An HDR and Silver Efex Pro weekend…March 23, 2009
What a fun weekend! Late Friday, I got word that two photo-friends, Eric Lawton and Bob Lott, were heading to Longwood Gardens Saturday morning. I met these two fantastic photographers on my first trip to the Tetons and Yellowstone with the Nikonians Photo-Adventure Trip. If was fantastic to catch up, meet Eric’s family and hear about Bob’s latest adventures, especially his work with high dynamic range (HDR) photography.
HDR photography is a somewhat new and certainly interesting form of photography. The concept is to increase the total range of light that an image contains through the use of multiple images at different exposures. Huh? Okay, it’s not as complicated as I just made it sound.
Let me present an oversimplified example. Let’s begin by stating your camera’s sensor can capture 100 levels of light at a certain exposure (yeah, I know you spent a lot of money on your camera, but for this example, it’s only capturing 100 levels of light. It’s only an example!). For many images this range is fine because there are only 100 or less light-levels in the image and you’ll capture them all. (Okay, this is waaay oversimplified, but bear with me). Some high-contrast subjects, however, have many more levels of light than the 100 your camera is able to record – let’s say 500 levels of light. So what do you do? You decide on an exposure of 1/125th of a second, f8 and ISO 200. Let’s assign this exposure the value of 250. This means your camera has recorded everything from light-level 200 – 300 or half the light below the exposure and half above. Anything over 300 is lost in blown highlights and anything below 200 is pure black.
So how do you fix this? Simple! Take five photographs each at different exposures. The first records the 200 – 300 range, the second from 100 – 200 the third from 300 – 400, the fourth from 0 – 100 and the fifth and final from 400 – 500. The beauty of this is most cameras will do this bracketing automatically (read your manual under bracketing)! Last, you combine the images and create your final image.
Here’s an example from Saturday. Walking in to the main conservatory of Longwood Gardens is a stunning, glass-roofed building with an ever-changing display of plants and flowers. Photographically, the problem is the amount of light from the glass ceiling and the darker areas towards the bottom of the room. Here’s an example of a “normal” shot of the room. In it, I selected 1/80 sec, ISO 200 and f11.
As you can see the ceiling is washed out due to the amount of light and there are numerous dark areas towards the bottom of the room. To combat, I used a nine image series of images each with a difference of 1 stop. In the end I had four “overexposed” images, four “underexposed” images and one “properly” exposed image. I fed those into HDRSoft’s Photomatix software and it blends these together to give you the following HDR image:
HDR photography can also bring out enhanced detail in an image. Take these two images. The first is “normally” exposed while the second is an HDR using five exposures of 1 stop difference each.
The difference is subtle, but the HDR shows more detail especially in the darker areas of the image.
I hope that gives you some insight into this interesting area of photography. Give it a shot. It’s interesting stuff.
Here are a few other non-HDR shots from Saturday that I really liked:
Sunday, Jen and I decided to take a trip to the Philadelphia Zoo. Without children it was a great time to focus on taking some pictures. When I got back to process some images, I decided to make a few black and white images.
At the last camera club meeting, I was asked if I would give a presentation on B&W post-processing. “Sure”, I replied, “It’s two minutes in Silver Efex Pro!” That’s all I know!
Nik Software’s Silver Efex Pro is an award winning and highly recommended B&W conversion software. Seriously, it’s all I use and I just use the default settings. I’m using it from inside Aperture. For me, I right-click my image, select Edit With and Silver Efex Pro and after it starts take the default settings with the click of the Save button. I’m done!
Here’s a couple from today’s zoo shoot:
If you’re looking for some additional software, I’d highly commend the Nik Software Complete set. It imcludes Silver Efex Pro along with the other Nik Software tools – Color Efex Pro, Dfine, Sharpen and Viveza. I’ll post more about these cools packages in a later entry.
I hope you enjoyed this entry. Check back often…