9 and 10 stop ND filters

[Jonathan Cross]

I am interested in long exposures for waterfalls, seascapes and similar.  Has anyone any experience of the 9 and 10 stop ND filters from the likes of Hoya and B+W?  If so, how do the images turn out?  Are the filters really ND or just gray, i.e. do they introduce a color cast?  Also when using a reasonable digital camera such as a Canon 5d Mk2 or similar, is there a signiifcant noise problem with long or bulb exposures when using these filters.

Jonathan

[fike]

This image was a panoramic using a ten stop ND.  They are hard to work with because they are sooo dark that you can't focus or check exposure with the filter in place.  The viewfinder shows blackness.  The LCD live preview shows blackness.  

I personally think that the B+W ones introduce a slight brownish cast, but I haven't gotten a color checker out to see if that is really true.  

I would suggest going for something more like 6 stops. B+W calls an ND 3.0 a 10 stop filter and claims that it filters 99.9% of light.  BW Ten Stop Filter at B&H

More detailed description of the shot and setup at the link below.
http://www.trailpixie.net/general/woodland_photog.htm

[Mark_Tuttle]

they do indeed add a brownish tint, from my experience starting  with the -6 stop.  I have a B+W -13 stop ND using a Phase One P45 back, and I couldn't balance a GMB color chart until Adobe introduced the DNG profiler software.  Since that experience I made a series of general profiles for lighting that I usually find myself in so that I'm close to the color balance I can work with.  Perhaps this is an issue only with the long exposure with the Phase One back and wouldn't affect Nikon or Canon in such a dramatic fashion so ymmv.

as for exposure I shot with the lens wide open at iso 400 then backed up my exposure to f8 at iso 50 for whatever number of seconds needed.

This image was a panoramic using a ten stop ND.  They are hard to work with because they are sooo dark that you can't focus or check exposure with the filter in place.  The viewfinder shows blackness.  The LCD live preview shows blackness.  

I personally think that the B+W ones introduce a slight brownish cast, but I haven't gotten a color checker out to see if that is really true.  

I would suggest going for something more like 6 stops. B+W calls an ND 3.0 a 10 stop filter and claims that it filters 99.9% of light.  BW Ten Stop Filter at B&H

More detailed description of the shot and setup at the link below.
http://www.trailpixie.net/general/woodland_photog.htm

[erick.boileau]

They are hard to work with because they are sooo dark that you can't focus or check exposure with the filter in place.  The viewfinder shows blackness.  The LCD live preview shows blackness.

with a camera like the 5D Mark II you can frame and check all perfectly with the live preview , even with a very dark filter

[Luis Argerich]

I use a ND400 from Hoya with a 5DII.
Regarding casts sometimes in very long exposures a magenta/reddish cast is unavoidable. This is due to infrared radiation. The camera has an IR filter but is not really very strong, that is why you can take IR photos with a IR filter. With a strong ND and very long exposures some IR radiation defeats the camera IR filter producing a cast. Photos with direct sunlight are more likely to get a cast. The cast can be corrected with WB and edition so it's not a big deal just a little annoying. The important thing is that filter quality is not the issue but the quality of the IR filter in the camera and you are not able to change that.

About noise. Noise in long exposures is the same as in short exposures (more or less) until termal noise kicks in. This depends on the exposure time and the temperature where you shoot. In night photography I tend to use higher ISOs in summer and lower ISOs in Winter and I don't think this will be a factor in daytime exposures using a ND filter. Others can chime in with their experiences.

Cheers,
Luis

PS: ISO50 doesn't make sense shooting RAW and RAW is almost mandatory if you are using a dark ND filter.

[Paul Sumi]

I use a ND400 from Hoya with a 5DII.
Regarding casts sometimes in very long exposures a magenta/reddish cast is unavoidable. This is due to infrared radiation. The camera has an IR filter but is not really very strong, that is why you can take IR photos with a IR filter. With a strong ND and very long exposures some IR radiation defeats the camera IR filter producing a cast. Photos with direct sunlight are more likely to get a cast. The cast can be corrected with WB and edition so it's not a big deal just a little annoying. The important thing is that filter quality is not the issue but the quality of the IR filter in the camera and you are not able to change that.

Another discussion about this phenomenon, with examples:

http://www.naturescapes.net/phpBB3/viewtop...050&start=0

Paul

[markhout]

Tried this last summer with a Hoya filter and can confirm the IR purple cast.



See here on Flickr for tech details.

[jasonrandolph]

You didn't mention it, but I thought I'd put in a plug for Singh-Ray's Vari-N-Duo.  It's a screw-on ND filter and polarizer that varies from 2-1/2 to 8 stops with a twist of the wrist.  it allows you to focus/frame, then increase the ND to your desired level, and then expose.  It's more expensive, but worth every penny.  If you don't want the polarizer, they have the Vari-ND which is essentially the same filter without the polarizing element.  They also offer an add-on to bring the density up to 13 stops (I forget the name of the add-on).  Professional quality (and a price to match, but again, it's very much worth it).

[Ben Rubinstein]

Does Cokin/Lee make filters with that strength? That should help with the framing problems, you slot it in and out as needed.

[Paul Sumi]

If you don't want the polarizer, they have the Vari-ND which is essentially the same filter without the polarizing element.

+1 on the Vari-ND.  It's a very versatile tool, and not just for long exposures.

Paul

[Paul Roark]

I prefer a linear pol in front of a circular one.  I've found only B+W or Heliopan don't degrade images significantly when stacked.

Paul
www.PaulRoark.com

[Mark_Tuttle]

PS: ISO50 doesn't make sense shooting RAW and RAW is almost mandatory if you are using a dark ND filter.

If this is in reference to what I wrote above, I shoot iso 50 because the higher settings aren't as clean.  Perhaps on your Canon this isn't an issue, as it isn't on my 5d2 but I only use the filters on the Contax or Cambo with the P45 back.

[Luis Argerich]

I thught you were using a 5D2. ISO50 in the 5D2 is fake so it won't help achieve longer exposures. It's the same as taking the shot in ISO100 overexposing 1 stop.
Cheers

If this is in reference to what I wrote above, I shoot iso 50 because the higher settings aren't as clean.  Perhaps on your Canon this isn't an issue, as it isn't on my 5d2 but I only use the filters on the Contax or Cambo with the P45 back.

[Derryck]

The Fader ND is a cheaper version of the Singh-Ray at about $60-80. You can see what it does here

[Jonathan Cross]

Another discussion about this phenomenon, with examples:

http://www.naturescapes.net/phpBB3/viewtop...050&start=0

Paul

So if it is an IR issue has anyone tried a 9 or 10 stop filter with a filter that blocks IR better than that on the sensor?

Jonathan

[Scott O.]

I have used both the Singh-Ray Vari-ND filters without issue and with great success.

[Wally]

for the most part ND filters have little to no effect on IR light, in fact if you shoot with IR film such as Efke IR820 you can use a regular 10 stop ND filter and get close to the same results as if you used a real IR filter. The only difference is that the ND filter still let in a bit of visible light.

What is happening is that when you use deep ND filters you are cutting back on all the visible light but the IR passes right through as if you had no filter in place so you wind up with say 90% IR and 10% visible light hitting your sensor. Your sensor has a filter in front of it that will filter out most of the IR but it still lets through enough IR to give color casts.