I have been discussing HDR photography with friends and colleagues for the past few weeks, but it seems what everyone needs is a really good example. I have published a bunch of HDR photos on my Flickr page. But the real question is where do you really need this. Since discovering this technique, I find my self looking for shots where the dynamic range is beyond that which my camera can handle. I set up these shots just to see how it will look. Continue reading
Comments sowed the seeds of doubt about whether HDR photography is worth the trouble. As a hobbiest I have not really spent much time manually manipulating RAW format pictures. My camera (Canon G6) has a 10 bit per pixel sensor, which gets then compressed to 8 bits per pixel in the JPG. That is potentially 10 f-stops (EV) of dynamic range. Somewhere I found a web page listing the G6 as having a luminosity range of 1:650, which is between 9 and 10 EV. I hear better cameras can get 10 to 11 EV. Maybe, as you say, that is enough. Clearly combining pictures taken +2 EV, and -2 EV could potentially potentially add 3 or 4, giving the total range around 13 or 14 EV. How do I know whether I need the extra range?
How important is this dynamic range, anyway? The human eye records an instantaneous dynamic range of 1:30,000, a range of 1:200,000 if you allow a couple of seconds for the iris adjust, and 1:1,000,000 if you wait 20 minutes for the eyes to adjust to darkness. All of these make the 1:1000 of a camera seem tiny. But how much do you really need? Continue reading
A few days ago I found out about High Dynamic Range (HDR) photographs. A short search on the web will bring you lots of information, but somehow I have been living just fine completely oblivious to HDR.
The threory behind HDR is that film (and digital cameras) have a particular dynamic range that they are sensitive to. Light intensity values that fall outside of this range, tend to get smashed together and “washed out”. You can see this easily if you take a picture of someone with the sky behind them, but set the exposure so that you can see their face. Continue reading