Now, the question becomes you have gone through all these changes, you have done exactly what you want to do this image, you have made it everything you wanted it to be. Do you save the 16 bit version of the image or do you save an 8 bit version of the image? Because you can't save back to JPEG at this point. Standard JPEG format does not support more then 8 bits of data per channel. The JPEG 2000 format does, but that's not a format that's really caught on all that briskly.

So, I recommend you steer clear of that format, unless you are just editing images for yourself. If you intend to save a 16 bit image that you want somebody else to open, you are going to have to output that image to the TIFF format or to PSD format and you can tell that's the way it's going to be because if you press Command+S at this point or Ctrl+S on the PC, you are going to bring up the Save As dialog box as you can't over right the original file.

Alright, I am going just go ahead and escape out of that. Here is what I recommend that you do. If you are sure that you have made exactly the kind of changes to the image that you want to make, then there is no reason for you to stay in 16 bit anymore, you might as well down sample to 8 bit. You do that by going to the Image Menu, choosing Mode and choosing 8 bits per channel or you can of course press my keyboard shortcut Shift+F3 if you prefer and when you do that it's going to go ahead and convert that information. I am also going to flatten the image, remember that I still, if I press the Tab key you can see that, I have still got this threshold layer that's just sitting around here. Well, I am not using it anymore, it did what I needed it to do.

So, I will go up to the Layer Menu and I will choose flatten image, just the easiest way to get rid of that layer. I can also drag it to the Trash Can inside the Layers {alette if I prefer. Photoshop is going to ask me if I want to discard the hidden layers that's the whole idea of Photoshop, so go ahead and click OK, in order to accept that modification. Now, you can go ahead and save this image to the JPEG file format and the wonderful thing about it is your color targets will be retained. So, JPEG does accommodate little things like color targets, little bits of Metadata like that.

Now, what I love about going into 16 bit, applying the very, very specific levels modifications that we have applied and then going back into 8 bit is that we are still left with the smooth histogram. If I press Ctrl+L to bring back up the Levels dialog box, notice that, there are a few spikes in here, but there are always spikes inside of a histogram. Generally speaking, we are getting a pretty smooth result here, what we don't have is those big black spikes going on that will go all the way to ceiling, nor do we have wide gaps in between inside the histogram as a result of the interpolation that happened when we went from 16 bit to 8 bit. And we ensured that we didn't make any destructive changes to the image until we had accepted the final results. So this is good, I am going to cancel out of here, I just wanted to see that histogram and of course you can also check out the histogram inside the Histogram Palette if you like.

The final thing you might want to do is, go to the Image menu, choose Mode and then choose CMYK Color. If your commercial printer wants you to submit a CMYK image, why then go ahead and make that conversion then save the image out as a JPEG file or you can for certain printers and you will want to talk to yours, certain printers would prefer you just go ahead and submit an RGB image as long as it accepts as an Adobe RGB image which this one is and put them in charge. Let them take care of the conversion to the CMYK space, in case they make some last minute tweak to their CMYK profile or in case they decide to change the process for some reason or other.

So, now you have an idea the final thing to do would be to go to the File Menu, choose the Save command in order to update your changes. I am not going to do that because I don't want to overwrite my original file. But now you have a sense of how you can take advantage of the 16 bit per channel image editing mode and the more complex functions of the Levels dialog box in order to invoke a very, very specific and very, very accurate color correction here inside of Photoshop CS2.