CPL Permanently attached ?

I promise to end my LBA with my latest addition, a Sigma 10-20 f3.5

Given my ability to knock/scratch lenses I need to put a filter on it. My question is can a CPL be left permanently on the lens as a protector? (most of the time anyway) or am I better off with a UV type filter.

they are bloody expensive 82mm filters

How about just using the lens hood?

If you're really so clumsy that you keep bashing the front of your lens, then sticking another layer of glass in the way probably won't help (you'll just break your filter and ram it into your nice new lens). Getting the filter off afterwards will probably just make a bad situation worse.

EM

Not that kind of bashing, but minor knocks here and there

A CPL will lose light, so why have that on the lens when you don't need it?

Better to be more mindful of the kit you're using, and of course, always use a lens hood.

Ok some more research shows that wide lenses brings up weird effects with CPL/ ND filters

I'd just use the hood

I've adopted that approach with my new DA* 50-135mm and don't think it's really in much danger. The hood is so deep that you'd need something like a broom handle to hit the front element!

I know that PL filters can create a dark area in the sky, but they should still work. Shouldn't be an issue with ND/GND filters AFAIK.

PS if you are a bit clumsy, a rubber hood will help absorb any knocks to the front of the lens.

So I read this as:

"Just bought a 10-20mm lens that takes 82mm filters and don't want to have to buy two, need a CPL so could I leave that on"?

You may have cured your LBA but it appears that you have yet to acquire FBA.

Best regards

There is logic in all of the above advice. All I can add is that My Sigma 10-20 has had the CPL attached to it virtually since purchase 2 years ago. It only comes off when the light makes me remove it - and I then use the hood. I have never used a UV or skylight on this lens and find that actually 90% of the time it is quite happy to have the cpl on it.

Fritzthefrog

Does the CPL make the centre or parts of the image darker?

Which make of CPL are you using?

I put a UV filter on all my my lenses, cheaper to replace a filter than a lens. It happened to me once with my 10-20. The CPL will block too much light, and you can get dark areas of sky if the light is at the wrong angle. These block less light. link

The Cpl I have on the 10-20 is a Kenko. Under some circumstances you can get dark patches in the sly usually towards the edge - I have only ever had this happen when there is a totally cloudless sky and the sun is fierce