ND not so neutral?

NorthernFocus · December 25, 2008

I recently started using a 3 stop ND filter for the first time. I used it on a couple of waterfall shots with good results. But then I used it for a sunrise seascape shot and it totally altered the color of the shot. I thought "neutral density" meant it alters brightness/luminosity only with no alteration of color.

Here's the shot in question. I was totally bummed because this looks like it was taken with some kind of rose colored filter. The lighting that morning was much more yellow than red. I tried altering WB and color tone in PP but in order to go far enough to get rid of the red, it doesn't look natural.

Comments/suggestions will be much appreciated...

dlplumer · December 25, 2008

Well it may not be what you wanted or what you saw, but it sure is beautiful

wfeller · December 26, 2008

Maybe it's not the tool you were looking for, but looks like it's one worth learning to use. Have fun with it.

kdog · December 26, 2008

I don't actually know the answer to your question, but I've made a mental note to be sure to bring my ND along on my next beach vacation. :ivar

jbr13 · December 26, 2008

Very nice photo either way! Did you try a photography with out the filter? I am wondering if it was the filter or maybe length of exposure. I can bring on colors like that sometimes by using a longer exposures at sunset. Just a thought.

J

pyry · December 26, 2008

I've heard that some very dark ND-filters tend to be blue rather than gray, but I haven't come across this. My guess would be that the camera guessed it's WB wrong, including the green/magenta offset.

It looks very nice as it is, but if you want to try to correct the tint again, I would try the WB with offset or fiddle with the hue in the reds.

NorthernFocus · December 26, 2008

I did not try a shot without the filter. I did bracket however and the shorter exposures are even darker/redder. But they are all relatively long exposures. This shot was 1.6s and the shortest one I took that AM was 1/1.3s.

I guess I shouldn't overthink it. In this particular lighting situation the filter brought out the red in the light and that's all there is to it. Based on feedback here it seems others like the photo so what the hey...

Thanks to eveyone who commented.

astockwell · June 5, 2009

What brand filter where you using?

Depending on the brand, some are not as neutral as they advertise. I have experience with Cokin and Hi-Tech, and Cokin's gave me a purple cast to all my shots, so I bought Hi-Techs instead, and then called Cokin on it, and they told me it was my technique that caused it. I use the same technique on the Hi-Techs, and never have a problem. What it is depending on the brand, their filters can caused different wavelengths of light to not make it through the filter to the sensor, so one wavelength of light will tend to dominate the scene where the filter was, depending if it was a grad, or a a solid, and it also depends on the quality of the IR filter on you CMOS.

Here is good reading:
http://www.fredmiranda.com/forum/topic/649248

-Andy

Hikin' Mike · June 5, 2009

astockwell wrote:

What brand filter where you using?

Depending on the brand, some are not as neutral as they advertise. I have experience with Cokin and Hi-Tech, and Cokin's gave me a purple cast to all my shots, so I bought Hi-Techs instead, and then called Cokin on it, and they told me it was my technique that caused it. I use the same technique on the Hi-Techs, and never have a problem. What it is depending on the brand, their filters can caused different wavelengths of light to not make it through the filter to the sensor, so one wavelength of light will tend to dominate the scene where the filter was, depending if it was a grad, or a a solid, and it also depends on the quality of the IR filter on you CMOS.

Here is good reading:
http://www.fredmiranda.com/forum/topic/649248

-Andy

I don't have any GNDs, but I've heard the same thing.

Regardless, It's an excellent image!!

dlplumer · June 5, 2009

Ron Coscorosa uses lots of ND and GND filters with long exposures. I'll bet he could shed some light on this (no pun intended). Now that I think of it, his soft landscapes almost always have considerable pink/magenta type tints. Send him a PM, and let us know what he says.

Dan

NorthernFocus · June 5, 2009

Man this thread came back from the dead

But better late than never. Thanks for the info, Andy. I was using a Cokin ND filter. I did read the article but I think it confused me more than anything else. But I get the general drift which was the point of my original post. At least now with digital, ND filters may not be so neutral

Thanks for the comment, Mike.

Dan, good idea. I will PM Ron too

.

coscorrosa · June 5, 2009

dlplumer wrote:

Ron Coscorosa uses lots of ND and GND filters with long exposures. I'll bet he could shed some light on this (no pun intended). Now that I think of it, his soft landscapes almost always have considerable pink/magenta type tints. Send him a PM, and let us know what he says.

Dan

I don't know anything, you all should know that by now

Even with my Singh-Ray filters (which are more "neutral" than the Cokin filters), there is a very slight color cast, much more noticeable on the 3-stop than the 2-stop which isn't really an issue. If my photos look pink/magenta it's either because the actual sky/conditions, or because I processed them that way (by changing the color balance or playing with curves or changing the white balance), moreso than the filter. I often do change the color balance (increasing the reds and decreasing the greens).

anwmn1 · June 5, 2009

I use ND filters and graduated filters on occassion. I think there are indeed slight color casts depending on the brand but it can easily be adjusted for by changing the White Balance either at time of shot or in post process.

I too like the shot you ended up whether it was intended or not.

astockwell · June 6, 2009

anwmn1 wrote:

I use ND filters and graduated filters on occassion. I think there are indeed slight color casts depending on the brand but it can easily be adjusted for by changing the White Balance either at time of shot or in post process.

I too like the shot you ended up whether it was intended or not.

Yes usually you can fix it with change of WB in camera with a custom WB, or fix in post. Another reason to shoot in RAW.

astockwell · June 6, 2009

astockwell wrote:

What brand filter where you using?

Depending on the brand, some are not as neutral as they advertise. I have experience with Cokin and Hi-Tech, and Cokin's gave me a purple cast to all my shots, so I bought Hi-Techs instead, and then called Cokin on it, and they told me it was my technique that caused it. I use the same technique on the Hi-Techs, and never have a problem.

-Andy

Basically my technique is to meter with the grads and solids on the camera, and then capture. I usually have pretty good luck with this. If the meter is underexposed still at 30 sec, then I switch to Bulb, and calculate after that.

The girl from Omega Satter (Cokin's USA Rep), told me I was supposed to meter with the filters off the camera, then put them on and capture, without changing the shutter speed once I put them on. I told her she was batshit crazy. I said "So once you meter, and then put the grads or solids or combo thereof on the the camera, you're not supposed to compensate the exposure for say the 3 stops of ND you just put on. She said yes, that is the way she did it, and she never has a problem with color casts. I told her because her shots were black (underexposed)

. She said they stand by their product, and she has never heard any reports of color casts caused by their product. I showed her numerous internet articles and forum posts proving it, and she still defended her techinque. Moron.

-Andy