your image.
Hi, John.

Thanks for your thoughtful response. I have selected the above sentence because one of the things that I find hard in getting the white balance right for is some artificial lighting situations. To my eye, white doesn't look white in many lighting conditions. If I do a manual white balance, the colors are pushed too far toward white. I lose the apparent bias of the actual view. If, on the other hand, I select a built-in white balance, I often get an accentuated bias. Is this some odd physiological quirk of my vision, or do most people find the same problem? When I'm trying to get the color riight (which, for my aspirations as a shlubby amateur means capturing what I am seeing), I can only come close if I am near a computer whose monitor I trust, and download the image while I can still check against the truth. It's quite a painful cycle. I assume that either I am interested in maximizing something that other people don't care about or other people have a much better system for doing it than I do. If the latter, how do you get your colors right?


tclune is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 2:42 AM.