Calculating exposure difference with ND Filter

[benjyman345]

hello,
I was wondering, how do i calculate the difference between exposures when using a Neutral Density (ND) filter?

I.E. 2x, 4x, 8x

Thanks

 

[Alex_B]

there are different ways of labelling ND filters. I guess the numbers you gave just mean you multiply by 2, 4, 8, ...

 

[Torus34]

http://www.ephotozine.com/techniques/viewtechnique.cfm?recid=329

 

[Big Mike]

If you are using a modern camera (with a built-in meter) then once you put the filter onto the lens, the meter readings will be compensating for the filter.

You do have to calculate it manually when you are using a hand held meter.

 

[Alex_B]

If you are using a modern camera (with a built-in meter) then once you put the filter onto the lens, the meter readings will be compensating for the filter.

You do have to calculate it manually when you are using a hand held meter.

Well, if you use a 64x filter in dim light (to get ultra-long exposure), then the sensitivity of the built-in meter is usually not sufficent to give really accurate values (all you see is black ).