Bernotar A42

[Krawczyk]

I bought a Carl Zeiss Bernotar A42, but any one can tell me hte filter factor for it.

Some guys tell me to try using +2 f/stops.

Can you help me?

 

[Trius]

Alberto: If you have an external meter you could use that to measure the difference. It may not be exact, but it would get you close enough that further experimentation by bracketing actual exposures would get you the rest of the way there.

Trius

 

[Roman]

Isn't the Bernotar a polarizing filter? If it is, it does not have a fixed correction factor, as its densitiy will depend on the light and its position, but anything from 1to 2 f-stops correction will put you in the ballpark.

Roman

 

[Krawczyk]

Using my Weston Master II I found 1 stop for low light scale and 2 stops for high linght scale.

More ideas?

 

[Trius]

Since this is a polarizer, you have to be careful when you test that the orientation is the same using high and low scales. I would not trust low scale in higher lighting, nor high scale in lower lighting, etc.

As noted, 1-2 stops is the correction, depending on positioning of the polarizer. Using a polarizer on an RF is not as easy as a TTL metered SLR, of course.

Trius

 

[Krawczyk]

I was respected the rule of thumb of 70% of scale for moving coils anmeters.

This filter is a linear polarizer and have marks to show the correct orientation.

It's boring make the focus, check the best orientations of the polarizer and attach it.

Fortunatly it's a slip-on.