billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

If you are just starting out I would suggest a starter kit. I did this and now use the NiSi system filters. But, I started out with a cheap kit and got some very nice shots, I still have the kit and use it when I need a specific color that I don't use much. The holder comes with several different MM sizes, one will fit your lens. Yes, it is cheap, but they hold up to hard use and they produce good results. And it includes at least three ND filters. My kit included a 3, 6, and 10 stop ND filters and at least 3 ND graduated filters. It really is an easy way to start out.
https://www.amazon.com/Concept-Square-Graduated-Compatible-Cameras/dp/B01FJ7JL6W/ref=sr_1_3?ie=UTF8&qid=1509626390&sr=8-3&keywords=photography+filter+kit&dpID=51o%252BlSudfVL&preST=_SY300_QL70_&dpSrc=srch

repleo Loc: Boston

Sorry. My mistake. Thanks for correcting.

Jerry G Loc: Waterford, Michigan and Florida

Just glad I could help. The buying guide is great, thanks for pointing it out.

mizzee Loc: Boston,Ma

I had a variable and returned it. I was shooting under cold, misty conditions and condensation occurred between the filters. I spoke w the pros who were running the workshop and they said that condensation is not uncommon w variables. They suggested a 6 stop ND.

GEG Loc: Pennsylvania

I bought a Breakthrough 4D filter in August and I’m very happy with the quality. Well made, true colors, etc. I didn’t buy a variable filter because of the concerns about optical quality and color, but Breakthrough may have broken through :)) those issues!
Geoff

rydabyk Loc: Florida Panhandle

Breakthrough Photography has some excellent, albeit expensive, filters, they're also just getting the square ND and GND filters in stock. I believe they're the only tempered glass filter makers around. The holder they make is only $49 but it's not in stock yet, as soon as it shows up I'm planning on getting one to have as a back-up. I use the NiSi system right now and have had no issues with it, I just want to move to the tempered glass.

Robert Bailey Loc: Canada

One problem that can occur with "cheaper" filters (I presume it would be those)
is that they are not actually "neutral", they are grey, and they affect not just
the exposure in a neutral way, but they also affect the tonality of the image.
(I had two Cokin ND graduated filters that did this, so I replaced them with
another brand (Singh Ray).

tracs101 Loc: Huntington NY

NiSi system? What is that? Just curious. I'm in the process of acquiring filters and plan to go Breakthrough Photography all the way. Damn the torpedo's, full speed ahead. Can't take the $$$ with me.

rydabyk Loc: Florida Panhandle

A filter system similar to Lee but it incorporates a CPL into the holder.

https://www.amazon.com/NiSi-System-Adaptor-compatible-Singh-Ray/dp/B01MY6TSJM/ref=sr_1_5?ie=UTF8&qid=1509633645&sr=8-5&keywords=nisi+filter+system&dpID=41-v-wRM64L&preST=_SY300_QL70_&dpSrc=srch

https://photographylife.com/reviews/nisi-filter-system

amfoto1 Loc: San Jose, Calif. USA

Exactly WHAT do you plan to do with the ND filter?

If you want the filter for still photography, then you usually only need one or two fairly strong ones to "shift" the exposure settings quite a bit. For still photos, an ND serves to allow slower than usual shutter speeds OR larger apertures than would be possible with the camera's native settings... or a bit of both. Either a single 6, 8, 9 or 10-stop filter or a pair such as a 3-stop and 6-stop that can be used individually or together to also give 9-stop effect are usually all that's needed.

If you want them to shoot video, then you're more likely to want a variety of strengths, including some weaker ones to have greater control over exposure factors (which are less adjustable with video, than they are with still photography).

You might even want a Variable ND for video... But those are expensive. Far from cheap, but less expensive Variable (around $100 or more, depending upon size) tend give uneven effects and cause ugly tints in images. Better quality Variable do better, although they too aren't entirely free of these issues, but are VERY expensive ($300-$400 isn't uncommon, depending upon size).

Do NOT go too cheap. Get high quality, multi-coated filters such as B+W MRC or similar. So few filters are needed with digital photography, it makes little sense to buy cheap and end up with a lot of degradation to your images.

I'm presuming you AREN'T looking at buying Graduated ND filters... all the above applies to solid ND, specifically.

Grad NDs really aren't necessary for digital photography. They were important for scenic shots on film, but with digital there are several post-processing techniques that do a much better job than a Grad ND ever could. And with Grad ND, there's really no choice but to get the oversize, rectangular type (most of which are optical plastic so are rather easily damaged, aren't multi-coated... and harder to store and carry around, difficult to shade well with any sort of lens hood).

SteveLew Loc: Sugar Land, TX

I have the Lee filter system and a series of graduated filters .3, .6 and .9 I also use my 10 stop ND filter for shooting during daylight since it provides more dramatic lighting then without the ND filter.

SusanFromVermont Loc: Southwest corner of Vermont

The variable ND filters are problematic, as others have mentioned. If you want an ND that is the same darkness throughout, the circular ones will be OK. If you want a graduated ND, then the rectangular ones are what you should use. Although a lot of people do use the holders, it is not necessary. I actually find the holders to be inconvenient if I want to switch from shooting with the filter to shooting without it. Hand-holding the filter is easy to do, just takes a little practice - make sure it covers the whole lens, and don't press it against the lens too hard or you will get camera shake. [Easiest to do with a tripod, but still easy without.]

I use Singh Ray rectangular Graduated ND filters and B+W circular polarizer filters.

jwohlhueter

Speaking as a landscape photographer this characterization of Grad ND filters couldn't be farther from the truth. I can only assume the poster has been frightened away by the care and setup needed to use them properly. If post processing is so much better than a Grad ND why isn't it better that any Solid ND? The high dynamic range issues of sunrises and sunsets as an example can be balanced with Grad ND's and eliminate the need for post processing. No bracketed images needed. All ND filter manufactures tout Grad ND filters and offer videos on their web sites. Singh-Ray highlights 76 recognizable pros that use their Grads. If the OP wants to do landscape work Grad ND's will serve him or her well and become indispensable.

jackm1943 Loc: Omaha, Nebraska

I have the Hoya 10 stop filter and am very pleased with it, no color shifts.

srherrmann Loc: Baton Rouge, Louisiana

I have a complete set of the Hoya PROND filters and am quite pleased with them.