Over the years as I have worked with film scans, then raw images captured with DSLR cameras one of the interesting things I have found to be true is that the more you "tweak" or adjust an image in Photoshop or Lightroom the more you are degrading pixel data. Now, before I get too many comments here - I will offer up of course that to see this in an image most of the time you'll have to take an image to extremes before it will fall apart, but not all the time.

As the old saying goes: "Garbage in, Garbage out." This is obvious when it comes to both film scans and digitally captured images. A bad scan can only be so good no matter how much work you do in Photoshop or Lightroom. (And by the way I do use Lightroom to work up the majority of my high-resolution films scans since it works on tiff images the same as it does with raw files.) And in regards to digitally captured images, a poorly exposed image can be recovered to some degree but the file integrity will never be as good as it could have been had the image been exposed properly.

So, what I am getting at here, is that in my experience one needs to be very careful to capture the image in the camera with the best possible settings if one is going for the best file quality in the end. Why, you might ask? Because in the end the more sliders you move to adjust the image in Lightroom, ACR or any raw processing application the more you are degrading the image quality of the original raw file. For most images it is an imperceptible amount of image degradation. In some instances, like with noise reduction, we are actually helping the image quality but this as well could be overcome using proper lighting and lower ISO's in camera. Try adjusting your white balance in Lightroom to an extreme and you'll see all kinds of artifacts show up that don't appear at the normal settings. If you take some sliders to extremes you'll notice the difference very easily. But even if you don't go to extremes and you really look at your images closely as they were shot and after processing one can see a very slight degradation. Now, whether or not this is apparent in a print, even a large one is a whole different matter.

When printing, I often add a lot of sharpening to my images so they appear tack sharp on matte papers which have a lot of ink spreading out when it hits the paper. In fact the images look pretty crunchy just before they get printed. In this era of 30-inch monitors, we often see much more detail in our images on the monitor than anyone else ever will. Hence, just how much you can push an image depends on many factors obviously - personal taste, an effect you are trying to create or how the image will be displayed.

If you want to see for yourself just how much an image can be degraded take any image in Lightroom, switch to grayscale mode and then make some radical slider adjustments in the grayscale dialog and zoom in to 1:1 and hit the before and after mode which is the backslash key (\) on Mac. You'll begin to see what I am talking about very quickly. As an example I have converted a color film scan to grayscale in the images at right. Check out the before and after here and you'll see right away what I am talking about - especially if you look at the artifacts in the sky behind the climber in the black and white version.

The moral of this story is just be aware of how much you can alter your images and what effect that will have in Lightroom and Photoshop.

That's it for this session. See you next week.

Adios, Michael