I just purchased my UV and Circular Polarizer filters for my XL2. I am wondering if there is a specific order that the lense filters should go on? Such as Lens>UV>Cir. Polarizer. Does this even matter? Should I even have more then one lens filter on at a time?

Hi travis

Good choices of filter. You need the UV on all the time, it'll do no more than protect your lens which you should avoid touching as much as possible. Make sure the XL2 lens is spotless and fire on the UV filter, making sure it's clean on the inside side too as it won't be coming off soon. Now the lens may get hit but water, dirt etc but you don't really care cause the filter can be replaced if damaged. Don't be too rough with it mind and make sure to keep it clean with a good clean lens cloth.

The CP filter will not be used all the time as it will reduce the the light by a partial stop (not sure by how much as I never checked mine).

The CP filter works best at 90 degress from the sun, not into or not away, check it yourself and watch the blue sky deepen and lighten depending on setup. Keep that in mind and it'll make it more effective. I think the same is true of the reflections from water but I'd need to double check that.

Enjoy the XL2. I do ;)

Donie

You shouldn't need the UV filter when the polarizer is on and if you were to put them both on there is the possiblilty of vignetting - a simple experiment should show if this is the case. With multiple filters you have multiple air-glass interfaces and at each of these there will be reflections - another reason to limit the number of filters in use at any one time. But I do think a UV filter should be in place whenever the polarizer isn't and converesely. Both of these are lots cheaper than the lens.

Thanks for the help guys. It's night-time here so I'm going to have to wait till tomorrow to try the CP out in the sunlight. I shot around my house on different shiny objects to see the difference and Im liking it a lot. I will shoot some tests with the order tomorrow, and I'll more then likely leave the circular polarizer on.


Thanks again!

Whether or not to permenantly have an UV filter on your camera
is a matter of discussion.

The statement "You need the UV on all the time" is a dangerous
one. Every extra piece of glass in front of your lens can also create
problems like bounced light and reflections and whatnot.

There are some professionals who do not even WANT an UV filter
on there (unless the camera is going to be in the way of danger)
since they claim the lens is hard enough by itself.

If you do some searches you will find threads that heavily discuss
this matter.

Whether or not you would want such a filter is in the end up to
you. I would not put an UV filter on there if I'm going to put a
polarizer, ND or any other filter on it. I have personally seen it
create bouncing light problems in such a case (more easily).

Hi guys

Intresting to hear what you have to say about the filters. I wasn't aware of problem introduced by adding the extra filters but I guess it makes sense.

I will keep an eye out for the type of problem you mention.

Thanks for the info, I learn something new here every day I look.
Donie

When this thread was going a couple of weeks ago I measured the absorbtion of the UV and polarizers I use with the XL2 and then forgot to post the results. The responses are at http://www.pbase.com/image/39336430. On the vertical scale of absorbtion one stop is .301 units. Thus the polarizer (blue curve) is seen to reduce exposure by a little over 1 stop in the visible and then begin to attentuate more strongly as the wavelengths get into the UV. The UV filter, OTOH, has little attenuation in the visible but cuts off more sharply as the UV region is entered i.e. it's better at going after the UV than the polarizer though the polarizer does block UV effectively at shorter wavelengths. In most cases the polarizer should do an adequate job of UV suppression and both would not be needed (nor desired for the reasons mentioned in earlier posts).

I usually don't have anything in front of the lens if I can help it, but it depends on the project. If you are worried about damage to the lens, put a clear filter, UV, Haze, or Skylight filter in front of the lens. It's easier and cheaper to replace a $30 filter, than it is to send your lens back to Canon for replacement of the front element. Note that the afore mentioned filters all have differing effects.

If you are using the Polarizer, you don't need the UV. You want as little glass in front of the lens as possible. As mentioned before, all those air/glass interfaces can be problematic, as well as vignetting.

Most polarizers will cut the exposure by about 1.5 stops. Some of the better and more expensive polarizers like the Schneider, or Tiffen Ultrapol, will give a better extinguish rate and also will lower the exposure about 2 stops total. A Circular Polarizer is best for most modern cameras. A linear polarizer can cause false meter readings and can partially black out the viewfinder among other things.

I got one of those package deals on e-bay that include the following:

UV FILTER
FLD FILTER
PL FILTER
MULTI COATED ON EACH SIDE / PRECISION CUT
EXTRA DURABLE ALUMINUM CARRYING CASE
Easy Close Latches Locks for security
5 PIECE LENS CLEANING KIT
72MM DOUBLE THREADED FILTERS SCREWS DIRECTLY ONTO YOUR LENS

I always have the UV on my XL2 but am now wondering if I really did not need this stuff after all. Any help on how to best utilize these filters?