Another Neutral Density filter thread ;)

[Compaq]

I've been wanting one, and the ultimate question is: how many stops of light should the filter absorb? I believe something like 4 is the most common. However, I've been doing some highly scientific tests from our terrace: All tests at f/22 and ISO-100 to achieve the longest possible shutter speed


So, a few days ago is was overcast at around 12 o'clock, midday. I set the camera to spot metering and metered off the water. I got 1/20th of a second. Applying a 4 stop ND filter would give me a shutter speed of one second. Is that sufficient for a real blurry water? Let's say I'm shooting waves hitting the shores. Those aren't moving very fast, and I would perhaps only be able to get one wave hitting the shore - and not get that silky soft gaseous water.

Another day it was sunny, and I metered off the water. I got a shutter speed of 1/100th of a second. Four stops down from here would be 1/6th of a second.

The third test I did was on an overcast day, just before it gets darker. I got a shutter speed of 1/8th of a second. Four stops down from here would be around 2 seconds. Better, not not quite the shutter speed needed for shooting waves, I would think.

And not to mention that it wouldn't always be ideal to shoot at f/22. As Bryan Peterson would have said it, I may come across "who cares" subjects, or when depth of field isn't really of great importance, and still want a long shutter speed in the day.

So, how are you guys doing this? I've been watching videos and done some testing now, and I'm a little befuddled as to what grade ND filter I would need.
Uber long shutter speeds aren't always the best, of course. I've seen several images on here of rivers with a one second exposure. Reveals some detail, yet blurry water. Perhaps the ideal thing would be to have 2 ND filters?

 

[480sparky]

Not just 2 ND filters, but as many as you need. One ND filter will only accommodate one need. Having two will accommodate three. Three will accommodate seven. Four....... fifteen.

 

[kundalini]

Do you have a CPL (circular polarizer) yet? That would be my first filter suggestion. They offer ~1-1/2 stop of light.

I use a 3 stop ND filter and it has worked for me.

I also have the three filter GND kit by Cokin.

 

[Robin Usagani]

I'm loving my 3 stop as well. If 3 stop is to much, you can always up the iso one stop. 3 stop is my happy medium especially because I can extend my low iso down to 50.

 

[analog.universe]

I have a 10-stop that's great for the blurry water effect... but it's definitely only useful in extreme circumstances. I was able to get a shutter over 3 minutes at f/9 like half an hour after sunrise. I've been wanting either a 3 or 4 stop to go along with it. Most of the time the 10 stop is so extreme you can't see through the viewfinder, or use in camera metering...

 

[Robin Usagani]

10 stops... Yikes.. You can probably weld or shoot a solar eclipse with that thing. You can always stack ND filters too.

 

[analog.universe]

You can always stack... but you'll inevitably lose some contrast and pick up some flare doing that. How much is too much certainly depends on the shot though.

 

[kundalini]

If you're not sure which one to get, you could always go with the Singh-Ray variable........

Singh-Ray Filters: Vari-ND Variable Neutral Density Filter

 

[analog.universe]

I considered the singh-ray at one point and decided against it due to certain anomalies. The way it works is by rotating 2 polarizers with respect to each other, so you not only get a neutral density, you also get polarization on 2 axes, as well as the effect of the interaction of that polarization. Depending on the directionality of light in the scene I saw some pretty weird and unpredictable results... color shift in skies relative to viewing angle, etc...

 

[Mike_E]

Another problem with stacking is vignetting. If you're using a wide angle you've got problems unless you get the 77mm filters and use an adapter on lenses less than 77mm.

 

[Trever1t]

I just ordered a 10-stop B&W filter myself for a first ND, knowing I will be buying a couple few more later but wanted the 10 stop first

 

[Derrel]

I just ordered a 10-stop B&W filter myself for a first ND, knowing I will be buying a couple few more later but wanted the 10 stop first

"Go big or go home!" I've seen some pretty incredible shots on the web using those 10-stop ND filters...it REALLY allows the photographer to explore the temporal aspect of photography much more than was possible with d-slrs that have a base ISO value of 200, as compared with the old-time ASA values of 6,8,10,12,25, where looooooong exposures were pretty normal when the lens was stopped down and/or the light levels were low. I think one thing you ought to definitely try with your 10-stop ND filter is to do a few city shots, where you eliminate most or all of the people moving by by getting the exposure into the 1 to 2 minute range.

 

[Trever1t]

T'was one thing on my list of things to do with it exactly. I've been scouting around San Jose for a good view

 

[Compaq]

I appreciate all your help, truly. 10 stops would unravel a few creative possibilities, no doubt... as would a 4-5 stop one. Which one to get, hehe. And which filter thread size...

 

[analog.universe]

I just ordered a 10-stop B&W filter myself for a first ND, knowing I will be buying a couple few more later but wanted the 10 stop first

This is exactly what I did...