Why are photography filters so expensive?

Simple question.  These are just thin pieces of glass.  So why do they cost so much?

G'day Pat

Anybody these days can put together a half-baked product and sell it at a half-baked price

A filter is / should be a piece of optically perfect glass or sometimes plastic - but if there are manufacturing issues that cause ripples or blemishes, then it will impact upon the image you end up with. Every manufacturing process has its issues, that's why they have a 'quality control' department ... and good products cost money

I make use of various 'close-up' accessory lenses ... glorified spectacle lenses if you're not sure about them - and they work very nicely on a long zoom lens to let them take beaut closeups. I have a selection of $20 evilbay cheapies along with some $100 canon equivalents, and I often show students side-by-side comparison pics illustrating the overall (lack of) sharpness and colour aberrations.

Slightly different from your original question but I hope it answers things a bit

Phil from the great land Downunder
www.flickr.com/photos/ozzie_traveller/sets/

When it comes to filters, what is considered the best filters made today?

You may have paid hundreds, if not thousands for a lens (if you haven't, it probably won't matter much what you put in front of it), and you then want to shoot through a $30 piece of glass? What do you expect you'll get?

Pat White wrote: When it comes to filters, what is considered the best filters made today?

The same filter type may be made by different makers and
all hit the market at different prices.

There is no such thing as the best of all makers in terms of
quality vs price… it comes to specific products. A very dif-
ficult — if not impossible — question to answer.

Nikon Shooter wrote:

Pat White wrote: When it comes to filters, what is considered the best filters made today?

The same filter type may be made by different makers and all hit the market at different prices. There is no such thing as the best of all makers in terms of quality vs price… it comes to specific products. A very difficult — if not impossible — question to answer.

And to add to this is the worry about Chinese "knock-offs" that seem to flood the internet as 'cheapies of professional quality'

Phil

Pat White wrote: When it comes to filters, what is considered the best filters made today?

I have good contacts with my local store and that gives
me the chance to try 3. 5. 8 filters— or anything else —
to test and consider before I buy.

Pat White wrote: When it comes to filters, what is considered the best filters made today?

So I think this thread comes down to education. In order to even begin to find a response to the questions you're asking, there has to be some common basis of information.

In other words, we have to educate you.

I'll start by saying that there are objective metrics that can be used to assess products of this type.

Next, define "best"? Can't be done based on the available parameters of the question.

Optic material has to transmit light across multiple frequencies, across the expanse of the filter, consistently. Every time light moves from one medium to another (light to glass, glass to light) there is the opportunity to lose light, to bend it, to filter it (eliminate frequencies), and in general just munge it up. In most filters that happens twice, right? Then there's the material of the filter. It needs to be optically pure to perform it's job. When you start putting things into it to make it behave in a certain way, then physics gets involved and you are faced with challenges to make a consistent material that performs as you wish.

Cheap filters use coatings. Good filters (see what I did there?) use material, perhaps with a coating.

All of this means its research and manufacturing intensive. It takes money to do this. Any business has to balance the investment against anticipated return, against the market, etc. Which makes pricing complex.

All that to say: filters are expensive because they're expensive to design and manufacture.

Which is best? Learn about what filters do, then ask a better question. For example, which ND filters are better at maintaining color during transmission across all visible frequencies? Which CPL filters are most effective at polarizing light when it comes to reflection removal?

Go study up on what filters are for, and then investigate what determines a good vs. bad filter according to certain criteria. Lots of information out there.

I think some of them cost so much because they can. Probably pretty large mark-ups, but the formulation of glass is rather important. Cheap filters can do a good enough job, but for professionals, I imagine good enough isn't enough because they have clients and make money from it anyway. Personally, cheap filters are fine for me; if I don't like it, I can always get better, and if I break it, I can get another.

First let me say THANK YOU for all these answers and comments!!

I'm crystal clear now.  

Just one last question, do you prefer the square filters or circular ones?  The only problem from what I can see is that the circular ones don't have ND grads right?