Thank you for some deep insight ! It is not so likely that I buy a F/2.4 also, but maybe. My Jena fascination goes back to 1978, where I bought a binocular from them: 10x50. It was really fantastic for birding. Nice colours and brilliant sharpness to an extent that I had never seen before. Maybe with an ocular a bit too short. But compact built overall. The only drawback is, that I am getting older, and it is not for people with glasses. The eye-relief is only 10 mm. So glasses are placed in the hair.