shot as Jpeg, saved as PSD..still lossy?

[dijitul+philm]

My understanding of a Jpeg file is that, all other plusses and minuses vs. RAW aside, one of the very negative characteristics of a Jpeg is that more data is lost every succeeding time that the file is opened and then saved. If a shot is taken as a Jpeg and then saved in Photoshop as a PSD or TIFF file, is it no longer a 'lossy' file - that is will it no longer lose data when opened and saved unless intentionally compressed? One of the main reasons I shoot RAW is to avoid a "lossy' file.

[cmar]

you are correct.
every time you save as a jpg, you loose data and quality.
If you save as a PSD or TIFF you do not loose anything.
If you shoot jpg, it is a good idea to save it as a tiff the first time you open and save it, unless it is somthing you do not plan of keeping or modifying ever again.

[kb244]

Think of it as this simple Equation

"Garbage in Garbage Out" in otherwords if it was lossy/crappy/etc to start with theres nothing you can do to regain the quality.

[cmar]

Think of it as this simple Equation

"Garbage in Garbage Out" in otherwords if it was lossy/crappy/etc to start with theres nothing you can do to regain the quality.

I think what dijitul+philm was getting at is more like

saving jpeg multiple times.
garbage+garbage+garbage=garbage

saving jpeg when shooting, then converting to better format
garbage+exellent+exellent=goodstuff

[scottbergerphoto]

The above posts are a little inaccurate. You don't lose data each time you open and close a jpeg. You lose data each time you open, edit and resave a jpeg. If you shoot jpeg, you should resave them as tiff files to avoid that.

[Bodog]

I think what Karl was emphasizing is that any data lost from the original .jpg is gone forever and will not be regained by later saving as a .Tiff or .Psd file.

[kb244]

What bodog says, and cmar, you cant do garbage+execelent, the results gona be no better than the original save.

[Avalonthas]

IF you got a descent camera (5MP and above) then always go with RAW. Its the best choice.

[dijitul+philm]

This is what I like about this forum - the scope expands interestingly from the original question or observation, in this case mine, to often include a large amount of input directly as well as indirectly-related to that topic. I do mainly shoot RAW but my S70 also enables a fairly high quality JPeg (for a Jpeg!) and so before I start doing very many JPeg's in certain limited situations, I wanted clarification as to whether "lossy" becomes "non-lossy" when converting a shot-as-JPeg into a TIFF or PSD, etc. - and it seems it does indeed. As mentioned by one or two threaders, I'm not interested in turning garbage into beautiful by so-doing; I'm just making sure that if I edit a keepable JPeg into a fairly decent shot that it won't gradually turn into a crappier and crappier shot as a lossy file if I edit or even simply re-save it numerous times. Becoming non-lossy is cool! Right?

[kb244]

Pretty much the concept is true, Jpegs saved as non-lossy tiffs will not be lossy, its just however having oringinally been saved as a lossy file, the destination will become larger because it'll take in account all the smushed pixels from the previous lossyness. Though only reason I can see saving it in a loss-less format is if you did some touch ups you wanted to preserve.

[dijitul+philm]

The clarification I was seeking when I opened this thread was answered - and that is that a lossy(JPEG) can indeed be converted into a lossless(TIFF,PSD) file. Moderator Scott mentioned that re-opening and then re-saving JPEGs only results in additional lost data if the file is edited when re-opened. But editing virtually always results in a degree of lost data doesn't it? I forget where I read that simply the process of opening and then re-saving a JPEG will lose some data even if no editing is done (as in opening it just to print or e-mail) and that was my reason for initiating - I think most people who use editing software have had files that they opened numerous times. If converting to TIFF or PSD didn't terminate the original lossy aspect of the file, then there would be even fewer times when one would want to shoot JPEG as opposed to RAW. That being said, I think that it is maybe becoming a bit overly fashionable to shoot strictly in RAW. My S70 shoots 7.1MP JPEGs in addition to RAW and, in certain lighting conditions, I feel the camera's own editing if carefully programmed gets excellent results. When I went to Paris and Venice last year I shot 47 36exp rolls of film. As you can likely guess by the rambling nature of this post, I often have enough free time on my hands for editing RAW files - but if just 20% are keepers, that would have been 300 images to edit - and a lot of CF gigs or uploading gear. Does a JPEG in the right situation screw up all that many more pixels than in RAW-editing? I vote for MOSTLY-RAW but if JPEGs become lossless, I think they're being increasingly under-appreciated considering the features and capabilities of many cameras now. I need a drink of water. Happy pixing!

[Bodog]

Hi, Dijitul. Just to expand a little further... :D You mentioned that just opening the file to print or send e-mail will result in data loss to the .jpg file. That is not true. It is SAVING the file that results in loss. Example: Open the file in Photoshop, set some print paramenters, print the file, then close Photoshop without saving would result in no additional loss. But, open the file in Photoshop, make no changes, then select FILE > SAVE and then saving it WOULD result in additional loss. Everytime the file is SAVED, the compression algorithm is re-run, and more data is thrown away. Otherwise, you can view the file, print it or send it without any loss. That said, your practice of converting the file to tiff or psd format from the start is still a good one.
Sorry if I've flogged this to death, but it seemed from you last post that there was still some confusion.

[CyberDyneSystems]

The trouble with the idea of shoot jpeg then save as PSD is that you are not gaining any file size savings by shooting jpeg (the .PSD file or .tif file will be MUCH larger file size then an original raw file)

So if you don't intend to shoot jpeg to get a smaller file size,.. then why on earth would you shoot jpeg to start with?

[tim]

I was about to post the same thing as bodog - every "save as jpeg" operation results in image degredation, whether it's done in photoshop or in the camera. Opening and printing make no difference at all.

[defordphoto]

The trouble with the idea of shoot jpeg then save as PSD is that you are not gaining any file size savings by shooting jpeg (the .PSD file or .tif file will be MUCH larger file size then an original raw file)

So if you don't intend to shoot jpeg to get a smaller file size,.. then why on earth would you shoot jpeg to start with?

More photos on the CF. Quicker writing and buffer flushing. More FPS.

[defordphoto]

I was about to post the same thing as bodog - every "save as jpeg" operation results in image degredation, whether it's done in photoshop or in the camera. Opening and printing make no difference at all.

Correct. We must also remember that many software packages do not offer loss-free rotation too.

The interesting this is that all my race photos that I post are processed as a JPEG and resaved. Resaved at 12 quality that results in a larger file and probably no noticeable loss to the eye, but resaved nonetheless.

However, when printing large I convert to TIFF for no loss.

[dijitul+philm]

Thanks for the input, Bodog. That was the area I was initially trying to clarify : what does and what does not result in the compression algorithm to kick in and make a lossy file even weaker. So if one opens a JPEG, prints it in Photoshop and then goes to File>Close(close the file not Photoshop) or to File>Exit, there will be no loss but if to File>save or to File>Save as then there will be loss, correcto? I hope so. Incidentally, after reading your post, I re-read my last one and, though it rambled and careened wildly, I think I did actually say in the 4th and 5th lines that i felt that the opening and then re-saving of a lossy could affect it but not that just opening it would. I said that the reason for opening might be just to print but not that opening it was a lossy action. Whatever, thanks to all. Regarding file size: converting a JPEG to a TIFF is big alright, but isn't saving a RAW in both an un-edited version (advisable with RAW) as well as in an edited version as a TIFF or PSD, etc. a pretty big space hogger? I don't know the numbers on that.

[cmar]

More photos on the CF. Quicker writing and buffer flushing. More FPS.
Exactly, and the fact that I doubt most people could tell the difference between an image saved once as a jpeg in the camera, and one shot raw after they have been adjusted and printed by most methods, or published on the web.

If you are a pro and your paycheck hinges on that perfect shot, go ahead and banish the jpg. For the rest of the world, shooting jpeg, then saving the keepers as tiff not loose you anything.