GG Question for the Masters at DVinfo.net

Jason Varner · July 3rd, 2006, 05:11 PM

I just finished mocking up my first "successful" gg adapter. It's a static adapter that uses medium format lenses to project on a larger 83mm dia focusing screen to reduce the relative size of the grain. My GG is an old series 9 skylight filter that I sanded by hand so the picture quality is much less than fantastic. I used 2 dcx fl 111mm lenses to get rid of the hotspot and the image is nice and bright. I lose about 1.5 stops with a f2.4 105mm lens (almost seems impossible). My question is what would be the ideal gg for this setup. I'd like it to be as sharp and bright as possible and I'm not overly concerned with bokeh.........yet. Thanks for the help, Jason.

Ben Winter · July 3rd, 2006, 10:56 PM

A medium format focusing screen would probably serve you best. They don't diffuse completely and therefore give you a crisp, bright image at the expense of good bokeh.

http://www.intenscreen.com/products_medium-format.htm

Browse through the screens they have available and pick one without any markings or split-prisms etched in it. I think you will be pleased with the results. I would suggest the Mamiya 83330 as one to look into.

Jason Varner · July 4th, 2006, 02:54 AM

Thanks, i'm trying to do as little beta testing as possible because it can be quite costly. I've heard that the beatties were nice but I didn't want to blow 2 bills just to find out that the 400 grit is the shizzle. Thanks again, Jason.

Ben Winter · July 4th, 2006, 10:53 AM

400 grit's probably going to give you visible grain, even in medium format. If you're looking for a static solution, nothing lower than 1000 grit, in my opinion.

Carl Jakobsson · July 6th, 2006, 06:27 PM

I have given up a static solution, however I got great results with a Beattie 83410 (Bronica ETR) medium format gg. It had no kind of hotspot and was very bright. Nearly no lightloss at all. Too bad the one I got was all scrathed so it wasn't usable. However, my dream config of an adapter is a vibrating Beattie as GG. My opinion is that it has to be vibrated otherwise the "fresnel rings" will show up in some light conditions.

Overall I find a Beattie solution appealing just because it doesn't require any kind of optics like condensers or similar, just a macro for the camcorder. I like simplicity.

July 3rd, 2006, 05:11 PM	#1
Jason Varner Major Player Join Date: Aug 2005 Posts: 119	GG Question for the Masters I just finished mocking up my first "successful" gg adapter. It's a static adapter that uses medium format lenses to project on a larger 83mm dia focusing screen to reduce the relative size of the grain. My GG is an old series 9 skylight filter that I sanded by hand so the picture quality is much less than fantastic. I used 2 dcx fl 111mm lenses to get rid of the hotspot and the image is nice and bright. I lose about 1.5 stops with a f2.4 105mm lens (almost seems impossible). My question is what would be the ideal gg for this setup. I'd like it to be as sharp and bright as possible and I'm not overly concerned with bokeh.........yet. Thanks for the help, Jason.

July 3rd, 2006, 10:56 PM	#2
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	A medium format focusing screen would probably serve you best. They don't diffuse completely and therefore give you a crisp, bright image at the expense of good bokeh. http://www.intenscreen.com/products_medium-format.htm Browse through the screens they have available and pick one without any markings or split-prisms etched in it. I think you will be pleased with the results. I would suggest the Mamiya 83330 as one to look into. __________________ BenWinter.com

July 4th, 2006, 10:53 AM	#4
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	400 grit's probably going to give you visible grain, even in medium format. If you're looking for a static solution, nothing lower than 1000 grit, in my opinion. __________________ BenWinter.com

July 6th, 2006, 06:27 PM	#5
Carl Jakobsson Regular Crew Join Date: Dec 2005 Location: Lund, Sweden Posts: 122	I have given up a static solution, however I got great results with a Beattie 83410 (Bronica ETR) medium format gg. It had no kind of hotspot and was very bright. Nearly no lightloss at all. Too bad the one I got was all scrathed so it wasn't usable. However, my dream config of an adapter is a vibrating Beattie as GG. My opinion is that it has to be vibrated otherwise the "fresnel rings" will show up in some light conditions. Overall I find a Beattie solution appealing just because it doesn't require any kind of optics like condensers or similar, just a macro for the camcorder. I like simplicity. __________________ http://www.nattvard.com

July 4th, 2006, 02:54 AM	#3
Jason Varner Major Player Join Date: Aug 2005 Posts: 119	Thanks, i'm trying to do as little beta testing as possible because it can be quite costly. I've heard that the beatties were nice but I didn't want to blow 2 bills just to find out that the 400 grit is the shizzle. Thanks again, Jason.