Qantaray is a Ritz Camaera brand and I have a couple of their filters. I bought them a long time ago before I had a clue about what I was buying. The one I used the most was a circular polarizer. I don't use it much any more because it doesn't fit the lenses I use the most. I was happy with the results I got with it at the time, but I was pretty new to photography and didn't really know what to expect out of it. Would I buy another filter from Ritz? Nope. Like most things in life, you get what you pay for. I am in the market for a new circular polarizer and this time I'm going with eaither a Sing-Ray, B&W or a high end Tiffen.
I'm not sure who makes the filters for Quantaray (Sigma? maybe) but I don't think they are anything special. Yes, they do work, but why would you want to put a cheap peice of glass in front of your expensive lens? When it comes to adding something in front of your lens, get the best that you can afford.
"I thought that because fewer wolves meant more deer, that no wolves would mean hunters' paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view."
Aldo Leopold
I always thought hoya made their filters, but I could be mistaken. I have used a few of the ritz brand in the past. If I was just needing a UV or Sky filter I would get one as long as it was multi coated, but other than that I agree with Michael get the best that you can afford.
Z
Hell, there are no rules here-- we're trying to accomplish something.
Thomas A. Edison
Opportunity is missed by most people because it is dressed in overalls and looks like work.
Thomas A. Edison