ND filter exposure & color balance off???

I just bought a brand new B&W 6 stop ND filter. Took pics with it. The images end up being under exposed by 2/3 to 1 stop and I have to dial in about 1200 deg C more color temp to restore white balance (the filter is cool).

Oh, and the corners show more light fall-off with the filter than without. This is with UWA lenses. I haven't tried with normal or tele focal lengths.

Is all of this normal???

Yeah, they are common problems that you have to work around for the most part. When you see 9/10 stop long exposures people will often opt to make them black and white due to the colour issues. The cheaper filters tend to suffer more from colour cast, vignetting and unevenness.

Someone who has tested a lot of ND filters might be able to give advice on which ones work well.

Even the best are not neutral. No matter what ND you use you will need to adjust the color in post some. The better ones just require less adjustment than the good ones do.

Learn to work with what you have. If you try to find perfect filters especially with ultra wide lenses you will go broke.

I have tried a lot of filters and B&W were my favorite until I came across breakthrough photography. Poke around the web and check out reviews. I highly recommend them.

Peripatetic wrote in post #18563374
I have tried a lot of filters and B&W were my favorite until I came across breakthrough photography. Poke around the web and check out reviews. I highly recommend them.

I second this, there is very little color balance difference with Breakthrough's filters, even the 10 stop.

Optical vignetting on an UWA when using an ND filter is going to be unavoidable. The light entering the edges of the frame is traveling at an obtuse angle. making the filter effectively thicker the further from the center of the frame you get. It's usually not too bad though, and easily corrected in post.

Have you tried establishing a custom color balance before shooting with your ND filter? It's real easy to do with Canon cameras, I don't know about other brands...