What's the best way to save a file in Photoshop?

[saykimchi]

I'm looking to archive some of my recent photos. They've been shot as RAW files, and I'm editing them in Photoshop. I normally save my files as JPEGs but I know that they're lossy, and if I want to reedit them, I'll be losing some of the quality.

I'm wondering what's the best file format to save in (using Photoshop CS3) after doing a small amount of clean up on each photo - sharpening, white balance adjustments, cropping etc. I want to have the smallest file size, but still have the versatility to be able to edit the photos at a later date if I so choose.

Your help is greatly appreciated!

[ladyups]

This is just an idea, Bryan, but why don't you just burn the RAW files to a CD or DVD as is...kind of like saving the negatives from film. As to what to use on your 'altered' images, I'd save them as a Photo Shop file or TIFF. Either one, I believe would save it with the layers. If you want to just save the flattened image for viewing quickly, save a a jpg and reference the file to your raw file. Meaning, leave the raw file name intact and add altered or some such to the name and save it as a jpg.
This way, if sometime in the future, you want to use that jpg file for something else and are going to edit it, you will have a reference to the original raw file so you can open it and do the editing on it. Jpg files only lose quality when they are edited. Just opening the file doesn't degrade it. Only when you edit and re-save, does this occur. I think I have this understanding correct...if not, I'm sure one of the more experienced photographers will correct me.

[coffee]

I'm looking to archive some of my recent photos. They've been shot as RAW files, and I'm editing them in Photoshop. I normally save my files as JPEGs but I know that they're lossy, and if I want to reedit them, I'll be losing some of the quality.

I'm wondering what's the best file format to save in (using Photoshop CS3) after doing a small amount of clean up on each photo - sharpening, white balance adjustments, cropping etc. I want to have the smallest file size, but still have the versatility to be able to edit the photos at a later date if I so choose.

Your help is greatly appreciated!

Like Mary said the only way jpegs lose quality is if they are re-saved. Just having them on your computer doesn't make them lose quality. Also copying and paste and moving them doesn't make them lose quality either. So if you are only editing them once, then saving, they will stay that way till you resave the same image for some reason like re-editing them.

However, after I edit a RAW file, I save it the biggest jpeg, and TIFF. Then if I need to re-edit, I load up the tiff, then edit and re-save. No lose that way.

[saykimchi]

However, after I edit a RAW file, I save it the biggest jpeg, and TIFF. Then if I need to re-edit, I load up the tiff, then edit and re-save. No lose that way.

Thank you Mary and Joseph. That's just what I thought to do. I just wanted to double check the best file format - TIFF vs PNG vs whatever else! Thanks for your help!

[ladyups]

Thank you Mary and Joseph. That's just what I thought to do. I just wanted to double check the best file format - TIFF vs PNG vs whatever else! Thanks for your help!

Glad to be of help, Bryan. I would not bother saving your photos to the png format through. This format is for saving images without a background. Kind of like the Gif format. And its used mainly for the web or in my case, for scrapbook images. The scrapbook community has kind of taken over the png format for producing images to be used in layered formats without backgrounds. So...tiff or a very low compression jpg is your best bet. I save my jpgs at 300 dpi and at the highest quality that I can...usually the 12 on the scale. If I do want to edit the jpg file, I'll open a duplicate of the original and then save it as a tiff before I do any editing. This saves the duplicate without any loss of quality and I can always do a save as to jpg if I wish.

[jerryph]

There is a minor argument that one day TIFF is going to go fade away and that DNG (which is a Digital NeGative), is the format to save in... however, I do something similar to the others here, in that I shoot ONLY in RAW and edit it down to JPG for final viewing/printing. So most of the time I have only the RAW and largest JPG format saved to my backup system.

However, if it is a file I plan to work on in the future, I will save it either as a TIFF or a PSD (not a png, which is a web display format file). I use the TIFF or PSD formats only on pictures that are true keepers and/or had a lot of work put in to them.

All the others I save the RAW files of the pics that I want to save and the JPGs.

[skeuos]

I generally save as PSDs for edited files, and keep an original of the RAW backed up. If you make sure to turn off "maximize compatibility" when saving the PSD, you can shave several mb's off the file size.

steve

[saykimchi]

If I do want to edit the jpg file, I'll open a duplicate of the original and then save it as a tiff before I do any editing. This saves the duplicate without any loss of quality and I can always do a save as to jpg if I wish.
Are you saying that you save the file as a jpg (let's call it picture.jpg). If you want to edit it in the future you duplicate picture.jpg, save it as a tiff (picture.tiff) and then edit picture.tiff. Once you're done editing, you'd save it again as a jpg (maybe new_picture.jpg?

If you save from raw to jpg, save from jpg to tiff, edit the file, and then save again from tiff to jpg, (raw->jpg, jpg->tiff, edit, tiff->jpg) is there any loss of quality?

[saykimchi]

Also, what kind of compression do you use when saving as a tif?

[coffee]

Also, what kind of compression do you use when saving as a tif?

Those are the default setting I believe, and is what I use. I really have no idea what a few of those settings are, but I've always used what ever the defaul started me out with and have never changed them. The only differance between those settings and mine is I use a PC.

[ladyups]

Are you saying that you save the file as a jpg (let's call it picture.jpg). If you want to edit it in the future you duplicate picture.jpg, save it as a tiff (picture.tiff) and then edit picture.tiff. Once you're done editing, you'd save it again as a jpg (maybe new_picture.jpg?

If you save from raw to jpg, save from jpg to tiff, edit the file, and then save again from tiff to jpg, (raw->jpg, jpg->tiff, edit, tiff->jpg) is there any loss of quality?

No, there is no loss of quality to the edited version as long as you edit it as a tiff file. Then if you just want to save it as a jpg, you would do a save as and save it as new_picture.jpg. No loss of quality except for the compression of saving it as the jpg and I don't compress anymore than the lowest compression. I'm not sure why this works, Bryan, but its what all the books I've read say to do if you want to edit a jpg file. Save the original jpg file as is and do a duplicate and save as a tiff. As to your steps above, saving from Raw to jpg would lose quality, since you are saving to a jpg and its a lossy file format. Anytime a jpg file is opened, edited and then re-saved it loses more quality each time. So if you were doing lots of editing on the jpg file and hitting the save button ever so often, then editing some more, each time it is saved it loses quality. That is why they say to duplicate the jpg file and then save it as a tiff file BEFORE you start editing on it. That way, each time you hit the save button, it doesn't lose any quality. You would lose some more quality when you saved it as a new jpg file but not as much as you would if you edited and saved the jpg file over and over again. I hope I'm making sense!

[ladyups]

Also, what kind of compression do you use when saving as a tif?


I don't use any compression. I have the none ticked.

[coffee]

But the question is, is the quality the same if you save your edited RAW to a TIFF, as apposed to the edited jepg to a TIFF, and back again?

I converted an edited jpeg to a TIFF, and it was the exact same size as the edited RAW to a TIFF of the same photo. I don't know what this tells me. But I can tell you this: If there is no quality loss at all in these two was of doing it, then I have no reason to save TIFF's really.


No, there is no loss of quality to the edited version as long as you edit it as a tiff file. Then if you just want to save it as a jpg, you would do a save as and save it as new_picture.jpg. No loss of quality except for the compression of saving it as the jpg and I don't compress anymore than the lowest compression. I'm not sure why this works, Bryan, but its what all the books I've read say to do if you want to edit a jpg file. Save the original jpg file as is and do a duplicate and save as a tiff. As to your steps above, saving from Raw to jpg would lose quality, since you are saving to a jpg and its a lossy file format. Anytime a jpg file is opened, edited and then re-saved it loses more quality each time. So if you were doing lots of editing on the jpg file and hitting the save button ever so often, then editing some more, each time it is saved it loses quality. That is why they say to duplicate the jpg file and then save it as a tiff file BEFORE you start editing on it. That way, each time you hit the save button, it doesn't lose any quality. You would lose some more quality when you saved it as a new jpg file but not as much as you would if you edited and saved the jpg file over and over again. I hope I'm making sense!

[ladyups]

Well, Coffee, I'm not sure how you are coming up with your same size file sizes. I tested this with my raw file. I first processed my raw file at 16 bit, brought it into PS and saved it as a tiff image. Then all I did (no editing here) was re-saved it as a jpg but I had to adjust the mode to 8 bit instead of 16 cause you can not save a 16 bit image as a jpg. The difference in my files was tiff at 144.62mb and 10.63mb for the jpg. Since I did change the bit mode, I went back in to my CR and processed the same image as an 8 bit image and opened it up in PS. From there I saved it as a tiff and then (without editing again) saved it as a jpg. My results...the tiff was 72.32 mb and the jpg file was a meager 8.30 mb. Quite a bit of difference in file sizes.

In my second test. I opened the unedited jpg file and edited it by adjusting the levels and the brightness. Nothing else was changed. I saved it as a tiff and then opened that edited tiff up again and saved it as a jpg file. My edited tiff image stayed the same at 72.32 mb but my converted to jpg file increased to 10.6.

I can't answer why the change in file size on the jpg, maybe someone with more knowledge than I have could. But, I do know that my tiff images are WAY bigger than my jpg files are.

[jerryph]

No, there is no loss of quality to the edited version as long as you edit it as a tiff file. Then if you just want to save it as a jpg, you would do a save as and save it as new_picture.jpg. No loss of quality except for the compression of saving it as the jpg and I don't compress anymore than the lowest compression. I'm not sure why this works, Bryan, but its what all the books I've read say to do if you want to edit a jpg file. Save the original jpg file as is and do a duplicate and save as a tiff. As to your steps above, saving from Raw to jpg would lose quality, since you are saving to a jpg and its a lossy file format. Anytime a jpg file is opened, edited and then re-saved it loses more quality each time. So if you were doing lots of editing on the jpg file and hitting the save button ever so often, then editing some more, each time it is saved it loses quality. That is why they say to duplicate the jpg file and then save it as a tiff file BEFORE you start editing on it.

There is a hole in that logic. Maybe it's me. :)

You said that you use the following procedure:
- RAW to TIFF
- TIFF to JPG
then...
- JPG to TIFF
- TIFF to JPG

Yes?

Basically using this process, though file size in one case is increased (JPG to TIFF), you are losing a TON of original data in the picture, not restoring the original data lost when first converting from TIFF to JPG the first time.

The RAW file, irrespective of if it is smaller than a TIFF file or not, is the file with the most *picture data* as it is basically nothing more than data from your camera's photo sensor and then converted into a 8, 12 or 14-bit file (depending on your camera capabilities and settings).

Even converting THIS file to TIFF... there is some possible minor loss of irreplaceable data, but it is minor.

Now... going from TIFF to JPG is a **huge** loss of data that can never be recovered. It is destroyed and gone forever. If I take that same newly converted JPG file, and convert it back into a TIFF file, the resultant TIFF file will be bigger than the JPG, but it does NOT mean that the data lost during the initial conversion from TIFF to JPG is restored... becuase if it was, that would mean that the JPG did not lose any data during the process and would be called a lossless file, which we all know, JPG isn't lossless, it is a known lossy file. The file is bigger becuase the TIFF format is an uncompressed file format and JPGs are highly compressed files. TIFF decompresses a file. It is not the *real* original data anymore... thats gone forever.

If there was no loss in data, take 1.TIFF file save to 1.JPG. Close the file, reopen 1.JPG, save it to 2.TIFF and compare file sizes to 1.TIFF. Are they the same? No, 2.TIFF is a LOT smaller. Why? Lost data.

If I take a TIFF file and save it continually, no data is lost. If what you say is true (that converting back and forth, TIFF>JPG>TIFF>JPG results in no losses), then I suggest you try this procedure about 20 times. You will see that by the 5th time, the picture starts to look poor, and by the 20th time, is pretty much unusable.

When we take pictures, if ultimate quality retention is desired, we cannot introduce a lossy format ANYWHERE into the process except as the LAST step. At the moment we introduce a lossy format, precious data is lost and forever unrecoverable.

That means that you cannot transfer back and forth from TIFF to JPG and back again, and expect to have the same quality picture, because the moment you used JPG... you lost a *lot* of data.

This is why it is critical in your workflow to use strictly lossless formats (ie: RAW, TIFF, PSD) throughout the editing process and the absolute LAST thing we do... is convert to JPG, because THERE is where a ton of data is forever lost, but it is necessary becuase the format that the web accepts are highly compressed format files and becuase most picture processing labs use only JPG (though some few professional labs still may use TIFF for large sized output files like posters, billboards, etc...).

If you need to make further edits or changes on the JPG, scrap it, go back to your previously edited TIFF or PSD (you can use the RAW, but you would have to do ALL the editing over as you cannot save edits to a RAW file) and save it again as a JPG.... or if it is a minor edit, you can edit the previously outputted JPG and save that. To the untrained eye, you can go about 3-5 edits without major visual degradation, however *I* wold know its not the best quality possible, and I would not settle for that if ultimate picture quality was a priority... I would edit the last lossless file and overwrite the previously created JPG.

In this manner, my pictures are finalized in the greatest possible rendering quality with the least amount of data loss and highest final output possible.

[coffee]

Well, Coffee, I'm not sure how you are coming up with your same size file sizes. I tested this with my raw file. I first processed my raw file at 16 bit, brought it into PS and saved it as a tiff image. Then all I did (no editing here) was re-saved it as a jpg but I had to adjust the mode to 8 bit instead of 16 cause you can not save a 16 bit image as a jpg. The difference in my files was tiff at 144.62mb and 10.63mb for the jpg. Since I did change the bit mode, I went back in to my CR and processed the same image as an 8 bit image and opened it up in PS. From there I saved it as a tiff and then (without editing again) saved it as a jpg. My results...the tiff was 72.32 mb and the jpg file was a meager 8.30 mb. Quite a bit of difference in file sizes.

In my second test. I opened the unedited jpg file and edited it by adjusting the levels and the brightness. Nothing else was changed. I saved it as a tiff and then opened that edited tiff up again and saved it as a jpg file. My edited tiff image stayed the same at 72.32 mb but my converted to jpg file increased to 10.6.

I can't answer why the change in file size on the jpg, maybe someone with more knowledge than I have could. But, I do know that my tiff images are WAY bigger than my jpg files are.

I'm not trying to compare files sizes between RAW, TIF or Jeps of the same file. I know tiff will be large RAW samller and jpg smaller yet. My question was this, and I know this is confusing.

My question is with tiff files only. Is converting a RAW to a tiff, the same quality as converting a jpg to a tiff all of the same photo?

The reason I asked this was in referance to your comment on converting jpgs back to tiffs for editing, then resaving as a jpg. This is a good way to edit a jpg becasue you won't lose quality of that jpg.

But if you always start with the original tiff from the raw, it has to be a better quality as oposed to starting with the original jpg, converting to a tiff, then saving back to a jpg. At least that is what common sense tells me. Once in jpg format, you lose a lot of info. So if you start with that as your editing process instead of the original tiff, you don't have as much info from the start.

The reason I want to know this for sure, is I have over 100 gigs of tiffs that I may be able to do away with if I'm wrong. If there is no quality loss in going from jpg>tiff>jpg or editing compared to tiff>jpg, then I can save alot of space by not saving tiffs. Man is this confusing. hehe

I had a question about this elsewhere and got a few responses. It was told to me that quality is lost if you start your editing process in any fassion with a jpg, as opposed to starting your editing process with a tiff. Hope that clears the question up.

This might be a good time to ask Peter if he has anything he can add to this. Thanks

[coffee]

This makes sense to me Jerry. If it were any other way, there would be no reason to save tiffs other than for layers, and the trade off in files size wouldn't make sense.



There is a hole in that logic. Maybe it's me. :)

You said that you use the following procedure:
- RAW to TIFF
- TIFF to JPG
then...
- JPG to TIFF
- TIFF to JPG

Yes?

Basically using this process, though file size in one case is increased (JPG to TIFF), you are losing a TON of original data in the picture, not restoring the original data lost when first converting from TIFF to JPG the first time.

The RAW file, irrespective of if it is smaller than a TIFF file or not, is the file with the most *picture data* as it is basically nothing more than data from your camera's photo sensor and then converted into a 8, 12 or 14-bit file (depending on your camera capabilities and settings).

Even converting THIS file to TIFF... there is some possible minor loss of irreplaceable data, but it is minor.

Now... going from TIFF to JPG is a **huge** loss of data that can never be recovered. It is destroyed and gone forever. If I take that same newly converted JPG file, and convert it back into a TIFF file, the resultant TIFF file will be bigger than the JPG, but it does NOT mean that the data lost during the initial conversion from TIFF to JPG is restored... becuase if it was, that would mean that the JPG did not lose any data during the process and would be called a lossless file, which we all know, JPG isn't lossless, it is a known lossy file. The file is bigger becuase the TIFF format is an uncompressed file format and JPGs are highly compressed files. TIFF decompresses a file. It is not the *real* original data anymore... thats gone forever.

If there was no loss in data, take 1.TIFF file save to 1.JPG. Close the file, reopen 1.JPG, save it to 2.TIFF and compare file sizes to 1.TIFF. Are they the same? No, 2.TIFF is a LOT smaller. Why? Lost data.

If I take a TIFF file and save it continually, no data is lost. If what you say is true (that converting back and forth, TIFF>JPG>TIFF>JPG results in no losses), then I suggest you try this procedure about 20 times. You will see that by the 5th time, the picture starts to look poor, and by the 20th time, is pretty much unusable.

When we take pictures, if ultimate quality retention is desired, we cannot introduce a lossy format ANYWHERE into the process except as the LAST step. At the moment we introduce a lossy format, precious data is lost and forever unrecoverable.

That means that you cannot transfer back and forth from TIFF to JPG and back again, and expect to have the same quality picture, because the moment you used JPG... you lost a *lot* of data.

This is why it is critical in your workflow to use strictly lossless formats (ie: RAW, TIFF, PSD) throughout the editing process and the absolute LAST thing we do... is convert to JPG, because THERE is where a ton of data is forever lost, but it is necessary becuase the format that the web accepts are highly compressed format files and becuase most picture processing labs use only JPG (though some few professional labs still may use TIFF for large sized output files like posters, billboards, etc...).

If you need to make further edits or changes on the JPG, scrap it, go back to your previously edited TIFF or PSD (you can use the RAW, but you would have to do ALL the editing over as you cannot save edits to a RAW file) and save it again as a JPG.... or if it is a minor edit, you can edit the previously outputted JPG and save that. To the untrained eye, you can go about 3-5 edits without major visual degradation, however *I* wold know its not the best quality possible, and I would not settle for that if ultimate picture quality was a priority... I would edit the last lossless file and overwrite the previously created JPG.

In this manner, my pictures are finalized in the greatest possible rendering quality with the least amount of data loss and highest final output possible.

[coffee]

I just had to know if your test example would hold true Jerry. It didn't seen to. I just did a test where I converted from jpg>tiff and back to jpg 20 times. Each time starting with the newly saved jpg. Each time deleting the used files so I wouldn't get confused :-). There is no quality of loss to the file at all from the original jpg at full size. I also zoomed in by 3200% where I had about 25 pixels in the frame, and there is still no quality drop at all.

And it was interesting that the end file was almost .20 of a meg bigger. Not saying it increased quality, just interesting that it wouldn't be the same size.

Later I will post a few shots of this test when I have more time.

I would really like someone else that may have 10 minutes to conduct the same test. This would be huge to me and many others out there if this test proves true. Having 100's of gigs in space that would otherwise be taken up with tiffs would be great.

I'm not saying I would never save tiffs again if this were true. But up to this point all of my tiffs are flattened at 8 bits. So if this is correct, and since I don't save tiffs with layers at this point, I would have nothing to gain saving the tiffs if I can convered the edited jpg to tiff before re-editing.

[admin]

If there was no loss in data, take 1.TIFF file save to 1.JPG. Close the file, reopen 1.JPG, save it to 2.TIFF and compare file sizes to 1.TIFF. Are they the same? No, 2.TIFF is a LOT smaller. Why? Lost data.

Jerry, if your final format was TIFF, it would be the same or very close to the size of the original tiff file. Tiff files do not lose their file size based on the color information in them. In other words if I create a blank page in Photoshop, make it the same dimensions + save as TIFF it would be similar file size as your original TIFF.

As an example, create a new document in Photoshop, make it 100x100mm, RGB, 8-bit, 300dpi and save it as TIFF. It will be 4,206,464 bytes in file size.

Now open any of your photos, crop them to 100x100mm, make sure they're RGB, 8-bit, 300dpi and again save as TIFF. Filesize? Very close to the above - the one I just did was 4,219,196 bytes.



I just did a test where I converted from jpg>tiff and back to jpg 20 times. Each time starting with the newly saved jpg. Each time deleting the used files so I wouldn't get confused :-). There is no quality of loss to the file at all from the original jpg at full size. I also zoomed in by 3200% where I had about 25 pixels in the frame, and there is still no quality drop at all.

And it was interesting that the end file was almost .20 of a meg bigger. Not saying it increased quality, just interesting that it wouldn't be the same size.

Later I will post a few shots of this test when I have more time.

I would really like someone else that may have 10 minutes to conduct the same test. This would be huge to me and many others out there if this test proves true. Having 100's of gigs in space that would otherwise be taken up with tiffs would be great.

I'm not saying I would never save tiffs again if this were true. But up to this point all of my tiffs are flattened at 8 bits. So if this is correct, and since I don't save tiffs with layers at this point, I would have nothing to gain saving the tiffs if I can convered the edited jpg to tiff before re-editing.

Introducing a lossy format at any stage of saving process means a LOSS of quality. So let's take your JPG - TIFF - JPG situation. And for simplicity ignore the initial JPG quality loss.

Step 1 - opening original JPG is our starting point
Step 2 - Saving as TIFF file = NO QUALITY LOSS
Step 3 - Saving TIFF as JPG, introduction of lossy compression = LOSS OF QUALITY!

Joseph, EVERY TIME you save anything as JPG, you do lose quality. Quality cannot be measured purely by the file size. Lossy compression technologies attempt to eliminate redundant or unnecessary information from your file. This method is one where compressing data and then decompressing it retrieves data that is DIFFERENT from the original data. If you saved your file 20 times, you were basically opening a DIFFERENT file each time (unless you didn't close it each time). If you used the lowest compression, perhaps the visual loss wasn't that obvious, but if you placed photo 1 and photo 20 side by side, the difference would be there.

[coffee]

Jerry, if your final format was TIFF, it would be the same or very close to the size of the original tiff file. Tiff files do not lose their file size based on the color information in them. In other words if I create a blank page in Photoshop, make it the same dimensions + save as TIFF it would be similar file size as your original TIFF.

As an example, create a new document in Photoshop, make it 100x100mm, RGB, 8-bit, 300dpi and save it as TIFF. It will be 4,206,464 bytes in file size.

Now open any of your photos, crop them to 100x100mm, make sure they're RGB, 8-bit, 300dpi and again save as TIFF. Filesize? Very close to the above - the one I just did was 4,219,196 bytes.




Introducing a lossy format at any stage of saving process means a LOSS of quality. So let's take your JPG - TIFF - JPG situation. And for simplicity ignore the initial JPG quality loss.

Step 1 - opening original JPG is our starting point
Step 2 - Saving as TIFF file = NO QUALITY LOSS
Step 3 - Saving TIFF as JPG, introduction of lossy compression = LOSS OF QUALITY!

Joseph, EVERY TIME you save anything as JPG, you do lose quality. Quality cannot be measured purely by the file size. Lossy compression technologies attempt to eliminate redundant or unnecessary information from your file. This method is one where compressing data and then decompressing it retrieves data that is DIFFERENT from the original data. If you saved your file 20 times, you were basically opening a DIFFERENT file each time (unless you didn't close it each time). If you used the lowest compression, perhaps the visual loss wasn't that obvious, but if you placed photo 1 and photo 20 side by side, the difference would be there.

What I did was load a jpg in PS and save as tiff. Then I would close out of that file in PS and load the new tiff and save as jpeg. Then I would close tiff in PS and load newly saved jpg and that would be considered one save. I did 20 saves, and there is no visual differences in either file, even zoomed in to over 3000% I can see no visual differences.

I just checked a color sample of the same pixels in each file, and there was a 1% or a number changeof (1) in 2 or three color catagories. So maybe this is one change that is taking place if I did this right, but no visual change that I can see even zoomed in that close. So I don't know.

It was said twice that after 20 rounds of saving that there should be a visual difference. I wonder why I'm not seeing it on my end. I don't want to beat a dead horse, but I'm trying to decided if I want to keep my flattened 8 bit tiffs in lue of Mary's workflow of using jpg>tiff>jpg to edit. And from what I'm seeing on my end is if there is a quality drop, it's not happening inside of 20 rounds of saves. I don't know, if you throw actual editing in those rounds is that going to be the difference here. Can changes to the files thrown into the mix degrade it to the extent that it is more noticable?

Thanks for the input. I might try this test again on a different file later today, it only takes about 10 minutes.

[pauld]

Hi,

Why do you all want to "save as" at all.
You have the raw file, it never gets better than that.
Lightroom editing does not affect that file, it creates a parameter file on the side (.xmp).

You can go back to you original raw file any time without any loss whatsoever.

Paul.

[coffee]

Hi,

Why do you all want to "save as" at all.
You have the raw file, it never gets better than that.
Lightroom editing does not affect that file, it creates a parameter file on the side (.xmp).

You can go back to you original raw file any time without any loss whatsoever.

Paul.

This is very true. As for me, I always shoot in RAW, and never delete RAW files, but I do delete the sidecar xmp files. I just can't stand to have thousands of those around cluttering up stuff. And from what I can gather, xmp files only hold your initial RAW changes before opening up in PS, and the only change I make at that stage is sometimes white balance changes. I believe this stage is Camera RAW? Is this right?

And the fact that unless it's something very special, I only do basic editing that isn't hard to reproduce from the RAW. This is the reason, plus running low on hardrive space, that I'm thinking about deleting most of my tiffs. I know hardrives are inexpensive compared to what they use to be, it's still hard to afford new anything these days. But the thought of deleting the tiffs scare the h*ll out of me. :)

[jerryph]

As an example, create a new document in Photoshop, make it 100x100mm, RGB, 8-bit, 300dpi and save it as TIFF. It will be 4,206,464 bytes in file size.

It's the starting point of an 8-bit file that makes the difference, Peter. Most modern dSLR cameras now create 12 or 14 bit RAW files and when saved as a TIFF, come out as a 16-bit TIFF, not an 8-bit version. Saving that file to an 8-bit JPG... that is one heck of a loss of data right from the start, and I feel the main reason why I am seeing file size differences that are pertinent to our discussion. :)

Here is what I just did:

Looking at a real life test that I just completed, if I start off with a 14-bit uncompressed NEF (Nikon Raw file), the size is 25.0 MB (or exactly 26,214,400 bytes). This file is called JPH_001.NEF.

I take that file, and do a "save-as" to a 16-bit TIFF. This new file size without compression is exactly 69.0 MB (72,351,744 bytes). This file is called JPH_0001.tif.

I then save the TIFF back to a 8-bit JPG. This file size (at the setting of 12, which is maximum size), comes to 6.78 MB (7,110,656 bytes). This file is called JPH_0001.jpg.

Now, if I convert JPH_0001.jpg back to an 8-bit TIFF, the file size becomes precisely 34.5 MB (36,208,640 bytes). A huge difference from the 69mb size earlier. This file is called JPH_0001a.tif.

Just for fun, lets use JPH_0001a.tif and convert that back to a JPG format. The file now becomes 6.78 MB (7,110,656 bytes). This now matches the size as JPH_0001.jpg. This file is called JPH_0001a.jpg

I see where you came from, and I can cede that I was incorrect in saying that if further back and forth savings between TIFF and JPG will result in additional file size losses and that was due to my error of not taking my testing far enough as I did this last time.

But, I still offer the point that most modern dSLR cameras do not output 8 bit RAW images (even Canon's basic XSi model outputs 12-bit RAW files). Most cameras that output RAW format files are either 12-bit or 14-bit files that when imported into Photoshop, will retain more of the data captured by the photo sensor than if you import it into Photoshop as an 8-bit file (where large losses are incurred). To add to the consideration, you also have various levels of RAW file compression available sometimes (compressed or uncompressed... and some like Nikon have something called LOSSLESS compression to add to the confusion).

So, seeing things a little clearer now, my workflow was not all that far off. I want to keep things in as high a format as possible and as a last step, convert only then to an 8-bit JPG for final output. The only place that I was not clear was that I kept everything in 16-bit until I was ready to output to that final JPG file.


http://www.proudphotography.com/forum/gallery/files/1/0/0/0/filenames.jpg

[jerryph]

...but I do delete the sidecar xmp files.

...And the fact that unless it's something very special, I only do basic editing that isn't hard to reproduce from the RAW.

The XMP files hold the ACR settings that you made before importing the picture into PS. I can sometimes get very involved with the pic at this stage, and so I do save them. The fact that they are tiny, they have no real impact on my HD space.

If you do not make many changes, then it's of no real consequence and you are obliged to recreate these changes the next time you play with the RAW file... or not even used if you play with the TIFF file instead.

But the question we learned now to ask is... are you playing with the full sized 16-bit TIFFs or are you cutting down right from the first save and using 8-bit TIFFs? :D

[coffee]

The XMP files hold the ACR settings that you made before importing the picture into PS. I can sometimes get very involved with the pic at this stage, and so I do save them. The fact that they are tiny, they have no real impact on my HD space.

If you do not make many changes, then it's of no real consequence and you are obliged to recreate these changes the next time you play with the RAW file... or not even used if you play with the TIFF file instead.

But the question we learned now to ask is... are you playing with the full sized 16-bit TIFFs or are you cutting down right from the first save and using 8-bit TIFFs? :D

Hehe. Hummm.. Maybe I should answer this with a question. What would I be missing by not going with 16-bit to start with? In the end you still have to convert the tiff to 8 to get a working jpg. So let's put this into printing perspective. If I took two edited jpg's to get processed- One was edited from 16btiff>8btiff>jpg, and one was edited from 8btiff>jpg, would there be a printing difference? Say I could only print so big with the 8b start, but larger with the 16b start?

This is a fun thread, and informative. Forgive me for playing dumb.......but who said I was playing? :)

[jerryph]

You get to work with a 8-bit lossless file, for one... lol

A more complete answer is HERE (http://www.photoshopessentials.com/essentials/16-bit/). :)

[admin]

It was said twice that after 20 rounds of saving that there should be a visual difference. I wonder why I'm not seeing it on my end. I don't want to beat a dead horse, but I'm trying to decided if I want to keep my flattened 8 bit tiffs in lue of Mary's workflow of using jpg>tiff>jpg to edit. And from what I'm seeing on my end is if there is a quality drop, it's not happening inside of 20 rounds of saves. I don't know, if you throw actual editing in those rounds is that going to be the difference here. Can changes to the files thrown into the mix degrade it to the extent that it is more noticable?.

Joseph, I'd very much like to see your files #1 and #20 JPG. Full size. Can you send them to my email please?

[jerryph]

Peter, confirmation or education is always appreciated... post your results here, please! :D

[admin]

Sure will do Jerry, that's what I was going to do.

[coffee]

Joseph, I'd very much like to see your files #1 and #20 JPG. Full size. Can you send them to my email please?

Both tests are sent. Test one shows little to no quality drop, test two shows a good amount of loss in quality. The only difference I can see in the two start jpgs is the crop. The first wasn't cropped, the second test started will a large crop.

Admin you emailed me bout not receiving the files. I have all four files zipped and sent the first time but got returned due to file size. I'm going to split these two tests up and try again. But the first test total is 13 megs. That may still be too big, but will try.

OK, all 4 files were sent in separate emails. It looks like they sent ok.

[jerryph]

Its not all SMTP servers, but as a general rule, try to keep a maximum of 10MB of attachments per email message. That way they won't get bounced. :)

[admin]

OK, so I checked both Joseph's tests. Both display a significant quality loss after 20x saved as JPG, although the first photograph is visually less affected. The reason is the algorithm used by JPG compression where the most affected parts will be midtones, and highlights such as skin tones and lightly coloured areas, because they are "easier" to compress. There is relatively small amount of tone variation in them.

In simple terms what JPG does is when it sees 10 shades of yellow concentrated in a larger area, it decides that it is ok to just use an "average" yellow and uses 4 shades. There goes your 6 shades of yellow and the file size is reduced. It will be harder to see the degradation in areas full of detail and colour variation. But as you continue saving your JPG file, the variation continues to decrease to the point where it becomes visible. Speed or how many "saves" you can do before you start noticing it depends on the photo and the amount of compression used when saving the file.

Every photo has areas that are easier to compress and the ones that cannot be compressed too much. This is why Joseph's first test did not exhibit dramatic compression degradation in general, but after closer look at the midtones and highlights, it's visible.

What I've done here is I opened the original photo and placed a 20x saved one on top of it in Photoshop into new layer. Simply turning the top layer on and off shows the differences quite nicely. I created a set of detailed animated gifs so that you could see the changes for yourself. The images change every second.

PHOTO 1
detail a:

http://www.proudphotography.com/forum/images/peters/1st_attempt_animated2.gif

Degradation is visible on skintones, JPG artifacts become more obvious.

detail b:

http://www.proudphotography.com/forum/images/peters/1st_attempt_animated1.gif

This one is even more dramatic and the degradation shows as "maps" on lightly coloured fabric.

PHOTO 2

http://www.proudphotography.com/forum/images/peters/2nd_attempt_animated.gif

In this shot compression artifacts are showing quite badly.

Conclusion? I think after reading this whole thread you can come to conclusion yourself. Saving as JPG equals quality loss. The more you save the more you lose, no exceptions. If you're happy to trade some quality for the amount of disk space saved, then use lossy compression as your last step in your workflow. Not at the beginning, not in the middle and certainly never more than once.

[coffee]

Great presentation. You explained it and showed it very well. Thanks for taking the time certainly.

I think I will be holding onto my tiffs for a while.

[coffee]

One question concerning your presentation:

Does the fact that photo 2 was cropped before the test make any differrence in the amount of quality loss compared to photo 1?

[jerryph]

Nicely done, and thanks!

It took a few seconds before I started seeing the alternating pics, and I was staring at the circles before the file finished downloading and wondering... "what is he showing???". As soon as the download completed, of course the "before/after" effects were obvious. :D

Thanks Peter!

I also found this page that discusses it a little as well:

http://www.scantips.com/basics9jb.html

[jerryph]

One question concerning your presentation:

Does the fact that photo 2 was cropped before the test make any diffrerence in the amount of quality loss compared to photo 1?

I am sure that because the resolution was a little less, that we saw the artifacts a little more, but as you can tell, it hits harder with certain tones and is there in larger as well as smaller files.

In talking about resolution, one of the big reasons we want to output 14-bit RAW files instead of 12-bit files (if your camera supports both), is that when you lighten shadows, you get far superior results with the 14-bit files and the shadows look a little splotchy if you do the same change on a 12-bit file.

Basically, when you have more data, you have more "leeway" to play and correct and the issues are less obvious.

[ladyups]

Well, this thread turned into quite the eye opener, didn't it! I enjoyed all the test and input. I'll rethink my process of just saving my raw files as negatives and then using them when I want to edit. I don't see any reason to save both the raw and the tiff files. I'll probably just save my psd files so I can keep all the layers and adjustments. Since I don't keep both on the computer, I'll back up the raw files to DVD and the external and save the psd files on my hardddrive. Since I'm striving really hard to get the image right in camera, I'm hoping that I won't have to save anything more then the raw file eventually.

Thanks to all of you; Jerry, Coffee and Peter; for researching and testing all this theory.

[ladyups]

Nicely done, and thanks!

I also found this page that discusses it a little as well:

http://www.scantips.com/basics9jb.html


Wow, Jerry, was this a blast from the past! I have Wayne Fulton's Scantips book and have had it for over 14 years. My first and only scanner was/is a Microtek Scanmaker E3. And I still use it! I've had to upgrade the SCSI card at least 3 times to make it compatable with each new upgrade of computers but its still working like a charm. Wayne was where I learned how to operate the scanner. I hadn't check to see if his site was still up or not. Thanks for taking me back in time!

[ladyups]

To anyone that wants to know, I did a test of a RAW file. The original RAW file is 9.27mb in size. I converted it into PS as a 16 bit, 300 dpi file that all I did was use the auto adjust settings and sharpened it by 25 in CR. Once I had it in PS, I duplicated the layer and added some smart sharpen. This was just to add another layer to the file. I then saved it as a PSD file and then did a save as to a tiff file. The PSD layered file was 370 mb and the tiff file was 482 mb. So....to save some space, in my opinion (and you all know how valuable that turned out to be) saving as a PSD file would be better than a tiff file. Now, maybe I could have downsized the tiff file by flattening the layers but then I wouldn't have the ability to go back and undo any of my changes if I wanted to. The only reason I can see that I would save as a tiff file would be to have the ability to share with other folks, since most programs can read tiff but only PS can read PSD files. You can save it as a png file but only as a non-layered copy. If I'm wrong in my thinking, don't hestitate to correct me....I'm just learning too!

[daltoned]

I being reading this thread with interest and the various tests for file sizes. Re the 16bit files that cannot be saved as Jpeg's, I wonder has anyone saved in Jpeg2000 which is one of the save as options. If used, would others have difficulty opening/viewing such files and are there any other reasons not to use this.

[coffee]

I being reading this thread with interest and the various tests for file sizes. Re the 16bit files that cannot be saved as Jpeg's, I wonder has anyone saved in Jpeg2000 which is one of the save as options. If used, would others have difficulty opening/viewing such files and are there any other reasons not to use this.

http://forums.techguy.org/digital-photography-imaging/146825-new-jpeg2000-format.html

[daltoned]

Thanks Joseph, lot of reading on the link, will have to do some tests and see how it is.