[Konvas] OPF18 zoom behind the lens filter holder

[Ole Dost]

The 10-100 Zoom for the 16mm Kinors have no filter holders at the rear end.
There´s simply a small glas filter that is screwd over the rear end. There´s
a neutral glas in case no filter is needed. And the original set contains
several glas filters –mostly two different ND and two different conversion
filters. I have been using quiet often. I can see no loss of image quality
when using them. But I think those very tiny srew filters are not compatible
to other lenses.

Regards,

Ole

 

  _____  

Von: cinema-bounces at konvas.org [mailto:cinema-bounces at konvas.org] Im Auftrag
von Bruce Taylor
Gesendet: Dienstag, 11. November 2008 00:01
An: Konvas Discussion List
Betreff: [Konvas] OPF18 zoom behind the lens filter holder

 


Oh knowledgeable ones:

 

I have been slogging through the Russian/Western filter holder
incompatiblilties for a while now, and I feel like I'm about halfway
through. I have a set of Rafael's 4x4 and 4x5.65 adapters for the swingaway
Kinor and standard Konvas matte boxes. I have a 6x6 Arri studio matte box
that will need modification to handle the big 35mm roundfront anamorphic and
OPF18, and I am trying to find a deal on the incredibly expensive 6.6x6.6
filters that will fit it. 

 

In the meantime I have been looking into the rear filter holder on the
20-120 Lomo (OPF18) zoom. I found a 30.5mm filter that seems to fit, though
I need to check further into clearance and possible vignetting issues.
However I am concerned about possible depth of focus issues. I seem to
recall reading someone familiar with the lens saying it isn't anything to
worry about, but I am concerned. Does anyone here have any specific
knowledge or experience with this? I seem to recall the 10-100 zoom for the
16mm Kiinors had to have a clear filter in place for this issue? 30.5mm
filters are cheap, I got an Tiffen ND6 at FilmTools today for $15. A 6x6
filter on the taking end would ding me about $300. I had a client that used
optical ND gels at the rear and had no problems, but they obviously aren't
very durable.

 

Thanks,

 

Bruce Taylor

www.Indi35.com

 

 

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