Lately I have been trying out different types of merging multiple exposures into one final image. It is technically interesting, and very challenging, but it really distracts from the actual picture making process. At least when you don’t have the necessary knowledge and skill.
So far I have been using the following tools:
- Photoshop, manual HDR merge using masks and layers.
- Photoshop, automatic HDR merge function
- PhotoAcute, HDR to DNG format
- PhotoAcute, noise reduction
- PhotoAcute, resolution increase
- Helicon Focus, focus blending
- Photoshop, image stitching
To summarize my positive experience so far:
PhotoAcute HDR and noise reduction to DNG works very well. This method actually blends bracketed shots to expand the dynamic range, or shots with equal exposure to reduce noise, which in effect also expands the dynamic range. The result is saved back to a DNG raw file which can be imported to LightRoom and processed like any other RAW file. The thing you will notice is that you can suddenly pull down the highlights using the rescue slider without weird artifacts, and you can pull up the shadows using the fill light slider much more before you see any noise.
Helicon Focus worked remarkably well. I haven’t managed to come up with that much use for it yet, but I will have it in mind for future use. Once you get the focus bracketing down, you can really control the depth of field. It is easy to use, and the output is really high quality. The licensing is a bit strange. You can either buy a one year license, or a life time license. Each comes in both regular and pro edition.
Photoshop image stitching. I have heard that CS2 had some problems, but as far as I can tell, CS3 is coping well. So far, the actual shooting is a bit difficult, I’m waiting for my RRS pano clamp, which hopefully will make things a bit easier.
Photoshop manual HDR merge. I’ve done this a couple of times from two exposures. One for a bright sky, and one for the dark foreground. It is time consuming, but works very well. Sometimes it is better to use this than any automatic HDR blend since you have absolute control of the blend.
What does not (yet) work for me:
Photoshop automatic HDR. I find it very difficult to create natural looking results using this technique. I’m not saying it is impossible, or the technique is not good, it is just that I haven’t cracked the code yet. I’m not sure if I will ever try. The combination of PhotoAcute and manual merge seems enough for me.
PhotoAcute resolution increase. Haven’t managed to get good results so far. The results looks quite soft, but I have a suspicion that proper sharpening will help. That is if the input files are good. The pixel count will be increased by a factor 4, and a resolution increase of 50-60% is said to be achievable, but it is difficult to determine just by eye balling.
Things to avoid:
The most stupid things I have tried is to combine several blending techniques in one image. Like stitching with HDR blended shots. This is done by others on a regular basis, but it really requires that you have the skill required to do each of the blending techniques separately. Also, while being pretty cool if you’re a technically minded person, it will most likely distract you from the important task, which is to make a strong image. You should really try making the shot without these techniques first, only doing merges if you can’t solve it any other way. Also, you must practice the technique. It is difficult to get good results.
