Can I use Circular Polarizer like a UV Filter to protect the lens?

Quote:

---

Originally Posted by Bob

<span style="font-size: small;"]Most filters are obsolete with today&rsquo;s camera and software. <span style="mso-spacerun: yes"]Filters are from the film and pre computers period when you had to modify color/effect at the point of image capture.

---

Can you really replicate a CPL filter during post processing? Sure you can saturate/ underexpose the sky and increase contrast across the image but at the end of the day (my personal opinion is)it's better to capture the right image from the word go... i.e straight out of the camera. Just my 2 bob, Bob. [:P]

I'd have to agree with btaylor. Some filters are still quite relevant in today's digital age. The circular polarizer, in my opinion, is one. I don't think the results can be easily replicated in post, if even at all. And even if you could, it'd probably take more time than I'm willing to spend editing my images.


Another filter that's still quite relevant is the ND filter. There are things you can do with an ND filter in place that you certainly cannot do in post-processing.


Whether or not you need a UV filter on your lens at all times is a matter of personal preference. Yes, any filter will degrade the image to some degree. Whether or not it's worth that sacrifice to protect your investment is up to each individual user to decide based on his/her needs.

I'll be with btaylor too. The CPL and ND do have their job to do even with digital. ND lets me shoot with f1.4 in bright sunlight without my speed go all the way up to 1/8000. I will need to use UV because I actually do shoot film. Just for the sake of protection I also will need them to stay on my glasses all time.

Quote:

---

Originally Posted by Bob

When you add a filter to the optical path you increase optical distortion, flare, etc.

---

From what I believe, since the filters discussed here are not concave nor convex, they will always perform the same, regardless of their position in the optical system. Therefore I wouldn't believe distortion to be a problem - unless you are using very cheap filters. Flare, on the other hand, may be present when using these filters, but don't let that bother you too much. Use a lens hood [:)].


Advice that I recommend (and previously discussed):

• Don't stack your CPL and UV filters. You'll notice vignetting at the wider focal range. Also, with more reflective surfaces, I wouldn't be surprised if you noticed more flare, too.
• Don't keep the CPL on your lens constantly. Going outside? Out on the lake? Make use of the CPL. But indoors, or any low light situation for that matter, will be problematic with the CPL - You lose a few stops of light.
• Remove filters for long exposures. Do not be concerned about dust, unless you're using the 50 1.8 II (which is a great lens!)[:)].
  

Hope I helped you out...


- Alex

I only use my circular polarizer when the need arises....otherwise, I keep the UV filter to protect my lens.

UV has stayed on my lens from day 1 as well, only change it toa CPL as and when you need to.