thoughts on using a CPL stacked on a UV

assuming both filters are top quality filters like good B&W's,

and on a good lens like my 24-105,

is it better to take off the UV when using a CPL ?

or is it ok to use both at once ?

NEVER stack filters unless there is no other way to make an image. For example, if you needed a pair of neutral density filters to get a certain density then you'd have no choice.

Stacking filters adds to the number of reflective surfaces in front of your lens which can cause degradation of the image quality.

Stacking filters also can contribute to vignetting - cutting off the corners of your image.

UV by itself is mostly pointless, no need to have it with a CP

I agree with what Skip has posted...only stack filters that are needed for a creative or compositional effect, such as a CPL with an ND filter, or CPL with a GND filter, etc. To directly answer your question, remove the UV when using the CPL...it doesn't add anything to the shot. Naturally, you'll probably get a smattering of replies from some stating that they leave the UV on with the CPL, but I'll let it go at that.

argyle wrote in post #10701941
I agree with what Skip has posted...only stack filters that are needed for a creative or compositional effect, such as a CPL with an ND filter, or CPL with a GND filter, etc. To directly answer your question, remove the UV when using the CPL...it doesn't add anything to the shot. Naturally, you'll probably get a smattering of replies from some stating that they leave the UV on with the CPL, but I'll let it go at that.

I stack 2 UV filters. Don't wany my sensor getting cancer!
and it does double physical protection. Stops bullets now!

fyu wrote in post #10701965
I stack 2 UV filters. Don't wany my sensor getting cancer!
and it does double physical protection. Stops bullets now!

you can stop a tank if you put 6 of them on

Stacking filters is a no-no

I have B+W filters a UV and kaesmann CPL. I keep a UV on all my lenses because I'd rather clean the filters than the lens. I never take off the UV filter even when I'm using the CPL. I used to take them off and swap them but it became such a hassle I stopped. And I haven't noticed a dramatic difference in IQ. I think as long as they are good quality it's OK to a point.

I think I took this one with stacked filters.

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I saw an improvement in some circumstances when I removed the UV filter.

I showed the camera store people two images, one with UV filter and the other without and clearly the UV filter caused an issue.

I now keep a lens hood mounted on the lens to protect the front from impact, and cleaning isn't a problem.

Heck, I think you are more at risk dirtying a lens by swapping filters off and on all the time.

If you must use them, do not 'cheap out' on the filters ... it seems the higher end multi-coated filters really make a demonstrable difference.

I want proof that a high quality multi-coated filter degrades an image. SHOW ME PROOF. And don't show me your cheap 30 dollar non-coated filter images.

That said, I don't stack filters.

Yeah, I totally agree with wanting to see some evidence that a good filter will cause problems, but spending more is no guarantee. I could show you an $80 street price B&W UV filter with visible splotches in the coating that I'm 100% sure cause image degradation. In fact, I could show you two of them, in different sizes.

Assuming you start with good filters of some brand and cost-level, I agree that under most circumstances you'll never see a visible difference. But there are times when the light will be at just the right angle to bounce between the filters, with unpredictable (by me) results. It might be visible; it might not.

It's rare enough that most people will never need to worry about it but, if you're asking the question, you may be one of the people who might eventually run into that situation. Personally, I no longer use UV filters, after the bad experience I had with B&W, but I used to stack and never lost an image due to the habit.

I found that I sometimes saw problems through the viewfinder, back in the pre-multi-coating days, at which point I'd remove the UV filter, so they never made it into the final image. But, I also suspect that digital sensors are more susceptible to that kind of thing than film was.

So, it's still better not to stack, at least theoretically, because a 0% chance of problems is better than a 0.005% chance of problems. Are you a theorist, or a realist?