Keeping the lens filter on. at DVinfo.net

Andy Wong · September 8th, 2008, 01:19 PM

Hey everyone, new to this whole filming and 35mm wot-not business.

I usually keep a UV filter attached to my camera lens for protection, but remove it whenever I attach my Letus adapter. However, one time, whilst removing the adapter, the lens mount ring accidently slipped at an angle and knocked into my camera lens, creating a tiny scuff mark.

So it got me thinking... can't I just keep the lens filter attached to my camera at all times and simply attach the adapters on top of that? Or will it affect light and picture quality?

I use the Letus rod support system which keeps the adapter secured in its position (I hope) with that underbelly screw.

Bob Hart · September 8th, 2008, 08:24 PM

Internal reflections, slight light loss and subtle effect on relay focus are the only things I can think of.

Relay focus may be affected in two ways :-

Refractive effect of the glass filter, which might introduce softness issues in parts of the image. An optical effect which alters the actual focus distance would be very subtle and is known to me as a problem only with extremely wide lenses like fisheyes.

Added distance between camera lens and groundglass in some instances might put the grounglass just out of reach of the camcorder focus range but is unlikely as the Letus relay focus position tends to be set towards the closer end of the focus range which allows some wriggle room across camera types.

September 8th, 2008, 01:19 PM	#1
Andy Wong New Boot Join Date: Aug 2008 Location: UK Posts: 20	Keeping the lens filter on. Hey everyone, new to this whole filming and 35mm wot-not business. I usually keep a UV filter attached to my camera lens for protection, but remove it whenever I attach my Letus adapter. However, one time, whilst removing the adapter, the lens mount ring accidently slipped at an angle and knocked into my camera lens, creating a tiny scuff mark. So it got me thinking... can't I just keep the lens filter attached to my camera at all times and simply attach the adapters on top of that? Or will it affect light and picture quality? I use the Letus rod support system which keeps the adapter secured in its position (I hope) with that underbelly screw.

September 8th, 2008, 08:24 PM	#2
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Internal reflections, slight light loss and subtle effect on relay focus are the only things I can think of. Relay focus may be affected in two ways :- Refractive effect of the glass filter, which might introduce softness issues in parts of the image. An optical effect which alters the actual focus distance would be very subtle and is known to me as a problem only with extremely wide lenses like fisheyes. Added distance between camera lens and groundglass in some instances might put the grounglass just out of reach of the camcorder focus range but is unlikely as the Letus relay focus position tends to be set towards the closer end of the focus range which allows some wriggle room across camera types.