# 1x filter



## &Denekamp (Jul 6, 2005)

Hey,

I have a (probably silly) question..

the other day, I saw someone with exactly the same cam as I have, an Olympus IS-100. Only, the focus ring looked different from mine. at his you could read the printings on the lens. On mine, those printings are half hid behind another piece of glass, a screwed on filter as I discovered. on the filter it says: B+W (that would be the brand) 52E (that'll be the diameter of the lens) 010 (filter number i guess) 1X (magnification). That is all clear to me, but what I was wondering, what is it there for..? does it act as protection for the actual lens? Does it filter anything? what does it do..? all I know is that its stuck on the lens, you can't screw it off like you could with a normal filter.. maybe is't glued on, I don't know.. 

so, if you can tell me anything about this thingy on my lens, that would be nice  

Niels


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## Meysha (Jul 6, 2005)

It's a UV filter. Stops UV rays from getting to the lens and film.

I've been meaning to ask a question about this myself. I know that the UV filters worked on the film cameras because there was some issue of them affecting the blues in the film I think. But do they still work on Digital cameras? My gut feeling is that it wouldn't work - because film sensors work differently to negative chemicals. Does anyone know?


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## Meysha (Jul 6, 2005)

Ooops should answer the rest of your questions too.

Most people use the UV filter as a lens protector as you guessed because it doesn't affect the visual light (red, green, blue) but it only stops non visible UV light from getting through.

That's really strange you can't take it off. I would've thought you could've. That E after the diameter makes me think you can take it off. The E represents the thread size, not that it really matters anymore coz they're all the same. Maybe you're twisting it the wrong way.

Remember: Lefty loosy, righty tighty. (just a little thing to remind me which was to turn the taps to turn them on or off.)


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## ferny (Jul 6, 2005)

Push down on the filter and turn it. Try not to hold it too hard or you'll distort it (whilst you're holding it) and it'll be harder to get off. Try wrapping something rubber around the edge of the filter to get a bitter grip. It'll come off (if not glued and I can't see why it would be), it'll just need some gentle persuasion.



> B+W UV Filter UV 010
> 
> This UV Filter blocks the invisible UV component of light from the sky, which can cause blur and to which many color films react with a blue cast.  These filters should be called UV-Blocking Filters, because there are filters for technical applications that pass UV radiation and block all the other wavelengths.  Nevertheless, the short term "UV Filter" has become established among photographers.  UV Filters are ideal for photography in high altitudes (in the mountains), by the sea and in regions with very clean air.  The pictures gain brilliance and disturbing blue casts are avoided.. Because the glass is colorless, color rendition is not altered, aside from the elimination of the unwanted blue cast, and no increase in exposure is required.  That makes a UV Filter very suitable as protection of the front element of the taking lens against dust, flying sand, sea water spray and the like, and it can be kept on the lens at all times.  It is recommended for analog color- and black- and- white- as well as digital photography.  UV Filters from B+W are also available in Slim mounts for wide-angle photography without vignetting.


http://www.bwfilter.com/bw4.html


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## &Denekamp (Jul 6, 2005)

Ok, makes sence 

but.. why doesnt it just say its an UV "blocking" filter? 

I just found out that the pentax I own has one on it too. but for the pentax, I also have a separate (sp?) UV Haze filter.. so that a bit odd.. also a bit unnecessary I'd say hehe..

anyway, thanks for all the info!  And I'll try to unscrew it to the lefty..

Oh, one more thing.. sorry. If it protects the lens, how would it do that? I mean, if I get a scratch on the uv filter, i will still see it on the photo, right? or is it due to the fact that its replaceable? So I don't need to buy a new lens when I scratch my uv filter (I think I've just answered my own question )


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## SLOShooter (Jul 6, 2005)

Meysha said:
			
		

> Ooops should answer the rest of your questions too.
> 
> Most people use the UV filter as a lens protector as you guessed because it doesn't affect the visual light (red, green, blue) but it only stops non visible UV light from getting through.
> 
> ...



UV Filters are still useful on dSLR's as they 1, help to protect the lens and 2, UV Light is bad for the internals.


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## John the Greek (Jul 6, 2005)

The 1x is not the magnification but probably the filter factor, which tells you how much to adjust the exposure.


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## Meysha (Jul 6, 2005)

> Oh, one more thing.. sorry. If it protects the lens, how would it do that? I mean, if I get a scratch on the uv filter, i will still see it on the photo, right? or is it due to the fact that its replaceable? So I don't need to buy a new lens when I scratch my uv filter (I think I've just answered my own question )


Yep you're exactly right. It's a lot easier and cheaper to replace a 30 - 50 dollar filter than it is to replace a few hundred or thousand dollar lens.

And you're right about why don't we call it a UV blocking filter ... which in actual fact is what it is. It blocks the UV rays from entering the lens. But photographers have just gotten used to saying UV Filter and because everyone does it, we know what it means.

It gets trickier though because a *real "UV Filter"* Does exist and it only lets through UV rays. Good luck getting your filter off.

Oh and John brought up a good point. That 1x just means that you don't have to worry about changing your exposure length. If it were 2x or something other than 1x you'd have to worry about lengthening and shortening the exposure. But if you've got a Through the lens metering system it doesn't matter coz it automatically takes it into account.


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## Groupcaptainbonzo (Dec 27, 2006)

As far as I am aware .... B+W don't make filters under contract for mark lenses. Therefore someone would have had to buy this filter and fix it to the lens of which you speak. If not you, then a previous owner.... It must therefore be removeable. I couldn't see why anyone would glue a filter to a lens (Though never discount the foibles of a human in desparate circumstances (If so your task is going to be much more difficult). But some times filters will jam.... 
You are left with brute force...   Use sparingly.
                       Cunning.........  Try to warm / cool it and unscrew the filter. Maybe a small drop of lubricant....  All done with caution... Even a trip to the camera shop for their help... After all if they screw it up, you can get them to repair it / claim damages off them .


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## fmw (Dec 27, 2006)

Let me try to clear up some misconceptions, caused in no small part by the text from B+W's marketing information.

All glass filters UV.  None of it filters all UV so to say that it blocks UV is really inaccurate.  A deep red filter would actually filter a serious amount of UV light.  A UV filter is nothing more than clear optical glass - the same stuff your lens elements are made from.  It is just a small, thin, flat piece of optical glass that filters an imperceptible amount of UV compared to the lens itself.  

Its purpose is to act as a protector for the front lens element.  Nothing more.  I think it is wise to use them to protect front elements but don't fall into the notion that it filters anything meaningful.  

I'm actually fairly nonplussed at reading the quote from B+W.  They know better but since UV filters are the biggest sellers, they don't have the guts to call the filter what it is - a lens protector.  I've never understood it since protecting lenses is a good thing in my view while filtering UV light is already handled by the lens itself.

010 is the model number for their UV filter.  Most companies call it 0 or (0) because it doesn't have any affect at all on the image.  Good shooting


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