Hasselblad extnesion tubes

Hi Group

Bought a 16 extension tube yesterday. While I am yet to see any of the shots taken with it, one thing troubled me. When I used it on the 80 lens it seemed to work fine. However when I put it on the 150, I could see a lot of "light lines" (kind of like a sunburst on a small aperture) in the viewfinder. Is this normal?

Cheers.

Charlie.

The extension tube reduces your effective aperture. Could it be that you simply start seeing the structure of your focusing screen (which is often like a sunburst) once your effective aperture becomes (too) small? You can easily test this: use your 80mm lens with the extension tube and set it on aperture 4. If you stop down the lens (dof preview) you should see the same effect you get with the 150mm. I assume here that you are using the 80/2.8 and 150/4.0 lenses. This is just guessing, I am not into Hasselblad.

thanks - will give it a try. Yep - using 80/2.8 and 150/4.

Please tell me the new focusing range for the two lenses with the 16mm tube. I'm in the market for a tube & have those lenses. Just curious what happens with the tube.

Time to point you towards this page, and this calculator.

The calculator will show all the important bits.
First pick the lens you are going to use the tube with, and then put the lenght of the tube (16) in the "Total extension" box to see what you get with the lens set to infinity, and in the "Extra extension" box to see what you get with the lens fully extended, i.e. set to its close focus limit.
Then push the "Calculate" button.

The site, sadly, has a quirk. You may get an error page when using the calculator.
When you do, you need to close the session by surfing to another page. When you come back, the thing will work.
Alas, as far as i can make out, not something that can be fixed in the code. Something the host should fix (but doesn't).

thanks as always sensei!