jpegs, 8 bit or 16 bit

[CynthiaM]

I have some older files that are jpegs that I've been working on and would like to enlarge to about 10x15 for prints.  If I make any edits in Lightroom and then want to export to Photoshop for more work, should I be choosing 16 bit or 8 bit in the external editor dialog box?  Is there any advantage to letting lightroom bring these into photoshop as 16 bit?  Somehow it would seem that somewhere along the way, the programs have to make up pixels, data, create something that isn't there, to do this and I'm not sure if that is desirable.  I know that 16 bit is preferred if they are raw files, but what about the jpegs?

[digitaldog]

JPEG is only supported in 8-bit so the additional data you capture device might have provided is long gone.

But when editing such data in LR, its going to be converted to a high bit, wide gamut data to process that data. So I suppose it wouldn't hurt to export in 16-bit (NOT JPEG of course) especially if you plan more work in Photoshop. Do as much as you can in the LR pipeline, leave the local edits, and edits not possible in LR (blending modes) for PS.

[CynthiaM]

JPEG is only supported in 8-bit so the additional data you capture device might have provided is long gone.

The images were captured as jpegs.  This was before I started shooting raw.

But when editing such data in LR, its going to be converted to a high bit, wide gamut data to process that data. So I suppose it wouldn't hurt to export in 16-bit (NOT JPEG of course) especially if you plan more work in Photoshop.

Now, I usually shoot raw (don't forget, the question pertains to old jpegs) exporting as 16 bit tiffs in ProPhoto colorspace for output to k3 inks.  Would you recommend bringing in these jpegs in prophoto as well if output will be to K3 inks?

Do as much as you can in the LR pipeline, leave the local edits, and edits not possible in LR (blending modes) for PS.

I do whatever I can in Lightroom.  Saves a lot of layers.