Variable ND Filter

booda

booda

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Name
Gurj
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Ive just bought a Variable ND Filter from 7dayshop for £33.99

http://www.7dayshop.com/catalog/product_info.php?cPath=777_1&products_id=111258

Looks really good and did some minor tests yesterday indoors. I used my Sigma F1.4 wide open with shutter at 1/30 and ISO on 1600....it totally blew the picture out...i then put the ND filter on and adjusted it with the same settings and got a fantastic exposure...

What I wanted to ask is how many people use the variable filter and will it be good for outdoor portrait shots....not checked what the quality is like on the computer yet but seems impressive on the LCD....do you have any examples of pictures you have taken using this kind of filter....

thanks
 
I assume it is using 2 polarising filters and rotating one of them, while the second one is fixed.. Interesting to see what it does and doesn't do to reflections
 
I use a DIY one, but I haven't tried it for portraits yet. I do plan on using it for some portraits, but for some specifically unusual effects.

I'm not sure why you'd want to use a VND for normal outdoor portraits, unless you're wanting to really open up the lens for shallow DOF under very bright light, but even then I'd reach for standard ND filters rather than a VND.
 
markmullen said:
As a disclaimer I'm not a portrait photographer but why would you use a variable ND for portraits?

Even wide open at on a 1.4 with a low ISO were you still finding the shutter speed out of range on a 5D2?
Click to expand...

I suppose that if you want nice shallow DOF, but want to slow the shutter down just enough to capture a hint of motion blur (from a veil blowing in the wind, or a couple dancing perhaps :shrug:), then an ND filter is the way to go :).

Of course, I'm not a portrait potographer either, but I was bored and fancied a stab at answering a question today :D.
 
Naboo32 said:
I suppose that if you want nice shallow DOF, but want to slow the shutter down just enough to capture a hint of motion blur (from a veil blowing in the wind, or a couple dancing perhaps :shrug:), then an ND filter is the way to go :).

Of course, I'm not a portrait potographer either, but I was bored and fancied a stab at answering a question today :D.
Click to expand...

But the OP was using ISO1600, wouldn't you just try ISO100 and work up?
 
markmullen said:
But the OP was using ISO1600, wouldn't you just try ISO100 and work up?
Click to expand...

I assumed that was just an extreme test.. open up the lens as far as she'll go, crank up the iso and push the sensitivity. See how fr you can go and have the VND pull it back. It doesn't sound like a sensible bunch of settings, and a VND at such an extreme level of ND is very unlikely to produce an image that most people would be happy with. The harder you push a VND the more interesting (or dictracting) the artificats become.
 
yes, I was pushing the settings quite high to see what I could achieve....the reason Im asking about portraits shots is because of shooting weddings outside in very bright sunlight and wanting to get a shallow depth of field without overexposing.....luckily I wont run into this problem very often as I can set my iso to 50 which is very handy......maybe thinking outside the box such as taking portraits shots with a blurred lake/fountain etc....
 
Sunny 16, ISO 100..

f/16 - 1/100
f/8 - 1/400
f/4 - 1/1600
f/2 - 1/6400

I wouldn't carry a cheap VND for situations where quality is critical, a high quality ND4 filter would give a better result.
 
Naboo32 said:
I thought that was only because he was testing the lens indoors :shrug:.
Click to expand...

it was - whats the point of leaving it on 100 when testing a variable filter....I was trying to use an extreme example to see how well the filter worked....gonna try and post some pics with the settings...
 
Cool :)!

Now that you have an ND filter for exposure control, you've turned the 'exposure triangle' (Aperture/Speed/ISO) into an 'exposure square' :lol: !
 
Naboo32 said:
Cool :)!

Now that you have an ND filter for exposure control, you've turned the 'exposure triangle' (Aperture/Speed/ISO) into an 'exposure square' :lol: !
Click to expand...

haha - yes....Im only testing to see how far I can push things....I would never use it for critical shots unless its landscape stuff....but you never know....it might have its uses.....
 
Well, I ordered one of these to see if it might be any use at all. The first disappointment was the fact that it's all plastic. The threads feel particularly delicate and I wouldn't be surprised if they gave up quite quickly.

First I tried it on my 10-22. Nasty vignetting at 10mm and the first sign of the notorious cross-pattern appeared at around 3-stops. At 22mm it did manage to get to around 5 stops before it became apparent. About what I'd expected.

I'd also heard of problems with IQ using longer lenses. So I stuck my 100-400 on a tripod and started playing. No matter what I did I couldn't get a decent image. After a while I wondered if it was something wrong with my technique, shooting at 400mm with long exposures. So I got out my 10-stop Heliopan and tried that. The result is below - 100% crops with the Heliopan on the left.

VND%20Test.jpg



So, it's useless on short lenses unless I keep it to below 5 stops. It's useless on long lenses. It feels flimsy. It's going back to 7DayShop as being 'not fit for purpose'.
 
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