ND filter help.

[Viridian]

So I'm looking into buying an ND filter but I'm torn on what I should get. The shot I have in mind that I'd want to use it for (besides also the other things you can do with a ND filter) is this: capturing motion of people inside of a large room. I've never used an ND filter before so I'm not sure what one would be best for that. I seen this one first: http://www.bhphotovideo.com/c/produc...l_Density.html
but then I thought 9 stops of light would be way too much for what I'm looking to do. Then I found this: http://www.bhphotovideo.com/c/produc...l_Density.html
I think this would be better because I have more control over how much more light I want to remove. My only concern is, if I was to stack all 3 of those filters to equal 9 stops of light, how bad would it effect the color, or focus of the shot? And also would vignetting be a problem if all three are stacked? Even if its a 77mm filter screwed on the front of a 52mm lens with a step up ring? The 52mm being the Nikon 18-55mm.

[Manfred M]

Hi Zach - I'm not convinced that you need a ND filter to accomplish what you are after.

The first question for you would be to ask if you cannot accomplish what you want to do with normal camera settings? Put your camera on a sturdy tripod, pick a low ISO setting and use a small aperture, cover up the viewfinder (to ensure that no stray light traveling through it impacts your exposure) and take a picture with an appropriately long shutter speed. I've never used a ND filter for any indoor work, I've never needed to. An exposure of a few seconds or even less should give you the effect you are after, I would think.

If you go crazy and choose a 9-stop ND, you'll likely get an image of the room and not see any people at all in it. If they keep moving, the only thing that will show up in the image are the immobile objects in the room.

Just as an aside, I use ND filters for specialty work and have 1, 2, 3, 5 and 10 stop ones. I have stacked the 1, 2 and 3 stop ones (using a Lee foundation filter holder). My 5 and 10 stop ones are 77mm screw in types.

For shooting with a 10-stop B+W filter (close enough to your 9-stop one for discussion purposes), I will either compose the image and then mount the filter or will use LiveView to do the composition. Your viewfinder will be totally dark and useless once the filter is in place.

My 5-stop filter is a Tiffen. I would not recommend stacking it or the Hoya filters as both companies use aluminum mounts and they tend to bind. Invest in a pair of filter wrenches (B&H sells these too), if you are tempted to go in that direction. B+W, Heliopan and others use brass mounts and these come apart a lot more easily.

[Viridian]

Yea that's basically why I kept looking when I found that 9 stop, but I also want to use ND filters to photograph the ocean, and waterfalls, and all of the typical ND filter shots, the shot of the room was an idea that the owner of the building asked me to do.

[Manfred M]

Depending on the amount of light, you will smooth out any wave motion with a 9-stop filter. Again, low ISO and small aperture on a very sturdy tripod will be required. Photographing around sunrise or sunset will help as well.

I don't know anything about the Hoya; most people will opt for either the Lee Big Stopper or B+W; both are 10-stop filters. The Lee is supposed to be a bit cooler than the B+W, I don't own the Lee, so can't compare.

I expect that the building owner is looking at something like a flash photograph using rear curtain / 2nd shutter setting and dragging the shutter. That way you will get a clear image of the people with trails behind them.

[Colin Southern]

Hi Zach,

Conventional NDs are a royal PITA.

- You need a collection of them

- If you stack them (especially with a wide-angle or ultra-wide-angle lens) then your problem won't so much be "vignetting" as it will be "outright obstruction" (as it cuts into the view).

And if you're shooting at the best times of day (golden hour) then the light changes rapidly and you'll need to muck around even more.

The solution is a variable ND filter (2 to 8 stops). Normally when shooting the likes of water etc you need aperture control for DoF but you also need shutterspeed control for motion effects; with a variable ND filter you set the aperture and shutterspeed you want and then vary the attenuation to balance the exposure. You can even vary the attenuation DURING the exposure (try doing that successfully with fixed ND filters!).

There are a few of them around, but be aware that if you've heard the term "you get what you pay for", that the term was actually coined from filter purchases! (OK that was a lie, but boy oh boy does it ever apply). So having said all that, THE variable filter to get is one of the Singh-Ray models (I personally use a couple of their older Vari-ND models). No, they're not cheap, but they are in a class of their own in terms of quality and will (if looked after) last a lifetime and even longer. A few here have bought one on my recommendation and I don't know if a single one who wouldn't buy it again without hesitation.

Happy to answer any questions about it. Here's a few images I've made with them ... (click for a better size)










(This last image is a composite of 3 or 4 planes landing (can't remember which!) - for the one that went full length on the runway I was able to vary the attenuation as it got closer and closer to prevent the lights blowing out the shot).

[Viridian]

Thanks Colin!
Have you heard anything about the brand Tiffen? A 150 dollar Variable ND filter is more in my price range more than a 350 dollar one to be honest hahah

[Colin Southern]

Thanks Colin!
Have you heard anything about the brand Tiffen? A 150 dollar Variable ND filter is more in my price range more than a 350 dollar one to be honest hahah

Not a brand I associate with quality to be honest. People think "oh - it's just a couple of polarisers -- should be easy to make", but the reality is that it seems to be harder than they thought, and they end up with colour shifts and cross hatching.

[Viridian]

Maybe I'll do some saving then, It'll be worth it