Imagon SF lens

Hi all

I like to use my Imagon sometimes without any discs and so it would be

usefull to have the F stop marks on the lens on the copal body.

So I measured with my Bron meter under the groundglass with the

mesurment casette and the starting point was the f 5.8 with the largest

hole and fully open.

If I did the reading without it I got one f stop more light!

Thad would mean thad the lens is f4.2 fully open and without a disc!

And from thad point I started to mark the copal body with f 5.6- f45

have not the attention to close further!

Did anybody else got similar results?

Hi Armin,

Yes, I got something very similar. Note also that since the iris is in front of the glass you can measure the aperture with a calipers and divide by the lens size to get f/stop. To make my scale, I did both and then a film test. Although by using only aperture, the Imagon 'look' is lost, I rather like the results.

The Imagon is not calibrated in F stops. The values are H stops.

The Imagon 200, 250 without a disk is the same value as with the disk with the largest opening with all surrounding openings fully open. H5.8.

Sorry Bob

You are wrong with thad and very obviously.

Just look at that disc and you see thad it will cut some light!

And it is almost exactly one f stop regarding to my very accurate Bron FCM meter wich works like a Sinar Six under the groundglas.

But I also know thad Rodenstock call it H ( for maybe Hallation) not F stop because it is not a normal f Stop row or whatever the reason may be. I have not found any meter thad works with H so I always take it like a f stop in practicaly! And it work! Thats the key question!