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Old Jun 18, 2005, 12:31 AM   #1
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i understand the difference between to two... lossy vs not etc... i have a 512 card (sony f 828 8mp) and get 130 jpegs on a card. (cf scandisk ultra II) When I get a picture that I find is great quality, I automatically convert it to a tiff, to prevent any further loss. as a jpeg, the size is usually 3.5mb. as a tiff they become 22.8.mb When I shoot in tiff, the file size is still 22.8.


style="BACKGROUND-COLOR: #000000"My question here is isn't file size a measure of quality?if we loose quality as soon as we shoot jpeg, even in its highest format (fine/large) the converted tiff, is the same size as the original tiff, which would mean that we really didn't loose any on the original jpeg shoot??? did i confuseanyone here???

thanks for clearing it up for me!!!
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Old Jun 18, 2005, 1:08 AM   #2
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Hi Dashboardgyno: With both the initial JPEG at highest quality and TIFF, the difference is mainly how the image will change when you edit and save.

"...When editing an image in several sessions, it is recommended to save the intermediate image in an uncompressed format such as TIFF or the editing program's native format . If you save for instance an image in JPEG, close it, open it again and save it again in JPEG with the same quality setting, the file size will not reduce further, but quality will have degraded further. So only compress after all editing is done.
[*]
[/*][align=justify]Cameras usually have different JPEG quality settings, such as FINE, NORMAL, BASIC, etc. Unless you shoot in RAW or TIFF, it is recommended to shoot in the hightest available JPEG quality setting. Note however that some cameras will compress more than others, even at their highest JPEG quality setting."[/align]
[align=justify]http://www.dpreview.com/learn/?/Glos...ng/JPEG_01.htm[/align]
[align=justify]http://www.dpreview.com/learn/?/Glos...ng/TIFF_01.htm[/align]
[align=justify][/align]
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Old Jun 18, 2005, 3:35 AM   #3
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With JPEG, file size is a measure of the amount of detail in the image, as well as quality. With TIFF, the file size is nearly the same for the same image size (in pixels), regardless of detail. (using uncompressed tiff)

style="BACKGROUND-COLOR: #000000"To demonstrate to yourself the difference, take a shot of a solid colored, flat surface using JPEG and compare it to one with a lot of detail. Thre will be a vast difference in file size. Converting both these pictures to TIFF, or shooting in TIFF format, will give the same file size.

style="BACKGROUND-COLOR: #000000"If you are concerned about getting the best image quality, shoot RAW, if possible, or TIFF, and get more memory if you need it.

style="BACKGROUND-COLOR: #000000"brian
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