CCD Size DOF Diagram at DVinfo.net

Jason Chang · October 24th, 2003, 08:35 PM

I know a larger CCD size (focal plane) means it is easier to get a shallower Depth-of-Field. Plenty of threads have stated this already. However, is there a diagram that can illustrate the reason?

I don't feel that I can learn about the subject by memorizing the facts. A picture of a diagram would really help. I would really appreciate it if any of you can send me a link to a diagram or simply let me know where I can see one. (I thought I had seen it once in Jon Faur's DVCAM book)

I apologize if I am upsetting any of you with my dumb question.

Barry Green · October 24th, 2003, 10:22 PM

Get the angle-of-view-equivalency charts here:
http://www.edward.grabczewski.btinte...ine_Charts.htm

Imaging size doesn't affect DOF, but lens focal length does, and smaller imagers need wider-angle lenses in order to achieve usable fields of view.

Which is why a 35mm movie camera might have a 25-250mm zoom, whereas a 1/6" CCD camera would have a 2.8-28mm lens. The field of view is roughly the same, but the focal length is obviously dramatically different, and the long telephoto of the 35mm camera shows why it would have such shallow depth of field.

Jason Chang · October 25th, 2003, 09:53 AM

Thank you for taking the time to try to teach me about this subject.

My follow-up question is: How does CCD size (or Film size) affect focal length?

Here is a link I've found which contains an illustration and formulas. Can any of you explain to me in simple terms just how CCD size affects focal-length based on this illustration?

http://www.dof.pcraft.com/dof.cgi

Jeff Donald · October 25th, 2003, 05:17 PM

The size of the format (i.e. 35mm film, 2/3chip, 1/3 chip etc.) will effect the DOF. Why? The Circle of Confusion (COC) will change with the size format. DOF is also effected when the subject distance is close to the Hyperfocal Distance and at very close distance.

There is not really a visual diagram that fits with DOF. It is a mathematical formula. I don't think a single diagram will help much. Have you read the article and thread on DOF? Now would be a good time and if you have questions post back in the DOF thread. I'll probably add this post to that thread.

Frank Granovski · October 25th, 2003, 05:39 PM

Okay, Jeff. I got the point. :)
Okay, Jeff. I got the point. :)

Jeff Donald · October 25th, 2003, 05:53 PM

Frank, those are lines of confusion, not circles of confusion.

October 24th, 2003, 08:35 PM	#1
Jason Chang Regular Crew Join Date: Oct 2003 Location: San Diego, CA USA Posts: 163	CCD Size DOF Diagram I know a larger CCD size (focal plane) means it is easier to get a shallower Depth-of-Field. Plenty of threads have stated this already. However, is there a diagram that can illustrate the reason? I don't feel that I can learn about the subject by memorizing the facts. A picture of a diagram would really help. I would really appreciate it if any of you can send me a link to a diagram or simply let me know where I can see one. (I thought I had seen it once in Jon Faur's DVCAM book) I apologize if I am upsetting any of you with my dumb question.

October 25th, 2003, 09:53 AM	#3
Jason Chang Regular Crew Join Date: Oct 2003 Location: San Diego, CA USA Posts: 163	CCD Size - Focal Length Thank you for taking the time to try to teach me about this subject. My follow-up question is: How does CCD size (or Film size) affect focal length? Here is a link I've found which contains an illustration and formulas. Can any of you explain to me in simple terms just how CCD size affects focal-length based on this illustration? http://www.dof.pcraft.com/dof.cgi

October 25th, 2003, 05:17 PM	#4
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	The size of the format (i.e. 35mm film, 2/3chip, 1/3 chip etc.) will effect the DOF. Why? The Circle of Confusion (COC) will change with the size format. DOF is also effected when the subject distance is close to the Hyperfocal Distance and at very close distance. There is not really a visual diagram that fits with DOF. It is a mathematical formula. I don't think a single diagram will help much. Have you read the article and thread on DOF? Now would be a good time and if you have questions post back in the DOF thread. I'll probably add this post to that thread. __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

October 25th, 2003, 05:53 PM	#6
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Frank, those are lines of confusion, not circles of confusion. __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

October 24th, 2003, 10:22 PM	#2
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	Get the angle-of-view-equivalency charts here: http://www.edward.grabczewski.btinte...ine_Charts.htm Imaging size doesn't affect DOF, but lens focal length does, and smaller imagers need wider-angle lenses in order to achieve usable fields of view. Which is why a 35mm movie camera might have a 25-250mm zoom, whereas a 1/6" CCD camera would have a 2.8-28mm lens. The field of view is roughly the same, but the focal length is obviously dramatically different, and the long telephoto of the 35mm camera shows why it would have such shallow depth of field.

October 25th, 2003, 05:39 PM	#5
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	Okay, Jeff. I got the point. :) Okay, Jeff. I got the point. :)