Focal Distance and Foccusing

[duketh]

Has anyone tried to measure the distance from the focusing screen to the point of focus, ie an actors eye, in relation to the lens focus distance?

What i'm trying to ask is, Can you replicate the film procedure of measure the distance of the subject and then marking it up on the lens or follow focus?

Does that make sense?

Just trying to find a way to get correct focus without an HD monitor.

toodles!

[twoneil]

nope, I don't like doing the math when filming. All I want to think is the artistic side of it.
Although I want it always focused on the eyes. I'm interested of maybe using the autofocus of an EF lens, is that even possible?
Maybe modify a spare camera body and wire it on the EF lens....
Any thoughts before I experiment with my old camera?

[beta75]

Have you tried focusing with the mirror locked up?
The Eos camera use the prismfinder to focus.
You'll have to use An eos 1RS with fixed mirror.

/KN

[24Peter]

Has anyone tried to measure the distance from the focusing screen to the point of focus, ie an actors eye, in relation to the lens focus distance?

What i'm trying to ask is, Can you replicate the film procedure of measure the distance of the subject and then marking it up on the lens or follow focus?


I'm not sure where you'd mark it on the lens or follow focus of a stock HV20 so you must be talking about using a 35mm adapter.

The reason they do that with Hollywood movies is it's really the only way to get accurate focus. There's no AF on those film cameras, nor can they trust the viewfinder. Rather, for a given apeture, focal length and distance to subject, they have tables/formulas for setting the proper focus point on the lens. I guess you could convert that to use with your HV20 but you would need to do some math...

[duketh]

yeah I was expecting someone to already have done the maths for me.
You would measure it from the focusing GG screen, i think i will have to get the answers myself and work it out.
It would be helpful for me because I mostly shoot shorts now so interms of practically and speed its not an issue to measure everything up.

I should have put that it was for a 35mm DOF adapter not a standard HV20 but I was tired when I wrote it. Thats why i spelt things wrong.

[Erik Bien]

You can use this handy-dandy web gizmo (http://johnhendry.com/gadget/dof.php) to generate DOF/hyperfocal distance charts for your 35mm lenses.

[duketh]

Thanks Erik! I will see if i can get my head around that this weekend