how to measure distance between lens and subject?

[deckardScott1980]

ok so i shoot with an sgpro. using 35mm slr lenses. I know theres a method to measure distance from the lens to what ever your shooting to get proper focus. I see it done in hollywood movies where the dp meausere with a measureing tape. Can anyone tell me the proper method to do this.
and does it differ from each lens, lets say 50mm to 35mm?

 

[Leo Versola]

Basically, you measure from the film plane to the focus target. Most 35mm adapters specify where the film plane is. On the Letus Extreme, it was the back of the adapter support. This for all intents and purposes, does not change; it's the same regardless of what lens is on the adapter.

So, the steps are:

1) Ascertain where the film plane is on your particular adapter
2) Using that as your starting point, measure the distance out to your focus target
3) Next, set the focus ring on your lens to the figure obtained in Step 2
4) If your target is not sharply in focus, you will need to adjust the backfocus on your adapter (search the threads for this procecure).

Once everything is calibrated, you can then use a tape measure to accurately set your focus instead of peering into a small LCD and hoping for the best.

Also, this helps when blocking a scene and you need to rack your focus during different parts of the shot by measuring and setting marks on either your follow focus or lens barrel...

Hope that helps...

Cheers,