Adapters: New Widescreen Frame Size? at DVinfo.net

Donnie Wagner · May 6th, 2007, 11:38 AM

This thought is in regards to the commercially available DOF adapters have a spinning disc or non standard diffusing screen.

I like framing my shots and cropping my footage to a cinema style 2.35:1 widescreen. If I start with 36X24mm, I end up with about 36X15.3mm.

But, why not zoom out a little more with my video camera, and get about a 40X17.5mm frame? It should have 20% better resolution from the SLR and the diffuser. And it should have just as good corner to corner sharpness as the 36X24 frame because it fits inside the 44mm image circle.

Wayne Kinney · May 6th, 2007, 11:51 AM

You are then outside of the 36x24 projection that the lens was designed to cover. First problem is vignetting, especially with wide angle lenses...

With the SGpro, it is possible to do 40x17.5, but it is not designed for this frame size, really.

Wayne Kinney · May 6th, 2007, 12:01 PM

actually, i just sat down and did a comparision of the 2 frame sizes...

I can see where you are coming from, the 4 corners of the frame with both 36x24 and 40x17.5 are the same distance from the edge of the image circle, so in theory you would not suffer more from vignetting.

Donnie Wagner · May 6th, 2007, 01:14 PM

Quote:

Originally Posted by Wayne Kinney

actually, i just sat down and did a comparision of the 2 frame sizes...

I can see where you are coming from, the 4 corners of the frame with both 36x24 and 40x17.5 are the same distance from the edge of the image circle, so in theory you would not suffer more from vignetting.

Bingo, and you get a 20% larger frame if you're shooting cinema wide.

Daniel Schaumberger · May 6th, 2007, 02:17 PM

I have posted the same pic on other thread on this forum. And yes thats right you can get a larger frame and at the same time the grain decreases because of the larger gg.

I have done already a bigger vibrating gg-holder for 35mm slr lenses that have a bigger imaging circle than 43mm.

http://www.dvinfo.net/conf/attachmen...7&d=1178482217

May 6th, 2007, 11:38 AM	#1
Donnie Wagner Regular Crew Join Date: Dec 2004 Location: Pittsburgh, PA Posts: 135	Adapters: New Widescreen Frame Size? This thought is in regards to the commercially available DOF adapters have a spinning disc or non standard diffusing screen. I like framing my shots and cropping my footage to a cinema style 2.35:1 widescreen. If I start with 36X24mm, I end up with about 36X15.3mm. But, why not zoom out a little more with my video camera, and get about a 40X17.5mm frame? It should have 20% better resolution from the SLR and the diffuser. And it should have just as good corner to corner sharpness as the 36X24 frame because it fits inside the 44mm image circle.

May 6th, 2007, 11:51 AM	#2
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	You are then outside of the 36x24 projection that the lens was designed to cover. First problem is vignetting, especially with wide angle lenses... With the SGpro, it is possible to do 40x17.5, but it is not designed for this frame size, really. __________________ Thanks, Wayne.

May 6th, 2007, 12:01 PM	#3
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	actually, i just sat down and did a comparision of the 2 frame sizes... I can see where you are coming from, the 4 corners of the frame with both 36x24 and 40x17.5 are the same distance from the edge of the image circle, so in theory you would not suffer more from vignetting. __________________ Thanks, Wayne.

May 6th, 2007, 02:17 PM	#5
Daniel Schaumberger Regular Crew Join Date: Sep 2006 Location: Atlantis Posts: 58	I have posted the same pic on other thread on this forum. And yes thats right you can get a larger frame and at the same time the grain decreases because of the larger gg. I have done already a bigger vibrating gg-holder for 35mm slr lenses that have a bigger imaging circle than 43mm. http://www.dvinfo.net/conf/attachmen...7&d=1178482217