8-bit vs. 16-bit

[e.rose]

So quick question...

There are certain filters in PS that you can't use unless your image is in 8-bit.

If I were to convert a 16-bit image, to an 8-bit image so that I could use the filter, and then convert it BACK to a 16-bit image once I'm done.........................

Is that going to make a really huge difference in photo quality by the end of it?

SPANKS!

 

[Robin Usagani]

If im not mistaken, you cant save a file to JPEG with 16 bit?

 

[unpopular]

No. When you convert to 8-bit, it removes tonal channel data to make it fit into the 8-bit palette. When you convert back to 16-bit it spreads the 8-bit data over the the 16-bit palette.

If you are running a filter that only affects color, you can apply the original 16-bit version to the back-converted 16-bit version in luminance mode, and retain 16-bit luminance, but not hue nor saturation. However, in RGB mode the three are interconnected. What this would mean exactly for the image I am not sure.

You could likewise apply the original in saturation, color or hue modes. But I have a feeling you wouldn't see a lot of benefit.

 

[pixmedic]

I thought you were talking about NES -vs- SNES....guess not

 

[unpopular]

Here is a very embarrassing thread I started when I was a relative noob. It covers a lot on the subject of up/down sampling, though it is pretty technical:

Histogramatic Error in 16 bit Mode - Photo.net Digital Darkroom Forum

 

[KmH]

Many Photoshop tools are 8-bit only tools because the amount of math they would have to do using 16-bits is prohibitive.

Do all your 16-bit edits before converting the bit depth to 8-bits to use the 8-bit tools.