First of all, I must point out that I am a rank amateur, who’s only been doing this a week – if you need an expert, move along there’s nothing to see here…… However, I’ve got some good results already, and most importantly I can tell you how to do it using only free software, and if you like it you can spend several hundred dollars later on the professional suite!
So what’s an HDR image look like? This is a fine example from Evgeni Dinev:
While a beautiful photo, this type of image is not always possible with a single shot, as a normal exposure may not capture all of the detail with regard to light and shadows.
High Dynamic Range images are achieved by the blending of 3 or more images together, taken at different exposures, in order if you like, to enhance the best bits of all three.
So first, you need to take the images, typically 3: one normal exposure, one under-exposure, and one over-exposure. If you’re lucky, your camera will have AEB or ‘Auto-Exposure Bracketing’. What this means, is that when this function is switched on, pressing the shutter button once will take 3 photos at the aforementioned exposures. If your camera doesn’t have this function, simply take 3 separate photos, changing the exposure manually. On my camera, the range is from +2 to -2, and it is best to set exposure to these extremes. One other crucial thing is that the camera should be mounted on a tripod, or resting on a wall or something – the 3 exposures must be identical for obvious reasons.
OK, once you’ve taken the photos, you will have three images something like this:
The Normal Exposure:
And the over-exposure:
Now the top one is an OK photo, the middle is obviously very dark, but you’ll notice more detail in the clouds, and the last one is just very bright. You can already see just what might happen if we bring the three together…..
So to put them together, let’s get the first piece of free software: The ludicrously named Qtpfsgui. Don’t even try to pronounce it.
Unzip it, and fire it up. Then choose ‘New HDR’, and browse to your 3 photos as above, and follow the prompts to click ‘next’. Just accept the default options as they are presented to you. The program will process the images and present you with a rather odd looking HDR image. Save it with a natty name to suit yourself, and then from the top menu, choose to ‘Tonemap the HDR’.
This is where the fun comes in, I don’t understand it fully yet, but just by playing with it, you can get some great results. First click the big green ‘Apply’ button at the bottom, and your new HDR will appear with the default settings applied. A word of warning here: the bigger the image to be processed, the longer it takes your PC to think about it, which is why the image pops up quite small – do all your initial processing at this small size, or the processing will take hours.
Simply move the sliders up & down, clicking ‘apply’ at each stage, and noting the effect it has on your image – there are no hard & fast rules, just experiment. when it looks close to how you want it, increase the size and click apply again – I have a fairly powerful dual-core PC, and processing a 2048 pixel wide image takes 4-5 minutes, so don’t think your PC has crashed.
If it all looks good (or close enough), choose ‘Save as LDR’ and give it a new name – this will now save it as a JPEG or other common graphic file. You can now show it off to the world, or if you want to do some further fine tuning, use another free program, like Paint.NET.
Here’s the final product (for now) of my 3 photos above:
Compare that to the original ‘normal’ exposure, and there’s more colour, detail and life to the photo.
Like I say, I’m a rank amateur, but I learned to do that in a couple of days, so there’s no reason you can’t. Claire, I look forward to seeing your first HDR……