RAW Conversion - 8-bit vs 16-bit

[Michele]

When I first started to shoot RAW, I always kept my images at 8-bit. THen last spring I found out that I should be using 16-bit and I tried that for a few months, but now I have found myself back at 8-bit. I know that 16-bit seems to hold your images together more in reference to the histogram, but how do you deal with the lack of speed on computer for editing? Is it really better to do 16-bit?

For me, I see that 8-bit has a pro side of faster computer when dealing with 8-bit, but I am not sure what other reasons I have. Pro for 16-bit is image quality when you look at the histogram, but I can't tell when I put two images side by side (one 8, one 16) and the drawback to 16-bit is slow, slow, slow computer speed.

What are your thoughts?

Michele

[mikej]

I always convert from raw to 16 bit tiff. Yes, it's a bigger file and a extra step somewhere along the process, but when I need that little extra bit of information in the shadows to pull out the shot, it's there.

I know that not all Photoshop actions can deal with 16 bit and even Photoshop 7 could only do a limited number of things in 16 bit. So I'd do all the things that would work with 16 bit first and then convert it to 8 bit to finish it up.

I didn't need it all the time, just like I don't need raw all the time... but I shoot and process everything the same so that my post processing is simplified and I don't have to remember which way I shot an image or processed it weeks or months later if I need to go back and re-visit the image or group of shots.

It just depends on how you shoot and how close your images are to being within the lattitude of your camera and properly exposed. The closer you are the less you need 16 bit or even raw.

Mike

[JKSeidel]

Mike summed things up pretty well. If it's a shot that matters, then 16 bit is the only way to go. The extra data can never be recovered once converted to 8 bit. As Photoshop progresses, there are more and more functions that will work on 16 bit images. Extra processing (CPU cycles & RAM) time is the price paid for having the extra data.

[ohenry]

Here's a practical demonstration of 16 bit processing vs. 8 bit processing.... http://www.visual-vacations.com/Photography/16_vs_8.htm

And here's what Bruce Fraser has to say on the subject ... http://www.creativepro.com/story/feature/7627.html


As you've said, larger files and slower processing are the downsides of 16 bit...but the upsides outweigh any negatives, at least to me.

[Michele]

Thank you all very much for your info. YOu all have given me something to really think about and take more seriously. Michele

[Neil V]

Definitely 16-bit all the time. After all the hard work I took to capture a scene I don't want to be throwing any of that info away. I find the biggest differences come in area's of fine tonal graduation, like a nice blue sky...

[dc2]

I would love to use 16bit on all my pics but just dont find it practical the files are huge ,
so I use it when its practical [ie not too many image's at a time]