Obtaining good filters for lenses with bulbous front elements has often been a challenge for me (and many others), but that was until I came across Nisi Filters which does not only produce “regular” 100 mm filters, but also offers very good 150 mm filter system solutions for a wide array of lenses which do not take regular filters, like for instance my Pentax 15-30.
We will in the following first have a look at the filter system itself before we move on and review some sample images. The review is not meant to be an in-depth scientific treatment of the filters. The point of view is more on the daily use side of things for the average photographer, as it were.
Pentax 15-30 and the 150 mm system filter holder:
Attaching the filter holder to the lens is a very smooth affair which only takes a couple of seconds. A screw on each side of the filter holder secures it to the lens:
It is actually possible to stack three filters in the filter holder:
The built quality of the holder is outstanding. “NiSi 150mm filter holders are made from aviation-grade aluminum with single element processed by CNC machine with Matte black frosted finish on the surface. The screw accessory are all made of copper and with black nickel plating. It’s durable and will reduce the influence of stray light on the imaging.” (Nisi Filters Australia)
The filter holder and a 0.9 soft filter:
The filters come in these protective and beautiful pouches (unfortunately the filters do not grow on trees ;)):
The four filters I have tested:
- 10 stop – long exposures for beautiful skies.
- 6 stop – long exposures (notably when dusk has set in and I haven’t time to wait for 2-3 mins long exposures) and waterfalls.
- 0.9 soft – balancing the exposure, that is, darkening the sky so that it is possible to capture a high dynamic range scene in one exposure. We usually use a soft filter when we do not have a very defined horizon line.
- 0.9 soft reverse – balancing the light during a sunset/sunrise when we have strong highlights around the middle of the frame.
One stop of light is doubling the exposure time. In other words, if my exposure reading in camera for instance is 1/20 sec and I then insert a 6 stop filter I will calculate the needed exposure time in the following manner: 1/10 – 1/5 – 1/2 – 1- 2 – 4 secs. The Pentax K-1 comes with a histogram in Live-View mode so that my math is at times a tad superfluous. 0.9 means that the filter can even out the light with approx 3 stops if necessary. Soft means that the filter gradually goes from 0 to 3 stops starting from approx the middle of the filter. A hard filter on the other hand will have a very defined “starting point” and is used for example when we are shooting an ocean scene which usually has a very clear and defined horizon line.
The three following sample images are only given some basic adjustments in Lightroom.
Sunrise Tyrifjorden, Norway. Pentax K-1 and Pentax 15-30. Nisi 10 stop and Nisi 0.9 soft at iso 100, 15mm, f11, 110 secs. Neither the 10 stop filter nor the 6 stop filter produce any color cast. They may warm the image a tad, but that may also be the camera’s auto white balance. The 0.9 soft filter did its job perfectly and the raw file was very well balanced in terms of light – the image was shot just before the sun was about to emerge on the far left. Worth mentioning is that this was a very high dynamic range scene. Some cloning work may be necessary around where the sun is about to emerge (those more whitish spots to the far left).
Zero color cast is of course of great importance to the photographers who prefer jpg. For those shooting in raw that is perhaps of less interest since the white balance can be adjusted in post.
I always insert the graduated filter (0.9 soft) when the camera is in Live View mode so that I can see how the filter impacts the scene and how far down I have to push it to obtain the balance in light I would like.
The same scene without any filters – shot immediately after the 110 secs exposure:
What is plain evident here is that there are several parts in the top left corner that are clipped and we lack highlight detail notably along the beautiful cloud in the very top left corner of the frame. In this instance exposure blending would have been necessary to rescue those highlights which means shooting extra exposures and blend those in for instance Photoshop. Exifs: iso 100, 15mm, f11, 1/10 sec.
Due to advanced nano coating flare is incredibly well controlled by the Nisi filters. Let’s have a look at an image shot after the sun had risen.
Nisi 0.9 soft and iso 100, 15mm, f22, 0.3 secs. First of all, the scene is very balanced in terms of light. Secondly, the only flare I can see is a red curved line at the end of sun’s bottom right spikes which shouldn’t be too difficult to clone out. That flare may just as well be produced by the lens or by dust on the lens or filter. A couple of notes: For a scene like this I would also shoot an exposure at for instance f8 or f11 to use as a base exposure in order to eliminate diffraction caused by the narrow f22 aperture. I would usually also shoot one exposure with a finger or several fingers covering the sun to have one flare free exposure which I blend in where necessary. This was, btw, a few minutes past six in the morning and we are in the end of April.
Using filters and capture everything in one exposure have several advantages: We can manage with less shots and hence save space both on memory card and hard drive. Post work is simplified considerably when we can omit exposure blending. And perhaps most importantly; many who shoot raw only use Lightroom for their editing so that exposure blending is outside their reach.
There is absolutely no vignetting when using the 150mm filters. Nada! It is possible to purchase 150mm polarizers to the system. In order to achieve desired polarization the filter holder has to be rotated (which is a part of its design) and that means that the use of a polarizer more or less cancels out the use of a graduated filter.
What about sharpness and details? Let us have a look at two very close crops from our first two sample images. As mentioned those images are edited in Lightroom and only basic raw sharpening is applied. The top cropped image is Nisi 10 stop and Nisi 0.9 soft. The bottom cropped image is without filters.
There is no loss of details and sharpness when using the Nisi filters (which perhaps is easier to see on my computer than on this blog site).
Nisi Filters is a China based company which produces high end filters to a reasonable price. The company has engaged a host of profiled photographers as ambassadors for the brand as a marketing strategy, but also as a way of receiving feedback on their products. What strikes me is Nisi’s drive to continually be in the forefront of things and the developers willingness to take into account feedback from the ambassadors and adjust things accordingly.
The filters are produced in high quality optical glass made in Japan and Germany. A well known fact is that glass is far more scratch resistant than for instance resin – after a year’s use my filters are still scratch free. Furthermore, the filters have various nano coatings which make them water repellent, finger prints are very easy to remove, flare resistance is outstanding and infra red light is prevented from reaching the camera sensor.
We will finish the review with an image shot with the Nisi 0.9 soft filter (150 mm) – the image is edited in Photoshop:
An overview of which lenses that currently are 150 mm system compatible is found here.