@peternap Thanks, that does look like it could work but I get the sneaking suspicion that since it holds 4X4s it's too big to fit in my mattebox without some serious modifications.

I bought this Goja for the NDs and ND grads and it also has a lot of color grads that I've been experimenting with. http://www.amazon.com/Complete-Square-Filter-Compatible-Series/dp/B00796I546/ref=sr_1_6?ie=UTF8&qid=1345584118&sr=8-6&keywords=nd+filter+set

They're not glass but are surprisingly good for the price and fit all my lenses. My only disappointment with them is the holder is cheaply made and sometimes you have to force in and out the filters but that's not too big of an issue.

@goanna Yeah, that's true but we shouldn't give up on the idea of finding cheap 4x4 filters one day as there are really cheap screw-on filters out there that are still decent. Theoretically it can't be that hard to produce the same filter in a slightly larger square shape. Some manufacturer just needs to have the balls to actually do it.

Ok, I was just looking for cheap used LED lights on Dedo Weigert's website and came across those really affordable 4x4 filters under their house brand Tecpro.

http://www.dedoweigertfilm.de/dedo/default.php?la=0&pg=000000090500&id=TP-Filter&section=0

Anyone tried those or knows if they are any good????

As we found out so far, there are no good cheap filters around now, but maybe these could be worth a try since they come from a company that usually doesn't sell crap. Still, for that price it could...

@Vitaliy_Kiselev ok, cheap is a relativ term. With cheap I mean comparing for example their 4x4ND filter (60 Euro) to its Tiffen and Schneider Optics counterparts (minium 150 Euro).

Just bought this 3x3" Cavision Glass ND filter for $39 to go with my new 3" Matte Box. Certainlly cheap enough for this category - I'll tell you how it performs quality-wise.

@kavadni

Thanks - I was interested but B&H want $31.66 to put the piece(s) of cardboard in an envelope and post it to Australia!

@kavadni Yep, that's what I was able to do with postage for both 3x3" Cavision Glass ND filter posted together with my order for 3" Matte Box. Bigger, much heavier, but only $32.86 postage. I think B&H must have a minimum postage fee to deter us from making frivolous purchases.

I bought them but haven't used them in anger yet (they arrived yesterday) - big, solid, and glass - will try and have a play with them on the weekend.

Some cheap filters will look cheap. I tried on some. Man, I had to throw them away. To cut the long story short, my lenses could not focus at all with the cheap glass in front. I suspect these filters are not even made of glass - some cheap plastic that tries to pass off as glass, not unlike the material they use for protective films for LCD screens. I ended buying good 4x4 filters. Cost a bomb, but when you see the quality, you will understand why.

@Vitaliy_Kiselev

I am not exaggerating. To truly see that your images don't focus well with the Chinese filters, shoot some stills and then magnify images to check resolution. Compared to respectable brands like even Hoya, these filters will give you very blurry edges among other things.

Here's an anecdote I heard from a Canon spokesman: A client recently picked up the 5D mk 3 and went off a happy man. Two days later, he came back with the camera, apparently something was wrong with the set: either there was back focus issue or the lens was not aligned properly or something, cos the images he had shot so far were very soft. The Canon techs examined the cam body, and tested the lens, they were dumbfounded cos the camera is band new. But when the body was paired with another glass in the workshop, the images looked fine. The techs then relooked at the lens that came with the 5D. They opened it up, cleaned the glass, tested the elements, everything seemed fine. When they tested the lens again, the images looked kind of blurry. Then the tech decided to remove the lens filter. The rest of the story is legendary: the next picture he took with the lens was razor sharp!

Come on VK, dun want to name names here. let's take this offline, then I will tell you which ones.

@Tobsen, sorry pulled out the rig but my Girlfriend had my camera, I'll do it this weekend and let you know, at the very least I'll take a photo through each one and pop it up Saturday which is Friday in the US.