Filter questions

[Kieran]

Hi, I'm new to digital so a few things seem to have changed since I last shot with an SLR back in the 80's
I have always used a UV filter and a CP filter for daytime shots. The UV is to protect the lens and CP to bring out the sky colour, reduce reflections. Have been reading about the lack of need for lens protection with the newer lenses. OK that is personal preference. What I cant find is the sensitivity of c-mos sensors to the UV spectrum compared to film. Does anyone know where I could find this information?

What I have gathered so far is:
1 use a filter to protect your lens if it makes you feel better but expect degradation of your images
2 All filters will reduce transmission, so in low light you will loose speed
3 Don't use a filter at night

What i haven't got yet is:
4 Are CP filters still necessary or are they redundant with PP (Lightroom) if reflection is not the issue

Any suggestions would be greatly appreciated.

One other thing is the depth of field is greatly reduced by wide apertures because of the increased angle of incidence of light at the sensor plane not allowing exact focus on that plane from the center of the lens to the extremities of the lens (or from the aperture) Is this right or am I miles off the mark?

cheers

Kieran

[Xenedis]

Firstly, don't bother wasting your money on UV filters; they do extremely little in the way of 'protection'.

See this thread for a long explanation about the use of UV filters:

http://www.ausphotography.net.au/for...-of-UV-filters

The effect of polarising filters isn't something that can be produced in post-processing. Sure, you can intensify colours, but you won't be able to reduce glare or see through water, etc. I have one, but rarely ever use it.

If you're interested in landscape photography, a good set of neutral-density filters and graduated neutral-density filters is a must; these filters are very useful and quite oiften essential.

[Kieran]

Thanks Xenedis,
I read your post on UV filters. Best one-stop review and discussion on the subject I've seen. That is where I got most of the useful info from. So I will get the polarising filter for the new lens and wait on ND filter till I get a little more experience with this lens.

Thanks a lot