What is RAW Format?

Little River Falls, Fort Payne, Alabama. February 14, 2010.

I’ve mentioned, in connection with my new camera, that I’m experimenting with RAW format images.  Several people have asked me about RAW, so I thought I would share what little I know about it.

Until I got this new camera (a Canon EOS Rebel T1i) my digital cameras saved images as JPEG files (some digital cameras use TIFF format).  In order to get the JPEG file the camera converts the light striking the sensor in the camera to something that we can see.  JPEG files typically are made up of 8 bits of data per color per pixel.  But the sensor can provide 14 or more bits of data per color per pixel.  We can see the JPEG image, but the conversion uses only part of the recorded data.

I know I’m showing my age, but think of the days when cameras used film.  A JPEG file is like a print or a slide — we can see the image.  A RAW file contains all the data the camera can provide (those 14 bits per color per pixel) but it is like undeveloped film — we can’t see the image until some processing is done.  In working with RAW format I have to do the work that the camera does with JPEG.

So what have I learned after a week of experimenting?  The most obvious thing is that RAW files are much bigger than JPEG files (about four times bigger in my case).  Another thing is that to take full advantage of RAW data, special software is needed (Canon included software with the camera).  On the other hand, since all of the sensor data is present, images can be ‘fixed’ in ways that might not be possible otherwise.  It is even possible to change some of the picture settings after the picture has been taken (it looks better with landscape settings than with standard settings).

Right now I’m not sure how much I will use RAW.  I’m cheating right now and am saving images as both RAW and JPEG files.  The card in the camera is big enough that I can take several hundred pictures before I have to download to my computer, so I’ll probably continue to do that while I learn more about the things I can do with the RAW format.


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16 Responses to “What is RAW Format?”

  1. bertN Says:

    Let us know the stuff you can do with the RAW format. I’m just a JPEG guy but I’m thinking of getting a camera with RAW capability.

  2. Pam Says:

    Wow, now I finally understand about RAW formatting. I have read what others have said and still not fully understood it.
    You explained it beautifully George, thanks.

  3. Rajesh Says:

    Beautiful shot of the waterfall. You given very useful insight into RAW format.

  4. MaryBeth Says:


  5. Fishing Guy Says:

    George: Have a great time with the new camera. I hope it all works out for you.

  6. Ruth Hiebert Says:

    Have fun learning.I have just started shooting Raw and am learning a little each day,or so it seems.

  7. Ginny Hartzler Says:

    Well, halfway through your explanation, i was wondering why anyone would want to do all that work if the camera can do it for them! But if you can alter the pictures in so many ways, I’m guessing it can be fun and rewarding. I would never be able to do it at all, so you are certainly not showing your age; at least you can understand and do this stuff! Just a regular camera software C.D. drives me nuts, and I have to get people to help me with it. I’m guessing you are technically and mathmaticaly inclined.

  8. happilyretired Says:

    I’m wondering if you see a difference w/o making alterations. One thing I’ve learned about Photoshop Elements is that experimentation can eat up LOTS of time 😉
    Hugs and blessings,

  9. Cheryl Says:

    Thank you for answering my questions as well. Very interesting and maybe someday I will move up to a bigger and better camera.

  10. connieemeraldeyes Says:

    My camera came with a trial photo editor for RAW, but it is a trial only and you have to buy the program and it costs a couple of hundred dollars, so I never even touched it. I think one of the photo shop programs will work with it, but those cost a lot too. Good luck using it.

  11. Carletta Says:

    I’ve known what RAW meant George and my son was explaining to me just last week that he likes working with it. I’m looking forward to seeing your new images. I think I’m content with JPEG’s. 🙂

  12. Becky Says:

    Great info George, better than all the tutorials I’ve been reading…

  13. Ginny Hartzler Says:

    Hope you see many more sunsets just as beautiful on this trip!

  14. Happyone Says:

    Thanks for explaining RAW. Another beautiful picture.

  15. Rose Says:

    When I take Raw, I always use the Raw/jpg setting also.

  16. Mary Says:

    I’m glad you explained some of this. I’ve never tired RAW but have wondered about it and what difference it would make to my photos.

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