[LargeFormat] Turner Reich Orange Filters

[Les Newcomer]

Clive I pulled my Kodak filters publication B-3 out and looked at some
filter graphs

The standard #8  yellow cuts out at 460nm and has 100% transmission  by 520nm



The # 12 is a Deep yellow and cuts out about 490nm and opens up at 540nm
 This is also called a minus blue filter.

#15 is a deepr yellow than a 12 with the numbers shifting to 510 and 560

#16 is a light orange with a steeper cut off than a 15  520 and 560


#21 is an Orange filter with cutoffs points of 540 and 580

#22 is deep orange with cut off points at 550 and 600

You can see that as you progress from a #8 to a #22 you are simply
absorbing more blue and green light.

Since most of the films from the early 20th c. were very blue biased I
have to wonder if TR didn't over prescribe the yellow filter so
customers would get more dramatic effects, thus claiming TR lenses to be better.

Les

Clive Warren wrote:
> 
> Some time ago we discussed Turner Reich 4x5 lenses - some people love 'em
> some have had bad experiences....
> 
> Think it was Ken Hough who has great things to say about them.  It seems
> that bad experiences may have been due to the fact that the lenses need to
> be refocussed when stopped down and that they should (always?) be used with
> an orange filter which was supplied with the lenses when new.  This is when
> using both lens groups together in addition to single lens groups for the
> longer focal lengths.
> 
> Hardly an APO lens - however apparently capable of excellent performance as
> they are a protar design with an additional element to avoid being sued I
> guess .......
> 
> If  Ken is listening then perhaps he can enlighten me - or maybe someone
> else knows - would like to find out the Wratten number equivalent of the
> original orange filter.  Can anyone help?
> 
> Cheers,
>              Clive
> 
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