Thread: A brief note on Neutral Density filters

Neutral density (ND) filters can be a handy addition as they allow you to stop down (reduce aperture or shutter speed) and to get more sharpness (or softness) in the image.

In my case they are particularly useful as there is usually an over abundance of light and so taking nice soft shots of water really is hard unless its a very rainy day or you catch everything in that 30 minutes of almost twilight we get up here in the north. For this reason I tend to only use either an ND6 or ND10. I have an ND3 but that's usually left at home.

The idea is the filter simply blocks some of the light and doesn't alter the colours. The common ND's are 1, 2, 3 and 6 stop and they can be stacked to get an additive effect. So if you have a ND1 and an ND2 you can stack them together and in effect have an ND3.

So for instance if you want to shoot a shot a 1/30 second f/16 then with an ND3 filter you could take the same shot at either 1/4 sec and f/16 or 1/30 sec and f5.6

The ND10 is a 10 stop filter and the best description is dark welding glass. This is good for turning bright sunny day into something useful as even at f/22 I can often not shoot as low as 1/30 second. So its impossible to get those nice smooth water shots with the angle hair effect of the water on the rocks.

So as an example here are two shots. The first I'll freely admit is a bit blown out and was just snapped off in a hurry. This was taken in program mode and the EXIF shows it as 1/50 sec and f/3.5.


So here's the shot set up with the ND10 filter. The camera was on a tripod, tethered shutter release and in manual. The EXIF on this is 120 seconds and f/18.


Of course the other aspect of ND filters is graduated ND's. With these one half of the filter is ND and one is clear. These are highly effective at removing the over exposure of a scene because of the sky given the darker lower light reading of the land. I can't give any examples as these are something I haven't used for a long time and presently don't own any.

Of course for a much more complete explanation of the ND filters its best to do a few Google searches.

[quote=mfc;949489]

Originally Posted by werdan

Hey DM, have you ever tried 2 polarisers together?

Back in 'the day', you could buy linear polarising filters rather cheaply.

you can still buy linear pol filters...{hadent seen them used this way but ill give it a burl

in regards to grad nd filters , ive been after a set of lee filters for over a year and there continuosly sold out{usa and gb}...likley ue to dig sensors crap response to contrast

plus there realy expensive

I've got a Lee holder (from G and Grad ND filters from Sing-Ray to fit. Works very well. I'm glad I got the larger size. I know a number of people who went the smaller size and ran into problems with wider shots.

I've also go a Vari-ND. Very handy for waterfalls and moving water after the sun has come up.