How to reduce the nd filter warm color cast?

[Marsu42]

I'm about to buy the Heliopan 2093 nd filter with 3.0 density. The manufacturer states (German: http://www.heliopan.de/produkte/graufilter.shtml) that this density produces a warm color cast that can be removed by "adding a Heliopan UV/IR filter in front of the ND filter".

Now I'm confused: a) all I find are UV *or* IR filters, what is the manufacturer talking about and b) does this work & is it necessary or is it trivial to remove the warm color cast in postprocessing?

Thanks!

 

[neuroanatomist]

The warm tone can be easily removed by adjusting the WB in post. I wouldn't stack another filter to get there...

 

[GMCPhotographics]

I'm about to buy the Heliopan 2093 nd filter with 3.0 density. The manufacturer states (German: http://www.heliopan.de/produkte/graufilter.shtml) that this density produces a warm color cast that can be removed by "adding a Heliopan UV/IR filter in front of the ND filter".

Now I'm confused: a) all I find are UV *or* IR filters, what is the manufacturer talking about and b) does this work & is it necessary or is it trivial to remove the warm color cast in postprocessing?

Thanks!

Sometimes the warm effect can be quite nice. I find the Heliopan warmth to be the most agreable of the ND colour casts. Yes in an ideal world there wouldn't be any....but in reality a little warmth can add a nice effect which is slightly more attractive than dialing it in via WB. I've yet to see an ND filter which doesn't have a colour cast and I've tried a few!
To remove, shoot raw and use WB select tool and choose a pure white item in the frame. Then tune the WB a little according to your eye and taste.

 

[wayno]

I find the charcoalley cast from my Hoya ND400 9 stop to be actually rather challenging to correct for. To deal with the tone it imparts, it's more than just WB. It's not unpleasant, just distinct.

 

[Menace]

Personally, not a fan of stacking filters - LR to fix warmth

 

[bluesphoto]

You can fix it with the white balance.
Or you can do it in photoshop with a method that can remove every colour cast ( doesn't always work well because it is based on the average of the image).
this is the one I use: Photoshop Quick Colour Cast Removal Technique
And here are some alternatives: http://www.udel.edu/cookbook/class/Tricks/color-cast.pdf and http://www.photoshopessentials.com/photo-editing/photo-filter/

 

[Marsu42]

You can fix it with the white balance.
Or you can do it in photoshop with a method that can remove every colour cast ( doesn't always work well because it is based on the average of the image).

Thanks a lot for the advice! I ordered the Heliopan filter today and am very eager to see the results, and I admit I hope that wb will fix it most of the time because with Photoshop I end up with a 100mb tif instead of a 20mb dng :-o

 

[bluesphoto]

Thanks a lot for the advice! I ordered the Heliopan filter today and am very eager to see the results, and I admit I hope that wb will fix it most of the time because with Photoshop I end up with a 100mb tif instead of a 20mb dng :-o

Wb can fix it but I personally alway fix it in ps because then you can work in layers because sometimes the colour cast is higher(more noticeable) in certain regions than in others so then you have to use masks.
And there is also the fact that white-balance only checks if the whites are white it doesn't necessary mean that the other colours are good after correcting wb.
Which most of the time they aren't(if you stack) because the nd's give a stronger colour cast.

 

[EOBeav]

I'm about to buy the Heliopan 2093 nd filter with 3.0 density. The manufacturer states (German: http://www.heliopan.de/produkte/graufilter.shtml) that this density produces a warm color cast that can be removed by "adding a Heliopan UV/IR filter in front of the ND filter".

Now that's quite a marketing ploy. "This is a great filter, but it creates some unwanted colorcast, so buy this other filter we make to fix it. "

 

[GMCPhotographics]

I'm about to buy the Heliopan 2093 nd filter with 3.0 density. The manufacturer states (German: http://www.heliopan.de/produkte/graufilter.shtml) that this density produces a warm color cast that can be removed by "adding a Heliopan UV/IR filter in front of the ND filter".

Now that's quite a marketing ploy. "This is a great filter, but it creates some unwanted colorcast, so buy this other filter we make to fix it. "

Yep, I don't belive in this either. I've read a few sites claiming that IR is the cause for ND colour casts...and yet I can see the same colour cast through the filter when held up in front of my eye. I have an IR cut filter (not from this particaulr brand) and no it makes no discearnable difference. Most DSLRs have a strong IR cut filter built it to the AA filter layer over the sensor. ND colour casts are a fact of life unfortunatly, so the trick is to find one which has a pleasant colour cast. When I spoke to Lee about this a long time ago, I was told that the dyes used are approximations of a linear light density reduction. no one dye can cut light across the whole colour spectrum and multiple dyes are needed to cover the whole range. These dyes aren't linear either, each dye has a curve and these are selected to approximate a neutral density. Multiple curves from multiple dyes causes overlaps and voids in the tonal responce curve, in reality the curve is quite wobbly and bumpy.

it reminds me of a quote from the late Douglas Adams "Science is what we dream of, Technology is what we get stuck with. then asked what defines technoligy, Douglas repsonded...that's easy....does it need a manual".
WB is not enough to correct a colour cast, becuase the cast isn't linear across the colour spectrum. WB will only give an approximation or averaged correction.

 

[pwp]

Now I'm confused: a) all I find are UV *or* IR filters, what is the manufacturer talking about and b) does this work & is it necessary or is it trivial to remove the warm color cast in post-processing?

It's only non-trivial if you shoot JPEG. If you're shooting RAW you have full control over colour in PP.

-PW

 

[paul13walnut5]

I've found it hard to eradicate entirely (I'm using the B+W 3.0 which has a strong amber cast) even with things like a qp card or grey card done in a test shot first.

I compensate WB in camera, adding in around 3000k over what a scene would usually be. This looks fairly close on the LCD, take a test shot with known colours (grey or QP, may need to up the ISO, open the aperture for practicality, I suppose you could do a manual WB instead here, if you have a neutral target)

You can shifty the WB slider at the RAW stage too, but I think there are secondary spectrums at work that means there is no magic bullet solution.

 

[Marsu42]

Now I'm confused: a) all I find are UV *or* IR filters, what is the manufacturer talking about and b) does this work & is it necessary or is it trivial to remove the warm color cast in post-processing?

It's only non-trivial if you shoot JPEG. If you're shooting RAW you have full control over colour in PP.

True and I shoot raw, but as paul13walnut5 full control doesn't mean easy control if it's not something that clearly falls into the wb or color slider category - so if each picture would need individual treatment it'd be easier to fix the problem while shooting with another stacked filter as the manufacturer suggests.

But from what I read, wb usually does the trick esp. if nobody knows how the real scene looked - my filter just arrived and I'll see this weekend how I can handle the color shift.

 

[RLPhoto]

Buy LEE or schnider optic.

 

[Marsu42]

Buy LEE or schnider optic.

If you're talking about schnEider :-> optics (B+W) - they are just releasing their 82mm nd filters, they much more expensive than Heliopan (probably early adopter's premium) and one of the above posts also states that b+w also has a color cast - so I went for the cheaper Heliopan w/o coating (it's not supposed to let through light after all).

 

[RLPhoto]

Buy LEE or schnider optic.

If you're talking about schnEider :-> optics (B+W) - they are just releasing their 82mm nd filters, they much more expensive than Heliopan (probably early adopter's premium) and one of the above posts also states that b+w also has a color cast - so I went for the cheaper Heliopan w/o coating (it's not supposed to let through light after all).

I haven't noticed a 3000K shift in color with any of my B&W filters. Even my old cheapo colkin ND filters aren't that terrible, but then again I'm using the Pro-glass LEE and Schneider 4X4 & 4X6 GND & ND square filters.

You might want to look into a square system, Its fantastic.

 

[neuroanatomist]

Buy LEE or schnider optic.

If you're talking about schnEider :-> optics (B+W) - they are just releasing their 82mm nd filters, they much more expensive than Heliopan (probably early adopter's premium) and one of the above posts also states that b+w also has a color cast - so I went for the cheaper Heliopan w/o coating (it's not supposed to let through light after all).

Schneider has had an 82mm 10-stop ND for a while (in fact, when I bought it in 2011 they were the only game in town for an 82mm ND3.0 screw-in). It does have a warming effect, you can see an example I posted in this thread.

 

[paul13walnut5]

I haven't noticed a 3000K shift in color with any of my B&W filters. Even my old cheapo colkin ND filters aren't that terrible, but then again I'm using the Pro-glass LEE and Schneider 4X4 & 4X6 GND & ND square filters.

You might want to look into a square system, Its fantastic.

In hindsight I should have went the big stopper route, though to be fair, the B+W was hardly a budget option.

I'm interested in the 3.0 filters you've used made by cokin, can't find these anywhere?
Had a look for the Schneider 3.0 filters as well, having bother finding them, other than as being sold under the sister B+W brand. I could find the Schneider square filters at up to 1.8 ND, but not as high as 3.0.

Just interested in the comparison you've made between the colour shift on my B+W 3.0 (N.B. 1000 NDx, 10 stop, not 3 stop) and the similar cokin and schneider filters you've used.

Can you give me a link to the Cokin 3.0 ND (1000x, 10 stop) filter? If they are as cast free as you say then I might end up getting one.

 

[RLPhoto]

I haven't noticed a 3000K shift in color with any of my B&W filters. Even my old cheapo colkin ND filters aren't that terrible, but then again I'm using the Pro-glass LEE and Schneider 4X4 & 4X6 GND & ND square filters.

You might want to look into a square system, Its fantastic.

In hindsight I should have went the big stopper route, though to be fair, the B+W was hardly a budget option.

I'm interested in the 3.0 filters you've used made by cokin, can't find these anywhere?
Had a look for the Schneider 3.0 filters as well, having bother finding them, other than as being sold under the sister B+W brand. I could find the Schneider square filters at up to 1.8 ND, but not as high as 3.0.

Just interested in the comparison you've made between the colour shift on my B+W 3.0 (N.B. 1000 NDx, 10 stop, not 3 stop) and the similar cokin and schneider filters you've used.

Can you give me a link to the Cokin 3.0 ND (1000x, 10 stop) filter? If they are as cast free as you say then I might end up getting one.

The Big stopper is my only 10-stop ND, I haven't used it more than twice compared to my GND's. Haven't seen a 3000K color cast but perhaps more like 500K cooler.

Colkin and Schneider don't make ND's that dark but on the ones I do own, a 3000K shift I haven't seen but I've only had the .3-.6-.9 filters GND's before I ditched Colkin all together.

IE: My fav's.

http://www.bhphotovideo.com/c/product/399443-REG/Schneider_68050656_4x5_65_Graduated_Neutral_Density.html

http://www.bhphotovideo.com/c/product/399272-REG/Schneider_68_056412_4x4_Neutral_Density_1_2.html

http://www.bhphotovideo.com/c/product/686370-REG/LEE_Filters_10_STOP_GLASS_4X4_4_x_4_Big.html

 

[Marsu42]

Schneider has had an 82mm 10-stop ND for a while (in fact, when I bought it in 2011 they were the only game in town for an 82mm ND3.0 screw-in).

Ok, in this case I was unable to find it for sale anywhere or simply forgot about it after seeing the price :-o

But concerning the original topic: I just stumbled across a link about "IR Pollution" that doesn't just result in a color cast but lower contrast, and this is said to be fixable with a combined ir/uv stop filter: http://www.leeduguid.com.au/blog/tips/bw-10-stop-nd-filter-nd-110/

However, this filter has a big drawback: "Interference filters do not work well with wide angle lenses; light rays entering at an angle cause differing color rendition, resulting in increasingly cyan corners. It should not be used on lenses with an angle of view wider than 60° (about 35mm on a full-frame 36 X 24mm sensor)."