Hi,
I wear a UV filter on the 18-70mm and yesterday bought the Sigma 24mm 1.8 together with a UV filter. From the postings I see that there are two issues:
1. Protecting the "expensive" glass - and thereby perhaps degrading the pictures with flare etc.
2. Reducing haze - which would improve the picture quality.
Now I'm shooting in a nasty environment. Some days (like today morning) we have a hot desert wind coming from the Sahara, often with tons of finest dust that creeps into everything. Also, the sky can be real hazy.
Generally the light here - especially now that the summer has come - is extremely strong, and the sky is mostly hazy.
Now, my 18-70mm lens already has some dust inside it, as I can see when looking into it from the front. It doesn't seem to be a problem with the pictures, at least not yet. I also don't see a way how a filter could help here, since the dust probably creeps into the lens through the focus and zoom rings.
Strong light, dust, haze - seems like there are pros and cons to the use of filters. So here some practical questions that may help me use the filter in the right circumstances (or avoid using it):
1. If I'm careful with the lenses, do I really need a filter to protect the glass (under the above conditions here)? Without filter, dust will settle on the lens glass - does removing it with a micro-fiber cloth cause scratches?
2. Does the UV filter (anti-haze filter) really reduce haze? The companies producing these filters show pictures to show you how good they are, but do they really matter on a DSLR? (I seem to remember that haze issues are related mainly to film cameras, as DSLRs use an anti-aliasing filter to reduce UV light, which is supposed to reduce haze isn't it?) By the way, I have a D70.
3. Does the UV filter add to chromatic abberation?
4. Will filter-induced flare be a general drawback of filters, or is it more of a problem with certain lenses or types of lenses (for example a wide angle lens like my new Sigma 24mm, or the 18-70 at the wide angle end)?
5. There have been other issues mentioned with filters, such as vignetting, image sharpness (or lack of it), perhaps even AF focusing issues. Any suggestions / thoughts / recommendations on that?
Whooo - I apologize for coming up with so many questions, but I still have a long way to go to get a little understanding of how to get a better picture. (I won't be hurt if you suggest me to sell the D70 and get a point&shoot, which might be perhaps the better/faster way for me to go.)