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Photoshop 16 bit as apposed to 8 bit- which should I use?

Forum|Forum|7 years ago
November 5, 2018
8 replies
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I'm working on a 50 pg illustrated children's book- w/ many pgs having photoshop high sized files. I am using stock photography that are mostly 8 bit. Should I stay w/ 8 bit or should I import all the stock photos into a 16 bit file when combining the photos? They are going to be printed by a CMYK printer. The main thing is that the images should be as sharp and clear as possible. So should the file I create be 8 bit or 16 bit?

Thank you.

16 bit or 8 bit photoshop

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Correct answer rob day

The advantage of 16-bits is you can make multiple color corrections to the image without dropping gray levels, but an Adjustment layer does pretty much the same without the file size overhead.

If the file starts as 8-bit there's no quality advantage in converting up to 16 bits, the file size would increase, but you wouldn't gain any gray levels—you still would still be working with the 8-bit file's original 256 gray levels. In that case you could lower the file size by going back to 8-bit.

The halftone screens book printers use are not capable of producing more than 256 levels of gray, that's why InDesign doesn't support 16-bit.

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estherk98039882Author

Known Participant

Thanks a lot for your ongoing help. In order to avoid future problems, can you please answer the following

1) Is it better that I work with the file that's saved on the computer as apposed to working directly from the external hard drive- or it doesn't make a difference?

2) Is it OK that work in Photoshop while I have the external hard drive connected? By being connected does it slow dorwn the computer?

i3) Every now and then, Photoshop gives me a "Program Error" message? Is it because I sometimes ha tve too many files open? Is there a way to maximize the programs that it should be able to withstand more file open and work faster?

rob day

Community Expert

Any drive can fail or have write errors, the only solution is to have a comprehensive backup system in place.

There are backup applications like Apple's Time Machine or Retrospect that incrementally backup to a local drive. In that case if there's a problem with a file you can go back to an earlier version. There are also cloud based solutions, which have the advantage of off site backups. Dropbox is incremental and cloud based and easy to use. A 1TB account costs $100 a year. Your Creative Cloud account also has cloud based sync'ing, but you have to save files to your computer's Creative Cloud Files folder at the top level of your computer's user directory. Adobe temporarily disabled the incremental feature of their cloud service last summer. You might consider using your external drives for archiving in order to clear space on your laptop, and work out of the CC folder.

I also think your workflow of editing and saving files in the Photoshop PDF format could be a problem. The only reason to use PDF would be if you have type layers that you want to output as vectors. I would consider doing all your editing work in Photoshop format (.psd), and if you are setting type, do a Save As or Save a Copy for placing in InDesign.

Can you share the PDF that is opening flat via Dropbox or your CC account?

i3) Every now and then, Photoshop gives me a "Program Error" message? Is it because I sometimes ha tve too many files open? Is there a way to maximize the programs that it should be able to withstand more file open and work faster?

If the files are large there could be a lot of Scratch disk usage—see Prefs>Scratch Disks for ordering the disk usage. If your internal drive is full that might a problem, by default the startup drive is the first scratch disk.

Optimize performance Photoshop CC

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estherk98039882Author

Known Participant

Thanks for your imput. I bought a new external hard drive

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estherk98039882Author

Known Participant

I 'm sure that it was checked as Preserve Photoshop Editing Capabilities"

The case I'm having now is not that I created a new file and had the options not correctly saved. The problem is that I saved an existing file as usual and for some strange reason, from then on it gives me the following errors:

"There was a problem reading the layer data. Read the composite data instead?" When I click on the button that reads "Read Composite Data" it opens in one flat image with lines all over it. When I tried reopening it on another computer it didn't allow to open it at all- just gave a new error message: "Couldn't complete your request bec. the file is not compatible with this version of Photoshop"

Does this mean that I lost the file- or is there a way to repair it?

And what is the cause - I want to avoid it from happening again. Is it the i5 laptop that has a problem or the external harddrive? What can I do to check what is the cause?

To add to that, there is a new problem : An entire folder containing images on my external hard drives gives me the following error message when I tried to open it on my i7 laptop (I work on two laptops- an i5 and an i7): "the files are corrupted"

When I tried opening it on my i5 it opened up normally BUT AN EMPTY FOLDER!

Is it the i5 laptop that has a problem or the external harddrive? What can I do to check what is the cause?

Maybe it's Photoshop the problem and I have to reinstall? PLEASE HELP ME-

I CAN'T AFFORD TO LOOSE months of work.....

rob day

Community Expert

And what is the cause - I want to avoid it from happening again. Is it the i5 laptop that has a problem or the external harddrive? What can I do to check what is the cause?

Sounds like something is wrong with the drive. I'm an OSX user, so I can't really help you with the hardware. For future projects you definitely want to look into a backup strategy, the easiest way to do that is a cloud based service like Dropbox, which does incremental backups.

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estherk98039882Author

Known Participant

What do you mean by "Sounds like something is wrong with the drive." ? what drive are you referring to, the external hard drive or the computer?

Does this mean that I lost the file- or is there a way to repair the file?

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estherk98039882Author

Known Participant

About where I saved it then- I'm not sure- more likely to the external drive. As with the extension, I'm almost sure that I saved it as a photoshop pdf file.

rob day

Community Expert

I'm almost sure that I saved it as a photoshop pdf file.

Did you check Preserve Photoshop Editing Capabilities?

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estherk98039882Author

Known Participant

The file is currently saved on the computer itself (and not an external drive).

The following info is from the "Properties" box- what comes up when I right click on the file's icon - this is exactly what it reads:

Type of file: Adobe Acrobat Document (.psd)

The same info comes up when I check the copy I have on the external drive.

When I work on larger files, I work with the file directly from the external hard drive- it is not a thumb drive- it is a Seagate (aprox 3 x5 size box) w/ 1.7 TB capacity, of which is 1.34TB free space.

rob day

Community Expert

So you saved directly to the external and then made a copy back to your laptop? What about the extension? Is the extension .psd even though the OS is telling you the file is a PDF?

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estherk98039882Author

Known Participant

I'm using Photoshop CC 2018 and also CC 2019- which do you recommend for my large files?

Here are the specs of my laptop:

Processor: Intel(R) Core(TM) i5-6300 CPU @ 2.40GHz 2.5

OS build: 17134.376

I also use another computer where I also work w/ the same large photoshop files: using an i7

I saved the file to an external drive. Is that the problem? Should I only be working w files saved directly on my computer? The reason why I usually work w files from the external drive is because I have limited storage space on my laptops.

I hope you will still be able to come up w a solution on how to save the file. And also please if you can answer all my above questions. thanks a lot

rob day

Community Expert

I saved the file to an external drive. Is that the problem?

It might be, is it a thumb drive? Does the file have its .psd extension? The file type shouldn't be Acrobat if you saved it as Photoshop Format.

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estherk98039882Author

Known Participant

I did as you recommended and downsized the 16 bit file to 8 bit- by going in Photoshop- Image> 8 bit--- but after having closed the file I AM NOT ABLE TO OPEN IT AGAIN SINCE THEN--- PLEASE HELP! Following message gives me: "There was a problem reading the layer data. Read the composite data instead?" When I click on the button that reads "Read Composite Data" it opens in one flat image with lines all over it. When I tried reopening it on another computer it didn't allow to open it at all- just gave a new error message: "Couldn't complete your request bec. the file is not compatible with this version of Photoshop"

The following info is from the "Properties" box- what comes up when I right click on the file's icon:

Type of file: Adobe Acrobat Document (.psd)

Opens with: Adobe Acrobat

I hope you can guide to save this file that took days to create- with tons of layers - when I checked the file size yesterday- after having realized that the file has a problem- it showed aprox. 250 MB SIZE. Now I rechecked on another computer and it showed 180 MB......

Be with success in saving my work... thank you so much

rob day

Community Expert

The following info is from the "Properties" box- what comes up when I right click on the file's icon:
Type of file: Adobe Acrobat Document (.psd)
Opens with: Adobe Acrobat

Looks like you had a problem with the save. What OS are you using? Did you save to the startup drive, or was it to an external or network drive? Were you doing a Save As to Photoshop PDF? Obviously the file type is wrong.

rob day

Community Expert

8-bit, but make any color corrections using non-destructive Adjustment layers.

It's unlikely that 16-bits will make it to output—if you are using inDesign for the book layout, it has no support for 16-bit—placed 16-bit images are sampled down to 8-bit when you export to PDF.

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estherk98039882Author

Known Participant

Thanks for the quick answer. What should I do with the existing 16 bit files I already created in Photoshop? Should I leave them as they are or change into 8 bit mode?

As you mentioned, I am using InDesign for the layout.

Thank you again.

rob day

Correct answer

Community Expert

The advantage of 16-bits is you can make multiple color corrections to the image without dropping gray levels, but an Adjustment layer does pretty much the same without the file size overhead.

If the file starts as 8-bit there's no quality advantage in converting up to 16 bits, the file size would increase, but you wouldn't gain any gray levels—you still would still be working with the 8-bit file's original 256 gray levels. In that case you could lower the file size by going back to 8-bit.

The halftone screens book printers use are not capable of producing more than 256 levels of gray, that's why InDesign doesn't support 16-bit.

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