4x4 glass filter distance to lens?

F

flowolf

Member
I have been using my mattebox for the second time now now and because I didn't place the 4x4 glass ND filter close enough to the lens, I am getting reflections from the glass in my footage. I also have a UV filter on all my lenses and wonder if the two pieces of glass may 'interfere' with eachother.

So my questions are:

Should I place the 4x4 filter and lens so close together they connect? (a little worried about scratches on the glass...)

Should I remove the (screw-on) UV-filter when shooting with 4x4 filters?
 
flowolf said:
I have been using my mattebox for the second time now now and because I didn't place the 4x4 glass ND filter close enough to the lens, I am getting reflections from the glass in my footage. I also have a UV filter on all my lenses and wonder if the two pieces of glass may 'interfere' with eachother.

So my questions are:

Should I place the 4x4 filter and lens so close together they connect? (a little worried about scratches on the glass...)

Should I remove the (screw-on) UV-filter when shooting with 4x4 filters?
Click to expand...

Since I'm not familiar with your matte box, and how far the filter slot/fixture is from the lens, I can't comment on the 'closeness', but general principles says... minimize the number of glass surfaces. So, unless there's specific reasons for multiple filters, use only the one needed for the shot.

A 'UV' filter really only becomes significant for 'vast vistas' worth of shots. For near objects, the amount of UV contribution of 'scatter' is minimal. The Wife gets on my case for not having a 'UV' filter on my lens, because we typically use it as a lens protection device... otherwise, it is almost useless for close up work, and can contribute to image problems such as multiple reflections of light sources, or flair from the sun, or strong light sources hitting the filter surface.

Some filters have coatings to lessen this sort of effect... but nothing works like nothing in front the lens...

In any case, the filter should not 'touch' the lens at all.
 
Do you mean you're getting reflections from the front or the back of the glass? It's very easy to get reflections from the back (the front should be protected by matte box and flags) if you don't have a donut or nun's knickers. Both of these block light from coming through from behind, around the lens. Donuts are foam discs that close down the wide opening of the matte box to the diameter of your lens; nun's knickers are a black leather boot that wraps around the lens and seals against the back of the matte box.

If you use neither and have some back light, you can easily see things like focus gears and glare in your footage.

And yep, if you want the sharpest, cleanest images possible, don't use UV or skylights on your lenses. Only use a filter when necessary for image control, and use the best filters you can afford.
 
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