I should know this

Converting a sRGB file from a PSD file...how much smaller will the resulting sRGB file be?

Nil. Colour space does not impact file size. Just converted a TIFF from its native AdobeRGB to sRGB and the file size remained unchanged.

One consideration is whether the PSD/Tiff is 8-bit or 16-bit, and if you want to keep, say, a 16-bit or you'd rather convert to 8-bit for using the sRGB for output (Web or "sharing"). If you keep the 16-bit file, you will need to convert to 8-bit for the output, which will in fact result in a smaller file.

If you are embedding the profile then there will be a matter of usually a few bytes difference between the data size of the different profiles. I did once have issues trying to get images down under the old POTN limit of 150 KB, I had for some reason ended up with some odd printer profile and the profile itself was over 1 MB. So the smallest file I was able to export, with Q0 and reduced to IIRC 800×333 pixels the file was still just over 1 MB. When I switched the profile back to sRGB the file size went down to about 5 KB. As long as you are using one of the standard spaces you will be fine though.

Alan

My kids have been nagging at me to convert my PSD's for print, just in case they might want to print some for memories down the road.
As I've got 4.5 TB of them, it will take some time unless there's a way to do them en mass, Y/N

chauncey wrote in post #18189587
My kids have been nagging at me to convert my PSD's for print, just in case they might want to print some for memories down the road.
As I've got 4.5 TB of them, it will take some time unless there's a way to do them en mass, Y/N

There IS a easier way to do it! Just teach them how! ; D

If you are using PSD files I am guessing you are using Photoshop or at least some compatible software that can open the files. It's not clear from your comments exactly what you want to achieve, but in Photoshop you could create an action that will then automate the process and this can entail several steps.

You could in theory save copies in sRGB as high quality flattened Jpegs, but make sure you choose a different destination or you will end up saving over the originals. Running automated actions is highly efficient with large numbers of files and unless your computer is very slow each file action is not likely to take more than a few seconds, which can all be left to run in the background. As mentioned by others simply converting the colour space will make no real difference to the file size.

Do you have access to Lightroom? A smart collection could gather all the psd files. You could then export them to an SRGB JPEG file. File sizes would be somewhat smaller.

rbeene wrote in post #18189682
Do you have access to Lightroom? A smart collection could gather all the psd files. You could then export them to an SRGB JPEG file. File sizes would be somewhat smaller.

Thats actually a good idea. Now that I think about it you could do the same in Bridge by searching for .psd and then go to Tools > Photoshop > Image Processor...

I should have made myself more clear...I want to convert them to a format to is likely to be acceptable
to the pro printers ten years down the road.

chauncey wrote in post #18189777
I should have made myself more clear...I want to convert them to a format to is likely to be acceptable
to the pro printers ten years down the road.

Well I have run the tests and for an 8 bit RGB file you will not be able to see the difference between a TIFF file and a Q10/80 JPEG file, and that is the format that I would use. When I did my tests I could only just measure some very small variations between the TIFF and a Q12/100 JPEG file, variations of the order of 1/256 or 2/256 on some channels of some pixels, and I just don't think anybody could see a variation that small, even in a print. The variation between the Q10/80 JPEG and the TIFF was of the same order as the Q12/100, although there was a similar level of variation between the two JPEG files, so it is apparent that although there are small variations from the TIFF for both, the exact variations are different. I would go with the choice of JPEG files at Q10/12 since the level of compression is very good, between 40-60% smaller than an uncompressed format, so they are easier to store, and also because I do not see JPEG being totally superseded by another virtually universal format. Also just about every lab, regardless of quality etc can handle JPEG files.

If you really insist on a format that is not JPEG then as far as I can see your only real option would be TIFF, but most labs that do accept TIFF files seem to want them in 8 bit colour and as a single layer. You can use lossless compression with TIFF files, and I would go with LZW rather than ZIP, although ZIP is now almost a universal standard for lossless compression, it is not always supported on all software that supports TIFF. Even LZW compatibility can be an issue at times though. Just make sure you don't go with TIFF and use JPEG compression, you might as well just use the JPEG format, and again compatibility can be an issue. Remember that a single layer 8 bit uncompressed TIFF file will occupy 3× the pixel count in Bytes, plus a relatively little bit for the EXIF data and colour profile, so they can end up taking up a lot of room, and 16 bit files of course need 6× the pixel count of data storage.

So other than JPEG I would say that a single layer, 8 bit uncompressed TIFF file is the most likely current format that will be supported by any labs in the next 10 to 15 years.

Alan

Been using TIFF files for as long as I've used Photoshop; except for a number of images when I was really, really starting, I've never bothered with PSDs. Other than PSD being the native format for Photoshop, there's little advantage in using it. So far, I've not run into anything PSD can handle that TIFF can't. TIFFs are also recognised natively by my computers OSes, and I can use PhotoMechanic (or other programs) to read them, tag them and bag them (export to JPEG or other formats for printing or the web, that is).

Ah, you mean convert PSD to Jpeg. I wonder if you can do that on just PSD files using Photoshop Image Processor, or maybe you write a small action to do it.

Alternately
- Find all PSD files using Windows explorer / search
- Drag into Photoshop, configured to open RAW files
- Save all. This will put them all into one directory though.

For maximum compatibility with photo labs save them as sRGB Jpegs. Normally I would just save images at maximum quality, but if space is still an issue a small amount of compression is unlikely to show up as reduced quality in print. Try saving one or two and opening them in Photoshop next to the original PSD and viewing them side by side at 100%.

For your own archives I would recommend switching from PSD to Tiff and then using Zip compression. There is nothing wrong with the quality of either format but PSD limits your choice of editing software options.

chauncey wrote in post #18189587
My kids have been nagging at me to convert my PSD's for print, just in case they might want to print some for memories down the road.
As I've got 4.5 TB of them, it will take some time unless there's a way to do them en mass, Y/N

With the great free FastStone Image Viewer, I'd do it like this.

I'd select all the applicable PSD files in a folder and invoke: Tools > Batch Convert Selected Images.

That would convert an entire folder of PSD files to JPGs in one sweep, resizing and/or renaming them in the process, if desired.

http://www.faststone.o​rg/download.htm