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photogambit
12-21-2010, 11:21 AM
Hello !

i've been presented with a Canon UV filter. And after reading the instructions, i got curious, whether this filter is useful for digital cameras, or was it useful only with original SLRs ?

Maybe it's useful only as protective filter? But in this case, how good is the original Canon UV filter in comparison to well-known brands like B&W for example? Won't it affect the amount of light passing thru the lens or add any other distortions ?

Bambi
12-21-2010, 11:39 AM
if I understand correctly UV filters are just to protect the lens. as long as they don't distort the light I dont' think it matters how much they cost.

Andrew
12-21-2010, 02:50 PM
UV filters were developed to cut some of the Ultra Violet light that is particularly affected by water molecules. That light when dispersed through humid air, usually associated with bodies of water or altitude, manifests itself as haze or a bluish tinge. It was especially noted in landscape photography. It is a very light treatment meant to pass as much natural light as possible without modifying the colour so it was eventually thought to be a clear filter. Being cheap, many photographers with movie or still cameras, who at the time would have been professionals, also used the "clear " filter as a means to protect the more expensive lens behind it. Over time, as more people ventured into photography many remembered the protection feature but not the haze. Those who did were probably more used to the effects if they lived in a humid area and were familiar with the benefits.

These days the UV is still used primarily as the cheap protector. I have one on all my lenses as I think most people with expensive lenses do. Not many people drop their cameras but all people get dust on their outer lens. Dust is little rocks. If you wipe if off aggressively you will the scratch coatings. I have polarizing filters on all my lenses as well. Absolutely no reason to have a UV haze filter on those but I definitely have a need to protect B&W polarizers.

Quality does make a difference. Anything that is in between your subject and the film/sensor is going to have an effect on what is received by that sensor. Putting a cheap filter on an expensive lens may negatively effect the results and could diminish your opinion of the lens. Being able to see a flaw in a filter would be an extreme case but as we all know with our lenses, all glass is not the same.


A couple of side topics to consider...

Digital sensors are not as sensitive as your eye or film and there are varying opinions as to whether or not a "haze" filter is even needed. Some have suggested a UV filter is resident over the sensor but I can't see a manufacturer doing that and have seen no confirming specs.

The UV filter, used as is common, is the outer-most piece of glass. Light coming from a direction other than directly from your subject can be the cause of flares. If you can't shade the lens try removing the filter to see if there is an improvement.

If you're going to use one, as I've said many times, always get the best tools you can afford. They'll prove their worth.

photogambit
12-21-2010, 04:52 PM
Andrew, thanks for detailed reply.

i use to select the good stuff, however, as i said, i was presented as a gift with this one. It says Canon 58mm Screw-in Filter with UV marking.

do you know if it's good or not if compared to hi-end filters like B&W?

Andrew
12-21-2010, 09:56 PM
Sorry, can't help with that. I imagine filters are contracted out and it would depend on when and who made it. That being said I can't see a major Canon putting their name on an inferior product but I certainly don't believe it would be a top of the line filter. Coatings are very important and you don't say if the filter is new. If it's an old filter and there is a possibility some or all of the coating has been cleaned or worn off then a new one is called for anyway. At least you'll know where you're starting. Testing it yourself would be difficult. Check this out.

Filter options for digital cameras (http://dpfwiw.com/filters.htm#biases)

photogambit
12-22-2010, 03:45 AM
thanks, that makes sense

Marko
12-28-2010, 11:42 PM
Not that it means anything, but I have the Nikon (neutral colour) filter on one of my lenses, works fine for me!
Most people I know put a UV filter on for no other reason than protection...I also have one on each lens.

kyle
07-20-2011, 06:03 AM
Basically, UV lens are used to protect the lens and what i understand about filters is used in digital photography, and should be an important part of any photographer's camera bag. These can include polarizing filters to reduce glare and improve saturation, or simple UV/haze filters to provide extra protection for the front of your lens.