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Old Nov 14, 2003, 4:25 PM   #1
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Default Requesting explanation of the various file formats

Being new to digital photography, I am only superficially familiar with the various file format options. My objective will normally be to take and preserve the highest quality photos I can with my Olympus C5060 which is a 5.1 megapixel camera. I plan to store images on CD and probably eventually DVD media, am not very converned about large files and am willing to purchase large capacity cards if needed.

Can someone explain or point me to links that explain the advantages, characteristics and differences between the various file formats a camera can store images in and, other than file size, why photographers chose one type over another for certain applications.

I have already read the digicam dictionary on this site. Thanks very much!
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Old Nov 14, 2003, 4:43 PM   #2
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Since you've read up a little already, then you probably know that TIFF is a lossless file system (no data is lost from compression).

JPEG can result in loss of detail and color (as well as adding undesirable image "artifacts"), but at the highest quality modes, this loss in usually minimal in most cameras.

Here is a good article on compression that you may want to read:


RAW is usually the best (if you need the best quality and most flexibility) way to shoot (in most camera models), since it bypasses the camera's internal image processing (hence the name "RAW"). This is the unprocessed data from the camera's sensor.

Sometimes when you use the wrong white balance, exposure, sharpness, contrast and other settings, it's very difficult to correct in software. This is because the data captured by the camera's CCD (sensor) has already been processed by the camera. By shooting in RAW mode, you bypass the camera's processing of the image captured by the sensor, so you have much more control over how it looks later.

Unfortunately, Olympus "lags" the industry in it's software used to process the RAW image format (you can't make the adjustments in exposure, white balance, etc., that other manuacturers allow).

Although he has not reviewed the C-5060z yet, Phil Askey (owner/editor of dpreview.com) has reviewed the C-5050z.

He says "You can essentially convert from RAW to TIFF or JPEG and that's about it, it's about time Olympus allowed its owners to fully exploit the advantages of RAW (digital exposure compensation, White balance modification, post processing options, dynamic range) otherwise it's pretty pointless having a RAW format on the camera."


But, you may be able to find 3rd party software that supports RAW images from your camera (each camera's RAW format is proprietary to the manufacturer). I have not researched this option for Olympus models.

My conclusion (from reading about how Olympus uses the RAW mode):

If you want the absolute best quality photos available, with the least amount of space taken on your camera's memory cards, shoot in RAW, then convert later with software.

Although you won't have the advantages of changing exposure settings, etc., like you would with other manufacturers that support a RAW format, RAW images would take less space compared to TIFF.

Also, Olympus may (speculation on my part) come out with better software later, allowing more flexibility with the RAW files you have saved.

However, for most people, JPEG (using the highest quality mode), would be perfectly acceptable (saving LOTS of space on your memory cards, compared to either RAW or TIFF formats).

My newest camera (Konica Revio KD-510z) does not have a RAW format. For most of my photos, I do not even use the higher quality JPEG mode (I just use the Normal mode). For special photos (that I may want to print at greater than 8x10" sizes), I'll use Fine Quality JPEG.

For my needs, the extra space required by the better modes is not worth the small difference in quality (since I'll rarely print photos at very large sizes). Others may prefer to shoot in their camera's best modes for everything. It's all a matter of personal preference, and individual requirements. Quality is subjective.
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Old Nov 14, 2003, 7:27 PM   #3
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JPG or JPEG are compressed files. By convention the compression varies from 0 to 12 quality. If you compress a 5Mp image with very high compression like quality 0 it comes out somewhere around 150k and is pretty crappy. A 5Mp file saved at quality 12 is around 3.6Mb and the compression artifacts are slight. Lower quality JPGs vary a lot in size dependent on content but the higher qualities are more consistent in size. Most consumer level digital cameras save at a fairly high quality giving about a 2Mb image at best JPG for a 5 Mp shot. The newer serious prosumer digitals have added a superfine quality that gives the full 3.6Mb of a best quality JPG. Your camera is one of them. I see no reason to save at a lower quality than that if you are serious enough to get a 512Mb or larger CF card. Donít even consider xD cards. They arenít any faster in the camera and cost too much. They arenít cross compatible if you decide to upgrade to a good DLSR some day either. It is doubtful that anyone but Olympus and Fuji will ever put them in cameras. CF is the standard for large serious cameras and SD for small cameras and other devices. xD will likely be an orphan.

TIFF is uncompressed and 8 bit from the camera. It is three times the size of a raw file and in no way superior except that you donít have to convert it after you download it. I see no practical reason to use TIFF directly from the camera. Just have the software convert the raw files to TIFF.

Raw is just the raw data from the CCD before it is processed. With most cameras you can set most parameters when you process the raw file, so it doesn't matter how the sharpening, contrast, white balance and saturation are set in the camera. Evidently the Oly software is a little weak in that department. The new Photoshop will process the files like other cameras but it is as expensive as the camera if you donít have an older version to upgrade. Another advantage of raw is that it saves the full color depth the camera can work in. Most good cameras process 12 bit and the new Minolta A1 uses 14 bit. If you use JPG or TIFF from the camera you get an 8 bit file. But if you convert the raw file to a 16 bit (28.8Mb) TIFF you keep the greater color depth. The new Photoshop will work with the 16 bit files a lot better than earlier versions.

Raw is also a very good way to archive your images. 5Mb per image is a lot better than 14.4Mb. And even if you canít make full use of them now with the weak Oly software they will eventually upgrade it or raw will be common enough that cheaper programs will be able to translate it. The free Irfanview already has a raw plug-in but it isnít the best.

I think it was John Lennon who said that life is what happens while you are making other plans. Less than optimum memories are what happens when you screw around saving your images at lower quality because your immediate needs donít require any more. One day you will look back and most of your memorable pictures will be of poor quality. Take and archive your images in raw if it isnít too much hassle and SHQ if converting the raw files becomes a drag.
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Old Nov 15, 2003, 4:39 AM   #4
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Originally Posted by slipe
JPG or JPEG are compressed files. By convention the compression varies from 0 to 12 quality.
The only convention is there is no convention...cameras and software use their own standards for rating the amount of compression...some cameras rate the level by the amount of compression while others rate the level by the quality of the photo (Olympus does this). On software, some talk about low-medium-high (again either picture quality or compression level) while others use a scale (the program I use has a compression scale that goes from 0-100).
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Old Nov 15, 2003, 6:56 AM   #5
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All of the editors I have use the convention set by Adobe way back when with the exception of Irfanview, which isnít really an editor. The cameras use their different and confusing quality but it is pretty easy to relate it to the scale in Photoshop by just opening a full sized image and running the quality slider until you get to the same size in Mb. Cameras that produce SHQ or Super Fine JPGs end up with the same size as qualiy 12 in editors or 100 in Irfanview. Everyone does seem to have their own idea of what HQ, Fine, Standard etc is though in cameras. I relate them to the Adobe standard and I then know what I am dealing with. I guess it isnít much of a convention if you have to convert to see what they are really selling though.

I thought all ratings were based on either quality or resulting file size.
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Old Nov 15, 2003, 10:10 AM   #6
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Thank you for your helpful replies.

I purchased an Olympus 512mb xD card when I bought the camera because I wanted to preserve the option of panorama shots which are only available when using Olympus cards. And although I fell victim to their arm twisting marketing, it's not the end of the world. The camera also supports CF cards which may be used at the same time and apparently the camera can be switched between them.

I plan to buy a 1Gb or larger CF card. Then, between the cards, I should be able to do a full day of shooting without running out of card. Assuming I like the results, I plan to buy a "card to CD burner" so I can transfer images to a permanent media in the field, format the card and keep going. The new Apacer CP200 looks promising. And my guess is that DVD burners are around the corner.

I have taken film photos for years with a Contax and Minilux. My limited first impression of my digital camera is that I am dazzled, recognizing that it may be a honeymoon syndrome. But one thing I have learned about cameras is that best usually means bigger and when you add bigger to interchangable lenses and all that means in terms of carrying things around, one's equipment can become an unpleasant taskmaster. Ultimately the camera that takes the worst photos is the one left at home!
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