Using rear mount filters on a Tamron Mirror lens

Mirror lenses have large front elements often 77mm and above. This means attaching filters can expensive, so manufacturers often include a rear mount option. This is a small filter thread, usually 30.5mm positioned behind the rear element. On the Tamron Mirror lens you need to remove the Adaptall mount to give you clear access to the filter. A standard UV protection filter is usually in place, but you may want to take advantage of one of the ND filters supplied, or even add a polarising filter as we are doing to illustrate this technique.

The filter screws in just like it would on the front and once in place is out of the way of fingers while ever the lens is mounted on the camera. This is fine for 95% of the filters you would consider attaching, but what if you have one with a rotating mount like a polariser, starburst or graduate filter? Once the lens is mounted on the camera the filter is out of reach.

When using filters like this, screw the filter in first then adjust the position so the gradient is horizontal or polariser in correctly positioned on the lens when it will be attached on the camera. See our using a rear mounted polarising filter guide.