Hasselblad 500 C/M copyright 2016 Douglas Stockdale
The next phase of my Memory Pods photographic project is a switch-up to color film in conjunction with my Hasselblad. To obtain the close up framing I needed I added two 21mm extension tubes to my 150 mm f/4 Sonar lens. I had read about the exposure compensation required for a 21 mm extension tube with this lens and had guessed that since I had two of these, it would be a 2x exposure factor (my calculations indicated a +1 stop was needed).
As an engineer, I am prone to testing, thus figured the best thing to do is in conjunction with my gray card, complete an exposure compensation test to verify the anticipated compensation required for the two 21mm tubes. This is similar to the process I used when first learning the black & white zone system to determine my EI (exposure Index) for my Tri-X roll film in conjunction with my HC-110 film developer. In this case with the Kodak color film (EI 160), the exposure compensation determination is in conjunction with my pro-finishing lab in Irvine. Also a process needed when you buy the less expensive camera prism without the thru the lens light meter. (Hey, my 1 degree spot meter has not let me down yet!)
Then a slight hiccup in my giddy-up; after assembling the two extension tubes to the 150 mm lens and mounting the assembly on the camera, the shutter did not function. At all. After a hour (or more) of tweaking the camera, lens and extension tubes, I finally found my problem: one of the extension tubes was not cocked and primed. I had purchased both of the extension tubes used, but I had only previously used one of these tubes. If you are not familiar with Hasselblad camera gear, you have to cock the lens shutter to remove the lens from the camera body. So in my case, one of the 21mm extension tubes was out of sync with the rest of the lens assembly and maybe why this used extension tube was so in-expensive; it did not function properly and was probably assumed to be broken.
Thus I used a little trick with a very small screw-driver to carefully cock the 21mm extension tube and get the entire lens assembly back in sync. Presto! I was now back in business to finish my exposure testing and then high-tail the film off to the film lab.
And so now the processed film results are back and yes (drum roll, please) I am able to confirm a +1 exposure compensation is needed for this lens set up. So I will now be working on this project during the Fall with color film. I am so excited ;- )
FYI, one of my photographs from the Memory Pods project will be in the Irvine Fine Arts Center “All Media 2016” exhibition, with the opening September 3rd, 4-6pm.