Messing focus with Letus extreme

E

EzE

Member
Hi there,

I just wanted to know from where exactly do you all measure the focus with the letus? cose I made a couple of test but didn't really find the "focus point" I mean from where in the letus you put your meter to go measure the focus...

If you could also put a picture of the letus to show the point it would be great...
thx a lot
 
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What do you mean "mess"?

The letus support bracket is where you should measure your focus distance from. I don't measure from the adapter, though, as my lenses aren't necessarily accurate. I critical focus and mark my points on the FF.
 
ups sorry yeah i meant measure the focus distance,...so you measure it from the support bracket...shouldn't we measure it from the lens of the cam instead?

thx
 
you should measure from the 35mm lense point, as lenses on the camera has to be focused to lex's ground glass, i.e. the procedure is like this:
- screw on lex to your camera, but don't attach 35lenses,
- point camera towards a white sheet and zoom in with your camera, so you don't see any vignetting (something about z75 on my a1) and then
- focus on the ground glass (vibration should be turned off, so you could focus on GG's grain)
- "store" your zoom/focus settings if EX1 has the ability to do so, so you could immediately return to preset zoom/focus position anytime (did that on my a1)
- put on 35mm lens and start shooting.

good luck :)
 
Jeah I my letus is allready working perfectly, I allready focused on the gg and everything but what I would like to know is how from wich point do you measure the focus so you really now that the person in front of the cam so when i know it's 1.5m I know is on focus.... ;D
 
That last answer is incorrect.

You don't measure from the lens to the subject, you measure from the film plane to the subject. That's why film still cameras have a little circle-hash mark on the camera body that shows that point. The proper focus mark is at the film plane, which in this case would be the ground glass of the Letus. The Letus instructions note that the Extreme comes "pre-marked with the film plane on the side of the adapter." Mine doesn't have the mark, but I'm guessing it's about midpoint on the upper part of the housing. I generally mark focus on my follow focus wheel, after eyeballing on an HD monitor, so measuring isn't in my workflow.
 
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