Compensating for Heavy Long Exposure Vignette

[nvw]

Hello,

I understand that with long exposure I should expect some vignetting however what I am experiencing seems a little much, I am looking for your thoughts on whether I am getting what is expected, if there is something I am doing wrong or if this is an equipment problem.

I am using a Sony A7RII with a Batis 25mm. I have the Formatt Hitech ProStop IRND 10, 6 and 3 stop filters. The attached image was taken with 10 and 6 stop filters for 1 minute. I have experienced the same vignetting with 13 and 10 stop filters but not as strong. I know my filters have a blue cast and perhaps that is the problem. If so, would I experience the same vignetting if I got Firecrest filters?

Thanks for your advice,
Michael

[Bart_van_der_Wolf]

Hello,

I understand that with long exposure I should expect some vignetting however what I am experiencing seems a little much, I am looking for your thoughts on whether I am getting what is expected, if there is something I am doing wrong or if this is an equipment problem.

I am using a Sony A7RII with a Batis 25mm. I have the Formatt Hitech ProStop IRND 10, 6 and 3 stop filters. The attached image was taken with 10 and 6 stop filters for 1 minute. I have experienced the same vignetting with 13 and 10 stop filters but not as strong. I know my filters have a blue cast and perhaps that is the problem. If so, would I experience the same vignetting if I got Firecrest filters?

Hi Michael,

Stacking thick filters will exacerbate the vignetting for oblique rays, because of their longer path through the filter medium.

Cheers,
Bart

[Paulo Bizarro]

After using the Lee Big Stopper filter, I would recommend using only one filter instead of 2. As you mention, you get less vignetting. I still get some vignetting, which I can correct in LR.

I think that your example photo is also underexposed, which does not help.

[nvw]

Thanks, Formatt Hitech is making a 13 and 16 stop single filter. I'll look into that.