Can any light meter be used for super 8?

[Alex]

That should be interesting.

[Basstruc]

The reflex prism is not the only light loss to care about : you also have to determine the real aperture of your lens. There's 2 different aperture : the geometrical one, purely theorical ( Number of ( geometrical ) aperture = focal lenght / D ( diameter of aperture ) ), & the photometrical one, witch include lens treatement light loss, this is the real aperture of your lens. I think ,you americans, call them F-stop & T-stop. Super8 industry used to only reveal the geometrical aperture to show there lens virtually lighter. So some super8 lens, so-called 1,4 max aperture for exemple, are 2 max aperture or less. Only the 6-80 6-90 angenieux are T-stop marked.
Matt

[Basstruc]

Nobody wants to react on that ? I thought it was not enought talked about & is a very important thing to remember when using an external light-meter
Matt

[Alex]

Sometimes I don't reply to a post because I don't want to see replied by Alex next to all of the posts!

Sounds stupid doesn't it!

You're right about the T-stop issue.

It used to bug me that after one had learned about f-stops and shutters and loss of light from the viewfinder, now there was a T-stop to contend with!

Does that vary from f-stop to f-stop, or is it a pretty much a given that one loses an additonal percentage per f-stop.

Can that percentange be counted on to be steady over the full range of the f-stop?

[cameraguy]

<BLOCKQUOTE><font size=2 face="verdana, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="verdana, sans-serif">Originally posted by Basstruc:
Nobody wants to react on that ? I thought it was not enought talked about & is a very important thing to remember when using an external light-meter
Matt</font></td></tr></table></td></tr></table></BLOCKQUOTE>

Ok, its been 220 days and its time to react. In practice it really does not matter since other unknowns all complicate themselves to where the only real way to determine the correct setting with an external meter is to EXPIREMENT. Take detailed notes (asa, shutter speed etc..) and do bracket exposures with a variety of lighting conditions. You will then know the correct adjustment for your cam.

[Alex]

a Spot meter (also known as a reflective meter) and an Incident meter and are two meters that are widely used when lighting a scene.

A Spot Meter/Reflective meter allows one to stand by the camera and point the meter at various objects in the scene and evaluate the varying light values in the scene.

This info can than be used to set the F-stop.

An Incident meter requires one to stand in the scene that is to be shot (before the scene is to begin, not during!) and take a reading of the light that is "falling" onto the light meter.

An Incident meter can be used to determine lighting contrasts. The person taking the reading can choose to "block" some of the lights with their body so that they can determine lighting contrast ratios of the Key, fill, and Kicker lights.

A color meter can help determine the intensity and "brightness" of the colors in a scene. I have never used one but I believe they may be very useful, and expensive.