ND filter issues on 3X Wide Lens
 

I am having focus (or maybe backfocus) issues with my 3X Wide lens on my XL2. Under some conditions, I am getting out-of-focus video when I don't have the ND filter in the correct position. However, I can't figure out what conditions and setting are the correct ones. Seems like under low light conditions the filter should not be on and under bright conditions, it should be off. If I don't get it right, the video is ruined because it very fuzzy. Can anyone teach me the proper conditions and settings for the ND filter and what causes this fuzzy video? Thanks.

Barry,

I don't have the XL2, but the principle's the same on any camera. ND filters for bright conditions, such as sunshine outdoors. This allows you to keep the iris open - if you close the iris too far you will get more blurred/fuzzy pictures.

Your camera will probably have a "sweet spot" for good images. I keep my iris at f1.7 - f2.4. If the image gets too bright (use zebra stripes and/or histogram to keep a check on this, as well as just looking at the image in the viewfinder or screen), then you turn on the ND filter. On my camera a I can set it to two different settings as well as "off".

On my camera, I've added an additional screw-on filter as well as the built-in ones for really bright conditions.

Indoors, or in poor light, remove or turn off the ND filters completely and open the iris up as wide as you need to get a decent picture.

If I place the camera on automatic, and look through the viewfinder on a bright day, with the ND filter off, the entire image looks slightly out of focus. Not overexposed, just out of focus. Then if I click the ND filter on, everything comes into sharp focus. Is this normal behavior? Should having the ND filter off cause the image to be out of focus?