red horizontal bar when using ND filters

[Charliedelta]

Hi,

Most of the times I use my ND filters (especially when I stack 2 of them together), I get a horizontal reddish bar roughly in the middle of the image, like the one in the attached image. Sometimes it's stronger, sometimes it's not like in this image. I noticed in backlight, and sidelight scenarios.

I'm not sure it's relevant, but I noticed with my Nikkor 24-70, and with my Tokina 12-28. As Filters I use a Hoya HMC Filter ND400, and a Hoya Pro1 Digital ND16.

What might cause it, and how to avoid it?

Thanks

 

[KmH]

See how much more noticeable it is opposite where the sun is?
It's a lens flare in the air gap between the 2 filters and or one filter and the lens front element.

 

[Charliedelta]

thank you Keith.

What would you recommend to do to avoid it?

 

[tirediron]

thank you Keith.

What would you recommend to do to avoid it?

Use only a single filter, shade the filter, aim away from the sun.

 

[480sparky]

Cover up your viewfinder. It's light coming in from there and reaching the sensor. You camera should have come with a simple slide-on plastic cover.

 

[HeldInTheMoment]

NiSi makes an anti-glare ND filter system, which I love, but the down side is they scratch easier. The glass itself does not scratch, but the anti-glare coating can. If you baby, or take good care of your gear, this may be something to look into. Though, if you are hard on your gear and USE it then it may not be a good choice for you.

Another option may be to use an ND filter with the foam backing to help block light between the filters/holder; though, this usually only really works for the first filter against the holder frame.

Looking at the filters you listed, it seems that are circular and screw onto the filter threads and/or each other to stack? I would suggest getting a 100x100mm filter system with a holder. The NiSi V5 is a GREAT system and goes with a CPL built in. Here is a link: https://www.amazon.com/System-Filter-Adaptor-Compatible-Singh-ray/dp/B017SD5OIY

The NiSi V5 is compatible with Lee, NiSi, Cokin, Hitech, and Singh-Ray 100x100mm or 100x150mm filters.

 

[HeldInTheMoment]

He is an example image I took last night with the new NiSi V5 System I just got.

Straight Out of Camera!

Nikon D7100
ISO 100
Shutter 8 Seconds
2 Second Timer
Tamron 24-70 f/2.8 @ f/9
NiSi V5 Filter Holder with CPL
NiSi 6-Stop ND Filter
NiSi 3-Stop GND Soft Edge
Manfrotto BeFree Tripod