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Old Jan 7, 2011, 6:39 PM   #1
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Default Questions about image formats and adjustments

When shooting images in RAW format, if image adjustments are made what format are you saving the finished image? What format do you save images to be printed? If I were to print a 5x7 how should I scale the image to keep from impacting the image quality.

Also, images saved as jpeg by the camera, I'm assuming these are compressed. If the image is rotated (portrait to landscape) in Photoshop does this further compress the image when saved? Generally will this greatly affect the image quality?
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Old Jan 7, 2011, 8:56 PM   #2
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Every time you save a JPEG image, it's recompressed. Many image editting programs have their own uncompressed image file formats so you can edit an image through multiple sessions without losing anything, and when you're done, you can save it as a JPEG. For instance, Photoshop, et al, allow you to use PSD files to store images without compressing them.

When you're working with an image, never save it overtop of the only original image file you've got. If it's RAW, you edit it and save it, you lose the original. If it's JPEG, you edit it and save it, you lose the original, and you compress it again so even the parts you didn't edit won't contain as much detail.

If you want the best quality printed images, don't scale them yourself. Let the printer driver do all the downsampling for you.
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Old Jan 8, 2011, 11:40 AM   #3
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Quote:
Originally Posted by TCav View Post
Every time you save a JPEG image, it's recompressed. ...
True, though it is an overstated problem. Try a repeated load-save-reload-save-reload- several tens of times then use your photo editor to subtract that from the original. Unless it is and extremely detailed and high contrast image, you won't see much difference.
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When you're working with an image, never save it overtop of the only original image file you've got. ...
Absolutely correct. And that is another reason you don't have to worry much about repeated JPEG saves. If you do a large enough number of them to make a difference, likely you would do well to start over from the original -some of those edits would probably be attempts to undo previous edits..
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Old Jan 8, 2011, 11:45 AM   #4
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An article on the subject by Mike Chaney:

JPEG Images - Counting your Losses
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Old Jan 8, 2011, 12:35 PM   #5
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Originally Posted by HDon View Post
Also, images saved as jpeg by the camera, I'm assuming these are compressed. If the image is rotated (portrait to landscape) in Photoshop does this further compress the image when saved? Generally will this greatly affect the image quality?
I'm too lazy to pull out my JPEG standards volumes on my day off, but my recollection is that orientation is one of the JPEG stream attributes separate from the image data itself. If that memory is correct, there would be no need to recompress the image data just to change the orientation. The main thing that I am not sure about is whther this is a property of the JPEG attributes or of JFIF -- JPEG is not a file format at all. It is a stream format. The usual way of writing a JPEG stream to disk is to use the "JPEG File Interchange Format" standard (not part of JPEG.) The JFIF standard may contain the attribute display orientation. I just don't recall. Either way, there would be no need to recompress the image data.

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Old Jan 8, 2011, 4:45 PM   #6
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JimC's link is good. This one relates printing to viewing distance:

http://www.northlight-images.co.uk/a...-Printer-51540

For 5x7 prints, it doesn't matter if you go TIFF or JPG.
Just in case, go TIFF.
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Old Jan 8, 2011, 7:19 PM   #7
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Without jumping into details as most of them have been covered I never shoot jpeg and never save an original as jpeg. I do eventually save as jpeg 12 after all editing is done and its the final output but keep the original RAW file.
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Old Jan 8, 2011, 9:02 PM   #8
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Thank you all for the info.

I've been shooting images and having the camera save them as both JPEG and RAW. I'm using the JEPGs as an index, as there is no thumbnail on the RAW images (and no way to preview), and its easier to quickly review the JPEGS to see which image I'm looking for and also to get an idea of what sort of adjustments (lighting, etc) I might need to make. I then use the tools in RAW to adjust, when finished open the adjusted image to PSE9, and "save as" renaming it and saving as a jpeg. Its eating up a lot of space, but I didn't really know what else to do. The majority of shots are portrait, and need flipped to landscape. I wasn't sure how much this was changing the image.
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Old Jan 9, 2011, 9:06 AM   #9
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Quote:
Originally Posted by HDon View Post
I've been shooting images and having the camera save them as both JPEG and RAW. I'm using the JEPGs as an index, as there is no thumbnail on the RAW images (and no way to preview), and its easier to quickly review the JPEGS to see which image I'm looking for and also to get an idea of what sort of adjustments (lighting, etc) I might need to make.
Using what software?

You're using a Sony A500, right?

There are many programs that can show you the embedded jpeg thumbnails and/or build previews for you.

Adobe Lightroom 3 handles them fine. Ditto for the free Google Picasa, the free Faststone Image Viewer (great free app for browsing images), Sony's Image Data Lightbox SR, Bibble Pro and a number of other programs.

What programs are not showing you previews of your raw files?

If you're trying to use Windows Explorer to browse images (or an application that uses Windows Explorer for browsing files) and see the thumbnails, then raw codecs are needed.

What Operating System are you using?

You can get the free Sony raw codec for both 32 bit and 64 bit versions of Windows Vista and Windows 7 here (which will allow WIC compatible applications like Windows Explorer to decode your raw images, so that you can see thumbnails when browsing folders). Here's a download link to the Sony codecs:

http://support.sony-europe.com/dime/...vr&m=DSLR-A500

If you're not using the latest 3.2 version of Sony's Image Data Suite software (Lightbox, etc.), I'd install it, too. You'll find it in the downloads section here:

http://support.sony-europe.com/dime/...GB&m=DSLR-A500

Or, see this "Sticky" thread for direct download links and comments about it's improvements:

http://forums.steves-digicams.com/so...-sr-3-2-a.html

If you're using XP, then you'll need to have SP3 installed to get WIC (Windows Imaging Component) features that allow the use of codecs to display raw files in WIC compatible applications like Windows Explorer. I think you can get WIC as a separate download for XP SP1 or SP2. But, I'd suggest just installing the latest Service Pack (3) for XP, since it already includes WIC. More about WIC here:

http://en.wikipedia.org/wiki/Windows_Imaging_Component

Then, try this 3rd party codec solution for $14.99 (I don't think Sony offers a raw codec for XP that supports newer cameras). BTW, if you can spare the $14.99, I'd suggest using this codec instead of the Sony codec, regardless of the Windows version you're using. It's what I use to browse raw files in Windows Explorer under 64 bit Win 7 when I use it (but, most image viewers have better browsing features anyway, so being able to see thumbnails of raw files in Windows Explorer is not really a "must have" feature from my perspective).

http://www.fastpictureviewer.com/codecs/
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Old Jan 9, 2011, 9:38 AM   #10
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BTW, if you dig around with Google, some sites still have the older versions of the FastPictureViewer Codec Pack online, which was "donationware" at one time (free to download, with the author asking only for a donation). Here's one example:

http://www.pcworld.com/downloads/fil..*****iption.html

But, Axel (the program author) discontinued the free versions later, since he saw loads of downloads with very few people making donations for his efforts. See more about that here:

http://www.fastpictureviewer.com/codecs/#freeversion

If you decide to use them, I'd make a donation to the author. Or, better yet, purchase the new version for $14.99. ;-)

Again, if you're using Vista or Win 7, Sony offers free codecs you can use with both 32 bit and 64 bit versions (see link in my previous post). But, the FastPicturerViewer codec pack is a better bet (fast, more features, more supported cameras without needing to install separate codecs for each manufacturer's raw files you want to see from within WIC compatible applications).
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