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I very well know jpegs are harmed by opening and saving them again. But some here are, or have in the past, only shot jpegs. When you keyword a JPEG, you are doing it without opening the jpegs. Yet the keywords have to be saved. Does saving the keywords on a JPEG hurt the image?

I'm thinking not, or so many people wouldn't have done it.

I keyword my Tiffs, then save the Tiff to jpegs, then toss the Tiff. But I sometimes remember some keywords I want to add to the JPEGs. Is that ok? No foul?

 

I've wanted this question answered forEVER. :)

Betty

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In LR or PS? No. Back in the days when it didn't know whether a camera was portrait or landscape, Windows used to resave a jpeg if you even rotated it, but I assume it's no longer relevant.

Anyway years ago I did 10 resaves and couldn't see degradation, but that was a compact at 6MP.

Edited by spacecadet
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It depends on the software. I believe Photo Mechanic will allow you to keyword without actually opening the file. Lightroom adds the keywords to the catalog and only seems to put them in the file when you export. If you open a jpg in Photoshop to add keywords then you risk degrading it when you save.

It's generally considered better to use "Save As" in PhotoShop whenever you save a jpg since you're not further compressing an already-compressed file.

 

fD

Edited by fotoDogue
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It's generally considered better to use "Save As" in PhotoShop whenever you save a jpg since you're not further compressing an already-compressed file.

 

fD

 

I don't get the logic of this as you are compressing the jpeg file whether you save or save as a jpeg file. There is no difference in fact.

 

I'm not sure of the answer to Betty's question. I recall reading somewhere that adding medadata in Bridge doesn't have any impact on quality as it doesn't affect the image data but I can't remember where I read this. Even if it did affect the image, it is unlikely that it would be noticeable unless saved multiple times. I must say though I don't understand throwing away TIFFs (or PSDs) after doing a lot of Photoshop work which I know Betty does. Storage is so so cheap nowadays.

Edited by MDM
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It's generally considered better to use "Save As" in PhotoShop whenever you save a jpg since you're not further compressing an already-compressed file.

 

fD

 

I don't get the logic of this as you are compressing the jpeg file whether you save or save as a jpeg file. There is no difference in fact.

 

I'm not sure of the answer to Betty's question. I recall reading somewhere that adding medadata in Bridge doesn't have any impact on quality as it doesn't affect the image data but I can't remember where I read this. Even if it did affect the image, it is unlikely that it would be noticeable unless saved multiple times. I must say though I don't understand throwing away TIFFs (or PSDs) after doing a lot of Photoshop work which I know Betty does. Storage is so so cheap nowadays.

 

Here's one reference though I'm sure if I continued to search I'd find more. According to Petapixel, "Every time you save those JPEG photographs, you lose a little piece of awesomeness."

 

http://petapixel.com/2010/02/04/saving-jpeg-photos-hundreds-of-times/

Edited by fotoDogue
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I often need to work on old JPEG's.  If I am going to do much I open it and then save it

as a TIFF until I do what I need to do.  Not a perfect solution but when working on an old

JPEG it is the best way from what I have tried.

 

Chuck

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It's generally considered better to use "Save As" in PhotoShop whenever you save a jpg since you're not further compressing an already-compressed file.

 

fD

 

I don't get the logic of this as you are compressing the jpeg file whether you save or save as a jpeg file. There is no difference in fact.

 

I'm not sure of the answer to Betty's question. I recall reading somewhere that adding medadata in Bridge doesn't have any impact on quality as it doesn't affect the image data but I can't remember where I read this. Even if it did affect the image, it is unlikely that it would be noticeable unless saved multiple times. I must say though I don't understand throwing away TIFFs (or PSDs) after doing a lot of Photoshop work which I know Betty does. Storage is so so cheap nowadays.

 

Here's one reference though I'm sure if I continued to search I'd find more. According to Petapixel, "Every time you save those JPEG photographs, you lose a little piece of awesomeness."

 

http://petapixel.com/2010/02/04/saving-jpeg-photos-hundreds-of-times/

 

 

I agree but I was just saying that it would probably take a lot of saves before degradation would be noticeable - it would depend on the image no doubt.

 

What I was disagreeing with is that I can't see how there could be any difference in how you save an existing jpeg file in PS: save or save as should give exactly the same result - easy to check by looking at the file size - too late for me to do this now - way past my bedtime.

Edited by MDM
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I often need to work on old JPEG's.  If I am going to do much I open it and then save it

as a TIFF until I do what I need to do.  Not a perfect solution but when working on an old

JPEG it is the best way from what I have tried.

 

Chuck

 True and surely the best way to work on JPEGS. However, I often have adjustment layers and maybe alpha channels in my images so I save everything as PSD (better than TIFF for Photoshop users). I only use JPEGS for sending out.

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I often need to work on old JPEG's.  If I am going to do much I open it and then save it

as a TIFF until I do what I need to do.  Not a perfect solution but when working on an old

JPEG it is the best way from what I have tried.

 

Chuck

 True and surely the best way to work on JPEGS. However, I often have adjustment layers and maybe alpha channels in my images so I save everything as PSD (better than TIFF for Photoshop users). I only use JPEGS for sending out.

 

 

 

Hi MDM

 

Are you up yet?  Hope you had a good night sleep.

 

I also only use JPEGs for sending out.  If you don't mind, can you elaborate a bit about PSD is better than TIFF for Photoshop users?  I have mixture of both formats and often wonder which one would be a better option.  I read somewhere, which I don't remember where, saying that, for 100% future proof, TIFF's better as it also supports layers, alpha channels, etc...

 

Sung

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Hi Sung - Yes and no. Staying up late and family getting up early don't make for good night's sleep but it's a beautiful day through the brain fog :).

 

TIFFs are going to be more future proof in that they can be opened by a vast range of different programs although I don't know how alpha channels and layers would hold up in general. But if you never intend to not have Photoshop which I don't (in other words, life without Photoshop for me is unimaginable), then I think PSDs are way better. I've had Photoshop since the mid-90s, I own CS6 and I now have a subscription to CC as well so no intention of not having it for the foreseeable future. If I did, I'd probably export my entire PSD archive as TIFF as well as JPEG.

 

Why PSDS? This is a personal finding but I find that PSDs are much more efficient in terms of speed of workflow than TIFFs when working in Photoshop if there are layers, presumably because they are tailor made for the job. TIFFs are unwieldy, taking longer to open and save, even more so in 16-bit. TIFFs are also larger on disk although not by a lot. Try it with 16-bit files and a few adjustment layers and I expect you will find similar. Also, and this comes from a discussion here a while back with the venerable David K, TIFFs can be more prone to corruption. This was according to David and I can't remember the reason.

 

 

Edited by MDM
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I do my keywording in Bridge, always. Work in LRCC, open into PSCC, tweak further. Save as 8 bit Tiff, then keyword the TIFF. In Bridge, you don't have to open the file to keyword it.

All I'm asking is that since I've added a keyword or two (I sometimes forget to add copyspace) and, I'm not opening the JPEG to add a keyword, does simply saving the keywords act upon the JPEG as if I had opened and resaved the JPEG.

 

I could wait to add keywords until I'm prepping the image after going through QC, but I might forget...you know the memory is the first thing to go. ;)

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Hi Sung - Yes and no. Staying up late and family getting up early don't make for good night's sleep but it's a beautiful day through the brain fog :).

 

TIFFs are going to be more future proof in that they can be opened by a vast range of different programs although I don't know how alpha channels and layers would hold up in general. But if you never intend to not have Photoshop which I don't (in other words, life without Photoshop for me is unimaginable), then I think PSDs are way better. I've had Photoshop since the mid-90s, I own CS6 and I now have a subscription to CC as well so no intention of not having it for the foreseeable future. If I did, I'd probably export my entire PSD archive as TIFF as well as JPEG.

 

Why PSDS? This is a personal finding but I find that PSDs are much more efficient in terms of speed of workflow than TIFFs when working in Photoshop if there are layers, presumably because they are tailor made for the job. TIFFs are unwieldy, taking longer to open and save, even more so in 16-bit. TIFFs are also larger on disk although not by a lot. Try it with 16-bit files and a few adjustment layers and I expect you will find similar. Also, and this comes from a discussion here a while back with the venerable David K, TIFFs can be more prone to corruption. This was according to David and I can't remember the reason.

 

 

 

 

Thank you for sharing your knowledge.

 

I have a lot of TIFF as well as PSD images both with layers.  I suppose I could create both versions for all of them for archival purposes.  :)

 

I only produce TIFF/PSD files for my best images, mainly for printing.  The majority of them are in DNG.

 

Sorry, Betty.  I didn't mean to hijack your topic.

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In Windows, if you want to add the keywords after you have saved your jpg, or are working on a OOC jpg, then you can simply go to the image in Windows Explorer, right click, click properties and add the keywords in the tags section then hit Okay. This certainly adds the keywords without resaving the jpg.

 

Jill

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I agree but I was just saying that it would probably take a lot of saves before degradation would be noticeable - it would depend on the image no doubt.

 

 

 

 

A number of years ago while attending a PPA (Prof Photogs of America) conference and juried print competition this topic was discussed.  Tests had been conducted on visible print quality degradation after multiple saves of JPG image files.  The conclusion was that noticeable visible print quality degradation didn't appear until after about 5-6 saves.

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I agree but I was just saying that it would probably take a lot of saves before degradation would be noticeable - it would depend on the image no doubt.

 

 

A number of years ago while attending a PPA (Prof Photogs of America) conference and juried print competition this topic was discussed.  Tests had been conducted on visible print quality degradation after multiple saves of JPG image files.  The conclusion was that noticeable visible print quality degradation didn't appear until after about 5-6 saves.

That's good to know. I seldom add keywords, but usually one or two, or a set out of 100.

Jill, I always forget to say I'm on a Mac.

Windows Explorer? I'm brushing the cobwebs away in my brain trying to remember that. ;)

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I agree but I was just saying that it would probably take a lot of saves before degradation would be noticeable - it would depend on the image no doubt.

 

 

 

 

A number of years ago while attending a PPA (Prof Photogs of America) conference and juried print competition this topic was discussed.  Tests had been conducted on visible print quality degradation after multiple saves of JPG image files.  The conclusion was that noticeable visible print quality degradation didn't appear until after about 5-6 saves.

 

 

Betty - you have marked this as best answer but this is not the answer to the question you asked. This relates to the question of how many saves does it take to cause noticeable image degradation. That is opening and saving an image, not adding metadata without opening the image in an editor. And there were several mentions of this before Phil's contribution.

 

What you actually asked was "When you keyword a JPEG, you are doing it without opening the jpegs. Yet the keywords have to be saved. Does saving the keywords on a JPEG hurt the image?" In fact from searching various forums, it seems that the general consensus is that modifying the metadata does not necessarily cause any degradation of the actual image but it depends on the software used (as fotodogue said in her first post). Some knowledgeable people say that this is because the metadata is contained in a separate area of the file and there is no effect on the image (again depending on the software). But I can't find a definitive official answer from Adobe. I'd love to see the official answer - I'm sure I did see it once but can't find it again. It's a bit like my eternal question of how cameras physically measure white balance. Nobody who knows seems to want to say.

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I agree but I was just saying that it would probably take a lot of saves before degradation would be noticeable - it would depend on the image no doubt.

 

 

A number of years ago while attending a PPA (Prof Photogs of America) conference and juried print competition this topic was discussed.  Tests had been conducted on visible print quality degradation after multiple saves of JPG image files.  The conclusion was that noticeable visible print quality degradation didn't appear until after about 5-6 saves.

 

Betty - you have marked this as best answer but this is not the answer to the question you asked. This relates to the question of how many saves does it take to cause noticeable image degradation. That is opening and saving an image, not adding metadata without opening the image in an editor. And there were several mentions of this before Phil's contribution.

 

What you actually asked was "When you keyword a JPEG, you are doing it without opening the jpegs. Yet the keywords have to be saved. Does saving the keywords on a JPEG hurt the image?" In fact from searching various forums, it seems that the general consensus is that modifying the metadata does not necessarily cause any degradation of the actual image but it depends on the software used (as fotodogue said in her first post). Some knowledgeable people say that this is because the metadata is contained in a separate area of the file and there is no effect on the image (again depending on the software). But I can't find a definitive official answer from Adobe. I'd love to see the official answer - I'm sure I did see it once but can't find it again. It's a bit like my eternal question of how cameras physically measure white balance. Nobody who knows seems to want to say.

I stand corrected. I based it on if you can open and save a JPEG 5 or six times before seeing degradation, then surely adding keywords, which might or might not count as an open/save surely will not see perceptible degradation. That's good enough for me.

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