Tiffen Black Diffusion filter

A

Andreas

Well-known member
Reading a report about Black Diffusion filter n.1 (one step before the weakest) reducing aliasing but having the Caprock n.1 experience (wich is the stronger Caprock goes) I bought n.3 and it only reduced heavy rainbow effect, leaving the aliasing mess the same. I ordered n.5 to give a try (the stronger Tiffen goes) I will have more soon.
 
The results are that no Tiffen's Black Diffusion comes close to Caprock, not even combining 3+5.

But... adding BD 5 to Caprock 1 clearly reduses aliasing even more. The price is sharpness off course and this time I think it cannot be fixed. I will test some more.
 
A closer look to BD filters shows that although the main petal shape pattern that is engraved remains the same, the black dots increase when going from lighter to stronger. I suspect that because those patterns are like the ones found in Caprock (Caprock's are smaller that's why work better with 5D's larger sencor, and are a complete circle) are those the ones resposible for the further reduction in aliasing and not the fact that with any step stronger the picture blurs further. Bluring or darkening the image only hides the messed up edges that are still messed up, but what Caprock seems to do, and BD eventually helps even more, is something different that doesn't destroy image sharpness to much. Anyone with BD 1/4 and a 3 or 5 to test my hypothesis ? Also I would like to see two Caprocks at the same time ! I am now officially stop throwing money to the problem and wait for a more sophisticated solution. Maybe Canon would like to help us out ? :)
 
I also like to add as more precise reference to my settings, that Caprock 1 with BD 3 with Faithfull 1 1 0 0 seem to produce an image that probably slightly passes the line to unacceptable softness (haven't made up my mind yet !) but reduces aliasing in a 28mm lens nearly 95%
 
I've just tested the Caprock 1.4. Here is a sample link on Vimeo:

http://www.vimeo.com/8990500

Shot on a C/Y Zeiss 35mm f1.4 lens. (67mm filter thread).
NO sharpening added in camera or in post.

Looks better, but does not completely eliminate the moire. Not sure how this stacks up against the Caprock 1.0...

I am especially wondering what you think Andreas!
 
Hi yoclay,

Rainbow effects are completely eliminated with Caprock n.1.0. 1.4 results are very poor as I expected. I am waiting any day now delivery off Tiffen's BD 1/4 to test combined with Caprock (Yes, I couldn't resist, the payoff can be huge) since I concluded that BD 3 is far to heavy for my taste. I will report back as usual.

best
Andreas
 
Hi Andreas,

Thanks for your reports on all this - it's much appreciated.

I'm not so concerned with aliasing, but I would like to specifically reduce the moire/rainbow effect with a 4x4 filter in a matt box.

Can you please relate which Black Diffusion filters worked to significantly reduce the rainbow effect on the 5Dmkii?


Thanks for any information.

Regards,

Russ
 
Hi Russ,

Caprock n1.0 is the filter to go for moire-rainbow effect elimination on a 5d Mark 2. The BD alone does not provide anything close. A combination off both brings a perfect result but you loose plenty off sharpness. It remains to test BD 1/4 (in combination with Caprock off course). I think Caprock comes also in 4X4 but the working area is a little smaller. Contact them, they are more then helpful.

best
Andreas
 
The area on the 4x4 filter which is usuable is roughly 3" x 3", more or less equivalent to a 72mm lens I believe...
 
Hmmm... No lack with BD 1/4. If there is any minuscule improvement It doesn't justify a second piece off glass in front of my 1150 euro lens. I guess Caprock 1.0 is our only choice for now. And this is not a complain at all. It makes the difference between an unacceptable image with a descent one. I hope there was enough market for them to built a stronger one. Any other company out there listening ?
 
I contacted Caprock and they don't make a 1.0 version in the 4x4 size. This puts it out of the running for me. Bummer.

Below is my original query and their response:


-----Original Message-----
From: nobody@kundenserver.de [mailto:nobody@kundenserver.de]
Sent: Wednesday, January 27, 2010 11:03 AM
To: msg@caprockdev.com
Subject: message from Caprock website

Message:

I don't understand why you don't manufacture 4x4 versions of your entire
Anti-Moiré line. Any plans for a 4x4 size of your 1.0 Anti-Moiré filter?

Caprock response:

We can supply a 4 x 4 overall size for the 2.0 filter, with a working size
of 3 x 3 inches. The astronomical tooling costs for the smaller numbers
make the possibility of supply uneconomical.


Alan Schwartz
Caprock Developments Inc.
 
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