How Many Exposures Should You Shoot for Great HDR Images?
I’m often asked how many exposures I use for my HDR images and tend to make myself unpopular by answering “As many as it takes.” This sounds glib but it is, in fact, the truth. Some people appear to be under the impression that you can get by with always shooting, for example, 3 images spaced 2 stops apart. This may work most of the time but that will likely be by luck rather than design. An outdoor scene will probably be captured fine using exposures from -2EV to +2EV but inside a cathedral with bright, stained glass windows, for example, it can take 11 shots (or more) spaced 1 stop apart (-5EV to +5EV) to capture the full dynamic range.
The point of bracketing for HDR is to ensure that you capture the entire dynamic range of the scene – as much shadow detail as you can get and all the highlights. To do this, you really have to check your histogram after taking a basic set of bracketed exposures and add to this set if needed.
These days, I typically start with either 5 or 7 images bracketed by 1 stop. The initial choice will depend upon the scene I’m shooting and my assessment of the dynamic range but it doesn’t really matter as long as you follow the next step. Once the initial bracket is done, make sure you don’t move the camera but review the brackets on your LCD with the histograms visible. The darkest image should have no blown out highlights (if you have the ability to turn on “blinkies” to warn of this, that’s really helpful) and you should see no significant bunching of data on the right of the histogram. The lightest image should have no solid shadows (data touching the left edge of the histogram). To be extra safe and to reduce noise in the shadow areas, I always try to ensure that my lightest exposure has no data at all in the bottom quarter of the histogram.
I’m often asked how many exposures I use for my HDR images and tend to make myself unpopular by answering “As many as it takes.” This sounds glib but it is, in fact, the truth. Some people appear to be under the impression that you can get by with always shooting, for example, 3 images spaced 2 stops apart. This may work most of the time but that will likely be by luck rather than design. An outdoor scene will probably be captured fine using exposures from -2EV to +2EV but inside a cathedral with bright, stained glass windows, for example, it can take 11 shots (or more) spaced 1 stop apart (-5EV to +5EV) to capture the full dynamic range.
The point of bracketing for HDR is to ensure that you capture the entire dynamic range of the scene – as much shadow detail as you can get and all the highlights. To do this, you really have to check your histogram after taking a basic set of bracketed exposures and add to this set if needed.
These days, I typically start with either 5 or 7 images bracketed by 1 stop. The initial choice will depend upon the scene I’m shooting and my assessment of the dynamic range but it doesn’t really matter as long as you follow the next step. Once the initial bracket is done, make sure you don’t move the camera but review the brackets on your LCD with the histograms visible. The darkest image should have no blown out highlights (if you have the ability to turn on “blinkies” to warn of this, that’s really helpful) and you should see no significant bunching of data on the right of the histogram. The lightest image should have no solid shadows (data touching the left edge of the histogram). To be extra safe and to reduce noise in the shadow areas, I always try to ensure that my lightest exposure has no data at all in the bottom quarter of the histogram.
