There are two types of Polariser, circular and linear. These names bear no relation to the physical shape of the filter itself but refer instead to the way the light waves are transmitted through the filter to achieve the polarising effect. Ideal polariser for autofocus SLR cameras. Slots into the Filter Holder which is then rotated. Reduces exposure 1⅔ stops when fully polarised.
When light from the sun bounces off a flat non metallic surface, such as glass or water, it becomes polarised with all of the reflected light waves vibrating in the same plane. This reflected glare can be removed by the polarising filter. On a clear sunny day, much of the light in the sky is also polarised, and the filter will give a very strong blue effect when used at 90 degrees from the sun - any white clouds will stand out impressively.
If used alone, the polariser can be placed into the filter holder and the holder rotated until the desired effect is achieved. If used with a grad filter, the grad should be positioned first, then the polariser added – you will have no rotation possible without turning the grad, but will have a choice of two axis of polarisation, achievable by turning the filter through 90 degrees.
The holder includes 2 filter slots and lightshield
The SW150 filter holder comes assembled with two filter slots, enabling you to use neutral density graduated filters in combination with other filters. The holder also comes fitted with a Lightshield. The shield helps to prevent unwanted back reflections and creates a light tight seal enabling the use of any of the Stopper Range of long exposure filters.
How to use the SW150 Stopper range
The Stopper should be placed in the rear filter slot, closest to the lens, with the filter’s foam seal facing the lens. If you apply slight pressure to the foam from the rear of the filter as you slide it in, this will ensure that the foam edge does not snag on the top edge of the Lightshield. Only slight pressure is required. Ensure that the Lightshield is secure. The filter should be accurately aligned with the edge of the Lightshield, with the filter’s foam snugly against it. This prevents any light leaking in behind the filter and causing flare. If using the holder in bright conditions, you should always shade the holder to avoid any direct sunlight hitting it. This is good practice in all conditions and limits the likelihood of flare and rear reflections. Don’t forget to cover the eyepiece when taking long exposures, to prevent light entering the camera through the viewfinder and fogging the sensor.
|SW150 Circular Polariser||1|
|SW150 105mm II Filter Holder||1|
|- Filter Pouch||1|
|- Face Blade||2|
|- Rear Blade||2|
|- Filter Guide||4|
|- Black Thumb Screw||1|
|- Rubber Light Shield||1|
Does not include adapter ring to attach to the front of lens, please see accessories.