Irix Screw-In And Gelatin Filters

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The Irix brand is known for its Swiss design and Korean production. The Irix 15mm f/2.4 was the first lens launched by the company in September 2016 and comes in Canon, Nikon and Pentax mounts. This is an ultra-wide angle lens designed for full frame DSLR cameras: its high-quality technology guaranteeing not only great optical performance but also unprecedented functionality at a competitive price. This lens, being the only one in its class, allows the opportunity to use screw-in and gelatin filters, which are also offered by the manufacturer.

It is easy to get interesting results when making use of the filters and some photos simply are not possible to capture without them. Irix offers a kit of protector filters: UV, ND and circular polarisers. These filters are built from optical glass, with special waterproof and oil repellent NANO coating; this protects them from stains and fingerprints and enables their use in extreme weather conditions. Each filter is equipped with a threaded frame, thanks to which you can attach it to an Irix 15mm. The front of the filter enables the placing of the lens cap during those times when not taking pictures. Neutral density filters from ND4 up to ND16 densities are also offered as gelatin filters. Irix equips every lens with a rear filter slot system to fully enjoy its image creation possibilities.

Wide landscapes are a field for polarizing filters. They are most commonly used to strengthen the colours or for dimming the blue sky. The Tatra Mountains (above) in the west gained in contrast with the foggy summits in the background being more pronounced. To obtain the best outcome, after placing the filter, it is recommended to rotate the movable part and observe any changes to the image by the viewfinder or on the camera's liveview. On the Irix lens hood, there is a little window that allows the rotating of the filter.

In the case of photos with a blurred background such as the above, the photographer will need to open the aperture to the maximum. However, because it can be difficult during sunny weather to set such a short exposure time or low ISO to maintain the correct exposure, the image may be over-exposed and the colours will pale. If so, a neutral density filter with a low-density factor will help. In this situation Irix suggests using the ND4, ND8 or ND16.

The construction of some ultra-wide angle lenses precludes the use of screw-in filters. Irix offers an alternative solution in the form of gelatin filters. These are small pieces of thin optical film placed in a tiny special pocket located in the rear filter slot on the back of the lens. For a winter picture like the above, taken with an Irix lens, an ND4 gelatin filter was applied, making it possible to open the aperture at maximum without risking the appearance of a big white stain on the skyline in the vicinity of the sun.

It may be the case that the photographer wants to make use of both the polarising and ND filters. In the above picture, a polarising filter allowed beautiful colours to be bought out of the mountain stream by reducing the reflections on the surface of the water; it was the ND filter that made it possible to get an extremely long exposure time which created the intricate streaks in the churning water. However, stacking two filters with wide optics may cover up the edges of the picture, giving a characteristic, strong vignetting effect. In this case, the screw-in polarising filter was placed in front filter thread and an ND gelatin filter in the rear filter slot.

Neutral density filters are helpful in HDR photography since they remove moving objects from the scenes and are secure from an adverse diffraction effect. On the other side, protection filters - apart from their basic function – enable you to create your own glycerin mask and that is why it is possible to acquire artistic effects without using Photoshop. It is worthwhile looking for examples of working with filters in the field, because many of them still remain as unexploited scopes for photography.

Find out more about Irix filters