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<p>[QUOTE="jtlee321, post: 5209475, member: 73983"]Hey Ray,</p><p><br /></p><p>So I will tell you why I shoot in RAW as opposed to JPEG. The difference between the two is the inherent information retained in the files. To keep it photography related, think of JPEG files as Chromes or slides. Slides are very unforgiving in terms of expose and white balance/color.. Slide film was designed for people who are a little more advanced and know how to capture a proper exposure and apply the proper filters to their lens to compensate for warm or cool light.</p><p><br /></p><p>Raw files are the equivalent of shooting on color negative film. The exposure range that negative film can capture versus slide film is quite substantial. If you overexpose by a stop or two, you can usually bring back quite a bit of information. Color balance can be corrected a lot easier during the print making process. It's why Ansel Adams shot on film rather than slides. He knew that when it was time to make the final print, he had a lot of head room to work with in terms of adjusting exposure. Obviously he was a competent photographer and could achieve a perfect exposure and shoot on slides, but he chose to shoot on film to allow for his creative vision.</p><p><br /></p><p>Here is the technical breakdown of a JPEG vs. RAW. A JPEG is an 8 bit representation of a scene. 8 bits of information are assigned to each of the RGB channels. That equates out to a total of 256 steps of white to black for each color channel. So 256 x 256 x 256 = ~ 16.78 million colors, which is enough for most applications. A RAW file is typically captured in 12 or 14 bit, depending on your camera. Mine gives me the option to shoot either 12 bit or 14 bit. Most people might think, well thats only a difference of 4 or 6 bits, how can it be that much better? In the world of digital information, for each increase in bit size, you double the amount of information. So an 8 bit file is 256 levels per color channel, a 9 bit file would be 512, 10 bits 1,024 and so on... So when you have 14 bits to work with, such as on most Nikon's, that gives you 65,536 steps per color channel for a possible ~ 281.47 trillion colors. That might seem overkill, but as soon as you start editing a file, you start hitting color pallet/space limitations. They start to present themselves as banding in areas of very small color differences, such as sky's or walls or the fields of a coin.</p><p><br /></p><p>The bits of a digital file are not distributed evenly from highlights to shadows. Nearly half of a RAW files bits are assigned to the highlights side of the histogram, then another half of the remaining bits are assigned to the upper mid-tones. Another half of the remaining bits are assigned to the lower mid-tones and the remainder assigned to the shadow end of the histogram. So approximately 7 bits of information are assigned to the brightest 25% of the image, 3.5 bits are assigned to the upper mid-tones, 1.75 bits to the lower mid-tones and the remaining 1.75 bits to the shadows. This is why when you try to brighten up an underexposed image, the shadow areas and lower mid-tones tend to develop a lot of noise. Overexposed images can have the highlights recovered much easier.</p><p><br /></p><p>Here are some example files.</p><p><br /></p><p>Here is an image saved as a JPEG originating from a RAW file as shot from the camera.</p><p>[ATTACH=full]1215433[/ATTACH]</p><p><br /></p><p>Here is another JPEG file from the same RAW file just with the exposure slider in Camera RAW adjusting down 2 stops.</p><p><br /></p><p>[ATTACH=full]1215436[/ATTACH]</p><p><br /></p><p>Here are 100% crops of the two images above.</p><p><br /></p><p>[ATTACH=full]1215435[/ATTACH] [ATTACH=full]1215434[/ATTACH]</p><p><br /></p><p>Now had I captured the first image as a JPEG, I would not be able to recover the highlights like I was able to do with the RAW file. My tethering software was showing me an improper representation of the exposure. So I actually shot the image about .75 - 1 full stop hotter than I would normally like. But the RAW format allowed me to correct in the RAW processing without having to reshoot.</p><p><br /></p><p>Now had I captured the image that we see in image number 2 and try to increase exposure, then noise would be introduced into the shadows and lower mid-tones.</p><p><br /></p><p>Another benefit of shooting RAW is white balance. A JPEG has the white balance you chose in camera to be burned into the image data. You can adjust for it later, but you will pay a price in image degradation. A RAW file is just that, the RAW information that the camera sensor recorded. A header is added to the file to show a preview of the image with the camera settings you chose, white balance, sharpness, tone curve, color space and so on... All of those instructions can be changed with no consequence to the image quality prior to conversion from the RAW data. So if you needed to make a change to a different white balance or process the image in a different color space those can be assigned and changed without harm. Then the image can be opened into an image editing program into a 16 bit environment. Further image editing can be done, with minimal image degradation.</p><p><br /></p><p>I hope this helps. If not, feel free to contact me and I could go deeper into with you, or anyone else.[/QUOTE]</p><p><br /></p>
[QUOTE="jtlee321, post: 5209475, member: 73983"]Hey Ray, So I will tell you why I shoot in RAW as opposed to JPEG. The difference between the two is the inherent information retained in the files. To keep it photography related, think of JPEG files as Chromes or slides. Slides are very unforgiving in terms of expose and white balance/color.. Slide film was designed for people who are a little more advanced and know how to capture a proper exposure and apply the proper filters to their lens to compensate for warm or cool light. Raw files are the equivalent of shooting on color negative film. The exposure range that negative film can capture versus slide film is quite substantial. If you overexpose by a stop or two, you can usually bring back quite a bit of information. Color balance can be corrected a lot easier during the print making process. It's why Ansel Adams shot on film rather than slides. He knew that when it was time to make the final print, he had a lot of head room to work with in terms of adjusting exposure. Obviously he was a competent photographer and could achieve a perfect exposure and shoot on slides, but he chose to shoot on film to allow for his creative vision. Here is the technical breakdown of a JPEG vs. RAW. A JPEG is an 8 bit representation of a scene. 8 bits of information are assigned to each of the RGB channels. That equates out to a total of 256 steps of white to black for each color channel. So 256 x 256 x 256 = ~ 16.78 million colors, which is enough for most applications. A RAW file is typically captured in 12 or 14 bit, depending on your camera. Mine gives me the option to shoot either 12 bit or 14 bit. Most people might think, well thats only a difference of 4 or 6 bits, how can it be that much better? In the world of digital information, for each increase in bit size, you double the amount of information. So an 8 bit file is 256 levels per color channel, a 9 bit file would be 512, 10 bits 1,024 and so on... So when you have 14 bits to work with, such as on most Nikon's, that gives you 65,536 steps per color channel for a possible ~ 281.47 trillion colors. That might seem overkill, but as soon as you start editing a file, you start hitting color pallet/space limitations. They start to present themselves as banding in areas of very small color differences, such as sky's or walls or the fields of a coin. The bits of a digital file are not distributed evenly from highlights to shadows. Nearly half of a RAW files bits are assigned to the highlights side of the histogram, then another half of the remaining bits are assigned to the upper mid-tones. Another half of the remaining bits are assigned to the lower mid-tones and the remainder assigned to the shadow end of the histogram. So approximately 7 bits of information are assigned to the brightest 25% of the image, 3.5 bits are assigned to the upper mid-tones, 1.75 bits to the lower mid-tones and the remaining 1.75 bits to the shadows. This is why when you try to brighten up an underexposed image, the shadow areas and lower mid-tones tend to develop a lot of noise. Overexposed images can have the highlights recovered much easier. Here are some example files. Here is an image saved as a JPEG originating from a RAW file as shot from the camera. [ATTACH=full]1215433[/ATTACH] Here is another JPEG file from the same RAW file just with the exposure slider in Camera RAW adjusting down 2 stops. [ATTACH=full]1215436[/ATTACH] Here are 100% crops of the two images above. [ATTACH=full]1215435[/ATTACH] [ATTACH=full]1215434[/ATTACH] Now had I captured the first image as a JPEG, I would not be able to recover the highlights like I was able to do with the RAW file. My tethering software was showing me an improper representation of the exposure. So I actually shot the image about .75 - 1 full stop hotter than I would normally like. But the RAW format allowed me to correct in the RAW processing without having to reshoot. Now had I captured the image that we see in image number 2 and try to increase exposure, then noise would be introduced into the shadows and lower mid-tones. Another benefit of shooting RAW is white balance. A JPEG has the white balance you chose in camera to be burned into the image data. You can adjust for it later, but you will pay a price in image degradation. A RAW file is just that, the RAW information that the camera sensor recorded. A header is added to the file to show a preview of the image with the camera settings you chose, white balance, sharpness, tone curve, color space and so on... All of those instructions can be changed with no consequence to the image quality prior to conversion from the RAW data. So if you needed to make a change to a different white balance or process the image in a different color space those can be assigned and changed without harm. Then the image can be opened into an image editing program into a 16 bit environment. Further image editing can be done, with minimal image degradation. I hope this helps. If not, feel free to contact me and I could go deeper into with you, or anyone else.[/QUOTE]
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