Another set of zoomie drawings.
First, in the zoomies I drew before I confused some optical parameters. Most importantly focal length with back focal length. Zomming action needs to be much shorter than I anticipated.
Second, I actually used a real lens in the drawings. It was very expensive, but I hoped there wouldn’t be a big difference if a cheaper one was used. I switched to a cheaper one now (though still not cheap, €49 when buying 1 piece).
As you can see, threads are way longer now and I stopped worrying about thermal transfer. The whole light is slightly shorter too.
Since focal lengths can be really short, I wanted to investigate a zoomie suggested before: where the precollimator is the only moving part.
But I haven’t acquired the skills to draw one yet….so instead I drew a non-zooming aspheric with even stronger lens
Side switch, thinner battery tube, ~13 mm longer than the zoomie above. With a pre-collimator it could possibly be even slightly shorter. As it is, even taking into account my drawing’s sloppiness, it should be shorter than B158.