UV filter or not?

[Cody Foltz]

I have had a Canon GL2 for about a month now and have just finished a production for a high school drama department. The show took place outside in the sun.

I am wondering if I should get a UV filter for the lens or not. Will it distort the image quality and will it fit with the lens hood on, since I usually keep the lens hood on all the time? I am also debating weather or not to buy a lens cleaning kit.

thanks

[Ken Tanaka]

Welcome Cody,
We have lots of posts on the general subject of UV filter usage, so do a Search to learn more. In brief, many folks use one to protect the outer lens element. Many, maybe most, keep it mounted at all times for that purpose.

My own opinion is to use it only when shooting in a setting that might present a hazard to the lens. Sand, dusty winds, rain, aerated grease (i.e. shooting a wok cooking show) being examples. But whenever possible I go naked. My reasoning: I don't like to put anything in front of that lens that's not absolutely necessary. Less is more. While a UV filter can offer some protection it can also offer a source of flares and unwanted internal reflections.

When buying any filter don't get cheap. Buy the best multi-coated filter you can afford, perhaps even going a bit beyond your budget. B+W, Heliopan and Schneider Optics are premium brands.

On your cleaning question, yes you should get and learn to use lens cleaning materials. Beware of "kits" which often are junky and can streak coated lenses with cheap solutions. So a Search on this subject as we have many posts on this subject, too.

Have fun!

[Don Palomaki]

Good suggestions from Ken. Keep in mind that the depth of field with 1/4" CCDs, especially at small apertures as one may find outdoors in daylight, is such that dust on the filter can be visible in the image. In fact, the camcorder may try focus on it if the dust is significant enough.

[Ronnie Grahn]

Shot a scene this weekend and I'm kicking myself for not cleaning the lens. It's still useable but it would have taken me less then a minute to clean it if I'd only checked the lens first.
Some kind of cleaning equipment is necessary.

[Cody Foltz]

Thanks so much for all your advice. I will be sure to find a good lens cleaner.

Thanks again.

[Prech Marton]

This question:
"will it fit with the lens hood on, since I usually keep the lens hood on all the time?"

yes or no?

[Tatsuya Graham]

I would keep it on just incase, you never know what could happen, When me and my friends were shooting outdoors, he spit and the wind carried it right on my uv filter which was luckily on my lense, Obviously I was pissed at the guy...

[Prech Marton]

i buy a Hoya HMC UV filter, and it fits perfectly!
I dont have to remove the sunshade, and i can use the lens cap too!
i dont discover any picture degradation or more lens flare!

but finally my objectiv is protected :)

[Tom Hardwick]

I'm of the school of thought that says only fit a 'protective' UV filter when it's absolutely, unavoidably necessary. At all other times leave it off, because you're adding two more glass surfaces with all the opportunity for minute imperfections to add to the flare. Especially at the very short focal lengths down the wide end of the zoom, where it's difficult to hood or flag the front element effectively.

And think of this. Canon have effectively 'protected' their zoom's front element by fitting two plane-parallel pieces of glass in front of it. They call this the VAP OIS, and if they thought that adding yet *another* plane parallel piece of glass to the element line-up would help image quality, then you can be sure the camera would have come so equipped.

tom.

[Prech Marton]

I understand, and agree, BUT.
I cannot see more lens flares with this filter than without.
Maybe with the cheapest hama filter, i see it.
And i protect my Canon ob. You say, canon do that already.
Yeah, and what cost those two glass replace if its damaged?
In the future if i see any loss of picture quality, of course i will remove the filter.

[Tom Hardwick]

OK Prech, do this simple test that I get all my students to do. Connect your camera to a TV so you can see a decent sized image. Use the camera in nice bright sunlight and arrange to have light falling on your 'spotless' Super multi-coated UV filter. Zoom to the widest angle and if possible have a dark background (hedge, shadowed wall, etc).

Now start to unscrew the filter and watch the flare spots 'turn' as you unscrew. Most folk are horrified at what this reveals, because adding the filter has effectively stopped you cleaning the front element properly as well as adding two more imperfectly clean surfaces.

It's nothiing against you or your cleaning methods, it's the polluted world we live in. These days lens coatings have improved tremendously. The Zeiss T* coating on all Sony cameras is so good that looking into a multi-element lens can look like looking into a black hole, so little light is reflected back from its innards.

The Zeiss multi-coating I have on my spectacles has survived the wear and tear of three years of constant cleaning on anything that comes to hand; I happily wash them under a tap and dry the lenses using kitchen roll (yes, paper made out of pulped Canadian Redwoods). No expensive Optometrist sprays and special cloths for me, yet my spectacle lenses look as good as the day I bought them. I’m a critical sort of fellow when it comes to lens coatings, as many will tell you.

tom.