Apologies up front...really bad pun in the title of the post. Maybe two, actually. Not to worry. I've seen my doctors, got my meds, and am starting shock therapy. :)

If you've circled me on Google+, you'll have seen in recent posts my photos of Chillon Castle in Switzerland. In processing one of them, I did something with Curves I hadn't done before - specifically setting a point on the Curve before starting the adjustment. How and why I did...

At right is the photo I was processing, a few adjustments already applied (notably zeroing out Saturation). So, so. The subject of the photo is wshed out, flat, low contrast. The roof of the wall and the tower are not grabbing attention. But I liked the dark framing the window provided. I wanted to adjust contrast for what's through the window, but not the window frame. I could certainly brush in contrast or definition, burn the subject, or a few other methods (there's always multiple ways to achieve and end goal). All these involve brushing, so careful masking is needed.

As I considered what method to use it occurred to me - most of the frame is very dark. I could fiddle with Curves, leaving the dark end of the spectrum untouched. I added a new Curves adjustment, picked a reasonable spot on the histogram and with a single click added what I'll call a "control point" to curve, then adjusted the lighter side of the curve for the main subject of the photo.

Very quickly, this had a great effect on the subject. I did do some more touches since I thought the sill of the window lost something after applying this Curves adjustment. Here, I opted to brush out the curves adjustment on the sill. Soft brush, not painstakingly detailed. And finished with other adjustments I typically do on my photos (ex: Sharpening brush).

By using the Curves adjustment to adjust the contrast, the results came faster and I avoided some fine grained brushing. Setting a control point before fiddling with the curve was very useful. I will admit there's a very slight change in the dark area of the picture...you can see that in the curve. To truly nail down a segment of the curve, I think multiple control points tightly grouped would do the trick.