Using a 16bit Image in Illustrator poster

Question

I'm making a poster and am used to using 8bit images. The photographer I'm working with insists on using a 16 or 32bit version of his photo in the poster I'm designing. I'm used to laying out designs in Illustrator and then linking a .psd, but since Illus only accepts 8bit images -- is this a job for InDesign? I'm wondering how other designers approach this... what's the workflow for say a higher end production shop?
If the photo is larger than 300dpi, is 16bit really necessary? I'm assuming that it couldn't hurt and that someone may direct me to a conversation on bit depth, but sheesh -- it takes forever to save 16bit .psd's!

Answer 1

Wade_Zimmerman wrote:
If that is what you think about the monitor then how would it all of a sudden make a difference in 32 bit since the monitor is still 8 bit. It is not rational....
All of a sudden after doing what? If you convert to a higher bit depth you will see no difference.
The gradient appears different because of 3 things:
1. 32bit works in a linear color space, it doesn't have the usual 2.2 gamma correction needed for 8 and 16 bit integer  files and the color spaces of monitor displays.
2. Photoshop displays 32 bit images in a special linear version of the current color space and to compensate is applying a display gamma correction of 2.2
3. The Gradient tool is designed for non-linear color space
If you want to make the appearance of the gradient the same you have to apply a gamma correction opposite of 2.2 which is 4.4545 by using Image > Adjustment  > Exposure. You can achieve the same for the gradient image if when converting it to lower bit, in the HDR Toning dialog, you choose for method, Exposure and Gamma, and for gamma enter 2.2. You should have also used the same method for you image example if you want it to remain with the same appearance but don't change the gamma.
Anyway, the purpose of my example was not to achieve the same or certain gradient look like the one in a non-linear color space, or to explain you all this above, but to demonstrate that 32 bit images are indestructible, At anytime during a workflow in a pipeline using multiple programs and image editors, 32 bit images can be altered freely without destroying the details in the highlights and the shadows and can be always re-balanced by choosing which detail range and in what degree will be displayed when converted to 8 bit, by simply referring to the 8 bit monitor and making it look good on it.