RAW vs. JPG, better color capture?

robscomputerrobscomputer Registered Users Posts: 326 Major grins
edited May 19, 2005 in Cameras
Last week I was at Fry’s an pickup up a digital photography book on sale. The book is published by O’Reily and titled Digital Photography: Expert Technique.



http://www.oreilly.com/catalog/dphotohdbk/



I’m just on the second chapater but came across something new that I never knew about. The author shows two different images, one taken in JPG format, the other in RAW format. The book shows both images right next to each other and the difference is amazing, it appears as if the JPG image is destaurated compared to the bright colors of the RAW image.



The author’s text describes the difference is because of the greater range RAW files have over JPG which give greater detail in the highlights and shadows. Now from what I read about RAW files are the greatest benefit is the ability to control of color and white balance. Does RAW offer better capture of color than even the highest level of JPG captures?



Thanks,

Rob
Enjoying photography since 1980.

Comments

  • cmr164cmr164 Registered Users Posts: 1,542 Major grins
    edited May 13, 2005
    ...
    I’m just on the second chapater but came across something new that I never knew about. The author shows two different images, one taken in JPG format, the other in RAW format. The book shows both images right next to each other and the difference is amazing, it appears as if the JPG image is destaurated compared to the bright colors of the RAW image.

    The author’s text describes the difference is because of the greater range RAW files have over JPG which give greater detail in the highlights and shadows. Now from what I read about RAW files are the greatest benefit is the ability to control of color and white balance. Does RAW offer better capture of color than even the highest level of JPG captures?



    Thanks,

    Rob
    Raw captures 12bits each RGB giving 4096 shades of each and 68,719,476,736 color combinations. Jpeg give 8bits each for 256 shades of each and 16,777,216 colors. That is the reason you get more latitude in correcting exposures. And yes better color capture. (note: the dynamic range does not increase as much as you might think from those numbers although it does increase.)
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  • mercphotomercphoto Registered Users Posts: 4,550 Major grins
    edited May 13, 2005
    The author’s text describes the difference is because of the greater range RAW files have over JPG which give greater detail in the highlights and shadows. Now from what I read about RAW files are the greatest benefit is the ability to control of color and white balance. Does RAW offer better capture of color than even the highest level of JPG captures?

    As stated, RAW files are often 12-bits in depth, which offers more "steps" in color transition. It also offers greater ability to alter images. Also remember that there is no way they printed the actual RAW image in the book. That RAW image must be processed into either TIFF or JPG before it can be printed and published. That process alone will result in some differences in color, detail, etc. because not all RAW processors produce the same results. Its also possible they manipulated the RAW file for optium image quality.

    However, once you convert a file to an 8-bit JPG, you are back to 8-bits once again. There is no escaping that. 8-bits is 8-bits and can only represent a certain number of color transitions. If you decide to shoot RAW yourself because of all the benefits it provides for those who heavily post-process files, you need to remember that. Convert the RAW files into a 16-bit format. If you convert to an 8-bit format you are throwing away a ton of data, and might as well have started with JPG in the first place.
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  • colourboxcolourbox Registered Users Posts: 2,095 Major grins
    edited May 13, 2005
    It's important to note that just putting the camera in RAW mode isn't going to get you any benefit on its own. The benefits only come after processing the RAW to get the exact quality you want. The analogy is a darkroom. Putting a photographer in a darkroom (RAW) can result in a better picture than the lab, but only if the person was trained in how to use the darkroom (how to use RAW). Otherwise, it could be a time-consuming disaster. If a photographer doesn't yet know how to use RAW or doesn't want to learn, they will get faster, smaller, serviceable prints by shooting JPEG (like sending out to a lab for prints). RAW is about having the maximum amount of personal control, which requires a certain amount of expertise, and also involves certain adjustments to your overall workflow, which can either greatly enhance your work if you do it right, or greatly slow you down if you do it wrong.

    If you are interested in RAW, I would strongly suggest reading a book like Real World Camera Raw. The book will seem like a lot of pages and detail for what seems like a simple format change, but it will also reveal to you a whole world of possibilities inside your RAW images.
  • robscomputerrobscomputer Registered Users Posts: 326 Major grins
    edited May 13, 2005
    Thanks for the info. I'm reading more about RAW's benefits and find the ability to further tweak images more important than just simply "auto sharpen" then upload.

    Also thanks for the link to the book. I'll check this out after I finish my current book.

    Rob
    Enjoying photography since 1980.
  • colourboxcolourbox Registered Users Posts: 2,095 Major grins
    edited May 13, 2005
    I should have mentioned that the book I linked to is for the new Photoshop CS2 so that new edition of the book is not out yet. Here is a link to the previous edition and its reader reviews.
  • leebaseleebase Registered Users Posts: 630 Major grins
    edited May 13, 2005
    I think the author did not present the issue correctly. All photos start as RAW. Then processing is applied to turn them into jpg's.

    The cameras have settings to boost saturation, contrast and sharpness so that the jpg's created "by the camera" an be very "punchy" as well.

    Likewise, you can take a raw file, and NOT boos the saturation, and create a washed out looking photo from a raw file.

    The benefit of raw, in this scenario, is that you can experiment AFTER THE FACT...and change your opinion from one photo to another.

    With in camera jpg, you choose your settings BEFORE you take the photo.

    That said -- you can still boost saturation, contrast and sharpness of a jpg -- it's just that you are working with less information at that point.

    Lee
  • CatOneCatOne Registered Users Posts: 957 Major grins
    edited May 16, 2005
    leebase wrote:
    I think the author did not present the issue correctly. All photos start as RAW. Then processing is applied to turn them into jpg's.

    The cameras have settings to boost saturation, contrast and sharpness so that the jpg's created "by the camera" an be very "punchy" as well.

    Likewise, you can take a raw file, and NOT boos the saturation, and create a washed out looking photo from a raw file.

    The benefit of raw, in this scenario, is that you can experiment AFTER THE FACT...and change your opinion from one photo to another.

    With in camera jpg, you choose your settings BEFORE you take the photo.

    That said -- you can still boost saturation, contrast and sharpness of a jpg -- it's just that you are working with less information at that point.

    Lee

    More specifically, RAW photos don't have a color profile applied. They are just numbers from a sensor, pretty much exactly what the camera recorded.

    To make an image, conversion will apply a color profile -- typically either sRGB or Adobe RGB. sRGB is most common for JPEGs, and it has a smaller gamut, which will make images appear more "punchy" or "saturated," but will lose dynamic range. It may look better initially (or at least pleasing), but there's less range. If you want to edit later, sRGB is a worse starting point.
  • DavidTODavidTO Registered Users, Retired Mod Posts: 19,160 Major grins
    edited May 16, 2005
    CatOne wrote:
    If you want to edit later, sRGB is a worse starting point.

    That depends on where you're going to end up. If you're going to end up in sRGB, then you should start in sRGB. And that's the reality for the majority of folks.
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  • mercphotomercphoto Registered Users Posts: 4,550 Major grins
    edited May 16, 2005
    DavidTO wrote:
    That depends on where you're going to end up. If you're going to end up in sRGB, then you should start in sRGB. And that's the reality for the majority of folks.

    Agreed. If you want the most flexibility, you probably want to edit in the color space you want to end up in, and edit in 16-bit mode, rather than in 8-bit mode. Less mathematical errors that way. Remember, converting from one color space to another involved a mathematical transformation. That transformation is done with integer arithmetic, and that inherintly involves round-off error. One set of errors going from the original color space to the working color space, and another set when converting back again. Plus every operation you do on the image involves integer math, hence the suggestion to do all that in 16-bit mode.

    I'm actually conducting an expirment that I should have answers for tonight. I shot about two dozens photos at a kart race in RAW+JPG mode. I normally shoot races in JPG mode. I take the JPG, do a mild curves adjustment and a sharpening run, add a text layer, then save back as a JPG at quality 10. Captured in sRGB, edited in sRGB, and saved in sRGB.

    For the RAW file I converted in Canon's EVU to a 16-bit TIFF file, using the same parameters used to capture the JPG with. This way my starting point is the same in terms of color and sharpness, its just that I have no compression losses or artifacts, plus I have all 12-bits from the sensor rather than just 8. I then did the same curves, sharpening and text, converted down to 8 bit, saved as a JPG at level 12. The resulting JPG is roughly twice as big as the in-camera JPG, and the adjustments were made with more data present.

    I made a 20x30" print, which I should get tonight. Will be interesting to find out if there is any difference. Actually, now I wish I had edited my in-camera JPG in 16-bit mode instead of in 8-bit mode, and had a third data point for my test. Maybe later this week...
    Bill Jurasz - Mercury Photography - Cedar Park, TX
    A former sports shooter
    Follow me at: https://www.flickr.com/photos/bjurasz/
    My Etsy store: https://www.etsy.com/shop/mercphoto?ref=hdr_shop_menu
  • mercphotomercphoto Registered Users Posts: 4,550 Major grins
    edited May 16, 2005
    mercphoto wrote:
    I'm actually conducting an expirment that I should have answers for tonight.

    Results are in. Can't tell the diff between the JPG or the RAW at 20x30".
    Bill Jurasz - Mercury Photography - Cedar Park, TX
    A former sports shooter
    Follow me at: https://www.flickr.com/photos/bjurasz/
    My Etsy store: https://www.etsy.com/shop/mercphoto?ref=hdr_shop_menu
  • MacHeadCaseMacHeadCase Registered Users Posts: 51 Big grins
    edited May 19, 2005
    This thread is a very interesting and an educational read for me! Thank you fellow DGrinners for bringing this up!

    I was wondering (I do realize this is more a question related to software than hardware, though) if there are any differences between sRGB and plain RGB? Is it only because sRGB is an Adobe technology? ne_nau.gif
  • colourboxcolourbox Registered Users Posts: 2,095 Major grins
    edited May 19, 2005
    I was wondering (I do realize this is more a question related to software than hardware, though) if there are any differences between sRGB and plain RGB? Is it only because sRGB is an Adobe technology? ne_nau.gif

    sRGB is not an Adobe technology. It was a color space created by Hewlett-Packard, Microsoft, and others. Adobe RGB is a color space offered by Adobe. It's a different size and shape than sRGB or the others. Neither is better, the question is which is more appropriate for what you do.

    There is no "plain RGB" color space, but sRGB is probably the closest to that. You could use the biggest possible RGB color space, but that would be bad because it would be impossible to display or print all of the colors and hard to edit without losing quality in 8-bit color. You could use the smallest possible RGB color space but then you wouldn't have any colors to work with. So companies offer a range of RGB color spaces that are various compromises between color range and flexibility and being a good match for your output. Some are bigger. Some are smaller. For some, the difference is not size but shape (the colors they cover). Some are a better match for video colors, some are shaped to cover all press colors, some are shaped to contain all colors available on film, etc.

    sRGB is probably the closest thing we have to a "plain RGB." sRGB is the biggest compromise of all, which means sRGB is the best at being "good" but not good at being "excellent." sRGB is what you use when you don't want to have to think about it. That's why HP and Microsoft designed it: so that there would be a "good enough" RGB that everyone could standarize on for consumers, so consumers would not experience color shifts across products.

    sRGB is fine for pros unless you are trying to extend your color range. For example you want to take full advantage of a printer that can print colors well outside sRGB. In that case you shoot and edit in a larger color space like Adobe RGB or ProPhoto RGB, but if you do so you must understand color management and make a few expert workflow adjustments to get the most out of larger color spaces.

    You can Google on "color spaces" for more information; many digital color books also cover the subject.
  • MacHeadCaseMacHeadCase Registered Users Posts: 51 Big grins
    edited May 19, 2005
    Ok thanks for the very informative reply, colourbox. If my pictures are aimed at being printed, like for instance calendars, does the colour space make any type of difference?

    And I will research this on Google to get a better grasp of the whole coulour concept thing, thanks! :D
  • colourboxcolourbox Registered Users Posts: 2,095 Major grins
    edited May 19, 2005
    Ok thanks for the very informative reply, colourbox. If my pictures are aimed at being printed, like for instance calendars, does the colour space make any type of difference?

    My opinion is you are probably fine with sRGB especially if the calendar is going to be quick-printed or color-copied. If you are going for a high-end calendar on nice paper at 150lpi or higher, and your photos were shot RAW or Adobe RGB, then you might benefit from editing in Adobe RGB if your end-to-end workflow is configured for it. In any case, if you are sending it out to be printed you need to talk to your printer and ask them what works well for their shop since each has their own workflow.
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