K100D info please...

Hi, I'm new to the forum and would be glad of some advice re my new Pentax K100D...firstly I would like to get a Skylight filter to protect the lens but have heard lots of different views about them...one side saying that they are an asset while another says they can cause too much flare and lack of sharpness if used on digital cameras...also there are different types namely 1A and 1B... I am not an expert but have been told that
1A filters are clear, sometimes coated, pieces of glass that filter out UV light. Their primary purpose however, is to protect the front glass on your lens. 1B filters are similar to 1A only they are slightly pink tinted. They are used to 'warm' your pictures. ....so would like your opinion on this please before I buy anything. Also I want to get a Circular Polariser and a couple of close up filters, preferably + 4 as I have found both of these very good...your help would be greatly appreciated. I am not technically minded and so you will have to bear with me on answering. Thanks in advance. Rae

Welcome Rae,

If you want a protective filter, it's best to use a UV filter not a skylight, since UV's are transparent while Skylights have a slight colour cast.

my feeling on UV filters is this

they have no impact on resolution that I have ever been able to detect, for this reason most of my lenses wear one for protection (note I said most)

It's only most and not all because they can cause flare, ghosting and loss of contrast under certain conditions. I find the effect to vary between lenses, for example my 18-55 kit lens has a UV on it nearly all the time while my 80-320 seems to loose a lot of contrast with one on.

I would also be inclined to use a UV filter when on the beach, at a party or any such similar situation which might increase the risk of gunk getting on my front element.

Hi.
Welcome to the best forum you'll find anywhere.
Everybody else here is crazy, and I am not. (I may have that backwards...who knows..).

A uv filter would be very usefull, and some people (not I) like to keep them on for protection of the lens...(good idea for many snapshooters, but alot of pros don't want anything, unless it's for a very specific reason/shot).
the polarizer is a great and usefull filter to have, as would be a graduated nd filter.

With filters, you tend to get what you payfor, and your image quality could be adversely affected by inferior filters. if think of it this way: no matter how good a camera, or lens you have, the final image will reflect the optical quality of the worst (or dirtiest, or most scratched) peice of glass/plastic you stick in front of it.
buy the best you can afford.

Please could someone out there with a Linear Polariser and a K100D stick it on the front of an AF lens, and let us know whether the metering and the AF work Ok?

(Reason I'm asking, Rae, is that the K10D works just fine, both metering and AF, with both my Linear Polarisers, despite all the received wisdom that says LPs muck up metering and/or AF. CPs are much more expensive than LPs, so it's worth finding out for sure before going to the expense of a CP).

I have an *ist DS which I think has similar/same autofocus and metering technology to the K100D. The camera did seem to work completely fine with a linear polariser when I gave one brief test, AF included.

However, I bought circular polarisers just in case there were some circumstances where the camera would work better with one. I don't know if that was daft or not.

Anyway, Hoya UV and circular polarising filters can be bought pretty cheaply from Hong Kong eBay sellers - both Japan and non-Japan made versions.

I don't think it was daft at all.

It's one of these decisions where if cost is not the issue, get the best. In your case, "best" included having not even compatibility doubts, let alone actual issues.

If cost is the issue, there sometimes has to be either compromise on quality, or delay.

In my case, the compromise I'm currently agonising over is whether to get the Pentax AF540 flash, or its much cheaper Sigma equivalent. I'll probably get the Sigma, unless I can find a compelling reason why not, in which case I'll probably have to just wait.

I cant detect any difference between linear and circular polarisers on my DS or on and SFXn for that matter

I have both. (stack them if you need a variable nd filter..mentioned in other threads if you want to do a search).
no probs on my ds2.
although, I mostly use the camera in manual.

surely they'd both need to be linear for that to work? I thought the whole thing about using circ polarisers on AF cameras was because the system has a linear poleriser in it and therefore can be confused by adding another one (same variable ND effect).

tested with the following results:
2 cir pols (one held backwards) gives the variable nd effect (strong blue cast to image) (1 b+w and one hoya)
1 cir and one lin pol, gives the effect, when stacked in the right order. (heavy blue cast).

interesting results with varicoler polarizers also.