[LargeFormat] Filters
Clive Warren
largeformat@f32.net
Sun Jul 7 18:36:29 2002
At 2:12 pm -0700 7/7/02, Brock Nanson wrote:
huge snip
>The real advantage to using glass is durability. I really hate having to
>use Cokin and the other 'soft' materials as filters. I'm always concerned
>about damaging them, scratching them when they require a dusting, etc...
>I also don't like the potential for light to get in behind them and cause
>unwanted reflections and otherwise lower contrast. That can't happen with
>screw on filters. However, it's impossible to do any graduated ND work
>with a screw on filter!
The optical resin filters are surprisingly tough - it's the same
material used for a lot of contemporary lens elements, although
whether it is used for a front or rear outside element on pro lenses
is another matter.
If you buy dyed in the mass filters then a small scratch does not
remove the filter coating as it would with a cheaper filter. If the
filters are shaded from direct (sun) light then there are not any
noticeable issues with light spill behind them.
Optically they are probably superior to polyester - which is usually
coated with filter material or surface impregnated.
Cheers,
Clive