Although I’m a huge fan of Lee Filters’ 10 stop neutral density filter, the ‘Big Stopper’, there are occasions when 10 stops simply isn’t enough.
Formatt-Hitech now market 13 and 16 stop versions of their Firecrest ND filters but I thought I would seek a more economical solution before spending another £100 on a brittle glass filter.
So I purchased a piece of 4 1/4″ x 3 1/4″ (107 x 82mm) shade 10 welding glass on eBay for the princely sum of 99p delivered (!) and mounted this to an old 77mm filter ring using double sided padded car number plate tape to make it light tight.
The welding glass is a tad rough around the edges so it is best to be careful when handling it and also not to go too near anyone when it is mounted on the lens and camera.
Obviously there are no UV or Infra Red filters on the welding glass (update – apparently they do block UV and IR) and it also gives a very strong green colour cast but this is easily sorted with a custom white balance or in Lightroom with a Temp of 5000 and a Tint of +150 (max magenta). Dull cloudy days are best as any direct sun creates very strange patterns on the image, straight edges also give very strong purple fringing or chromatic aberration but this is no problem if the image is converted to black and white.
My base exposure (with no filter) was 1/125 @ f11 at ISO200 on my FujiFilm X-T1, with the welding glass attached the exposure was 2 minutes @ f11 at ISO200 so the shade 10 is about 14 stops.
The great thing about the X-T1 is that Electronic Viewfinder (EVF) and rear display can ‘see through’ even a piece of glass as dark as this so composition and focusing can be achieved with the welding glass filter in situ.
Here are a few images from Calshot Spit in the New Forest National Park;