Promist 1/4 creating double images/reflections. Why?

[joshuajonesctva]

I have been testing out my new filter. I'm trying to mimic the Robert Richardson style. I used my Dedolight 150, pointed it straight down to the floor, and had a friend stand under it. There was a double image or reflection of the image back into the lens when I had the filter on. I was using my lens hood and removed the bounce board but it stayed there. What's the deal?

[David Mullen ASC]

Is the filter stacked against another flat piece of glass?

[joshuajonesctva]

Its the screw on kind of filter. I have a Zeiss 50mm 1.4, EF Mount for my 5D. It was the only filter on. My aperture was set at 1.4 if that makes a difference.

[David Mullen ASC]

Yes, but was the filter in front or behind another flat surface like another filter, or a protection filter on the front of the lens -- is the front of the lens flat or curved?

[joshuajonesctva]

The lens has a very slight curve. The was no flat surface in front or behind it. I have picture but I don't know how to upload it.

[David Mullen ASC]

I wonder if using a 4x5 filter in a matte box would movie the filter out far enough from the front of the lens to reduce the double reflection, or just make it smaller. Obviously the bright edge in the subject is reflecting on the face of your lens onto the back side of the filter. Normally a lens front has enough of a curve and is somewhat recessed to minimize this, but I guess your lens has a flat enough face to make it a problem, and you probably can't get the round filter any tighter to the front of the lens.

 

A titlable filter in a mattebox can allow the reflection to move higher or lower in the frame, sometimes all the way out of the filter is tilted enough.

[joshuajonesctva]

hm. I'll keep messing with it. Thanks for the help man! I checked out your website. Great stuff.