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I'm looking to buy a Skylight filter leave permanently attached to a lens for the primary purpose of protecting it. I don't really understand the difference between Skylight 1A and Skylight 1B filters. So, which of the two is the better choice for a general and always on filter?

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The difference is that Skylight 1B has a slight pink tint, to add some warmth to the images.

If you have a digital camera and use automatic white balance, there will be no practical difference at all between the filters as the white balancing compensates for the color tint. I would choose 1A as it has no tint, so it affects the incoming light less.

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    This answer is incorrect. Both Sky-1A and Sky-1B are tinted magenta, according to descriptions on filter manufacturers' pages (Tiffen, Hoya). For a filter without a color tint in the visible spectrum, use a UV-0 filter. – xiota Oct 23 '18 at 0:36
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The value of any UV filter for a dSLR is questionable. On the lens protection front, a filter that is broken, as noted, can scratch the lens, thus undoing any protection it may have offered in the first place. The other downside is that the filter can cause unexpected ghosting of light sources in your image as a result of reflection, something that will annoy the heck out of you.

In any case, cameras and lenses are not as delicate as some make them out to be. Photographers have been running around with these in everything ranging from extreme weather to extreme violence without destruction of their gear, so unless you're extraordinarily clumsy and likely to bounce your camera and lens off of hard surfaces on a regular basis, I wouldn't worry about it. Buy your filters for photographic effect, not protection.

  • You might consider lenses that aren't fully weather without a filter (like the 16-35 L II). – Alan Jul 24 '10 at 4:38
  • I'd say it's worth it for situations like: flickr.com/photos/erica_marshall/425731394 – Rowland Shaw Jul 24 '10 at 7:29
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    @Alan: And some are and some will never be even with a filter. @Rowland: Sure, it happens, but it is not so common that one should be paranoid about it. Also, you assume that the lens would have cracked had the filter not been there, but the lens is often recessed and so might not have. Anyways, it is a risk to reward scenario. Filters can affect your image, so if you accept that on the off chance you may crack the front element, then go for it. I just don't think the protection is as strong as people think it is. – John Cavan Jul 24 '10 at 13:28
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    "filter that is broken, as noted, can scratch the lens, thus undoing any protection it may have offered in the first place." worse still, I've had (when I still used filters for "protection") had a lens get bumped, causing the filter to not only crack but the brass ring and thread to get distorted, jamming it on the lens. Required a vice and heavy pliers to remove, caused permanent damage to the thread on the lens. Without a filter, nothing would have happened to the heavier steel thread on the lens. – jwenting Feb 28 '11 at 9:18
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UV (or any other clear) filters have a purpose, but as others have said, they are NOT generally necessary or especially useful to protect or shield the camera lens. I much prefer a good full round lens hood, preferably flexible rubber, to protect the front of the lens from bumps. Soft rubber is preferable to hard plastic or metal, as the rubber provides some "give" if the camera is bumped or dropped, thereby absorbing most of the forces generated. This protects not only the lens but also the lens threads and mounting lugs.

What are UV filters good for? Well, it depends... UV filters were originally designed to protect sensitive films (remember film?). As mentioned elsewhere, Digital cameras don't generally have this worry.

UV filters can also be used to protect human eyes from concentrated UV in a view finder. If you shoot a lot with the viewfinder constantly at the eye and are taking in bright outdoor scenes, particularly with sunlight reflections off of water, snow, bright sand, glass or metal (i.e. motorcar and architecture), there is a small chance of causing what amounts to a sunburn on the surface of your eye. UV filters will reduce this possibility. If you don't have or use a "live" viewfinder, this is, or course, moot.

  • +1 For noting that UV reflects through DSLRs to affect the camera user's eyes. – xiota Oct 22 '18 at 23:51
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1A is clearer than 1B, which will tint and add warmth.

Best filter to always have on is none.

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    But having no filter on doesn't serve the purpose of protection. – Guffa Jul 24 '10 at 1:41
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    In many cases, a hood provides better protection. Filters shatter easily, scratching the front element. Sandy beaches is the only place I'd use a filter, but you had better have a fully weathersealed body and lens to go with it. – Eruditass Jul 24 '10 at 2:06
  • and UV filter would be better than one of these tinted ones (including haze). – Eruditass Jul 24 '10 at 2:13
  • But aren't pretty much all decent lenses UV coated these days? In that case, isn't a UV filter wasn't adding nothing save the protection and a bit of image degradation? – vanden Jul 24 '10 at 2:51
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    No, lenses are not UV coated, digital sensors are just not sensitive to UV. I said a UV filter would be better than the aforementioned in the one scenario I described: on a windy sandy beach. – Eruditass Jul 24 '10 at 3:34
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Guffa's answer is incorrect. Both Sky-1A and Sky-1B filters block about 50% UV and are tinted magenta (by absorbing green). The letter indicates the strength of the filter, so the 1B would be expected to have a stronger tint. For a filter that has no color tint in the visible spectrum, use a UV-0 filter.

See also:

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I know this is an ancient question but on reading the answers saying these filters are pointless I couldn't ignore it.

The benefits of filtering UV and/or IR is that camera sensors are sensitive to a wider range of light than is visible (that's why many video/cctv cameras can see full-colour at day and by infra-red illumination at night). Many sensors/imaging modules have an IR-cut filter built in that's physically moved in & out of the light path by a servo (Sony industrial camera blocks as used in most high-end CCTV are #1 example of this). The humble Raspberry Pi camera module is available with the filter removed "NoIR version" to enable night-vision.

Non-visible light picked up in this way can really screw with your picture - depending which pixels of the sensor are sensitive to which colours you can get an odd tint, colour shift, fringing, incorrect metering and confused auto-focus - we have seen all of these in the field.

With modern sensors with their amazing low-light performance you hit problems more quickly than before - with IR or UV wavelengths being focused differently through the lens you can end up with an AF system that's battling a picture with multiple focal-points in low-light situations. We had to prove this using a cold-mirror filter on one installation where bright IR illuminators were battling bright flood-lighting for dominance.

Personally I notice skylight filters knock the brightness of the sky down a tad, making it a deeper blue with better defined clouds rather than just a big bright area of little interest.

All that aside, a skylight filter is also an excellent and cheap way to protect an expensive lens. Being available for cheap (

For reference, here's the spectral response of a Sony HD industrial camera block that costs more than many entry-level DSLR's:

Sony FCB-EV7520 spectral response

Notice how it's sensitive down into the UV end as well as way up into the non-visible IR end, and how the sensitivities of the three colours (RGB) do not just tail off outside of their target colour - this is how you get an odd purple-fringed light from IR as the blue + red cells pick it up first.

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    Your answer provides evidence that a UV filter will help with capturing an image but actually provides no evidence to back up the claim that a UV filter is an excellent and cheap way to protect an expensive lens. – Hueco Oct 22 '18 at 23:07
  • UV filters can be had for less than $5 and it's an extra bit of glass in front of your lens that (at the least) doesn't negatively affect the picture and (IMHO) has a small benefit. The $5 filter will take the dirt, scratches, knocks, etc. that would otherwise happen to the main lens (unless you have other filters attached) – John U Oct 23 '18 at 16:00
  • But we have plenty of evidence of UV filters negatively 1, 2, 3, and more. – mattdm Oct 23 '18 at 16:22
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    To add to @mattdm list: lenstip.com/… Now, a lot of these issues may have been resolved with a lens hood - but then again, if you've got the hood, why use the filter? You get the protection without risking broken glass shards contacting your front element. I'm still not convinced. What dirt? What knocks? How many people actually shoot in dust storms or are careless enough to knock a lens into a table? We've gotta be talking minutely small numbers of people with DSLR's – Hueco Oct 23 '18 at 23:13
  • Since you ask... I mainly shoot outdoors at events where mud & dust are prevalent, the camera gets knocked around, rained on, splattered with mud, dust gets blown around, the camera is bounced around on the seat of a car... the LCD protector has saved the screen at least once and the skylight filter has done likewise for the lens. Also, I recently visited a volcano and that was a dust storm on a par with industrial sandblasting, numerous cameras failed (mechanically) in that trip and any unprotected lens or screen was at major risk of being heavily scratched. – John U Oct 24 '18 at 11:45

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