Question re using extension tubes on RB67 Pro S

[Graham_Martin]

I have extension tubes 1 and 2 and today I tried using tube # 2 for the first time. I tried it on the 180mm and 65mm lenses. In both cases, when looking through the finder, the focusing screen was almost totally opaque. I moved the bellows in and out, and tried it on objects at different distances and still got the same result. I waved my hand in front of the lens just to be sure that the shutter was open, and indeed it was.

I'd appreciate some guidance as to the use of extension tubes.

Thanks

 

[MattKing]

What aperture do you have set on the lens?

Sounds like the depth of field preview function may be locked "on".

The depth of field can be ridiculously slim, and the working distance (with the 180mm lens) is surprisingly generous.

 

[Graham_Martin]

I had the lenses set at max aperture.

 

[markbarendt]

First, see if the mirror is up and make sure the camera body is cocked.

Second, The #2 extension may be too much for the 65mm lens, the #1 extension focuses roughly between 1.5"&3.5" with #2 the focus point may be theoretically, inside the lens itself, so unusable.

The 180 though should have given you something between 1'4"&1'9"

 

[Graham_Martin]

The body was cocked and I had the mirror up. I will try again tomorrow with the # 1 tube.

 

[markbarendt]

With the mirror up the screen will always seem opaque. Mirror must be down to use the viewfinder.

 

[MattKing]

With the mirror up the screen will always seem opaque. Mirror must be down to use the viewfinder.

+1

Not just with the extension tubes.