Survey: "protective" lens filters

Neil Harrington wrote:

The purpose of a filter is to filter, not "protect the lens."

No. A photographic sysem normally needs no "filtering." But there is
little sense in leaving a $1500-10 000 unprotected.

In many situations color adjustment may be desirable, but that is not
what we are talking about here.

Per Inge Oestmoen, Norway

"pioe[rmv]" wrote in message
news:Iqtic.9937$EV2.96832@amstwist00...
Neil Harrington wrote:

The purpose of a filter is to filter, not "protect the lens."

No. A photographic sysem normally needs no "filtering."

And therefore needs no filter. A filter removes or reduces certain
wavelengths of light. That's what it's designed to do and that's all it
does.


But there is
little sense in leaving a $1500-10 000 unprotected.

If the purpose of that flat piece of glass were to protect the lens, it
would be called a "lens protector"--not a filter. And, obviously, it would
not be made to cut off certain wavelengths of light. If protection were even
partially the purpose of a filter, why wouldn't they make them of tempered
glass?

I can remember when Spiratone sold plano-plano optical glass mounted in
filter rings for someone who didn't want or need a filter, just something to
protect the lens. I haven't seen any of those for decades and would be
surprised if anyone still makes them; I doubt they sold many. So much for
the market appeal and perceived usefulness of a non-filtering "filter."

Neil

In article ,
"Neil Harrington" wrote:

plano-plano optical glass mounted in
filter rings for someone who didn't want or need a filter, just something to
protect the lens. I haven't seen any of those for decades and would be
surprised if anyone still makes them

Then you must be shocked. Heliopan does make them. Just not very popular
as it isn't as effective in cutting UV as an UV filter and can't warm
like a KR1.5. But costs the same. Also has the same coatings - standard
or SH-PMC.

--
To reply no_ HPMarketing Corp.

"Bob Salomon" wrote in message
...
In article ,
"Neil Harrington" wrote:

plano-plano optical glass mounted in
filter rings for someone who didn't want or need a filter, just
something to
protect the lens. I haven't seen any of those for decades and would be
surprised if anyone still makes them

Then you must be shocked. Heliopan does make them.

Well, I'm not shocked but I am somewhat surprised. :-)

Neil

"Neil Harrington" wrote in message
.. .

[SNIP]

I can remember when Spiratone sold plano-plano optical glass mounted in
filter rings for someone who didn't want or need a filter, just something
to
protect the lens. I haven't seen any of those for decades and would be
surprised if anyone still makes them; I doubt they sold many. So much for
the market appeal and perceived usefulness of a non-filtering "filter."


They are certainly still made. Most of the OEM names, and some of the third
parties, make and supply them as standard as part of the 'kit' with their
more expensive big glass.



Peter

"Neil Harrington" wrote in message
om...

Didn't Al Gore invent the UV filter?

Yes, and also the new federally mandated environmental "water saving"
toilets that you have to flush 5 or 6 times.

Hear, hear! 5 x 1.6 gallons = 8.0 gallons.
1 x 3.0 gallons = 3.0 gallons
We can all thank Al Gore for wasting 5 gallons of water every day for each
of us......(Not counting the annoyance of having to clean up all the
stoppages)


Of the two, the UV filter is by far the least annoying, though equally
useless.

Bull Winkle wrote:

Hasselblad is over priced an is just a staus symbol for some
who can't think beyond the equipment ....

Same can be said for cell phones.
--

Stacey

Bandicoot wrote:

"Neil Harrington" wrote in message
.. .

[SNIP]


I can remember when Spiratone sold plano-plano optical glass mounted in
filter rings for someone who didn't want or need a filter, just something

to

protect the lens. I haven't seen any of those for decades and would be
surprised if anyone still makes them; I doubt they sold many. So much for
the market appeal and perceived usefulness of a non-filtering "filter."



They are certainly still made. Most of the OEM names, and some of the third
parties, make and supply them as standard as part of the 'kit' with their
more expensive big glass.

My 300 f/2.8 came with a non-filtering front piece of "protecvtive"
glass. Despite my recent decision to abandon filters except where
needed, the 300 will retain this OEM supplied protective element.

Cheers,
Alan


--
--e-meil: there's no such thing as a FreeLunch.--

In article , Alan Browne
writes
Bandicoot wrote:

"Neil Harrington" wrote in message
.. .
[SNIP]

I can remember when Spiratone sold plano-plano optical glass mounted

filter rings for someone who didn't want or need a filter, just something
to

protect the lens. I haven't seen any of those for decades and would

surprised if anyone still makes them; I doubt they sold many. So much for
the market appeal and perceived usefulness of a non-filtering "filter."

They are certainly still made. Most of the OEM names, and some of
the third
parties, make and supply them as standard as part of the 'kit' with their
more expensive big glass.

My 300 f/2.8 came with a non-filtering front piece of "protecvtive"
glass. Despite my recent decision to abandon filters except where
needed, the 300 will retain this OEM supplied protective element.

Cheers,
Alan


Alan, is that a Canon EF 300mm f/2.8? If so, the first "real" optical
element is a very large and expensive fluorite plano-convex element.
Fluorite is still used because of its unique dispersion characteristics
(which AIUI still cannot be achieved with ultra-low-dispersion glass).
However, it has the drawback of low hardness, and is thus prone to
scratching and damage.

Hence the plain glass protective element - a feature of all Canon lenses
with large fluorite front lenses - and you are very wise to retain it!
--
David Littlewood

David Littlewood wrote:

My 300 f/2.8 came with a non-filtering front piece of "protecvtive"
glass. Despite my recent decision to abandon filters except where
needed, the 300 will retain this OEM supplied protective element.

Cheers,
Alan


Alan, is that a Canon EF 300mm f/2.8? If so, the first "real" optical
element is a very large and expensive fluorite plano-convex element.
Fluorite is still used because of its unique dispersion characteristics
(which AIUI still cannot be achieved with ultra-low-dispersion glass).
However, it has the drawback of low hardness, and is thus prone to
scratching and damage.

Minolta. I don't know the composition of the front element glass, but
it is coated, of course. IAC, a flat piece of glass with no filter
characteristic on a large lens like that is one of the exceptions I'm
willing to live with...

--
--e-meil: there's no such thing as a FreeLunch.--