Announcement

Collapse
No announcement yet.

RAW vs JPG explain it to me one more time

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • RAW vs JPG explain it to me one more time

    So I understand what everyone has said about raw being better. I mean, I understand all of the reasoning behind WHY it is supposed to be better and probably IS better in difficult lighting.
    But I tried it out for the first time today. I set my camera to RAW+ jpg. Honest to goodness, I don't really see a whole lot of difference between the two.
    What am I missing? Here are both images. I did absolutely no editing except for a crop and reduction to put them online.

    Here's the jpg

    november 058 jpg

    Here's the raw

    november 058 raw

    Maybe someone with a better eye for the technical details can pick out the differences but I see very little. I think the RAW image is a little bit lighter and slightly less saturated, but other than that, I see nothing different.

    On another note, aside from the obvious that I need to fix where he scratched his face, how would you edit this photo? What steps would you take in either raw or jpg? Just curious what different answers I might get to that question. I have PSE 8 and LR 3.
    Last edited by NicoleScraps; 11-18-2010, 01:25 AM.
    Flickr Web Facebook Blog

  • #2
    I think where RAW really shines is when you want to make big edits to the image. If you post-process a lot and create a certain style for your images, you may not be able to get that look directly in camera, so giving yourself as much latitude as possible for editing is important.

    If you haven't seen them, check out the two part Jared Polen videos and images from his RAW vs. JPEG week.

    Photography, Digital Camera & Lightroom Tips — FroKnowsPhoto RAW vs JPEG Side by Side Comparison
    My flickr

    Nikon D5000 / Nikon 35mm f/1.8 AF-S lens / Nissin DI-866ii flash

    Comment


    • #3
      The Fro Knows!
      Nikon D7000:18-105mm VR Kit, Nikkor 35-70mm 2.8AF, Nikkor 50mm f/1.8d AF, Sigma 150-500mm f/5-6.3 AF, SB600
      Web Design of Palm Beach
      Photo Blog
      Become a Fan on Facebook

      Comment


      • #4
        Originally posted by NicoleScraps View Post
        So I understand what everyone has said about raw being better. I mean, I understand all of the reasoning behind WHY it is supposed to be better and probably IS better in difficult lighting.
        But I tried it out for the first time today. I set my camera to RAW+ jpg. Honest to goodness, I don't really see a whole lot of difference between the two.
        What am I missing? Here are both images. I did absolutely no editing except for a crop and reduction to put them online.

        Here's the jpg



        Here's the raw



        Maybe someone with a better eye for the technical details can pick out the differences but I see very little. I think the RAW image is a little bit lighter and slightly less saturated, but other than that, I see nothing different.

        On another note, aside from the obvious that I need to fix where he scratched his face, how would you edit this photo? What steps would you take in either raw or jpg? Just curious what different answers I might get to that question. I have PSE 8 and LR 3.
        RAW is nothing but data, or as many refer to it as the digital negative. It is lossless and not compressed, and basically it identifies each pixel and what it's supposed to look like. A RAW file is then compressed in your camera to a JPEG just so you can see it on your little LCD screen. Being that JPEGs are compressed files the camera is making the decision as to what pixels are kept, and which ones are discarded, and ultimately, that is the JPEG you'd wind up with if you were shooting in JPEG mode. It's not uncommon for more than 2/3's of the data to be discarded in this process. That's why shooting RAW with all the data gives you a better chance to recover and broaden the dynamic range of the image. In your example above you have to remember that you cannot see a RAW image as an image (it's data) and when you open that image in your RAW software, and then over to Photoshop you are really seeing the image converted to another industry standard (such as JPEG, TIFF, etc)
        I'm sure most would agree that it's better for you to make those decisions rather than allow the camera to do it for you...it's all about latitude Vs ease
        Vince "...the law of unintended consequences, sometimes, you get a truly memorable photograph"
        Gear: Canon G2, Canon 20D, Nikon D300...bunch of lenses
        My Flickr
        www.montalbanophotography.com

        Comment


        • #5
          Originally posted by autofocus View Post
          RAW is nothing but data, or as many refer to it as the digital negative. It is lossless and not compressed, and basically it identifies each pixel and what it's supposed to look like. A RAW file is then compressed in your camera to a JPEG just so you can see it on your little LCD screen. Being that JPEGs are compressed files the camera is making the decision as to what pixels are kept, and which ones are discarded, and ultimately, that is the JPEG you'd wind up with if you were shooting in JPEG mode. It's not uncommon for more than 2/3's of the data to be discarded in this process. That's why shooting RAW with all the data gives you a better chance to recover and broaden the dynamic range of the image. In your example above you have to remember that you cannot see a RAW image as an image (it's data) and when you open that image in your RAW software, and then over to Photoshop you are really seeing the image converted to another industry standard (such as JPEG, TIFF, etc)
          I'm sure most would agree that it's better for you to make those decisions rather than allow the camera to do it for you...it's all about latitude Vs ease
          JPEG doesn't "throw away pixels", it throws away colour accuracy.

          Both the RAW file and the JPEG have the same pixel count (if not in the same format, i.e. bayer pattern vs simple RGB grid).
          www.nickbedford.com | Fill The Key (blog)

          Comment


          • #6
            Originally posted by nickbedford View Post
            JPEG doesn't "throw away pixels", it throws away colour accuracy.

            Both the RAW file and the JPEG have the same pixel count (if not in the same format, i.e. bayer pattern vs simple RGB grid).
            If JPEG is a compressed file, how can it be the same pixel count as RAW..and why is a RAW file that's ~25MB Vs the same file converted to JPEG now much smaller? Where did they go after the compression algorithm got done with them?..or are those pixels just turned off in the process? And I'm not sure if RAW even has a pixel count, it being only data...is it not just a set of instructions that's used to create the image?
            Vince "...the law of unintended consequences, sometimes, you get a truly memorable photograph"
            Gear: Canon G2, Canon 20D, Nikon D300...bunch of lenses
            My Flickr
            www.montalbanophotography.com

            Comment


            • #7
              Originally posted by nickbedford View Post
              JPEG doesn't "throw away pixels", it throws away colour accuracy.
              Ummm, everything I have ever read on jpeg states that it in fact DOES throw away pixels when its compressing...

              From everybody favorite source Wikipedia
              "The compression method is usually lossy, meaning that some original image information is lost and cannot be restored (possibly affecting image quality.) "

              "JPEG is also different in that it is primarily a lossy method of compression. Most popular image format compression schemes, such as RLE, LZW, or the CCITT standards, are lossless compression methods. That is, they do not discard any data during the encoding process. An image compressed using a lossless method is guaranteed to be identical to the original image when uncompressed.

              Lossy schemes, on the other hand, throw useless data away during encoding. This is, in fact, how lossy schemes manage to obtain superior compression ratios over most lossless schemes. JPEG was designed specifically to discard information that the human eye cannot easily see".
              Camera Stuff....nuff said

              Flickr | Fine Art America | T.A. Wilson Photography

              Comment


              • #8
                Take the same picture and under expose it by 2/3 or 1 stop with an incorrect colour balance then try to fix each. Let me know which one does better.

                Raw gives you extra latitude when you or the camera makes a mistake. It can also allow some effects that are difficult if not impossible with jpg.

                @nickbedford - JPEG doesn't "throw away pixels", it throws away colour accuracy.

                Oh the semantics. Technically you are correct. jpg images have the same number of pixels but jpg does throw away the individual values of many pixels.

                @autofocus - And I'm not sure if RAW even has a pixel count, it being only data...is it not just a set of instructions that's used to create the image?

                Raw does have a pixel count. It is an image on its own and can be viewed in its native format (it looks very green). Each pixel in a raw file is a number (usually 12-14 bits) that corresponds to the amount of light coming through the light filter on each pixel lens. What is interesting is that each pixel in your camera is only one colour. Red, Green or Blue (RGB). There are 2 green pixels for each red or blue. The camera or your Raw software takes the information from each pixel and its neighbouring pixels and estimates the real RGB value of the pixel.

                An uncompressed TIFF file usually has a 24bit number for each pixel which is why it is so large. The most amazing thing is a jpg represents more information than a raw file.

                For more information - http://www.cambridgeincolour.com/tutorials.htm
                Last edited by jml79; 11-18-2010, 03:31 AM.
                Sony A100, Sony 18-70, Minolta 28-105xi, Sigma 70-210 APO. Kata 3N1-20
                Canon Powershot SX20is
                Lots more to buy, no money to spend.

                Comment


                • #9
                  Originally posted by digirebelva View Post
                  Ummm, everything I have ever read on jpeg states that it in fact DOES throw away pixels when its compressing...

                  From everybody favorite source Wikipedia
                  "The compression method is usually lossy, meaning that some original image information is lost and cannot be restored (possibly affecting image quality.) "

                  "JPEG is also different in that it is primarily a lossy method of compression. Most popular image format compression schemes, such as RLE, LZW, or the CCITT standards, are lossless compression methods. That is, they do not discard any data during the encoding process. An image compressed using a lossless method is guaranteed to be identical to the original image when uncompressed.

                  Lossy schemes, on the other hand, throw useless data away during encoding. This is, in fact, how lossy schemes manage to obtain superior compression ratios over most lossless schemes. JPEG was designed specifically to discard information that the human eye cannot easily see".
                  +1 Looks like we're in the same camp on this
                  Vince "...the law of unintended consequences, sometimes, you get a truly memorable photograph"
                  Gear: Canon G2, Canon 20D, Nikon D300...bunch of lenses
                  My Flickr
                  www.montalbanophotography.com

                  Comment


                  • #10
                    Neither of the articles that have been quoted explain exactly what data is discarded, just that some data is thrown away. When JPG compresses a file the data that gets thrown away is colour data. The pixels are still there. Take any raw, convert it to jpg and check the file details. It still has all of it's pixels. They are all there. Just some of the colour data is gone. The part that the human brain won't notice.
                    Sony A100, Sony 18-70, Minolta 28-105xi, Sigma 70-210 APO. Kata 3N1-20
                    Canon Powershot SX20is
                    Lots more to buy, no money to spend.

                    Comment


                    • #11
                      JPEG is an 8-bit format. Each pixel is represented by a series of 8-bits each for the Red, Green, and Blue color channels. 8 bits = 256 variations of color. JPEG also compresses areas of similar color together based on the 8 bit color values.

                      RAW is usually somewhere around 12-14 bit, so each pixel has a finer level of color detail stored. That, combined with the lack of compression explains why RAW files are larger than JPEGs, and why it's preferable to have the full range of color data available when making adjustments.

                      So, JPEG doesn't throw away pixels per se, but between flattening out the colors in each pixel and packing those rounded off pixel values together, the format causes losses in detail and color smoothness.
                      My flickr

                      Nikon D5000 / Nikon 35mm f/1.8 AF-S lens / Nissin DI-866ii flash

                      Comment


                      • #12
                        JPEG is a 24 bit format the way you described. 8 bits X 3 colours = 24 bits of information / pixel. Raw has one colour per pixel but more graduations of that colour by using 12-14 bits. JPEG still manages to 'describe' more information per pixel. The uncompressed equivalent of a JPEG is the insanely huge uncompressed '8 bit' (really 24 bit) TIFF.
                        Sony A100, Sony 18-70, Minolta 28-105xi, Sigma 70-210 APO. Kata 3N1-20
                        Canon Powershot SX20is
                        Lots more to buy, no money to spend.

                        Comment


                        • #13
                          I have saw many threads regarding this subject and the way I have always understood it is to be variable vs linear.

                          Raw being linear every pixel has the full 12/14 bits of colour information untouched its the same for each pixel. Where as Jpeg is 8bit variable it has 8bits of colour information which is calculated from the 12 Raw data but its variable its not the full colour information just bits of it that are calculated using gamma curves. Long story short it keeps colour transitions that you can see and discards the ones you cant.

                          When viewing an image this doesnt matter, when editing on a small scale it doesnt really matter but when editing on a large scale and your pushing colours around where your lost colours information is thats where the gaps are and thats why you get banding. With the RAW you have the extra colour information so you can push and pull the colours a bit more.

                          I could be wrong but it seems its all to do with colours and how much you want to move them around.
                          You cant fool all of the people all of the time, some of the time all of the people will some of time but not all of the time as some of the time all of the people will some of the time but all of the people will not all of the time !!

                          Comment


                          • #14
                            Part 1.

                            Ok, fast and not ideal, since I'm doing this at work on my lunch break. RAW is not about initial image quality--it's about post-processed image quality.

                            Here are two images that I shot with my Powershot S90 with My Colors off. Both are taken in Manual mode of the same scene in the same lighting at pretty much the same time with the same settings (6mm, iso 320, f/2, 1/200s. Handheld). Same resolution (i.e., the JPEG setting was L-fine; largest size, least amount of compression). The only difference is one is shot RAW, the other JPEG. Both shots were deliberately left in Tungsten white balance (this was shot under flourescents) and underexposed.

                            RAW:
                            Name:  592d447a31436416ca3fe5617a0f51fb.jpg
Views: 1
Size:  284.1 KB

                            JPEG:
                            Name:  e3aa8f48392aef275258e21d5c70c56e.jpg
Views: 1
Size:  216.2 KB

                            As you will note, there's not much difference to choose between the two of them (although weirdly, the JPEG seems more underexposed). They look pretty much the same. This is JPEG doing what it does best: coming up with a smaller version of the file that looks pretty much the same.

                            Now, I took both shots into Lightroom and did ONLY two corrections. I white balance corrected by using the whibal in the shot and the eyedropper (to eliminate human guessing), and increased the exposure in both by 1.5 stops. Then everything was exported from LR as JPEGs identically.

                            RAW:
                            Name:  f0b1466b4ab32fb8d3c5d14e3e3866ff.jpg
Views: 1
Size:  390.8 KB

                            JPEG:
                            Name:  c7bc0c8b6b564133307b1aee291e1542.jpg
Views: 1
Size:  311.4 KB

                            This is what we mean by recoverable data and latitude in post-processing. Remember that JPEG uses a "nearest-neighbor" algorithm. Colors that are close together are reduced in number. When you use something like Tungsten white balance that turns everything blue, or underexpose, which turns everything dark... you lose a lot of colors that you wouldn't have if you hadn't turn things bluer or darker.
                            Last edited by inkista; 11-01-2014, 04:23 PM. Reason: fixed attachment doubling from newer attachment feature.
                            I shoot with a Canon 5DmkII, 50D, and S90, and Pansonic GX-7. flickr stream and equipment list

                            Comment


                            • #15
                              Part II.

                              Ok, I hear you say. But I could adjust the JPEG to look more like the RAW. I just need to tweak the saturation and exposure a bit more.

                              Ok. Here's the best I could do by going hogwild with Lightroom sliders (blessed blessed virtual copies).

                              Name:  7cb06c85a305f91012d2bd4ba726d4e7.jpg
Views: 1
Size:  427.8 KB

                              Now, here's the thing about messing about with color data a little too much:

                              100% crops

                              Corrected RAW (which, remember, still only needed those two corrections):
                              Name:  49f3dea0dfed3b57e546ba4f7a2c824a.jpg
Views: 1
Size:  94.5 KB

                              Corrected JPEG
                              Name:  3787584e2fd0a77850c30419c6d6b07b.jpg
Views: 1
Size:  57.2 KB

                              Tweaked JPEG above:
                              Name:  d0d3468dd06ba561a9726d3a6366c618.jpg
Views: 1
Size:  75.6 KB

                              Note the funky reddish stuff in the blue binder area and the yellowish stuff on the red dictionary spine. It's actually starting there in the corrected JPEG, but since the colors are closer matches, it's not until I tweak that it starts to stand out. That's where the tungsten setting smashed together a bunch of colors that actually had more gradation, and data was discarded. Now, with all the tweaking, the JPEG compression artifacts have shifted color enough to appear, looking very much like color noise...
                              Last edited by inkista; 11-01-2014, 04:25 PM. Reason: fixed attachment doubling when attachment preview changed.
                              I shoot with a Canon 5DmkII, 50D, and S90, and Pansonic GX-7. flickr stream and equipment list

                              Comment

                              Working...
                              X