I have to admit I was thrilled when Nisi announced the S5 filter holder for ultra wide angle (uwa) lenses which cannot take regular filters (the 100mm system). Finally we now have a comprehensive 150mm filter system for lenses like the Pentax 15-30, the Tamron 15-30, the Nikkor 14-24 and other uwa lenses with a front element which excludes the use of a 100mm filter system.
The genius of the S5 filter system is that the polarizer is placed behind the filter stack and that it rotates independently of the square filters inserted into the filter holder. The S5 holder comes with two slots for filters so that one for instance can use a 10 or 6 stop filter with a filter that balances (darkens) the sky.
I am shooting the Pentax K-1 which comes with a stupendous live-view system which basically means that when rotating the cpl (circular polarizer) I can see how its various positions affect a scene even with a 10 stop filter mounted in front of the lens.
I am one of those who prefer to compose a scene through the viewfinder and not with the camera set to live-view mode. With a 10 stop filter in front of the lens that is more or less impossible. However, when I mount the S5 system to the lens (Pentax 15-30) all I have to do is turning a ring and, voila, the holder is secured to the lens, and this only takes a few seconds. A brilliant solution because it takes only a few seconds to remove the filter holder and fasten it again. In other words, I don’t have to remove the 10 stop filter in order to re-compose a scene – I just remove the filter holder itself with a minimum of loss of time.
A pano from three verticals shot with the S5 + cpl + Nisi 0.9 soft. Edited in Lr and Ps.
That a filter system is easy to use is vital when one is shooting sunrises or sunsets when time is limited and the stress factor at times is very high. In this department I can nothing but give the S5 filter holder system top score. Also worth mentioning is that when turning the wheel which controls the polarizer the transmission is very direct so that the cpl rotates without delay in its circular holder. See link at the bottom for my S5 demonstration video.
Next we have to investigate how well the cpl performs, whether the system produces vignetting or not and the overall image quality, that is, how does the system affect colors, details etc – all these factors are of great importance when out in the field shooting what may be a one-in-a-lifetime experience in terms of light and conditions. Last thing we want is to see our images ruined by a filter system with a lousy performance. All prior experiences with Nisi is that none of the above so far has been a concern, but let us have a look at some example images having in mind that the images are subject to jpg compression and WordPress’ not very good image quality algorithm.
The first two example images are only gently edited in Lightroom. The first image is shot without any filters:
Whereas the second image is 120 secs and shot with the S5 + cpl + Nisi 10 stop + Nisi 0.9 soft.
We would perhaps have expected vignetting in the image shot with filters but there is none. Furthermore, there is no loss of detail compared to the filter-less image – and the highlights are not clipped.
The following image is a 90 secs LE with the S5 + cpl + Nisi 10 stop. The polarizer was set in such a way that it enhanced contrasts in the sky and water reflections.
And this is a very close crop from the image above. Details look very well preserved in both Lightroom and Photoshop – due to image compression the details are a tad washed out here:
Again we will have a look at a LE image (100 secs) shot with the S5 system plus the Nisi 10 stop filter. I readily admit that my fondness of LEs is re-awakened after I got the S5 system. The cpl was adjusted so that it added contrast to the sky and brought out the reflections in the water. While working with the image in Lr and Ps I could detect no vignetting, color cast or loss of detail. There was, though, a very modest magenta cast on my foreground rocks, but I am not sure if that is due to the filters or me not finding the correct white balance when raw prepping the image in Lightroom.
Nisi S5 + cpl + Nisi 10 stop -100 secs – f11 – iso 100 – 15mm
As far as I can tell the polarizer does its job perfectly in those situations I have put it to test.
There is a slight possibility that when turning the wheels which control the polarizer in such a way that the polarizer is turned in the same direction as we would go about unscrewing it from its holder that the cpl might loosen so please check the cpl itself frequently that it is well tightened at all times.
Nisi S5 square filter holder system: http://en.nisifilters.com/s5-150mm-square-filter-holder
My S5 filter holder demonstration video: https://www.youtube.com/watch?v=AQktM3puMyM
Nisi official S5 demo: https://drive.google.com/file/d/0B2fDvvovYn8DUW95TlQ4T0t4Zmc/view
Nisi S5 + cpl + Nisi 10 stop – 40 secs – iso 100 – f11 – 15mm