Raw Conversion 16 or 8 Bit tiff

[Robert Mosner]

Hi Folks

I was curious how many people on the group convert raw files into the 16 bit tiff file format. None of the current computers, printers, or software handle 16 bit per channel files so what benefits would I gain by using the 16bit format? I realize photoshop has very limited support for the 16 bit format.

Thanks

[leony]

Do this:

Convert a RAW as TIFF in 16 bits, and then in 8 bits.
Open both files in PS.
Pull up curves (Edit->Adjustment->Curves).
Click Auto.

Now look at how many "white separations" each adjusted curve has. All the "verical white lines" is the info you've lost!!!

You will notice that 16-bit file has a lot less white lines than 8-bit file.

This is primarily the only reason. After that you can convert it back to 8-bit for more editing.

Naturally, this doesn't work if you start with an 8-bit image, and convert it to 16-bit one to adjust curves as info was already lost in 8-bit mode.

This, and the whiteballance, are the only two reasons to use RAW over JPEG that I know of.

[robertwgross]

Robert Mosner wrote:
I was curious how many people on the group convert raw files into the 16 bit tiff file format. None of the current computers, printers, or software handle 16 bit per channel files so what benefits would I gain by using the 16bit format? I realize photoshop has very limited support for the 16 bit format.


None of the current computers, printers, or software?

That is a bunch of bull. Who told you that?

I have thousands of 16-bit-per-channel image files, I edit some of them every day, and I print out some of them every day on an ordinary Epson printer.

---Bob Gross---

[Robert Mosner]

You may be printing out 16 bit tiff files, but you are only printing in 8 bits per channel with equates to 16 million colors. On the other hand 16 bit tiff files equates to Trillions of colors. As I mentioned in my previous post -- No computer, or printer can handle the extra color depth of 16 bit tiffs.

[rdenney]

Robert Mosner wrote:
You may be printing out 16 bit tiff files, but you are only printing in 8 bits per channel with equates to 16 million colors. On the other hand 16 bit tiff files equates to Trillions of colors. As I mentioned in my previous post -- No computer, or printer can handle the extra color depth of 16 bit tiffs.


Look, it isn't a matter of how many, it's a matter of which ones. Yes, Epson's printer driver will convert that 16-bit file into 8-bits on its way to the printer. But at least the 8-bits of information will be even distributed across the 16-bits of data in the file, instead of being skewed towards one end while the other end is spread too far, which is what you get if you to big edits in 8-bit images.

As to software and computers, I don't know what you are using, but my version of Photoshop is quite happy to open 16-bit files and edit them. The histograms only show me 8-bit representations of the tone curve, but the data is in the file.

Plus if you save them as 16-bit files now, then you'll be able to take advantage of new versions of software and hardware that already trend towards supporting 16-bit color depth.

Film has more tonal information than print materials, too, but I don't see anyone suggesting that it should have less just because paper does.

Rick "who finds he needs that color depth only when making big moves with curves or levels" Denney