Monday, November 10, 2008

An HDR Comparison

Poinsett Bridge - HDR

As I have mentioned previously, I have started experimenting with HDR photography and thought I would try a comparison between an HDR image and a standard photograph with my typical processing. This weekend my family and I went out along US Highway 11, aka the Cherokee Foothills Scenic Highway. Along the way we stopped at the Poinsett Bridge in Greenville County which is part of the Poinsett Bridge Heritage Preserve. The foothills were in full Autumn colors and we had a great afternoon drive.

More after the jump

While at the Poinsett Bridge I attempted to capture a few series of exposures to process using the open-source Picturenaut HDR software. The photograph above is the best of the attempts. It is seven frames of the same scene taken with the camera on the tripod and changing the shutter speed for each shot. I goofed up the exposure bracketing in the other attempts and didn't get acceptable results when I tried to process them.

I like the above photograph for a couple of reasons. It has a kind of dreamy look to it that is enhanced by the blurriness of the background trees and the foreground water and leaves. I think this happened because of the movement of the water between frames which also moved the leaves, and there was a wind which was moving the upper boughs of the trees. All of that movement combined to cause Picturenaut to average the tonal values on the various exposure together resulting in the blur you can see. I think it actually lends the image a painterly impression.

The quality that I like the best about the image is the lighting on the bridge itself. The highlights are fairly well controlled and the shadows are not too dark. However, even the bridge looks a tad impressionistic to a degree and required additional, selective sharpening to reduce that quality. I also tweaked the contrast and color saturation a tad in Capture NX2 for the entire image.

Pointsett Bridge

This photograph is one that I took "normally". It was hand held and exposed so that there were few if any blown out highlights on the LCD screen. I processed it using Nikon's Capture NX2 RAW processing software. While developing it, I added my normal contrast curve, boosted the colors a bit, and used the high pass filter for sharpening as I do with most of my photographs.

I like this version of the scene as well, but for different reasons. Everything is crisper and more clear in this photograph. It looks more like a photograph, I suppose, than a painting. However, I don't like the lighting on the bridge quite as much as the bright areas are just a bit too bright and bleed out some of the details. The differences in this quality can best be seen by looking at the keystone in the arch. In the HDR version, the keystone is nicely exposed/blended, while in the regular version it has lost some detail due to the bright sunlight.

Both images could certainly be improved with better field techniques and better processing knowledge. However, I think it does give a good look into the differences between HDR and normal processing. I am excited to continue playing around with HDR images. It seems to be an area that could broaden my processing capability.

In the end, both images serve their purposes and that is what it is all about.

Keep shooting.


John Brainard said...

I wish I had better tools at my disposal for HDR images. I'd spend more time learning how to properly expose for HDR. Oh well. :)

Your photos above are rather nice. They both have a very inviting quality to them, but I like the HDR version better. It's nice to see that HDR can be used for realistic photos.

Excellent work!

Craig Lee said...

Thanks, John. I have certainly seen some overly processed HDR images around which had caused it to get a bad name in some ways. However, at it's most basic level it is simply another way to capture and develop the scene and that is what I find interesting about it.

Pher said...

I'm going to shoot Poinset Bridge tomorrow, and I too do realistic (not horribly overdone) HDR photos. Thanks for this!

Craig Lee said...

Your are welcome. Glad I could help.

lsk said...

I just started playing with HDR today. No, the resulting pictures are not quite as CRISP, but then, the camera adds sharpness to most daylight photos, so sometimes look a little TOO polished. Where I really find the pleasure of HDR, is in lower quality lighting. Brings out the missing details. Wish they could come up with this system for action shots.. BTW. LOVE those Bridge shots.

Craig Lee said...

Thanks, Isk.

As for HDR action shots, I think that I remember reading about some experimental techniques using either high speed video or multiple cameras synchronized together. Either way, it was still quite expensive. Best to expose for the subject and use either single frame tone mapping, or layer masks in Photoshop.