ND filter, Issue or not

[Alex Uzan]

Hi Everyone,

First time I use ND filter on my camera, and I got strange results :

2.8 shutter 50

 

2.8 shutter 4000

I use a Hoya Variable NDfilter, and the exposure is set on the OSP logo.

Is this normal ?
Would i get Better results with fixed NDfilter ?

Thanks for your help

[webrunner5]

Looks normal to me.That is 6 stops different. Pretty much what your ND filter is at max I would suppose.

[Alex Uzan]

Yeah, I just watched the Dave Dugdale video about it

And I got my answer ?

[frontfocus]

yes, it's normals as in
a) you can get a color shift, especially from cheaper filters
b) variable nd filters use polarisation filters and thus can influence reflections and the sky 
c) when you go too far and use a filter without hard stops, an X will appear due to the way those filters work.

 

Yes, fixed nd filters offer better image quality, but you loose the flexibility. If you go for different fixed nd filters you might take a look at the xume manfrotto stuff.

[BasiliskFilm]

As above, and I guess you have discovered that with a very wide angle lens you get an additional effect of the oblique rays from the edges of the image having to pass through two layers of filter at an angle producing extra vignetting.

[1Ale82]

Polarizer filters always give strange results with very wide angle lenses and tangent light