HDR photography gets better all the time…but still we see lots of HDR processed photographs around that have loads of artefacts, in particular haloes, edge effects and strange unrealistic colours. I have been using HDR techniques for some years now and, during that time, my preference for software has changed as the software packages have improved.
Back in 2009 I found Picturenaut to be a good free HDR package. HDRi comparison…Photomatix Pro vs Picturenaut…a first look.
Picturenaut looked like it was going to be a really good free alternative for photographers who want to try out the process without spending a lot of hard earned cash. It has, perhaps, been overtaken in recent years by other open source software and a comparison of free HDR softwares is to be found here. So, if you are looking for free open source software, there is quite a bit around.
More recently I compared Oloneo HDRengine versus Photoshop CS5. At that time, I was still using a trial version of Oloneo, but I did go on to buy it and have used it with great success for a couple of years now. Recently, the friend who had introduced me to Oloneo suggested that many of her photo-friends were finding Nik HDR Efex Pro to be the best around, so I thought I’d have a look.
For today’s test, I used the following three exposures, all hand held and two stops apart…taken at high ISO (1600) on a Pentax K5 IIs.
Here are the raw files (click to enlarge):
With the three exposures together, all of the dynamic range was covered, with no loss of highlight detail on the underexposed version and no loss of shadow detail on the overexposed one. Noise was slightly more than I would have liked but would be able to be controlled by noise treatment should I go ahead with processing the files “for real use”. I did not perform any noise treatment on the samples beforehand.
All three softwares, Photoshop CC, Nik HDR Efex and Oloneo HDR Engine were quick and easy to use. Nik works as a plug-in, the Photoshop version is integral, but Oloneo is a stand-alone.
I chose, in each case, the nearest to a natural rendering preset as I could find e.g. “natural” or “photorealistic”. I made a minimum of basic tweaks so that they were all coming out at roughly the same brightness and colour saturation. I then saved each as a 16 bit tif file.
These are the resulting files (with no further processing done post HDR blend).
Oloneo HDR Engine:
Oloneo is a stand-alone programme and, at the time of writing, costs 49 Euros (it was cheaper than that when I bought it !).
This looks pretty natural and the stonework on the top left an accurate looking stone colour. The vaulting is glowing from the warm lighting but not over-saturated. The blue of the sky is not over-done (maybe could afford to be a bit deeper). In fact, I find this quite a pleasing rendition.
Nik HDR Efex Pro:
At the time of writing, Nik products cost $149, which is about £90, for the whole suite of plugins. The interface is easy to use and needs no explanation for anyone who has used HDR software before. Here is the blended image:
The resulting picture was, perhaps, a little less natural looking, with slightly higher contrast (easy enough to correct if you want a less contrasty appearance) and a bit more colour variation, the blues being a little more saturated, giving the stonework left-top a cooler look. The blue of the sky was a little tending towards green but the colour of the vaulting is very pleasant, in my opinion.
Photoshop HDR Pro:
Photoshop lags a bit behind, for my taste, producing a flatter looking original from the photorealistic setting, which will need a little more adjustment post-blending. However, some people will find this more real looking and may prefer it.
So, all three of our softwares have produced an acceptable overall appearance and could each be tweaked either in the software or in post to provide an even more satisfactory result.
Taking a closer look
As with all processing, the devil is in the detail. Looking for “ghosting”, caused by movement during the exposures, I found none of any significance in any of the three samples. However, there was a definite difference in noise levels…remember this is basic processing in the HDR software without any special treatments and just using the most natural looking preset with a bit of brightening or darkening to make all three samples roughly the same tone.
Here are the samples, looking for noise (click thumbnail to enlarge) from left to right: Oloneo, Nik, Photoshop:
The Nik sample was much noisier than the other two. Oloneo and Photoshop had produced similar levels of noise, which were not intrusive, considering the pictures were taken at 1600 ISO, but Nik had produced intrusive noise.
Here are the samples, looking for edge artefacts: from left to right: Oloneo, Nik, Photoshop:
There were no troublesome edge artefacts over most of the images. However, where there was the highest edge contrast, along the edge of the window – all softwares produced some artefacts here.
There is a strong blue bleeding of colour at the edge of the window. The sky is a little turquoise and a little pale…however, the wire mesh of the window is reasonably clean looking. There is very little noise in the stonework. The shadows from the wire frame on the tracery looks fairly realistic. Outside the window, the highlights are a bit strong.
The Nik Sample has an even stronger bleeding of the blue at the edge of the window and this part of the sample is very noisy. The sky is a strong blue. The wire mesh in the glass doesn’t look natural, and the shadows cast by the wire mesh has a “frilly” edge to it. Definition of the sky against the stonework outside is the best in this sample.
Photoshop CC exhibits very poor edge definition between the sky and stonework, both the inside and outside stonework, in this example. The sky is green. The blue edge effect around the window is a little less than in the other two examples and noise is similar to the Oloneo sample. The wire mesh is the second best looking as are the shadows cast by the mesh on the outside stone work.
The Bottom Line
This was a simple test, using a single set of images. It is worth repeating a number of times with slightly different setting and different images. I have just tried to emulate the results that somebody new to the software might achieve – that is, to make a blend of three images, choose a preset that gives a natural looking result and output to a 16 bit tif.
In this example, Oloneo is looking like the best choice. Overall, it exhibited fewer artefacts. Although the outside sky was a bit wishy-washy in the Oloneo example, it isn’t so far off acceptable and could be tweaked a bit more before output or improved in post. Noise was low overall and the wire mesh in the window and the shadow of the mesh looked pretty reasonable.
Nik was the most disappointing in some ways, perhaps because I had been led to believe it may be better than Oloneo. Although it provided a punchy looking result and had a very good GUI, the colours were less accurate and it exhibited the most noise and edge artefacts of the three methods.
Photoshop provided a solid performance – neither the best nor the worst. It needs some post-processing to correct the sky colour and deal with some flat areas of tone, but if you are already subscribed to Photoshop, I see no reason to doubt it will provide a satisfactory job.
There are some finished images of Sherborne Abbey here.
Chris Widdall – April 2014