I've been looking at filters and stuff.

I like taking landscape pictures but have come across the problem of contrast caused by the bright sky when compared to the dark foreground.

What is the difference between using a graduated ND filter to compensate for this and using photoshop / GIMP to cut a paste the two halves of differently exposed photos?

Apart from the fact that my photoshop skills are lacking greatly and it would look very poor if I tried to do that.

You can rest at night knowing you got the image on the day, and not constructing it in Photoshop.

Get a grad ND. Everyone should have one.
This and this were the products of an ND grad - I'm not sure if I'd be able to construct something like it in P.shop.

That's a good point actually.

I'm a fan of "what comes out of the camera stays" photography.

Although I do make a few minor tweaks in iPhoto.

Aside from the peace of mind of knowing you got it right first time, you also benefit from a better dynamic range in the area that's been darkened. When you darken part of the image in PS or Lightroom afterwards, you get odd effects if the highlights are saturated at all, where you see can grey areas where the blue of the sky (say) near the sun has been clipped to white, losing the colour, and then brought back down in post-processing. I'll see if I can dig out an example when I get home.

This image was overexposed in-camera and pulled back in Lightroom.
I've added no colourisation to this image at all.


Mark

A perfect example. Thanks Mark! And a beatifully composed shot, I might add. Even if it was overexposed :)

Nice image. How over-exposed was it? Were the clouds completely blown out?

Thinking about Timark's shot.

Is it possible to use 2 filters?

i.e. use a 3 stop filter to get the flowing water exposed correctly and smooth and then a graduated ND filter so that the sky isn't over exposed?

I think I need a graduated filter for my DSLR. Are these similar in construction to my polariser? This filter can be rotated on the lens so that the angle of polarisation can be adjusted.

EDIT:

Here’s a picture which really could have benefitted from one of these filters, I think:



As it stands, it’s under exposed at the bottom and over exposed at the top. I’ve pulled the settings around in Aperture so that some detail from the top comes back, but the bottom reflection is a bit too dark for my liking.

Yes. The holder for mine can take (I think, off them top of my head) 3.

Edd

No, they are rectangular in construction and fit into a holder so that the 'horizon' can be adjusted vertically as well as rotated. I think you can get screw-on ND grads but you wouldn't be able to adjust the horizon.


Yes, you could use spot metering to work out how many stops difference there are between the image and the reflection, and use an ND grad with the same number of stops.

I use a screw in ND grad, and yes, like a polariser, you can adjust the filters horizon.
It's a bit of a nuisance twiddling the polariser to get the effect you want, then adjusting the ND Grad while taking care not to disturb the polariser, but worth it.
I've a yellow grad for B&W film that's got a handy little handle on the rim of the filter. Much easier to use.

Alex - can you move the horizon laterally as well as rotating it?

Ah I see what you mean now - no, that's the disadvantage. The horizon on a screw in is always going to be ~50% down the filter. The Cokin/Lee filter holder systems would be a much better investment in that regard.

I’m glad that one has been answered for me. Thanks all. It will be the square type when I get some then.

Nick - the photo I showed was taken on my little Leica, and at the moment I don’t have any means of attaching a filter to it. I do understand the principles you explained. If I get the square types of filters, I could manually hold them in front of the lens, I suppose.