Iceberg Straight Ahead

I have no love for this fountain. I pass it regularly on my commute and because of the picturesque setting I am often inspired to photograph it. Many, many people are. The problems are, the ruins are fake and nearly every photo I take of the thing is boring. I thought the accumulation of blue ice at the base of the fountain was interesting though. Icebergs are not something you see very often in St. Louis.

Update: One of the advantages of having a queue for blog posts is that sometimes a scene evolves over the course of days. The weather has remained cold since I took the photo above and the fountain has increased its surrounding ice mass during that time. I wanted to get a picture of the fountain today because rest of the week is supposed to be warm. Who knows if I'll see this again? Unfortunately, I didn't get off work in time to catch the best light. Doubly unfortunate, I didn't have the right lens with me to get a close up. 

So, I made do and used it as learning experience. The picture below was shot in RAW so that I would have all of my 24 megapixels to buffer a generous crop. The RAW file also gave me more information to correct the difficult exposure in post processing. The end result? Not too shabby.  

There is one significant problem with this photo, however, that I didn't catch when I was on site. If you look closely at the tree limbs in the upper-left hand corner they appear to have a green tinge. That tinge is chromatic aberration (CA) which manifests as a fringe, or halo, of off-color on the boundaries of high-contrast transitions. The fountain ice has it too, a purple fringe in this case, which makes the ice look like its coming off the page in an unnatural way. 

Somewhat ironically, the CA in this photo is likely noticeable only because I was shooting RAW files as opposed to JPEG files. The reason for that is when the camera creates a compressed JPEG file it corrects for CA automatically. That process is not always completely successful but it does decrease the problem. To my knowledge, automatic CA corrections do not occur when creating a RAW file. Of course, it is possible to correct CA in a RAW file during post processing but I didn't have any luck with that with this photo.   

At some point, for my own benefit, I should write a geeky post on the science of chromatic aberration, what the camera does to prevent it and what the photographer can do to avoid or correct it. For now it is sufficient to say that the problem typically occurs when the photographer is shooting a high-contrast scene with a wide-open aperture. My bad, I must remember to close that thing more often.