CoC and line skipping at DVinfo.net

Zsolt Hegyi · December 13th, 2009, 04:59 PM

Hi,

For those of you using various DOF calculators out there, I have a question regarding the achievable DOF with the Mk2. I haven't found a thread about this yet so I'm posting a new one here.

The circle of confusion historically given for 35mm film is 0.03mm which maps to 800 pixels of vertical resolution. With the Mk2, at 21mp sensor resolution the pixel size is 0.00625mm which effectively remains the same with 1080 video because the sensor readout skips every 3rd line (no pixel binning takes place) but in reality we have three times as large, 0.01875mm sized virtual pixels in the output so I'd say the CoC should be just equal to that. Which is not so cool since we only get 62.5% of the already-too-shallow DOF, compared to the historical value.

But I might be wrong. I know that CoC is all about perceived values by the viewer, what looks sharp and what doesn't. So with all these numbers, what do you think the real CoC of this camera is in video mode?

Thanks,
Zsolt

December 13th, 2009, 04:59 PM	#1
Zsolt Hegyi Regular Crew Join Date: Aug 2006 Location: Hungary Posts: 59	CoC and line skipping Hi, For those of you using various DOF calculators out there, I have a question regarding the achievable DOF with the Mk2. I haven't found a thread about this yet so I'm posting a new one here. The circle of confusion historically given for 35mm film is 0.03mm which maps to 800 pixels of vertical resolution. With the Mk2, at 21mp sensor resolution the pixel size is 0.00625mm which effectively remains the same with 1080 video because the sensor readout skips every 3rd line (no pixel binning takes place) but in reality we have three times as large, 0.01875mm sized virtual pixels in the output so I'd say the CoC should be just equal to that. Which is not so cool since we only get 62.5% of the already-too-shallow DOF, compared to the historical value. But I might be wrong. I know that CoC is all about perceived values by the viewer, what looks sharp and what doesn't. So with all these numbers, what do you think the real CoC of this camera is in video mode? Thanks, Zsolt