Graduated ND Problem... Help!

[Destin]

I've been using Formatt-Hitech Firecrest filters for a while now for my landscape photography, and I absolutely love the system. I've used it exclusively on my D810 until now and have never had any issues to date.

This morning I tried it for the first time on my Fuji X-T20 and ran into a major issue that I can't seem to diagnose on my own. I was out shooting this foggy scene just before sunrise:

1.) This photo is taken with the CPL filter only.
Diagnoses_Grad-2 by Destin Danser, on Flickr

I noted that the sky was significantly brighter than the foreground so I added a 0.6 reverse grad ND filter for the next shot (only grad filter I had with me)

2.) This was the result with the grad on. Same exposure settings. Same while balance. Same everything, other than the filter.
Diagnoses_Grad-1 by Destin Danser, on Flickr

Both images are SOOC jpegs with no editing applied. Raw files appear similar, so it isn't a problem with the jpeg engine.

I've never noticed a color cast with this filter and I've used it a bunch of times. This was the first time using it on an x-trans sensor though.. could it somehow just not work well with that sensor format or something? Or is it just way too strong of a filter for this scene and the severe underexposure is revealing a cast?

 

[tirediron]

I'm not familiar with the holder for this system; is it similar to the Cokin or Lee holders which hold the edges but leave the top & bottom of the filter exposed? This looks very much like the magenta cast that affects Cokin NDs when the sun hits and exposed filter edge. I have a piece of matte black craft foam (Wal-mart, hobby aisle, <$1.00) that I use as a sort of makeshift lens hood to protect against the issue.

 

[Destin]

I'm not familiar with the holder for this system; is it similar to the Cokin or Lee holders which hold the edges but leave the top & bottom of the filter exposed? This looks very much like the magenta cast that affects Cokin NDs when the sun hits and exposed filter edge. I have a piece of matte black craft foam (Wal-mart, hobby aisle, <$1.00) that I use as a sort of makeshift lens hood to protect against the issue.

It is! This is a 100x150mm filter that slides into the front slot of the holder in front of the CPL. There are also small plastic covers that go around the holder to keep light from getting between the filters.. and I forgot those covers at home today.

I'll have to test this theory next time I go out, but it isn't something I've heard of before. I think you might be onto something though.

 

[tirediron]

Let us know!

 

[TreeofLifeStairs]

Let us know!

Wow, good catch.


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[CraigW0LV]

I use the Breakthrough Photography filters and have never had that problem. Could be the filter!

 

[waday]

Let us know!

Wow, good catch.


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@Destin, any updates on this?

 

[Destin]

Let us know!

Wow, good catch.


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@Destin, any updates on this?

Yes! Sorry forgot to update.

When that photo was taken I forgot that I also had a 6 stop ND filter behind the grad filter, plus a polarizer.

Essentially I had too much ND stacked and it was allowing a higher than normal percentage of UV light to pass through, causing the magenta cast.

This is a well documented issue across the web, though one I wasn’t familiar with. I’ve used the filters individually since then on the x-t20 with no issues.

The 6 stop ND filter was shattered on a recent sunrise shoot, so I’m looking into what brand I want to replace it with.

 

[waday]

Thanks for the update! And definitely good to know!

 

[mrca]

All vari nd filters are not created equal. The less expensive ones can create a color cast. I have used the Singray f2-8 stop for 10 years and NEVER had a problem including any patterning appearing. Don't break that one, it's expensive. I have cokin split nd's and hold in front of the lens with my fingers. I don't do much landscape so rarely use them but never had this issue either.

 

[Destin]

All vari nd filters are not created equal. The less expensive ones can create a color cast. I have used the Singray f2-8 stop for 10 years and NEVER had a problem including any patterning appearing. Don't break that one, it's expensive. I have cokin split nd's and hold in front of the lens with my fingers. I don't do much landscape so rarely use them but never had this issue either.

I use 100mm square filters and a holder, not a variable ND.