Review of the Sirui 100mm filter system
Background
At the end of 2017 I came from Alex TSE Imaging when I gave a lecture to an enthusiastic group of photographers and Africa travelers. Because of our shared interest in photography, we soon got talking.
While I was going through the extensive Sirui tripod line with Alex, he casually mentioned that a new line of Sirui filters would be launched shortly. Since I had been doubting my synthetic resin (so-called resin) filters for a long time, my interest was quickly aroused and we agreed to meet at the office of TSE Imaging to take a closer look at this new Sirui Filter Holder 100mm
The Hoya Optical Testing Facility Almere (HOTFA)
How do you determine filter quality?
The Hoya Optical Testing Facility Almere is located near the offices and warehouses of TSE Imaging and filters are examined for distinctive properties such as the strength, resolution and transmission of light. This test facility is unique in Europe. You may have come across a small version of the HOTFA at a photo trade fair, such as recently at the Professional Imaging fair in Nijkerk.
I myself am always skeptical when a manufacturer claims that its products belong to the absolute top, so the fact that these claims could now also be tested through tests was excellent for me. In this case, measuring is really knowing!
Resolution
Ideally, the resolution of a lens does not decrease when you use a filter. Unfortunately, practice sometimes shows something different. How can you be sure that you are selling (or buying in our case) filters that keep the resolution of a lens as intact as possible? Using the 'Resolving Power Test Target', which NASA also uses for resolution tests, TSE-Imaging determines the influence of a filter on the resolution. My LEE soft ND grad filter did not pass this test very well, the optical properties of resin / synthetic resin turned out to be far from optimal. The Sirui filters, on the other hand, showed hardly any distortion.
Transmission
The HOTFA also checks the percentage of light that passes through a filter. A glass filter without coatings (think of your window frame, for example) only lets through 90% of the light. Thanks to the use of multiple coatings, the transmission of filters can be as high as 99.4%.
The color rendering of a filter (the transmission of the different colors) is also tested with a spectrometer. You want a UV filter to filter out the ultraviolet light, but you want to keep the blue light as much as possible. Thanks to the HOTFA you can therefore measure how well filters do their job.
As can be clearly seen above, the Sirui filter has a nice even transmission of the visible color spectrum, exactly what you want as a photographer because you don't have to apply color corrections in your post-processing. It is also good to see that you lose some light intensity when using a polarization filter.
NB It visible spectrum has a wavelength between 380 nm (violet) and 780 nm (red)
The image above left clearly showed that my own observation, regarding a color cast on my resin filters, was confirmed by the measurements.
But perhaps more importantly: How do the Sirui filters combine with each other?
Because we often use a combination of a circular polarization filter (CPL) with a neutral density (ND) filter. That transmission must also be as good as possible. As you can see from the beautiful horizontal line that follows the combination of Sirui CPL with ND filter, that is also fine with this filter kit
The Sirui filter holder kit and associated 100mm filters
First you need the NDH001 basic kit with which you can get started with almost any camera right away. This kit contains the following items:
- 1 x 100mm filter holder with 82mm threaded mounting
- 1 x a round 82mm circular polarizing filter
- 1 x 82mm to 67mm adapter ring
- 1 x 82mm to 72mm adapter ring
- 1 x 82mm to 77mm adapter ring
- 1 x soft pouch with two compartments
Currently, the following rectangular filters are available as additional options:
100x100mm neutral density filters: ND8 | ND64| ND1000
100 x 150mm soft gradient ND filters: SGND4 | SGND8| SGND16
100 x 150mm hard gradient ND filter: HGND8
100 x 150mm inverted ND gradient filter: RGND8|RGND16
In addition to the basic kit, my own kit consists of the ND8, ND1000, SGND4, GND8 and RGND16
The glass filters are made from the German Schott Plate Glass B270, one of the clearest glass products available. Any filter has been treated with multi-layered anti-reflective coatings. In addition to the anti-reflective coatings that are nearly 100 percent light-transmitting, there are an additional six layers of protective coatings that result in a waterproof, oil-resistant, scratch-resistant and anti-static surface.
The filter rings and the filter holder are not made of plastic, but of industrial aluminum and they are finished with an anti-reflective matte black coating. Each filter is packaged for first use with a thin protective film that must be peeled off before use. Included is a protective padded case.
Slim Line Filters
The supplied adapter rings make the Sirui circular polarizer available for lenses with filter threads 67 mm, 77 mm and 82 mm. The 10-stop ND is only 2.8mm thick. Because the filters are so thin, you can also shoot with the most extreme wide-angle lenses from 16mm without vignetting.
Mounting and removing the filter on my lenses was quick and hassle-free. And just as important; iI found no visible color shifts with these filters, even with the 10-stop ND.
UPDATE: July 2018
Since writing this post a new improved version of this Sirui filter holder has been released, the full specifications of the current version are in the article: Sirui 100mm filter holder NDH100 V2
The Filter Holder
As mentioned before, hThe main body of the filter holder is made of the same aluminum as the filter adapters and is finished in the same matt black. The holder fits directly on lenses with a diameter of 82 mm and the included adapter rings for 67 mm, 72 mm and 77 mm mean that it can often be used immediately. Optional adapters are available for 55mm, 58mm and 62mm lenses.
Due to the ingenious construction you can choose to only work with the circular polarization filter. The filter holder itself can be attached in an instant so that you can also quickly work with the slide-in filters. The holder is designed in such a way that you can rotate the CPL independently of the filters. The holder itself clicks at 9-degree angles if you don't want to use the filter parallel to the horizon.
When I used it for the first time, I was a little afraid to push the square filter through in the holder. When you use it for the first time, the filters clamp fairly tightly in the slots. Fortunately, this disappeared after a few uses without them having a chance to shift under normal use.
I have used the kit extensively in Namibia for 3 weeks and am very satisfied with this new filter line. If you are a (landscape) photographer who still works with synthetic resin or normal glass plug-in filters, you will immediately experience an increase in sharpness and light transmission.
Normally I was used to always checking my images that were made with 1 or more filters in post-processing and correcting them for a color cast. I am quite a Pietje exactly, as witnessed by my study, which is completely painted in medium gray (128,128,128)..
So far I can skip that step when editing this recent batch of images!.
Even if you are not looking for a new line of filters, it can be nice to have your filters tested if you see the HOFTA present somewhere at a trade fair or event.
As hopefully has become clear from the above story, a good filter is very important if you want to get the most out of your photos. One of the basic conditions, just like your tripod of course.
During my trip through Namibia, I had the Sirui R-4213X tripod with me as a workhorse. 10 layers of carbon in 3 sections for maximum stability. Not a lightweight at 2.45 kilos, but the best choice given the Pentax medium format camera I had with me, especially given my sessions at night with shutter speeds of up to 3 minutes. The stability has turned out all right and I'd like to share a few images of the combinations of the filters with this tripod as a base.
Want to get started with filters yourself?
I regularly give workshops in which we also work with filters. Take a look at the website of Photo United for the current offer of my workshops.
