Oil on filters?

[bigbun]

Hi all,

i just bought a new B+W polarising filter for my 350D last week.

even before i get to use it, i left a ugly fingerprint on it.
so i proceed to clean it with a specatcles cloth.
the fingerprint is removed with ease,
then when i started to clean the rest of the filter, smudges began to appear!
when i look at the cloth, it's stained with alot of black oily marks.

after some close examinations, i realised the dirt/oil came from the filter's inner threads.
i happened to rub the cloth against the threads,
and i cleaned the filter using the same spot of the cloth..

:cry: now the filter looks like post-WWII filter...

just wanna ask u guys..
is it normal for filter's threadings to have lubricant of some sort?
is there any basic technique to cleaning filters?

 

[slaam]

search the forum!
apparently there's oil between the filters in a CPL
am not sure but i suspect its to prevent internal glare or cos lens air interface not good
so maybe the cloth siphoned out the oil ..

 

[LittleWolf]

ust wanna ask u guys..
is it normal for filter's threadings to have lubricant of some sort?

No, it's not normal. I suspect the origin of the oil you see is not the filter thread, but the rotating mount of the polarizer. Some kind of lubrication is needed there.

is there any basic technique to cleaning filters?

The best method is to disassemble them (take the glass out of the frame, clean it, and reassemble. Otherwise, it helps to clean filters (or lenses...) starting from the center towards the outside, so that any crud picked up will be deposited were it won't hurt much.

 

[photobum]

No, it's not normal. I suspect the origin of the oil you see is not the filter thread, but the rotating mount of the polarizer. Some kind of lubrication is needed there.

I agree with LittleWolf. These are lubricant. My B+W polarising filter has it too.

 

[bigbun]

The best method is to disassemble them (take the glass out of the frame, clean it, and reassemble. Otherwise, it helps to clean filters (or lenses...) starting from the center towards the outside, so that any crud picked up will be deposited were it won't hurt much.

oh.. didn't know the filter can be disassembled..
will try cleaning it that way later.
thanks for the advice!

 

[LittleWolf]

oh.. didn't know the filter can be disassembled..
will try cleaning it that way later.
thanks for the advice!

Just a word of warning: it is very easy to slip and scratch the glass with a tool when disassembling the mount. I would not go that route for "normal" cleaning, just as you won't disassemble your lenses for routine cleaning. Also, polarizers may be laminates which are more delicate than normal glass filters.

 

[denniskee]

it is not that difficult to dismantle the polarizer. as with opening up any filters, just take care not to scratch the glass.

opened mine, clean with soap, wipe dry, put into dry box, now still using.

 

[bigbun]

so what tool is needed?
is it just get a minus screwdriver n pry it open?

 

[slaam]

I must say that I dun have that filter and not disassembled it so i might be wrong
but read this review on B+W filter
there's a guy who complained abt it leaking oil
I rem a pic there a CSer posted a photo of a filter with a bubble inside.
though I can't find it anymore.
but I would exercise caution if you are going to try to disassemble it.
I might be wrong.. really..

http://www.photographyreview.com/cat/lenses/filters/b+w/PRD_85062_3133crx.aspx

do tell if the dissembly goes well curious