giganova
Well-known
Today I experimented using "welding lenses" (as they are called) as ND filter for long exposures. I purchased a pair of #10 welding filters from Amazon ($5 for a pair). Since these welding filters don't have a well defined diameter and rough edges, I purchased the cheapest E48 UV filter that I could find, plus a 48-52mm setup ring, removed the UV filter glass, and screwed the welding filter between the E48 and the step up ring, which gave a nice snug fit. Total costs: a whopping $15! 😱
The first pictures had light leaks and reflections all over the place, rendering the photos useless. So I put black electrical tape around the filter and step up ring to light-seal it, and covered the lens and M body with a dark cloth so only the front of the lens would not be covered. Why cover the M body with a cloth? Because -- believe it or not -- there is light leaking through the bayonet (!) when you have the shutter curtains open for a few minutes in bright day light.
Below is the first picture that I took today.
Some technical details: 5 min exposure with M4, 21/3.4 Super Angulon at f/11 on FP-4 developed at box speed. I bracketed the exposures and a 5 min exposure gave me the best result, which would otherwise be 1/500 sec at f/11 ("sunny 16"). This means that the #10 welding glass has an attenuation of 16 f-stops! Surprisingly, this cheap welding filter gives almost no loss of overall image sharpness. The corners are a bit softer and vignetting is more pronounced than before, but I can live with that.
Can't wait to get out and make more long exposure with this $15 contraption! 😀
P.S.: This will be last photo in Washington, DC, where I live, before I escape the city for the inauguration next week. Maybe you'll see more long exposures from the beach when I am back 😛
The first pictures had light leaks and reflections all over the place, rendering the photos useless. So I put black electrical tape around the filter and step up ring to light-seal it, and covered the lens and M body with a dark cloth so only the front of the lens would not be covered. Why cover the M body with a cloth? Because -- believe it or not -- there is light leaking through the bayonet (!) when you have the shutter curtains open for a few minutes in bright day light.
Below is the first picture that I took today.
Some technical details: 5 min exposure with M4, 21/3.4 Super Angulon at f/11 on FP-4 developed at box speed. I bracketed the exposures and a 5 min exposure gave me the best result, which would otherwise be 1/500 sec at f/11 ("sunny 16"). This means that the #10 welding glass has an attenuation of 16 f-stops! Surprisingly, this cheap welding filter gives almost no loss of overall image sharpness. The corners are a bit softer and vignetting is more pronounced than before, but I can live with that.
Can't wait to get out and make more long exposure with this $15 contraption! 😀

P.S.: This will be last photo in Washington, DC, where I live, before I escape the city for the inauguration next week. Maybe you'll see more long exposures from the beach when I am back 😛