Getting started with HDR photographymonday 9 November 2015, 20:33 by Iris van Liempt | 2264 times read | 0 comments
It has become clear that there is a lot of interest in HDR as a way of editing photos. Especially the tone mapping needed to rightfully view an HDR can create a surrealistic effect. Personally I think this is beautiful so this gave me good reason to get to work with High Dynamic Range again.
I say 'again' because I have already tried before but I didn't get the desired results then.
An HDR can be made in every situation. Personally I have decided to pay a visit to the st. Stevenschurch in Nijmegen (Holland). This church is open most weekends for visitors and it allows its visitors to take photos (as long as they are not used commercially).
What is HDR?
For a High Dynamic Range image, obviously you will need to choose a subject with a high dynamic range. The dynamic range of your camera is the amount of stops your camera can capture. When taking a landscape photo under a clear sky, for example, it is difficult to acceptably expose both the sky and the ground if you're not using a flashlight. The contrast between the two (the lightest point relative to the darkest point) is too big. The dynamic range of your camera is insufficient and this results is bleached spots (pure white) or pure black spots in your image.
To solve this problem you can work with (gradual) ND filters, like the nineties, or, like 2006, work with HDR. In HDR you combine multiple different images so both the highlights and the dark parts still contain detail.
The great disadvantage of HDR is that it cannot be viewed on current screens. This means that HDR always has to be scaled back to a standard 8 bits image that you can process as usual. This scaling back can be done by using tone mapping.
Capturing different exposures
In the church I took photos from different angles. With every angle I took photos from around two stops underexposed up to two stops overexposed. In doing this, you start by determining the right exposure for the image. This is the exposure you would have normally picked when taking a shot of the given subject (average exposure). It is easiest to use manual exposure. Start by setting the aperture to gain the desired depth of field and set focus to manual as well (after you have focused).
Using the average exposure as your point of reference you start by underexposing your shot by two stops (with my Canon 400D you reach two stops underexposure by reducing exposure with six clicks; every step is – 1/3 EV). Take a shot with these setting. Of course, your image will be way too dark. However, possible highlights will be well exposed; these would have been bleached when using an average exposure.
After this first photo you go back to average exposure and take a new shot. Then you overexpose by two stops and take your final photo. This last picture will mainly be overexposed, but it will cause the dark areas in your shot to be more visible.
Note that the method described above is a guideline; of course you can deviate. In any case, make sure you have a shot in which highlights are well exposed, a shot with average exposure and a shot in which dark areas are well exposed. You may need to have one or even three stops between shots, instead of two. Also, it is no problem to take extra shots with different exposures, for example to bridge huge differences in contrast.
Obviously, HDR requires you to use a steady tripod so the composition will be exactly the same for every shot you take.
When you are home and behind your computer, it is time to combine your shots. A much used software for this purpose is Photomatix. They offer a free try out version on their website as well. Photoshop can create and handle HDR files too.
At first, I tried to use the automated batch function that the software offers so I could instantly use my RAW files. For some unclear reason however, the result was a pink image instead of the desired HDR photo.
As an alternative I chose to convert the RAW images to Jpeg first, using Photoshop. Then I used these images as import files. This provided better images. For creating the end result, I practically just followed the standard tutorial of the software.
After the HDR image is created, you apply tone mapping to scale the image back to an 8 bits image. Photomatix can do this for you as well. In a screen provided with a preview, you can adjust the image to your own taste. It is up to you to decide if you want to give your image a natural look or to give it more of a graphic sort of effect, which I personally think is very beautiful.
Original text: Elja Trum
Translated by: Iris van Liempt
About the author
Iris started photography in 2012 and found a real passion in photography. She's attending the New York Institute of Photography and studies psychology.
Be the first to share your insights!
Share your insightsPlease note: Articles older than a week can only be commented on by registered users.
Do you want to leave your insights? Register for free.