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Kowa 883 Filter (1 Viewer)

z-ben

Well-known member
Having recently bought an almost new 883 prominar I have seen that Kowa sell filters "to protect the expensive fluorite glass" Does anyone use these and would they have a detrimental effect on the view and digiscoping results by affecting the light gathering abilities of the actual lens.
 

Rotherbirder

Well-known member
A good quality filter should have a negligible effect on the performance of your scope. For me, the benefits outweigh any possible downside many-fold. I have always used one on mine without any issue, neither practical nor optical.

RB
 

z-ben

Well-known member
Thanks for the quick reply I expect it would be best to use Kowa filter on a Kowa scope I will look into this once have sold my Nikon 82EDS . The bank balance is well and truly battered right now.
 

Binastro

Well-known member
I would go for a Kowa filter.

There could be faint ghost images from the flat surfaces, so I would use a lens hood also.
I assume the filter fits well below the lens hood.

Regards,
B.
 

jring

Well-known member
Hi,

the 883 is an air spaced doublet and as far as I know like the older Kowa fluorite scopes in Steinheil configuration with the fluorite crystal inside.

The only scopes with a fluorite front element I know of are the Takahashi FS series.

Joachim
 

Borjam

Registered User
Supporter
I got an 883 in March and I also got the filter. I use to watch seabirds at the shore in Winter and despite being on a high cliff there is a lot of salt spray. So I prefer to clean a filter I can sacrifice :)
 

dogbreath

Well-known member
I use a filter on my 883 - it screws on the end of the hood so negates the benefits of the scope lens hood. In truth, I have never had a problem with that but I can see that some people might want to put a hood on the outside of the filter. Get a good filter and I would have thought that any optical effects are negligible and I certainly cannot see any effect.

Why do I use the filter? For the reasons given. I would prefer to clean or replace a filter than the front element of my scope.

A Kowa filter is about £100. I got mine used from a reputable camera shop and it is a used Hassleblad filter - so perhaps a Zeiss or B&W manuafactured filter. 95mm filter thread. Paid £35 used.
 

Rotherbirder

Well-known member
I use a filter on my Leica APO62 and it screws on in front of the objective element and not on the lens hood, which can still be used without issue. As already said, it completely negates the need for lens cleaning and, in my case, it saved my objective from damage in a catastrophic strap failure as it took the shock out of the fall. Replacing a filter is better than a new scope! Buy - and use - with confidence.

RB
 

jring

Well-known member
Hi,

with old Leica 62 and 77mm Televid models a filter is a very good idea due to known problems of those models with coatings degradation, especially when exposed to salt water spray.

For other glass, not necessarily - a filter will always degrade the image to some degree - no matter how good.
And for protection on scopes the front element is usually quite deeply recessed even with the lens hood retracted, that a filter is not providing the same amount of protection in case of a fall as with photo lenses.

Joachim
 

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