ND - Graduated neutral density filters - which one to get?

[wedding photographer]

I like the look ND filters create. Which brand should I get? Is it really important to get an expensive one? Is there a visible difference?

How do you use them? Do you screw them on the lens or hold it in front of the lens when you take the photo? I saw both.

I am sorry about my silly questions. I have never used one.

Thanks,
Otto

[WesternGuy]

I like the look ND filters create. Which brand should I get? Is it really important to get an expensive one? Is there a visible difference?

How do you use them? Do you screw them on the lens or hold it in front of the lens when you take the photo? I saw both.

I am sorry about my silly questions. I have never used one.

Thanks,
Otto

First, there is no such thing as a silly question, at least not on this forum. Any question that serves to increase another's knowledge on a subject is never silly. (IMHO)

You might have been better off posting this in the Help forum, however, I will try and answer some of your questions as best I can and the mods can move it if they think it is better in that forum. I guess the first one is what do you want to use them for?

There are really two types of Neutral Density filters, what I will call the regular ones and the graduated ones. Let's deal with them one at a time.

Regular Neutral Density, or ND, filters are sort of like sunglasses for your camera/lens. Depending on the "density" of the filter, they cut down the amount of light coming into the camera and this forces you to lower the speed, increase the aperture, maybe change the ISO. This is one approach that I have used to get those "dreamy" style flowing images of water falls. The denser the filter the less light it allows to pass and thus the longer the exposure has to be for a given set of lighting conditions (I am assuming for now that all your images are outdoors - that is the only place I have ever used them, so I have no experience using them indoors.) You can get the ones that screw directly onto the front of the lens or you can get the type that are square and have a special holder that fits onto the front of the lens and then the filter is dropped into the holder. Very often these "drop-in" kind can be stacked to give a higher ND than you would get from just one. The ultimate is the variable ND that changes the density of the filter as you turn part of the filter and as far as I know these are only made in a screw-on variety and are very expensive.

I would refer you to this Wikipedia reference for more detailed information...
http://en.wikipedia.org/wiki/Filter_(photography)

What I have done is to buy the screw-in variety and then buy the filter that will screw into my largest diameter lens and then buy "step-down" rings, or adapters, for the smaller lenses, e.g. my largest lens diameter is 82 mm and a lot of my smaller lenses are 77 mm in diameter, so I bought an 82 to 77 mm step down ring. The 77mm end screws into the lens and the 82 mm filter(s) screw into the 82 mm end of the adapter. I do not know how you deal with different lens diameters when you are using the "drop-in" type of filters, because I have no experience with them.

The other type of ND filter is the Graduated Neutral Density filter or the Grad, or ND Grad, as they are often referred to. I have only ever seen these in the square, "drop-in" variey and I have never used them - I don't do a lot of sunsets/sunrises...

Basically a Graduated ND filter is just that, it is a piece of material that is quite dark at the top and quite light at the bottom, so the density of the filter gradually decreases from top to bottom. There are two subtypes, those that have a very sharp edge transition from the dark side to the light side and those that are simply graduated with no abrupt change in density anywhere within the filter. The sharp transition types are often used where the "edge" can be place along something like a sharp horizon, so that the sky will not be blown out in the final image and the scene is often exposed for the lighter side of the filter.

Filters are usually glass, just like lenses and you get what you pay for. I prefer to not have my filters determine the quality of the image that I record, so I tend to buy the better quality ones like Hoya and Tiffen, or Kenko Pro. Just like cameras and lenses, there are a number of manufacturers of filters and I am sure that everyone has their own favourite that they swear by (or maybe swear at sometimes ). These include Hoya, Tiffen, B &W, Heliopan, Singh-Ray, Cokin (they make the "drop-in kind"), Lee, Kenko (I believe they are made by Hoya), Rodenstock and others. Some of the manufacturers make different "levels" of quality in their filters, with some making a very expensive "pro" line as well as their regular filters.Whether or not there is a visible difference between brands, or even within brands, I cannot say, because I have never "experimented" with them - too expensive. Maybe others here have an opinion that they would care to share.

You can check this site out to give you an idea of the variety of filters and some prices, or you can go to B&H's site and search for "filters" and see what you get.

http://www.tiffen.com/filters.htm

http://www.bhphotovideo.com/

I know I haven't answered all your questions, but hopefully some of the URLs will help and you can always post back with more questions.

Cheers,

WesternGuy

[Chris350]

I started with Cokin ND Grads to determine which degree of shading I would most commonly use. Having determined that I prefer to use ND 4 or 8 with a soft transition I'm am going to purchase glass ND's in those values. The Cokins are good starting point but since they are resin they are not particularly durable. As stated buy them to cover your biggest lens front diameter. The reason to buy square Grads is they need to be moved up and down even side to side over the frame to position the transition point for the best effect. As with everything photographic, increased cost does equate to better quality, but there is also a point of diminishing return. I still use my Cokin set because I found that I am using the ND's less than I expected. A set of Cokins, with holder and ring, cost less then a single Sing-Ray or B&W