2014.09.30 update: If you do not understand HDR photography, I suggest you read the post and then come back here for an update. In an email from HDRSoft , they pointed out something so obvious I cannot understand why I did not see it before. While you want a series of photographs that are several stops apart for HDR, the reason that cameras change the shutter speed rather than the actual f-stop to achieve this result, is that changing the f-stop (while keeping the shutter speed constant) will not just affect the amount of light getting into the camera, bit also alter the depth of field; on the other hand, changing the shutter speed (while keeping the f-stop constant) only alters the amount of light getting into the camera, and not the degree of focus anywhere in the photograph. As Homer Simpson says, “Du-u-h!!!” I also became aware of an excellent FAQ they have.
I have had a few emails from people asking me to explain High Dynamic Range (HDR) photography a little more. Below is a photograph produced using HDR software that I recently took at Gilson Lake in New Hampshire. (More photos from that shoot to follow as soon as I can.) After that, the individual photographs used to create the final photograph are also shown.
The problem often facing photographers is how to manage scenes with both deep blacks and bright whites; or, in other words, scenes with a high dynamic range of light. If you open the aperture (also referred to as ‘f-stop’ or ‘stops’) enough to expose the parts of the scene that are dark, the bright sections will wash to pure white. If you close the aperture down to expose the bright areas properly so that you can see their details, the dark areas are just black.
HDR always uses an odd number of photos: a ‘normal’ baseline shot and then some number of photos with the aperture closed down and then the same number of photos with the aperture opened wider. Experience has shown that the best results are gained when each photo is two aperture settings away.
Thus the simplest HDR set of photos is one baseline photo exposed normally, one dark photo with the aperture closed down two f-stops and a third photo with the aperture opened up two f-stops above the baseline photo. Because of an article I recently read that experimented with the process and found no improvement over a five photo spread using 2 f-stops between each, that is what I use, and explains the count of photos I show below.
It is curious that while HDR talks about opening and closing the aperture, this is not what cameras actually do. In fact, modern cameras set up to take HDR photo sets simulate the effect of changing the f-stop by actually playing with the how long the shutter is left open: longer exposures are like stepping down the aperture up, shorter exposures are like stepping the aperture up.
Newer cameras come with the ability to do HDR photos in the camera. However, I have not seen any photograph produced this way that was nearly as good as one made using separate photographs combined afterwards using a good software product. For HDR shots, I use Photomatix by HDRSoft, which is generally agreed to be the best. Although at just under $100 it is not cheap, no one ever got into photography to save money, and the investment quickly pays for itself quickly with stunning photos. Even when taken by someone like me!)
Any camera set to take HDR photos must be in a manual mode, usually aperture priority mode. Most, if not all, Canon DLSRs can be set up to take HDR photos, by: 1) setting up Exposure Bracketing to two f-stops, and 2) setting the shooting trigger to high speed continuous. (I am sure manufacturers do the same thing. The HDRSoft website has both tutorials and a list of supported cameras.) That way the camera automatically takes the correct number of photographs with the aperture changes pre-selected automatically. While shooting from a tripod is preferred, steady, hand held shots also work well. (In fact, the sample below was hand held.)
And that is all there is to it. HDR photography is actually very easy and once you start you realize how many situations arise where it helps you create amazing photos.
Before viewing the photographs, I would also like to invite you to visit the poetry blog, the Book of Pain. As always, special thanks to my dearest Lyn, She Of Great Taste In All Things But Men, who does most of the photo selection. Thank you for dropping by the Book of Bokeh.
Produced via HDR:
Normal, “baseline” shot:
Four f-stops down:
Two f-stops down:
Two f-stops up:
Four f-stops up:
All photographs and comments ©2014 by John Etheridge with all rights reserved; not to be used without the expressed written permission of the copyright owner.