What ND filter for my 10-20mm?

What ND filters can I use with my Sigma 10-20mm? It has a 77mm filter size.

Which are good brands and what sort of prices am I looking at for a decent one?

Thanks.

Before looking at brands, etc., what is the purpose for the ND filter? Where would you be using it? How much effect (in "stops") do you need? Are you really looking for graduated neutral density or to knock down the light from the whole subject? Etc.

You really need to define your needs first. Then you can be given some logical information rather than us guessing first.

Well when I was on holiday I found out on too many occasions that I had trouble correctly exposing both the foreground and the bright sky behind without under or over exposing either of the two, and the other day when out taking photographs in the snow most of my photos could have done with the sky not being so over exposed. Such as this shot -

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I'm glad that I asked the questions that I did, as I had guessed that maybe you needed a "graduated neutral density filter" as opposed to a filter that is evenly dark all across its surface. That is in fact the case for the problem you describe.

I would suggest that you look at the Cokin system. Their system consists of an adapter that you screw to the front of your lens and square filters (I would recommend their "P" size) that slip into the adapter. You can rotate the filter and move it up and down. There are many different types of filters that can be put into the adapters.

The filter type that you need is called a graduated neutral density filter. They come in quite a variety of configurations. Some have smooth graduations between clear and the ND portion. Some have fairly sharp transitions. Some have more contrast (darker ND) than others.

Here's a few links on the Cokin filter system:
http://www.geocities.c​om …ltersystem/howi​tworks.htm
http://www.geocities.c​om …ltersystem/colo​rchart.htm
http://www.cokin.fr/

You may need to look at the lee filters with something as wide as the 10-20.

Definitely graduated ND filters. The Cokin holders are good, but their NDs have a reputation of not being exactly "neutral". I get compatible grads from Singh-Ray. They fit the Cokin holder well. The Cokin "P" holder accepts adapter rings (hence lens threads) of up to 82 mm. With an extreme wide angle lens like the 10-22, you may need to cut off the forward set of guides, leaving only 1 slot for filters, to prevent vignetting. The wider Lee filters are also an option - Singh-Ray makes that size as well.

As to which ones to get, I have a 2x soft edge and 3x hard grad, depending on both the light levels and the nature of the horizon. If it's a busy horizon, I'll use a soft grad. If there's a distinct break, I'll use the hard grad. I expect to add 2x hard and 3x soft in the not-too-distant future, and maybe even a 4x.

I have the Lee filter system for my 10-22mm canon.

I bought their 77m wide adapter along with THIS FILTER HOLDER - configured correctly it allows me to stack two filters without vignetting at 10mm - I was impressed.

Initially I bought a 2 stop soft ND grad (0.6). I was wrong to do this for two reasons. The soft grad is not a great deal of use for darkening skies as the grad effect starts too low down the filter to to effect the sky enough - so I'd look for a hard grad for scenarios like your photo.

Now I know the hard grad may seem too severe, but remember if you get the lee the filter is going to be very close to the front element, so the 'hardness' of the grad is not quite so pronounced.

Good luck

Ah yes, that's what I meant to say. Thanks for the help

What sort of prices am I looking at for these particular setups?

I had a look at the Cokin and Lee filters and adaptors onWarehouse Express but I'm not entirely sure what to pick, there seems to be so much choice.

I had read a lot about the benefits of ND Grad Filters with landscape photography and was really interested in purchasing one, until I got some tips from a pro. His opinion (and I've heard it echoed in here) is that with digital, the only filter you might really need with landscape/outdoor photography is a polariser and (depending on people's opinions on the "safety" issue) a UV. Everything else can be achieved in a program like Photoshop.
The technique is explained in this article:
http://www.fredmiranda​.com/article_2/
It may be more convenient for you to achieve your desired affect during capture, but this alternative might save you some dough.

I think you'd want the ZPro filters (same size as Lee), holders and adapter ring. Cokin's names aren't very helpful; I think maybe a gradual grey x4 is roughly the same as a Singh Ray 2 stop hard, and would be a good, inexpensive, place to start.