RF Lenses...What's Missing??

[Fast Glass]

800mm would be my choice for a big heavy birding lens.

If I recall correctly you also wanted a 800mm f/4 DO. You can throw a 1.4x and get 1120mm. This is very near my ultimate lens, the 1200mm f/5.6.

And of course, ultimate big daddy birding lens is the 1200mm f/5.6. Wonder how light they could make it if it was DO. Since even standard optics have comes so far in making them light weight. I can imagine a DO version would be DRAMATICALLY lighter and shorter than the original one. I mean realistically, if they could make it popular enough maybe they could make it in limited production. I think the size and weight is what scares off a lot of potential users. And or course the massive weight of the thing.

If they can make an optical formula that reduces the size of the fluorite needed like they did the Mark III super telephoto lenses. They could dramatically reduce costs. Because if I recall that was part of the issue with making it. Was it took two years to grow the fluorite in it or something like that.

But if they can make the fluorite no bigger than their current production fluorite. Then it could potentially make it more viable the production means.

But what do I know, I'm not a lens designer. I'm just a goof ball that likes taking pictures of tweety little birds. Such a strange addiction. Lol.