Which neutral density filer?

[JohnR48]

I want to buy a B+W neutral density filter for taking pictures of moving water and getting the milky effect.
Should I get a 3 stop or 6 stop? My local camera store is of no help at all.

Thanks in advance.
John

[Donald]

John

I don't know of any 6-stop filters, others than the fact that can be achieved with the Singh-Ray Vari ND. The likes of Lee make the 10-stop Big Stopper. There were supply problems with that for a while, but I hear they are improving.

However, the fact is that you don't need to slow things down that much to start blurring water. People start off thinking that you'll needs lots of ND loaded up to get the shutter speed way down.

The fact is that you'll be blurring reasonably fast flowing water at something around at 1/8th shutter speed. You don't have to be up at 2, 4, 8, 10 seconds etc.

But if it's, say, a beach scene, or lake scene, and the water is not fast flowing but you want to create that silky smooth look, then you will need to load up quite a lot of ND filter to slow your shutter down. That when you get into exposures of X, Y, Z minutes rather than seconds.

You've also got to think about what lighting condition you're going to be shooting in. Are you envisaging a tree-covered river/stream. If so, then you're going to be in shade a lot of, if not all, the time. So, you're going to be operating a quite low shutter speeds anyway, if you keep the ISO at 100. So you might not even need as much as 3-stops.

And finally - how much blur to you want to induce? Many of us think that the extreme 'cotton wool' type fluffiness takes it too far and is unrealistic. Others can and do produce stunning images by going down that route. It's about personal taste.

So, what does all of that tell you? That there is no simple 'Yes'/'No' type answer to your question. You need to evaluate what it is you want to create.

If, at this moment, you were at the scene you envisage - with no filters. What sort of shutter speed could you get down to? What sort of shutter speed do you want to achieve? The difference provides the answer to your question.

However, I'd be amazed if you needed anything like 6 stops to blur moving water in a countryside river. 3 would be too many for me in most cases.

[rpcrowe]

Donald has pretty well said it all.

IMO, it is a darn shame that Canon will not recognize the need for low ISO capability in their DSLR cameras other than the professional 1D (series). Having ISO 50 or even ISO 25 at our disposal would help us greatly. However, Canon only allows this in the 1D (series) camera capabilities. They would rather provide ISO in the billions, upteen quadrillion mega pixels, articulating LCD's and print from camera capability because these bells and whistles seem to sell cameras to the amateur market and amateurs are still the biggest purchasing group for DSLR cameras, even those in the Canon 7D range.

However, I can't condemn Canon too strongly, Nikon's lowest ISO in their D300 is ISO 200.

[Polar01]

John: I would suggest at the most a 3 stop, however I think that a 2 stop would be better as you could get more use out of it, to help cut the brightness of snow as I see that you are from Barrie a place at loves to get dumped on (snow that is). In time if you feel you need more, than stack on a 1 stop or a 3 stop to the 2 stop. B+W is a excellent maker of filters, I find on that the camera stores starts with a "H" sometimes is not that helpful at getting a lens filter in or take forever. Try the following link, it is in Vermont, they are very good, you will have to pay the duty (if customs thinks it is worth the paper work usually if over $100.00), and shipping ($5.00) no taxes, have used many times excellent customer service the link is as follow:

http://www.2filter.com/

Allan

[Colin Southern]

Donald has pretty well said it all.

IMO, it is a darn shame that Canon will not recognize the need for low ISO capability in their DSLR cameras other than the professional 1D (series). Having ISO 50 or even ISO 25 at our disposal would help us greatly.

Hi Richard,

I agree, but it's not that simple. Base ISO is 100 (as you know), but Canon do SIMULATE an ISO 50 (they call it "L"), but it's not a true ISO because all they do is digitally "halve" the signal, which reduces dynamic range be a stop (the 1D series do it, but at least some other Canon models do it too -- it just has to be enabled in the setup, and can't be used in conjunction with HTP).

The problem is when a signal only uses a portion of the sensor's dynamic range then it's easy enough to just keep amplifying the signal until the output is in the desired range -- but you can't do that in reverse; for a given aperture and shutterspeed, the photosites will overload past a certain point - at which point you lose detail

[Colin Southern]

I want to buy a B+W neutral density filter for taking pictures of moving water and getting the milky effect.
Should I get a 3 stop or 6 stop? My local camera store is of no help at all.

Thanks in advance.
John

Hi John,

I do a lot of this kind of shooting - and the short answer is "how long is a piece of string". Normally you'll want to control your aperture for DoF control - control your shutterspeed for water effect control - and that only leaves ISO or ND filters to balance out the exposure - and the amount of attenuation required can vary from "nothing" to "10 stops plus".

In my opinion, the Singh-Ray Vari-ND makes the whole process a zillion times easier; you just dial in the aperture you want - dial in the shutterspeed you want - and then dial in the amount of attenuation using the Vari-ND to balance the exposure no matter what it is (keeping in mind that ambient light levels also play a HUGE part in the amount of attenuation required).

A couple of examples ...

1/13th



90 second (effective)



1 minute (off memory)

[Tringa]

Lots of good advice here.

If you want a bit fun that doesn't cost a lot try some welding glass.

I don't know how many stops it is, but it is dark enough to block out almost all the light from the midday sun.

There is a risk of blemishes in the glass, you would need to set up a custom white balance to counter the strong green of the glass and find a way of attaching it to your camera - it usually comes in small rectangular sheets, so some filter holders may work - but it is very cheap, about £2.00 in the UK from Ebay.

Dave

[Glenn NK]

In my opinion, the Singh-Ray Vari-ND makes the whole process a zillion times easier; you just dial in the aperture you want - dial in the shutterspeed you want - and then dial in the amount of attenuation using the Vari-ND to balance the exposure no matter what it is (keeping in mind that ambient light levels also play a HUGE part in the amount of attenuation required).

Colin:

Please tell us more about this filter - sounds very interesting and useful. Realizing that the Singh-Ray filters are quite pricey and there is often a waiting list to get them, I've been reluctant to jump in and try them. I also realize that there are several different types, and a full set would be quite an outlay. As a result, I've just thought about them and forgotten about them.

Glenn

PS, those are some cracking good photos.

[Colin Southern]

Colin:

Please tell us more about this filter - sounds very interesting and useful. Realizing that the Singh-Ray filters are quite pricey and there is often a waiting list to get them, I've been reluctant to jump in and try them. I also realize that there are several different types, and a full set would be quite an outlay. As a result, I've just thought about them and forgotten about them.

Glenn

PS, those are some cracking good photos.

Hi Glenn,

That's an easy one

Singh-Ray Vari-ND

Singh-Ray

Singh-Ray Blog

Some of my Blog articles for them (<-Shameless plug!)

I've got a couple of Vari-NDs (77mm and 82mm) - they just ooooooze quality

[krispix]

John

I don't know of any 6-stop filters, others than the fact that can be achieved with the Singh-Ray Vari ND. The likes of Lee make the 10-stop Big Stopper. There were supply problems with that for a while, but I hear they are improving.

Just to even things up. Cokin list the following NDs:

ND2 = 1 Stop
ND4 = 2 Stops
ND8 = 4 Stops
ND100 = 6.2 Stops
NDX = 13 Stops

I have never seen that last two anywhere, so must assume they're special order.