Neutral Density Filters

[MrFish]

Why do I need one then, and if I do what the most useable - ND4 ND8 etc..

What advantage do they give over upping the F and slowing the shutter speed.

Can filters be stacked eg a polariser and an ND?

:thanks:

[Paul]

Why do I need one then, and if I do what the most useable - ND4 ND8 etc..

What advantage do they give over upping the F and slowing the shutter speed.

Can filters be stacked eg a polariser and an ND?

:thanks:

Firslty for those who are a bit confused, a ND filter stands for Neutral density filter and is probably one of the only filters that is still 'useful' in digital photography, with the ability of post processing filters in your digital darkroom.

Have you ever seen a pic taken in broad daylight with a long exposure time and thought, "how the hell has he done that without blowing the image"?

*COUGH*

http://fc01.deviantart.com/fs26/i/2008/147/c/6/Ghosts_by_Paulmalsop.jpg

This is due to the use of a ND filter. Basically it darkens your image so you can decrease your shutter speed/aperture by x number of stops, depending on the ND filter you have in place.

You have two options when subscribing into filter systems.

A)Round screw in style filters
B)Cokin P filter system = square slot in system.

Generally speaking you shouldn't have more than 1 filter on your lens at any one time, two is a max. It's pointless spending all that money on lenses only to suffer refraction errors caused by plastic filters, plus the more filters you add the higher the cahnge of vingetting.

Which do you go for A or B? Well it's upto you, if you go for B you are buying into a system which you can used between different diam lenses with the simple addition of a step up/down ring (which are pennies) - in short, once you have a bought into B (initially expensive) it is relatively cheap to maintain. That said if you cannot see yourself buying another lens in the near future and want to use the cheaper circular filters, then these are used for a single lens diam.

Other issues are, with the Cokin P system you can get graded ND filters, so you can use it to block out light from the sky while the forground is left untouched, whereas with the round ones you can oly get solid ND filters

I personally have a circular ND8, which is one of the darkest filters, i figured i could always work backwards if i needed, rather than opting for a ND2 and wishing i could block out more light. I stack my ND8 when i need it onto my circ polariser.

HtH's a bit

[Paul]

The cokin p system

http://www.fotolab30.com/xcart/images/detailed/d_731.jpg

the circular system
http://www.digital-cameras.com/pic/300x300/16/74/hoya_52mm_shmc_pro1_digital_neutral_density_8_filt er_2419.jpg

Further reading:-
ND filters (http://en.wikipedia.org/wiki/Neutral_density_filter)
Graded ND filters (http://en.wikipedia.org/wiki/Graduated_neutral_density_filter)

[MrFish]

Thanks for the explanation but without playing with one, I still don't get it. If the filter just darkens the image why can't I just select for example F32 and a slow shutter speed, or does the filter do more than just reduce the light hitting the camera. eg same thing as a slow lens might do?

Or am I confusing myself :confused:

[Paul]

the wiki link helps explain alot

[Nath]

Dave,

Also an ND Grad allows you to reduce the light (and thus exposure) from a scene with a bright sky, where you would normally have an ultra dark foreground (landscape). If you imagine the filter is darkened on 1 half and gradualy faded to nothing (there are also hard/soft/mid grads that vary the length of the graduation.

In simple terms, "it blocks the bright bits".

Also, f32 will produce a LOT of distortion and should be avoided (as would anything over f16).

Also, the other MUCH more expensive option is the Lee filter series (Think Canon "L" vs non-L).

[fras]

I still don't get it. If the filter just darkens the image why can't I just select for example F32 and a slow shutter speed


Say you select F32 and set your shutter speed so the scene exposes correctly, and that shutter speed works out as 1/500. What if you wanted a shutter of 4 seconds? That's when you use ND filters.

To test the theory just place some sunglasses in front of the lens, I sometimes do this to take longer exposures out and about if I don't have my equipment with me.

[MrFish]

I'll buy one and have a play :thanks:

[Paul]

I'll buy one and have a play :thanks:

if you got the money to spend, best idea :thumbsup:

[Sanghy]

Dave,

Also, f32 will produce a LOT of distortion and should be avoided (as would anything over f16).



:confused: So i shouldn't use f128 on my field camera (when the customs guys eventually le me have it back lol).

[gobyboy]

what field camera is that sanghy?

[Sanghy]

Toyo 45CF

[MrFish]

I've just read on a photography web site about making a variable ND filter.

You first put on a circular polarizing filter and then a linear polarizing filter on top.

The linear filter can be rotated to give a variable ND effect.

Any one tried this?

[gobyboy]

ah, very nice piece of kit. hopefully you will get it back from customs soon.
have you got a store room stocked up full of film :)

[Sanghy]

Not a storeroom a freezer :)

[Paul]

Mr Fish i always get you confused with Mr Jimbo. I think it's the 'Mr' part of the name and the red object in avatar, i've just realised you are two different people, i thought you had a split personality!

[MrFish]

i thought you had a split personality!

That makes 3 of us :p

[Paul]

That makes 3 of us :p

lol :thumbsup:

[Paul]

http://www.camerafilters.com/pages/nd.aspx

[onefivenine]

I got a set of ND filters a couple of months ago, and wouldn't be without them now.

I regularly stack multiple filters, all according to the lighting and the desired effect.

This shot was taken with a circular polarizer, 3 stop ND filter, and a 3 stop hard graduated ND for the sky.

I still needed to stop down to f/18 to get a long enough shutter speed to create that milky effect.

http://farm3.static.flickr.com/2321/2414453710_5b9fca798a_b.jpg (http://www.flickr.com/photos/onefivenine/2414453710/sizes/l/in/set-72157604531050384/)
ISO100, f/18, 3.2s, 24mm

[MrFish]

Very nice shot, and I like the colours, almost a black and white.

[onefivenine]

Very nice shot, and I like the colours, almost a black and white.

Thanks Dave, appreciate it!
It is a mono conversion with a subtle blue/green tone added.
I picked that colour of tone trying to keep it in theme with the sea.

[MrFish]

I noticed the green tint to the picture, looks very effective.