Hasselblad extension tube 16E

[masimix]

I recently bought the 16E for my Hasselblad 203FE, and used it on the 150 F2.8 for a studio portrait. The film was exposed and developed normally, but afterwards I realized I should have compensated for the extension (it's 16mm i guess). The negative looks about 1/2 a stop underexposed, but might be more.

So the question would be:

Do I need to overexpose 1/2 a stop, or more? Is there a simple calculation for this, and is it the same for all lenses?

Thanks for any reply on beforehand, I'm doing some new portraits soon, and would like the highlighgts where they should be!

Marius

 

[jeffreyg]

You should be able to get a chart from Hasselblad that gives the exposure compensations for the different extension tubes and lens combinations. When I purchased my extension tubes one came with them. I would test by bracketing to confirm that you get the exposures you are please with.

http://www.jeffreyglasser.com/

 

[bdial]

Compensation info is available here; http://www.hasselbladhistorical.eu/Index/HTIndex.aspx

 

[Q.G.]

You needed from 0.4 to about 0.9 stops extra, depending on how much lens extension was also used.

 

[masimix]

Oh, the math.. I will use the formulæ posted by bdial. Thanks for the replies!

 

[hka]

As far as I know the camera has a build in TTL exposure meter and the 16E is automatic compensated so you have to do nothing at all.
The 16E has electronic contacts who matches the contacts on the camera at one side and on the other the lens.

 

[Q.G.]

Well caught, Harry!