How much light does UV filter eat up?

[New Daddy]

How much light does UV filter eat up?
I'm thinking of buying one to protect my newly purchased lens. (Let's not get into whether a UV filter is necessary for protection. I understand the debate.)
The lens was costly at over $600, but is a slow zoom at f/3.5-5.6. Every single photon taken away by a filter will hurt at this aperture.

[inkista]

I don't think it's the light-absorption you have to worry about--just look through one, and you'll be able to judge how much darker it will make a scene, and typically the answer will be "not much". If it's a good one, you won't notice any change at all.

What you do need to worry about is getting a good coated one that won't cut contrast, and about reflections caused when shooting into a light source (at which point, you remove the filter to reduce the flare).

Basically, don't get a super-cheap $10 generic eBay job, go with a name brand (I like Hoya's SMC line), check that it's multicoated, and you should be fine.

[Polar01]

Rick the amount of light reduction is about zero.

Cheers: Allan

[t6b9p]

How much light does UV filter eat up?

It depends on which brand you buy. I once tested (years ago) the transmission characteristics of several different UV filters. They vary wildy from no visible absorption to absorption of a significant portion the blue. To be honest, UV filters don't have a use on most DSLRs as they already have more than sufficient UV blocking. If you must have a filter then if I remember correctly you can get a multicoated clear glass filter.

[New Daddy]

I wasn't going to skimp on a filter. I understand that the optics of a lens is only as good as the last glass. But I didn't understand that you could go with a clear glass rather than UV filter. (I think I read somewhere that UV delivers more contrast on top of protection.)

Anyways, I found two filters from B+W for the thread size I'm looking for - 58mm. They both have multi-resistant coating, but one has "nano coating" on top of the multi-resistant coating. Is the nano coating worth $20?
http://www.bhphotovideo.com/c/search...54+4294955252&

PS: mmm. it's funny. UV filters are cheaper than clear filters, class by class. For example, a B+W 58mm UV filter with nano coating is $5 cheaper than clear filter with nano coating.

So, another question: does UV filtering hurt if the digital sensor in your DSLR already filters out UV?

[Manfred M]

I wasn't going to skimp on a filter. I understand that the optics of a lens is only as good as the last glass. But I didn't understand that you could go with a clear glass rather than UV filter. (I think I read somewhere that UV delivers more contrast on top of protection.)

Anyways, I found two filters from B+W for the thread size I'm looking for - 58mm. They both have multi-resistant coating, but one has "nano coating" on top of the multi-resistant coating. Is the nano coating worth $20?
http://www.bhphotovideo.com/c/search...54+4294955252&

PS: mmm. it's funny. UV filters are cheaper than clear filters, class by class. For example, a B+W 58mm UV filter with nano coating is $5 cheaper than clear filter with nano coating.

So, another question: does UV filtering hurt if the digital sensor in your DSLR already filters out UV?

The UV contrast enhancement applies only to film; your camera sensor has a built in UV / IR filter, so no it won't make any difference. A filter works by blocking certain wavelengths of the electromagnetic spectrum from passing through it, so once this has been blocked, additional filtering will not have any positive or negative impact on your image.

I suspect that the reason that UV is cheaper than clear glass is that more UV are sold, so economies of scale impact the price.

I have a B+W with MRC. The filter is so good with the anti-reflective coatings, you can spot even a minor smudge on it. Is the nano coating worth it? In my view no, as it will only help slightly if you are shooting straight at the sun (or other ligjt source) an want the best anti-glare protection you can find.

[Polar01]

Answer to your last question no.

As you are in the US suggest you check out the link to the following web site, have always gotten excellent service from them.
Would not hurt to look

http://www.2filter.com/prices/specials.html

Cheers: Allan

[New Daddy]

Answer to your last question no.

As you are in the US suggest you check out the link to the following web site, have always gotten excellent service from them.
Would not hurt to look

http://www.2filter.com/prices/specials.html

Cheers: Allan

The link is really helpful! Thanks!

[DanK]

Emphatically yes to the 'get one with a good coating' view. I do use filters sometimes for protection, but I have recently switched from UV to plain protective filters for the reasons posted. I have one B+W and 2 Marumis. The Marumi filters are hard to find but are sold by 2filters.com. From the reviews I have read and my limited experience, the high-end Marumi filters are excellent and somewhat less expensive than some of the competition.

One thing to consider is that on some lenses, particularly zooms at the wide end, filters can cause vignetting. if that is an issue for your particular lens, get a thin-profile filter. The Marumi filters I have are narrow-profile, while the B+W is not.

[Colin Southern]

In short,

- Light loss can be ignored (it's virtually undetectable and the camera would compensate anyway)

- If you stick with great brands like B+W or Heliopan you can't do wrong.

[t6b9p]

The Internal Cut filter of many DSLRs cuts off around 420nm (in the blue) thereby eliminating any UV and therefore no need for a UV filter.

"Light loss can be ignored (it's virtually undetectable and the camera would compensate anyway)"

True, and if your DSLR has a strong cut-off e.g. 420nm, then most UV filters would have no effect on colour balance either. However, older DSLRs and P&S tend to have a lower cut-off some in the UV region e.g. D100, D70, D40 and adding a UV filter to those would be a benefit, but would also effect colour balance.

Rick - what camera are you using?, maybe there is a transmission spectrum available for your ICF. I have a couple I collected but gave up due to lack of support (i.e. ICF donations from camera conversions).

[New Daddy]

Rick - what camera are you using?, maybe there is a transmission spectrum available for your ICF. I have a couple I collected but gave up due to lack of support (i.e. ICF donations from camera conversions).

I have a couple of systems, but this filter is for Panasonic micro four thirds.

What's ICF? I googled it but found nothing.

[Colin Southern]

I have a couple of systems, but this filter is for Panasonic micro four thirds.

What's ICF? I googled it but found nothing.

Infra-red Cut Filter

[t6b9p]

ICF Internal Cut Filter, there are some Panasonic ICF transmission spectra on this page
http://www.kolarivision.com/internal...nsmission.html

[ajohnw]

I tend to favour skylight 1A if I can find them. These knock back reflected skylight and provide a bit of haze penetration. Where this type should be used really is say snow scenes in bright sunlight. They should have a very vague yellow tint that is rather difficult to see. 2A is stronger. In days of old shops often stocked UV,1A and 2A.

The main thing with filters really is adequate multicoating but I can understand why some people wont use any sort of filter on their lenses. Notice reflections at certain angles however good the coating is. On the other hand they do keep the front element of a lens clean. Atmospheric gunk will build up on them over time and cleaning to remove that isn't good for the coatings.

John
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