Steve Fenton

Automatic deep focal range photography

If you own a digital SLR camera, you have probably heard of High Dynamic Range photography, which is where you combine several photographs taken with different apertures to create a single picture with high detail in all of the light and dark areas.

Here is an example of HDR in action – normally, you would expect there to be areas where the shadows obscure the detail of the image, but by combining images at different exposures, and discarding the over-exposed areas in the light image and the under-exposed areas in the dark image, you get amazing detail across the whole picture.

View an example on Wikipedia

The best news is that modern DSLR cameras will now do the work for you, taking multiple shots with different apertures and combining them in-body without any effort at all.

So here is a suggestion that came up in conversation with a friend: Automatic Deep Focal Range Photography. This is where you set up the camera to take several shots adjusting the focus slightly between each shot. Essentially, the same as the automatic bracketing used in HDR photography, but instead of adjusting the aperture, adjust the focal length.

This would allow the best of several shots to be selected, for example in portrait photography you could select the shot with best focus on the eye – but could also be used to combine several shallow depth-of-field shots to highlight detail. If you have ever taken a photo of a hoverfly, you’ll know that you have to choose between focus on the eyes or focus on the wings.


By having a selection of shots with different focal lengths not only could you choose the best one, you could combine them to get the perfect depth of field by taking the area of focus from several shots and merging them together. Ideally, you would get the camera to do this automatically, but even having the shots taken in sequence with the focal length adjustment taking place for you would mean you can work on the set of images later on.

Written by Steve Fenton on