Adjustable ND filters

[osprey48]

I've just found out about the existence of adjustable ND filters. Are they any good? I've seen some on Ebay for under £6, so I'm a bit suspicious.Thank you.

 

[Dr Croubie]

In short, Price is proportional to quality.
Especially with Vari-ND filters, the worst and cheapest ones get colour-casts and even cross-hatching effects in some cases.
If you can't afford a good one (B+W, Heliopan, Singh-Ray, Lee, etc), I'd suggest just go with a handful of regular fixed-value NDs (you get better for your $ with fixed than varis)

 

[SMBooth]

I would go with fixed ND filters, besides the above the actual ND rating or f-stop value changes with the lighting conditions. On so it seems to me.

 

[AgX]

Consisting of two polarizers one must take account of the inherit characteristics of a polarizer which is

-) of course polarizing, with maybe unwanted reduction of reflection and a, even spatially varying, effect on sky colour

-) the dependability on angle of view (with super-wide angle lenses)

 

[fastw]

Don't waist your money, they're crap. Cost me $20 to find out.

 

[Jim Jones]

I've used crossed polarizers for an improvised variable density filter, but would choose quality ND filters for serious use.

 

[jp498]

I think they exist for video more than to replace a set of ND filters. You could adjust the ND filter (with aperture going the other way) to control DOF.

 

[osprey48]

Thanks. I already have a set of filters up to ND-8, but 8 seems to be the limit, which is why I was intereted in the variable one. But maybe I won't bother if they're no good.

 

[AgX]

By stacking all three of your static ND filters you'll get the same reduction as with a 1,6 variable ND filter, namely factor 64.

 

[mesantacruz]

Vari ND's suck, as mentioned/implied, and i myself have tried them. Although the expensive ones are multicoated, they also give you a cross hatch, that you can't get to because they have a physical stop. The cheap ones, just let you keep twisting and twisting.

If you want a big stop, there is a nd 32 on ebay, that i bought that does work, although it gives a strong blue cast, while not a big problem in b/w, it wouldn't work with color film.

the expensive big stopper (LEE's big stopper), also gives a strong color cast, but they send you 'settings' for white balance/color temp if you use Dig*tal. One of the reasons you often see these photos with 10 stops in black and white, is the strong color cast these nd filters give... i think i read somewhere that it's because they aren't true nd filters (i don't remember the rest).

anyway,

don't get vari-nd filters
do get nd32 equivalent to 10 stops, by my tests (don't forget reciprocity)

 

[jp498]

I can get away without ND filters in 4x5 by using a speed graphic; 1/1000 sec and iso100 film can handle about any amount of sunlight. Way faster than most lens-shutters. I have had to use ND filters with my 8x10 though as the ilex5 shutter isn't exactly fast because of it's size.

 

[Huub]

I can get away without ND filters in 4x5 by using a speed graphic; 1/1000 sec and iso100 film can handle about any amount of sunlight. Way faster than most lens-shutters. I have had to use ND filters with my 8x10 though as the ilex5 shutter isn't exactly fast because of it's size.

There are situations in which 1/1000 sec and 100 iso film won't give you the the effect you try to achieve. When I take pictures of streams and lakes I want shutter times from at least 1/4 sec, going down to sometimes half a minute and more. Stopping down helps of course, but a ND filter serves a very good purpose also. I always carry two of them: a 3 stops one and a 10 stops one. The 3 stops I also use when I want to take pictures wide open and there is more light then the fastest shutter speed can take, for instance when using the 360 tele-xenar in it's Compur3.