Lee's Upcoming 15-Stop Neutral Density Filter

[Mike Buckley]

See this.

[george013]

See this.

I I think the timetables with a 15-stop filter are not correct.
A 1-stop filterwill double the time, a 2-stop filter will 2^2=4 time the original. A 15-stop will 2^15=32768 time the original. So 1 sec will become 32768sec being 9.10h.
I'm curious where his time table is based on.


George

[DanK]

I I think the timetables with a 15-stop filter are not correct.
A 1-stop filterwill double the time, a 2-stop filter will 2^2=4 time the original. A 15-stop will 2^15=32768 time the original. So 1 sec will become 32768sec being 9.10h.
I'm curious where his time table is based on.
George

Right. If it were exactly 15 stops, this would be an 18hour, 12 minute exposure. However, the rating of NDs is often approximate, so perhaps it is a bit less than 15 stops.

In any case, I wouldn't find this useful. I rarely have occasion to use my 10-stop filter, and this would give me exposures 32 times as long as that. However, there must be some people who would find it useful, or they wouldn't have invested in producing it

Moreover, unless sensor technology has changed a lot over the past 4 or 5 years, there are limits to the length of exposure digital sensors can handle without problems from overheating. Of course, film avoids those problems.
.

[Mike Buckley]

However, there must be some people who would find it useful, or they wouldn't have invested in producing it

Donald recently posted a photo that he made by simultaneously using two filters that, if I remember correctly, resulted in 13 stops slower.

Moreover, unless sensor technology has changed a lot over the past 4 or 5 years, there are limits to the length of exposure digital sensors can handle without problems from overheating.

Though the article's headline and the conversation in the thread brings attention to exposures that last a really long time, the typical use of this filter would be for exposures lasting several minutes or less, not hours.

[Polar01]

Lets look outside of the usually use box for this filter. I often shoot landscapes @ f/16 and ISO of 100 to get the depth of field that I require using a Lee ten stop. What if someone wanted to shot at say f/2.8 and needed the same length of time? Well f/4 to f/16 is 4 stops and f2.8 to f/4 is one stop add them up, 5 stops in total. Looked at another way if your camera suggested a shutter speed of 1/2000 sec and you wanted 15 seconds then you need 15 stops and 15 seconds is not that long of a time.

Cheers: Allan