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Nogbad
10-07-06, 19:58
Hi all, have a question but seems a bit silly.

Anyway here goes.

I am wanting to take some images on my holiday into Wales in the next few weeks.

I want to slow the shutter down to obtain the desired "Milky" appearance of the flowing water.

I understand the concept of the shutter speed, aperture etc, and using an ND filter to give additional stops to acheive this.

However do I compose the image first and then put the filter on. Or do I put the filter on and then compose the image. or does'nt it matter? Silly question I know!

One more thing which density ND filter is best to use?
Thanks

Nogbad

yelvertoft
11-07-06, 07:46
Nogbad,

Depending on the light, you may not need an ND filter at all. To show some movement in a water flow, you will probably be using speeds of between 1/15th and 1 second. The longer the speed, the more milky the water will appear. If you are using your slowest ISO setting and shooting at dawn/dusk, you may be able to get these sorts of shutter speeds without resorting to an ND. Shooting at these times may also give you more flattering light than harsh midday sun.

As for composing before or after, as you will be using a tripod, I'd compose before adding the filter as this will give you a clearer view in hte viewfinder; you are less likely to miss spotting a stray object in the scene, but I can't see that it will make a huge difference if you put the filter on first.

Regards,

Duncan

Nogbad
11-07-06, 20:46
Hi Duncan, Many thanks I will be taking the shots at dawn so probably wont need an ND .

Thanks for your response.

Cheers

Nogbad

robski
11-07-06, 22:20
Nogbad

Another option to think about is to use a Polarising filter. This will reduce your exposure by 3 stops and help cutback some of the reflections. Sometimes the water surface can look like a mirror.