the travels & travails of an escaped lab rat

Gigapixels & High Dynamic Range Imaging

(or: “If you’re gonna to gloat, gloat big.”)

My current photography-related obsessions started innocently enough.

It was the middle of February, and I wanted to send a photo to a friend in Toronto showing how much I, too, was suffering through a miserable winter in Monaco (I actually had to wear a heavy jacket in the evenings — OMG).

After looking at the picture I had taken from my balcony, it dawned on me that the single image couldn’t entirely encompass just how much I was suffering in my Mediterranean surroundings.

But how to make the photo convey the statement I wished to pass along? The obvious answer was to take a bigger picture.

At first, I tried the camera’s built-in panorama function. That was a total waste of time. Not only was the in-camera stitching job horrible, the shot itself was limited to only five frames in prescribed directions. What I wanted — needed — was something far larger. I ended up constructing an image from 68 free-handed (taken without the use of a tripod) exposures shot with the camera in my cell phone (a Samsung SGH-G810 at the time), stitching them together and assembling the panorama by hand.

The result was just what I needed to show my friend how much I was commiserating over our mutual winter weather woes.

All kidding aside, I’ve always had a fascination with super-large resolution imagery. I find that having more room to work with in an image lets me put more content in more context in a single frame. The only trick is planning and executing a shoot so that assembly of the final photo won’t be a total nightmare (using a tripod helps immensely).

In addition to panorama shooting, the other trick I often pull from my imaging bag of tricks is the use of High Dynamic Range (HDR).

Basically, by taking multiple photos of the same image using different exposure settings, I can collect a greater dynamic range of luminances than I can with a single frame at the “correct” exposure. Through a process of range compression and tone mapping, I can then combine the multiple exposures to produce a single image that better represents the wide range of intensities found in real scenes than standard photographic techniques and methods would otherwise allow.

I been playing with panoramas for several years, but started really working with HDR only when I got my hands on a camera that allowed me to manually bracket exposure settings for my photos. Most recently, I’ve begun experimenting with combining the two techniques — panorama and HDR — to produce some really stunning imagery.

The only downside to this kind of photography (aside from the not-insignificant investment in camera and accessories) is that it takes time and planning before the shoot, and it takes a lot of time after the shoot in post-production to assemble the multiple ginormous layers and to process the combined colour map for the final image. Unfortunately, it’s not a method you can easily adapt for use with spontaneous photography (which is not, however, going to keep me from trying).

Sometimes, six megapixels in 4:3 just aren’t enough to say it all.

Loading Images
Monaco - View South from Balcony (2009) pano++Monaco - View East from Balcony (2009) pano++


Posted in Journal by madsci on March 23rd, 2010 at 10:58 pm.

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