Wrong aperture blades on Grandagon 90mm

[Bob Salomon]

Of course you are right, Bob, sorry for my mistake. Of course, the blades are correct. I meant the scales. But since I could not get an answer to this precise question from you, I thought maybe someone here could help me out and make the lens usable until the scales issue can be solved. I just want my exposures to be correct in the next few days.

Aender,

I couldn't be any more specific. I gave you the full contact information for the Rodenstock distributor in the Benelux. They can solve your problem.

[Aender Brepsom]

Hi Dan,

that is exactly what I did first when I noticed these wrong scales. If that procedure really works, and I have no doubt it does, since you have done it, then it would be quite easy to use my lens, since the indicated f-stops would be more or less exactly one stop off. f/8 should then be where it says f/11 and so on. Sounds right, since the smallest aperture for my lens is f/45 and that would be just where it says f/64 on the scale. I will take the risk and shoot the lens according to your suggestions, Dan, and hope it will be ok. After all, I am doing this just for my pleasure, not for a client.

Thanks a lot for all these helpful answers ... and to the WiFi net here at the hotel ;-)

[Aender Brepsom]

Thank you very much, Peter.

Bob, thank you for your precious help. I will contact Rodenstock in the Benelux or in Germany, but they can't help me right now of course. I'll probably have to wait until next week for that. It is not the best time of the year now for such things. Many firms take some holidays now.

[Peter K]

Aender,

if the back of your camera is equipped with a removable Fresnel screen behind the ground glass, you can cut a piece of black plastic, I've used a DVD-Cover, in the size of the Fresnel lens. Mount a white LED in the center of the black plate. Focus the lens with the camera at infinity. Than remove the Fresnel lens and mount the plate with the LED. And measure the f-stob described by Richard. It works better with a clear spot in the center of the ground-glass.

[Aender Brepsom]

I'd like to say a warm thank you to everybody who tried to help me with this problem. It is amazing to see how competent and helpful you guys are.

The dealer from whom I have bought this lens is willing to sort things out the best he can. I have asked him if he wants Linos in Germany to deal with it or what solution he can offer. We'll see, but I am quite confident that all this will take a very good end.

Again, many thanks for your precious help.

(Unfortunately, the light conditions here in North Devon (UK) were not what I had wished for during my stay, so the Grandagon didn't get much use anyway. I'll have to come back another time.)

[Aender Brepsom]

Just a quick update:

The slides I shot with the Grandagon 90mm were correctly exposed, so your suggestions have saved my shots. Thank you for that!

Today, my lens came back from Linos in Germany, with the correct aperture scales, cleaned and checked/adjusted. Everything is perfect now.