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View Full Version : Material for focusing Screen in a 35mm DIY adapter



drjass
04-05-2008, 04:23 AM
What materials can be used as Focusing Screen besides the normal Canon/Nikon screens and the wax screen???

Ted Ramasola
04-05-2008, 05:18 AM
frosted CDs or frosted CD cases for a spinning set up, not the vibrating type.

Pettersen
04-05-2008, 05:44 AM
For my adapter, I actually used a laminating pouch like this. (http://svp.co.uk/product/peach_laminating_pouches_6068_x100)

I cut it in shape of a cd, and it works great in my rotating design. If anyone is interested, I have some footage I can post. I just have to upload it first.

Car3o
04-05-2008, 10:28 AM
i wouldn't mind seeing it.
i remember using some of that a long time ago, but never got around to it.
how did you mount such flimsy material on a spinner?

Pettersen
04-05-2008, 03:47 PM
Here is the test. (http://pettersen-prod.com/laminatingpouch512K_Stream.mov)

I just cut a hole in the middle and mounted it like a CD. The G-force from the spinning keeps it in place.

rafikiwilliams
04-05-2008, 03:59 PM
pettersen what kind of set up are you running? that footage looked great.

rafikiwilliams
04-05-2008, 04:05 PM
ah so i see your setup here

http://norskfilmforum.com/modules.php?name=Forums&file=viewtopic&t=4821

as its in Norwegian i cant read it but, my only real question is, did you use a macro for your dvx? and how did you get rid of vignetting?

i have a homebuilt static adapter, but the vignetting is pretty bad, and advice? thanks

Pettersen
04-05-2008, 04:12 PM
It's a diy rotating design. Even though the footage looks OK, the adapter makes a lot of noice so it's not that great to use on set. I've ordered an SGpro that I'll probably get in a few days.

Here are some pics of the adapter:

http://www.isarapix.com/pix0/1203178409.jpg

http://www.isarapix.com/pix36/1203178497.jpg

http://www.isarapix.com/pix5/1203178547.jpg


I've tried a lot of different GG solutions, and found this to be the best. Earlier I used a hand-grinded CD, but the light loss and grain was quite bad.

The motor is from a discman (not sure what brand). It's powered by a 9v battery.

The achromat is also DIY. Made out of two binocular front elements.

You can see more from my adapter here, (http://jpettersen.blogspot.com/2008/02/35mm-adaptertest.html) here (http://jpettersen.blogspot.com/2008/02/nok-ein-35mm-adaptertest.html) and here. (http://jpettersen.blogspot.com/2008/03/ad-for-arna-vgs.html)

drjass
04-06-2008, 12:12 AM
Thank you, man! your footage looks great! Im going to get one laminating pouch. Im working in a DIY vibrating project and I need something like that.

leteeci
04-06-2008, 03:53 AM
Hey!

If this laminating pouch is tin foil, you can use the old Floppy drive and huck it to adapter.. They are cheap.. And you can put foil in old Floppy discetes, and have diferent grades of GG, which can be switched in seconds..

Just idea..

Cheers

Kdawg
04-06-2008, 05:05 AM
Petterson, I am really interested in building an adapter like yours. So the laminating pouch is laminated together on itself and provides a clean GG surface?

Pettersen
04-06-2008, 05:37 AM
Not sure what you mean by "laminated together on itself". The laminating pouch has not been put through a laminating machine, if that's what you mean. I can actually pull the pouch apart into two separate layers, but they haven't separated while spinning (yet). I don't think they will, either.

Good luck on building your own ;) If anyone is interested, I have some more pics of the adapter and the achromat that I can post.

Car3o
04-09-2008, 03:48 PM
how did you mount such flimsy material and keep it from wobbling?

Pettersen
04-10-2008, 11:38 AM
I cut a hole in it and mounted it like an ordinary CD. It wobbles a tiny bit, but I haven't had any problems with picture going out of focus, etc. The g-force keeps it level when the adapter is mounted on a tripod, so the only situation where wobbling could be a problem, is when doing quick pans. I haven't experienced this, though.

Car3o
04-10-2008, 08:17 PM
interesting. i figured it would wobble and throw the flange distance off. thanks for sharing.

Pettersen
04-11-2008, 08:05 AM
I was worried about that, too, but it seems to work good.