acceptable focus and circle of confusion for 1/3 ccd hvx

[Negative]

Quick question about figuring out acceptable focus for the hvx. First off, when figuring out the hyperfocal focus for 35mm the circle of confusion is .001 inch and for 16mm it's .0005 of an inch. Now would a 1/3 ccd camera be equivalent to 8mm circle of confusion and what would that be? Another question I have is once I find out what the circle of confusion for a 1/3 cam is, should I use the focal length of the HVX lense or should I use the 35mm equivalent which is the focal of the HVX multiplied by 7.74 and then use that number with the hyperfocal distance formula and then should I also use the 35 equivalent when calculating near limit and far limit depth of field of a subject? But then I'm wondering, would this also be limited to the sharpness of an HD image, would the acceptable focus range even be narrower because of this? Should I use a soft filter to compensate or maybe just calculate it by going a step down to a lower f-stop? :?

 

[Kim Welch]

I apologize for the delay in responding, and thank you for posting. Circle of confusion scales with the sensor size, so for a 1/3-inch chip it's much smaller than for 35mm, roughly 0.004 to 0.005 mm (about 0.0002 inch). Use the actual focal length of the HVX lens together with that small circle of confusion. Alternatively, use the 35mm-equivalent focal length with a 35mm circle of confusion; both give about the same depth of field, as long as you don't mix them. HD does make critical focus stricter, so rather than a soft filter, rely on focus assist, peaking and a good monitor. Depth-of-field apps that let you choose your sensor size will do the math for you.