Long exposure help

[akcron]

Hello all.

I have just placed an order for a Adjustable ND filter from 7dayshop so i can try long exposure photos.

I have done a bit of reading on the subject i have a tripod remote etc, but i cannot find a chart or anything to tell me whats the correct exposure time for say a nd4 or nd7 etc if there is such a thing.

Any help and any tips for a newbie on taking long exposure shots would be welcome.

Thanks all.

 

[hollis_f]

One of the many problems with a variable ND is that you've got no way of telling how many stops it is set to. With a proper ND you know that it's 6-stops, for example, and can easily figure out how to adjust exposure (double the shutter speed 6 times or half the aperture three times). But with the VNDs you can't tell.

They also let a lot of infra red light through, which doesn't affect the exposure (because there's a filter in front of the sensor). But it does affect the exposure meter - which doesn't have a filter. So you can't rely on auto-exposure either as it will underexpose everything.

If you have LiveView with exposure simulation then that should work. Otherwise it's a matter of guesswork, trial and error.

Combine that with the known problems with wide lenses (cross patterns appearing beyond 3-stops) and with tele lenses (see below) they're not really worth the hassle.

 

[akcron]

OH! b****r!:bang: