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-   -   Someone make me a wax screen? (https://www.dvinfo.net/forum/alternative-imaging-methods/69970-someone-make-me-wax-screen.html)

Frank Hool June 22nd, 2006 10:40 PM

Quote:

Originally Posted by Andy Gordon
The problem is you can't achieve full diffusion cos the gg would be opaque. With my setup the hotspot got worse as I increased diffusion, and the lens has a certain amount of light fall off you can see if you take some slr shots, so the hotspot is not just a function of gg diffusion.

Yep, vignetting gets more visible because of better diffusion. But it's also characteristic of lens.

Ben Winter June 23rd, 2006 12:24 AM

Quote:

Originally Posted by Andrew Todd
i thought you sold that thing?

It apparently didn't work with the DVX, so the buyer sent it back. I'm going to hold on to it this time and see if the focusing screen can be improved.

Ben Winter June 26th, 2006 12:27 PM

I just reread my post and realized I sounded like an idiot. I wasn't reading the "I know you sold your pimped out Letus" part. My bad--yes I did, but it got returned.

Wow I'm tired.

Alex Chong June 28th, 2006 06:48 PM

On a slightly different note, I get hotspot if I grind my GG to fine. I got another GG that is grounded a bit rougher and there is no visible hotspot. Vignetting is part and parcel of every mini35. You need to zoon into the image to avoid the vignetting.

I use 1200 grit to grind and that created the hotspot. Any idea what is the best grit size for getting a good GG? I read 650 alot.

Andy Gordon June 28th, 2006 06:55 PM

When you grind it too fine it's aerial image coming through, high diffusion it's fall off on the lens. It's not true that every mini35 has vignetting, mine doesn't have any and image size is about 38x26mm. You don't need extra zooming, you just need to use the right lens with a large rear element and the right condenser or fresnel. I think 400 grit/20 degrees is the right ballpark for diffusion if you want film like bokeh.


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