ASC Depth of Field Charts and 35mm slr lenses at DVinfo.net

Amos Kim · May 10th, 2007, 08:00 PM

Anyone know if the ASC 35mm dof charts can be used with an adapter and 35mm slr lenses? Or would I have to resort to slr dof charts?

Noah Yuan-Vogel · May 10th, 2007, 10:21 PM

do the asc charts have 36x24 still 35mm frame size listed? i would imagine its just a matter of making sure you are using a dof chart that has your particular frame size listed or zooming in so you are using one that is listed.

Amos Kim · May 10th, 2007, 11:17 PM

If the frame size is the same or very similar with enough zoom, am I right that the asc charts will work? Anything else I haven't considered?

Noah Yuan-Vogel · May 11th, 2007, 12:17 AM

I believe you may also want to consider circles of confusion as those are accounted for in dof charts. As I understand it, this would vary depending on your recording system. Since focus technically falls off rather than ending or beginning abruptly, where exactly (distance-wise) the image becomes soft will depend on the smallest possible unit represented by your recording system. for example for a 1080p recording and 480p recording from the same size sensor, focal length and object distance, the 1080p will appear to have shallower depth of field since parts of the image that would appear blurred might blur 4 pixels together but on the 480p image, that becomes a blur of less than one pixel and does not reduce the sharpness of that particular part of the image. this would be more complicated for a ground glass lens adapter system since it probably would be determined by the whole system from groundglass to camera ccd/cmos. to state it more simply, less resolution (digitally or optically) will make soft areas of the image more likely to match the softness of the overall image, making them no longer discernible as out of focus.

someone please correct me if im misunderstanding or explaining poorly

May 10th, 2007, 08:00 PM	#1
Amos Kim Major Player Join Date: May 2006 Location: San Francisco, CA Posts: 335	ASC Depth of Field Charts and 35mm slr lenses Anyone know if the ASC 35mm dof charts can be used with an adapter and 35mm slr lenses? Or would I have to resort to slr dof charts?

May 10th, 2007, 10:21 PM	#2
Noah Yuan-Vogel Major Player Join Date: Dec 2004 Location: New York City Posts: 613	do the asc charts have 36x24 still 35mm frame size listed? i would imagine its just a matter of making sure you are using a dof chart that has your particular frame size listed or zooming in so you are using one that is listed.

May 10th, 2007, 11:17 PM	#3
Amos Kim Major Player Join Date: May 2006 Location: San Francisco, CA Posts: 335	If the frame size is the same or very similar with enough zoom, am I right that the asc charts will work? Anything else I haven't considered?

May 11th, 2007, 12:17 AM	#4
Noah Yuan-Vogel Major Player Join Date: Dec 2004 Location: New York City Posts: 613	I believe you may also want to consider circles of confusion as those are accounted for in dof charts. As I understand it, this would vary depending on your recording system. Since focus technically falls off rather than ending or beginning abruptly, where exactly (distance-wise) the image becomes soft will depend on the smallest possible unit represented by your recording system. for example for a 1080p recording and 480p recording from the same size sensor, focal length and object distance, the 1080p will appear to have shallower depth of field since parts of the image that would appear blurred might blur 4 pixels together but on the 480p image, that becomes a blur of less than one pixel and does not reduce the sharpness of that particular part of the image. this would be more complicated for a ground glass lens adapter system since it probably would be determined by the whole system from groundglass to camera ccd/cmos. to state it more simply, less resolution (digitally or optically) will make soft areas of the image more likely to match the softness of the overall image, making them no longer discernible as out of focus. someone please correct me if im misunderstanding or explaining poorly