As above really. Seen these and heard of them but what do they actually do? What sorts are there?

Thanks :)

to big a subject really for a quick reply,better to buy a book

but in short they mess with light ie exposure and are only really of use for trannies,have little effect on film (although polarizers do)

you can keep a filter,UV usually,on a camera to protect the lense,thats the main use

digital of course is all about software so they are an irrelevance in todays horrid world of digital fiddling

Most common ones you will need are polarisers, UV (or skylight) and ND.

Polarisers reduce the effect of polarised light. They reduce reflections off things like water, and they increase saturation of colours. If your camera is is AF (and it most probably is) you will nedd a circular polariser.

Linear polarisers will affect the AF and it won't work properly.

You can also rotate polarisers to strengthen or weaken the effect (although this as nothing to dowith it being a circular polariser!)

UV filters are simply to protect the coating of your lens from UV light. They also help to reduce the effects of haze. I always keep one on the end because if I knock the lens, I'd rather break a £30 filter than £200 lens.

ND filters just reduce the amount of light coming into the lens, and have no colour correction, hence 'neutral density'.

You can get different strengths (2,4,8 etc.) which allow you to stop more and more light coming through. These are useful in bright conditions where you want a lower shutter speed, but do not necessarily wish to use a smaller aperture.

Also, you can get grduated ND filters, which are dark at the top, then gradually fade to trasnparent at the bottom. These are usually used to darken skies in landscape shots so you can get a more even exposure. Avoid the screw in types though, as the grad is the half wa point, rather limiiting. Get somehting like the Cokin system, so you can place the horizon where you wish.

Hope that helps

Geezer

Unless, of course, you were talking about digital filters, which are something else entirely - they're mathematical operations that can be performed on an image to enhance contrast or sharpness, or to blur, brighten or darken, alter saturation or provide other effects.

Then there are the graduated filters which sometimes come in useful in landscape photography, there are starburst filters, and red/green/yellow for black and white photography, there are screw-in filters, slot-in filters etc. etc. - try going to some of the manufacturer sites and having a read about all the various filters available.

Cokin (www.cokin.com)
Schneider (B+W) (http://www.schneideroptics.com/filters/filters_for_still_photography/)
2filter (wide range) (http://www.2filter.com/)

It's interesting that Andy mentioned digital filters, as I tried some out recently and found them to be indistinguishable from the real thing, particularly colour correction filters. Some nice effects can be produced with digital warm up filters - in Photoshop they are even named 81A, 80B etc. If you feel, like dba, that there's something not quite right about it, that's fair enough, but I can't really see the problem. In both cases, you are altering the original scene.

Polarisers are a different kettle of fish, it's not really an effect you can recreate digitally. Just to add to Geezer's comments, a polariser gives the strongest effect when the camera is at 90 degrees to the light source (usually the sun).

If you are into landscapes, then a graduated ND filter is indispensable. As Geezer says, the best ones are adjustable. The problem with the Cokin ones is that they are grey grads rather than NDs. The best ones are from Lee filters, but do cost quite a bit :)

I was thinking of digital filters along the lines of USM actually. I've never really played with digital versions of 'real' filters - and since I only have Photoshop 5.0LE, the ones you mention aren't available anyway!

I sometimes fiddle with WB after shooting in RAW mode, but that's about it. Am I missing something really worthwhile?

I've seen the digital filters in Photoshop CS but not used them. Call me old fashioned but I'd rather try and get the shot right rather than trying to correct it later. I understand those who like to use them and wouldn't castigate anyone for doing so as I can see where they would be useful if you had limited options to save a shot. By the way Andy, before Photoshop built the filters in, there were several other programs available (some of them free) which would do the same thing.

I suppose tweaking images in a computer is one of the big advantages of digital photography but lets not forget there are still many people still using film. Ahh...you youngsters today have it far too easy, in my day...blah blah :):D:):D

I sometimes fiddle with WB after shooting in RAW mode, but that's about it. Am I missing something really worthwhile?

Do you adjust Levels? I have PS Elements 3, which is a vast improvement on previous versions, but in CS you have Curves, which (I think) is a more adjustable version of Levels.

I normally just do Levels and USM, but selective use of levels on different parts of the image - the sky for example - can make an enormous difference.

STi-Frenchie, less of the youngster comments ;) My first proper camera was a Canon AV1, which cost me 3 weeks wages in 1980 :D Nowadays, I much prefer the post-processing control I have over my images, as opposed to in the past when I was reliant on the processing lab.

Photoshop 5.0LE has curves too - it's one of the features that I know was removed from Elements but left in on LE.

I did play with it for a while - levels & gamma too - but although I understand how they work and what they can do, I'm actually finding that I'm using them less and less. I'm not sure whether that's because I'm now concentrating more on composition and less on getting bland photos technically spot-on, or whether I'm just getting lazy.

Any chance of an example or two from the 'filter fans' to show what you've achieved with them?

Any chance of an example or two from the 'filter fans' to show what you've achieved with them?

Just had a look and I haven't actually got any! I have tried the filters, but not actually used them in the finished image. Make of that what you will.

What I tend to do is tweak Levels/Saturation or use Color Variations, which I find surprisingly good - for example it is easy to get a Fuji Velvia type look by choosing 'less green'.

I have lots of holiday 'snaps', taken by various family members on a Powershot S40, and it is amazing how some of them can be improved.

I do agree with you that composition is ultimately more important, but I quite enjoy getting the most from them in PS :)

Usually the only post-processing I do is to tweak the curve slightly and USM - Nikon images are just a wee bit too contrasty for my taste and when I use my old AF35-70 zoom, they are even more contrasty as it's a lens well known for this particular trait.