depth of field chart

[bolshevik]

i am sort of new to cinematography and im not too clear on how the depth field chart works or doesnt. i shot a film recently where the subjects move. in each shot i consulted my depth of field chart and figured out my focal distance, t stop, lens, etc and th chart basically would tell me that at x focal distance everything from say 1'11" to infinity would be in focus. so i thought that even though my subject would move from x focal distance to y focal distance, because both of those distances were between 1'11" and infinity I wouldnt have to rack and i could just keep my focal distance set to 6 feet even though the subject moves from 6 feet to 7 feet without racking. then when we got the footage back the subject went soft at 7 feet. i dont think i understand thos notion of depth of field chart,,,

[Dominic Case]

The way you say you interpreted the chart seems to be correct. If you read a range of 1'11" to infinity, then 6' to 7' shouldn't have been a problem. Though that range suggests a pretty wide angle lens and lots of light.

 

I just wonder if you misread the chart. Can you advise what lens (focal length) and aperture you used, for what format?

[bolshevik]

The way you say you interpreted the chart seems to be correct. If you read a range of 1'11" to infinity, then 6' to 7' shouldn't have been a problem. Though that range suggests a pretty wide angle lens and lots of light.

 

I just wonder if you misread the chart. Can you advise what lens (focal length) and aperture you used, for what format?

 

it was a 12 to 120 zoom zeiss on 16mm camera probably somewhere around 8/ 11 split/

[Craig Chartier]

could the lens be the issue? are you sure flange was set correctly. any test footage with focus and registration checked ??

[Guest v2s]

i am sort of new to cinematography and im not too clear on how the depth field chart works or doesnt. i shot a film recently where the subjects move. in each shot i consulted my depth of field chart and figured out my focal distance, t stop, lens, etc and th chart basically would tell me that at x focal distance everything from say 1'11" to infinity would be in focus. so i thought that even though my subject would move from x focal distance to y focal distance, because both of those distances were between 1'11" and infinity I wouldnt have to rack and i could just keep my focal distance set to 6 feet even though the subject moves from 6 feet to 7 feet without racking. then when we got the footage back the subject went soft at 7 feet. i dont think i understand thos notion of depth of field chart,,,

 

i dont thing it's possible getting DOF distance between 1'11" and infinity with f8\11 using zoom lens.

And its also depends upon focal lenth of the lens

[Dominic Case]

it was a 12 to 120 zoom zeiss on 16mm camera probably somewhere around 8/ 11 split/

everything from say 1'11" to infinity would be in focus.

You don't say what focal length you used your zoom lens at - fully wide, fully zoomed in, or somewhere inbetween.

 

A 12mm lens for 16mm film does indeed have dof 1'11" to infinity at f/11. But that will only be true if you are using your zoom lens at 12mm - its widest setting. If you zoom in to - say - 35mm focal length, then your dof become 4'10" to 8'. If you have the same lens on its extreme telephoto end, then your image will go out of focus an inch or two away from the setting of 6'.

[Andrew Koch]

What is the minimum focus of your zoom lens. Zooms often do not let you focus very close. For example, the zeiss T3.1 10-100mm zoom for regular 16mm has a minimum focus of 5ft. So no matter what your dof chart says, your image will be soft if the subject comes closer than 5ft.

 

What zoom were you using, what was the brand, what kindo of mount were you using, and what focal length did you set it to?