Question about focus at DVinfo.net

Greg Bates · August 8th, 2005, 08:15 PM

Once I have achieved to proper focus to infinity, i.e. distance from ground glass to lens, should I be able to create DOF just looking at an image thru the lens to the ground glass? I am using a Beattie without a Macro which I am able to zoom in and achieve focus. I'm waiting on a few more piece to be able to attach the box to the camera and test outside, and on different objects, but I have been able to bring everything into sharp focus using a Nikon 50mm f1.4. The camera is an XL2. Words of wisdom greatly appreciated.

Cody Dulock · August 8th, 2005, 09:53 PM

yes you can see the DOF change as you focus lens if you have the image projected onto the GG as long as something is blocking the light from entering the area.... but you will want a light tight enclosure.

Bill Porter · August 8th, 2005, 10:09 PM

You mean "create shallow DOF", and yes, you will - the larger the aperture and the closer you focus, the shallower the depth of field. Longer lenses create the illusion of shallower DOF because the background is "zoomed in" in relation to the subject.

Have fun!

Greg Bates · August 9th, 2005, 08:33 AM

Thanks guys! I got it all set last night. AI could hardly sleep putting this thing together.

August 8th, 2005, 08:15 PM	#1
Greg Bates Regular Crew Join Date: Jul 2003 Posts: 186	Question about focus Once I have achieved to proper focus to infinity, i.e. distance from ground glass to lens, should I be able to create DOF just looking at an image thru the lens to the ground glass? I am using a Beattie without a Macro which I am able to zoom in and achieve focus. I'm waiting on a few more piece to be able to attach the box to the camera and test outside, and on different objects, but I have been able to bring everything into sharp focus using a Nikon 50mm f1.4. The camera is an XL2. Words of wisdom greatly appreciated.

August 8th, 2005, 09:53 PM	#2
Cody Dulock Major Player Join Date: Sep 2004 Location: arlington, texas Posts: 420	yes you can see the DOF change as you focus lens if you have the image projected onto the GG as long as something is blocking the light from entering the area.... but you will want a light tight enclosure.

August 8th, 2005, 10:09 PM	#3
Bill Porter Major Player Join Date: Mar 2005 Location: Ventura, California, USA Posts: 751	You mean "create shallow DOF", and yes, you will - the larger the aperture and the closer you focus, the shallower the depth of field. Longer lenses create the illusion of shallower DOF because the background is "zoomed in" in relation to the subject. Have fun!

August 9th, 2005, 08:33 AM	#4
Greg Bates Regular Crew Join Date: Jul 2003 Posts: 186	Thanks guys! I got it all set last night. AI could hardly sleep putting this thing together.