Equipment Part 3 - Accessories/Filters

Big up to Rodney Trotter on 365 - the jedi master at long exposures

As Diego says, B+W is a manufacturer of filters. German if I remember correctly. That means you're getting Teutonic Deutsch Efficiency and a top quality product. They're not cheap though - so make sure you get the biggest one you can afford otherwise you may be fooked later...I'll explain that further - when I started out, all my lenses were 58mm filter thread. So I bought the 58mm ND110. No problem with that - I didn't have any bigger threaded lenses.Now though I have a 5DMKII and I'll be buying a lens purely for landscapes - but that has a 77mm filter thread (I think). My B+W won't fit and I'll need to buy a 77mm ND110 You can buy 'step-down' rings which you can attach to your filter to get it to fit a smaller diameter thread - so you can make a 77mm filter fit a 58mm thread... but you may need to remortgage to get a 77mm B+W ND110.Yes, it was me who had some extreme waterscapes taken with it... but I've not done a 10 minute exposure yet... basically the 10 stop filter takes away 10 stops of light meaning you have to expose 10 stops longer to get a correct exposure.

In real world terms - if your camera meters a correct exposure of 1/125th at f16 without the filter on, the correct exposure with the filter on is only 8 seconds at f16. (And so on)Now, to be fair - if you're doing sunsets and whatnot then light is going to be fading fast and you may find that an ND4 or ND8 may give you the results that you want. If I remember rightly, an ND4 is a 2 stop filter, the ND8 is a 3. Normally this is plenty for already low-light shots, and it's what most of the sunset at the coast type pictures you see on the front of photo mags are taken with. These are cheaper than the ND110!Where the ND110 comes in handy is for daylight shots where you want the long exposure to smooth out the water, or blur a waterfall... Otherwise an ND8 or ND4 may work fine...Then you have the choice of whether or not you want a screw in filter (attaches to the front of your lens - the B+W only comes in screw in form) or a slot in one.

The slot in ones (usually Cokin 'P' series - or something labeled 'P type' - for amateurs) have one benefit in that they are square/rectangular and slide into a holder - meaning that no matter what thread size you have on your lens you can use the filter!You do need to buy some bits though... you need a holder for the filters, and a mounting ring for the lens. You buy a mounting ring to match the thread size of the lens you're using, screw it in, attach the filter holder, then slide your filter in. If you have different size thread lenses you just buy different mounting rings - everything else is the same... You do get a much more varied range of filters though...The Kood series (compatible with the 'P' format), while cheap, is quite good - have a look at http://www.premierink.co.uk/ for pricing.

Finally you have the ND Grads. These are filters (again ND4, ND8 etc) which are grey one half, the other half clear. These are typically used for landscapes - as the sky is usually much brighter than the ground if you use an ND grad with the grey bit over the sky then you can get nicely detailed clouds without blowing the highlights. As there is no filter over the ground then that exposes perfectly as normal.In my camera bag I have...Cokin P filter holderCokin P 58mm mounting ringCokin P ND8Kood 'P' ND8 gradB+W ND110

More on ND Filters:

Ahh - but it depends on what you want your filter to do.

If I remember correctly, an ND8 = 0.9 which is about a 3 stop of light reduction. The ND110 = 3.0 which = 10 stops of light.So, if you're shooting at night, and want to go a bit longer with the exposure an ND8 will probably suffice, it'll get you a 30 sec exposure. But - if you want a daytime long exposure your ND8 won't do a damn thing. The ND110 will give you around a 30 sec exposure into bright sunlight, minutes elsewhere during the day. Sunsets you're talking minutes as well. But it depends on what you want to do with it. If you're after late eve - night time 30 sec exposures flattening out water, ND8, maybe two stacked together is the way to go. Obviously if you buy 3 of them and stack them you're getting close to a 10 stopper...If you want daytime long exposures then get yourself a 10 stopper The prices for the 110 are expensive - but it gets the job done

10 stop - Removes 10 'stops' of light. Basically means exposures take 10 times (or more) longer than when not using it. Allows you to do really long exposures and completely smooth out the ripples in the water. Rodney Trotter's (in 58mm thread size) cost £41 incl next day delivery from Warehouse Express (B+W ND110 if you're going to look for it) http://www.flickr.com/groups/nd110-filter-group/

Basically, that filter gets rid of 10 stops of light and you've got to get
them back somewhere in order to have a correctly exposed photo. So, you could up
the ISO, have a larger aperture or slow down the shutter speed.What I do is
compose the shot with the filter off and make a note of the readings. Then I put
the filter on, camera to manual focus and manual settings. I make the aperture
the same as I took the reading from, the shutter 10 times slower than before and
take the pic.Then I check the histogram to see if there's a nice even spread or
any blown out or underexposed areas. If so I adjust accordingly.It's not an
*exact* science and it's all down to experimentation

Polarizing Filters:

Polarizing filter removes reflections and increases color saturation without affecting the overall color balance. It’s the most useful filter for landscape photographer, followed by the graduated neutral density filter, which could be replaced by the high dynamic range technique. Polarizer filter reduces haze and reflected sunlight. It has the most effect when shooting at a 90 degree angle from the sun. Get the best result when sun is overhead or behind you and close to the horizon. Polarizer filter has an attached rotating ring for orienting the polarization angle, rotate the ring will adjust the effect. There are exceptions, when the field of view is too wide, you will see uneven blue in the sky, or, you are taking multiple exposures for photo stitching, polarizer filter should not be used in these cases. (cheers to photo 96.com)