DIY Neutral Density filter?

September 15, 2007 7:18 AM

Photography: How to make your own DIY Neutral Density filter?

I'd like to make my own neutral density filters at home. They are sold at the photo store, but are a little pricey. Has anyone successfully attempted making their own neutral density filter, no matter how silly it looks?

posted by sidereal to Technology (10 answers total)

They are pricey for a reason. Good filter glass will degrade your photos; cheap filter glass is like a big fingerprint in the center of your lens. This is an item on which the shop has a pretty good markup. Ask for a discount and see what you get, especially if you are a regular customer.
posted by caddis at 7:47 AM on September 15, 2007

How about a cheap piece of smoked plastic/plexiglass/glass? Like in old (decorated in the 80's) offices, they have smoked glass between cubicles and stuff? And I'm sure there are all sorts of other sources, like those cheap plastic inboxes that always seem to be made out of smoked plastic. Just make sure it's not 'frosted' too...

I'm sure the quality won't come anywhere near that of a real ND filter, and you might have problems like color tints. But who among us photographers hasn't resorted to tacky improvisations when we didn't have the real thing?
posted by fogster at 8:34 AM on September 15, 2007

I would recommend buying the filter, I just picked up two at my local camera store (used) for not that much, so try looking on ebay. Otherwise I would tell you that maybe you could give some nd gels a shot, but I guess it depends on what you are trying to do. Maybe you could just use a slower speed of film or set the iso lower?
posted by tev at 10:30 AM on September 15, 2007

I can't imagine this would really be a worthwhile use of your time. Making good-quality optical glass components is hard, and a crappy filter will ruin photos like nothing else.

If you really need to do this, what I'd get would probably be one of those square filter holders (Cokin) and then see if you can get a light grey/smoke theater gel cut into a shape that will fit.

But more seriously, there's a ton of photographic equipment around for next to nothing. Just keep an eye out in the bargain bins of photo stores (they're going out of business fairly quickly), yard sales, eBay, and similar.
posted by Kadin2048 at 10:42 AM on September 15, 2007

nthing sucking it up and buying it. Cut corners anywhere else, but never on your optics.
posted by dmd at 11:06 AM on September 15, 2007

You don't mention what you might need them for. Perhaps if we understood your purpose (we do know what they are normally for) we could respond better.
Anything you stick in front of the lens has to be optically perfect or it will degrade the image. The cost of the filter is the cost of a guarantee of "least possible harm."
posted by johngumbo at 11:23 AM on September 15, 2007

I've had some luck with tinting material cut to fit in between two UV filters (just to hold it in place), but I was using it for long exposure drawing-with-an-LED-light kinda things, and I wasn't too concerned about the quality of the optics.

For anything else you probably want the real deal, I'd see if I could find a used one. Or maybe ebay; they have a number of different sizes and some are as cheap as $10.
posted by quin at 11:52 AM on September 15, 2007

Response by poster: Thank you for all the responses. The cogent impression I get is don't do this, it's a waste of time. It sounds like rolling your own ND filter is akin to saving money by rewiring your basement yourself, hey, how hard could it be?

Right, got it. I'll put the crowbar in the wallet and pick up a $20 Conkin ND4. ($20 is a lot for me)

johngumbo, it's for the usual, like wanting a big aperture in broad daylight to reduce the DoF. My 50mm prime at f1.8 in daylight just lets too much light in sometimes.

Thanks for the answers!
posted by sidereal at 2:46 PM on September 15, 2007

Good for you. I recommend that you buy used, especially at your local camera shop where you can see that it is in good shape. You can get good deals there. For a high end filter that may have gone for $60 new, they will pay maybe $5 and perhaps much less. They will want $20-25 for that, perhaps $10 to $15 for a cheaper one. Group some purchases and ask for a discount and it might be even less. At a good store they will accommodate. Even if you are not a repeat customer you can probably get 10 to 15% off at most stores, even without a grouped purchase. You can always bargain on used stuff. When you take shipping into it, it is probably cheaper than eBay, plus you get to inspect.

Another thought, do you have a polarizer? Those are up to 2 f-stops, and neutral. They cost more money than an ND filter, and an auto focus camera needs a circular polarizer which is even more (about $80 for a decent one new). A polarizer is an awesome tool, making all your skies look better etc. Anyway, if you don't have one it probably adds $20, as a good large (55mm) circular polarizer, used, is probably around $30 to $45, but smaller ones are cheaper. Take my prices with a grain of salt though as I haven't bought one, except at cost from a family member, in a few years. You might do better than what I think.

One more thing to watch for, if your camera has a wide angle zoom or prime focus lens, make sure you get a filter that has a narrow body. This is most important if you get a polarizer as with their rotating front section they tend to stick out further. You don't want the filter to intrude into the lens' field of view.
posted by caddis at 3:39 PM on September 15, 2007

You might want to look into buying a filter holder and its matching filters. (Use for positioning gradiated filters, etc.). It might be cheaper in the long run since each filter doesn't need it's own screw mounting.

There are also ND filters that can go 2-8 stops just by turning a bevel. Also cheaper in the long run if you needed several different ones.

I agree it's a pain to pay so much for something so specialized in use. Like the flash socket bubble levels....$20?!
posted by cowbellemoo at 5:12 PM on September 15, 2007