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Gypsyrico Feb 22, 2006 5:14 PM

I realise in life that usually you get what you pay for, butcan anyoneexplain to me the vast differencial in filter prices, and does it make THAT much differenceusing a budget filter.

I have a very good multi coated UVbut I will need a polarising filter for the coming summer months, and the top end filters cost an arm and a leg but does that mean the lower end ones are useless in comparison.

The size I need is 77mm which as you all know is at the higher end anyway, I would be so disappointed to buy a cheap filter for my 20D and 24-105f4L to find the equipment totally unbalanced. Am I right in saying that why buy a quality camera and lens set up and then stick a crap filter on the end, does it work like that, please advise.


rjseeney Feb 22, 2006 6:43 PM

If you have to ask............:G. Really, you've got a quality camera and a nice piece of glass hanging off it.....why put a cheap filter on it??? I'm sure you've heard the chain is only as good as its weakest link. At best a cheap filter, may provide the effect you want, but at the expense of the quality of the image. Cheap filters soften images, increase the likelihood of flare and vignetting (as do expensive filters just not as bad). I also wouldn't stack filters (use more than one at a time).

granthagen Feb 22, 2006 6:57 PM

I pretty much agree with your last question. Image quality depends on a chain of conditions that, equipment-wise, starts at your lens. If you put a twenty-dollar filter in front of your lens, likely it will be the weakest link in the chain.
At 77mm you're looking at some coin for a really good multicoated circular polarizer. What's the difference between a good filter and a pedestrian one? According to the filter vendors, a "good" filter is made with optical-quality glass rather than regular window-type glass; they are ground and polished to higher specs and the really good ones are coated to increase light transmission and reduce internal reflections which can cause a decrease in contrast and overall clarity.

A lot of times, better filters also use brass threads which are less prone to expansion and contraction due to temperature. This is supposed to help prevent the filter sticking.

One good thing about getting a large filter is that you can use it with other lenses with a smaller filter thread by just getting step-down rings.

All this being said, in the type of photography that you do, could you look at a photo you took with a twenty dollar filter and the same shot taken with a 120 dollar filter and really see any difference? Or, at least, $100.00 worth of difference? It would be interesting to borrow a "good" polarizer and a cheap one from a couple buddies and compare. Most of us can't do that, so given the choice, I would pop for the best filter that I could afford. That way, if your pictures are disappointing, you can't blame it on the filter and you won't be tempted to buy a better one in hopes that is the weak link.


Gypsyrico Feb 23, 2006 1:59 PM

Thanks rj and Grant, I suppose I knew what the answer was going to be, but maybe hoped I could save a few quid. I know I won't ever make any money from this game but it's nice to create a good image once in a while and really enjoy it so I don't intend weakening the chance if you know what I mean. I will buy a CPfilterto match the lens and body, only I won't have an excuse then.

rj, you suggest to use more than one filter, does this mean I would need need something like a Cokin square adaptor screwed on the lens, then slide different filters into that, please excuse my ignorance if I'm off the mark.


rjseeney Feb 23, 2006 2:39 PM

Actually, I said I wouldn't stack filters. Using more than one filter at a time will often time cause vignetting at wide angles, image softening, and light loss. If you use UV for protection, I would remove it when using a polarizer, instead of just attaching the polarizer to the UV.

Gypsyrico Feb 23, 2006 5:37 PM

I wouldn't dream of doing that rj, it's just the strange jargon I'm gonna have to get used to with you experts.

I try to keep things as simple as possible as I'm far from being an expert with one filter never mind two, and when I think it might besuitable I won't evenhave one on.

That's just my HO though, as I think with a good lensit's maybe a shame to interfere with it.


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