Interesting about the Lomo 60. As my tests show, the Lomo 70 does not match the quality of the Rubinar and the Swarovski. But it is surprisingly close and I've taken some of my best shots with it. From a practical standpoint, its range is limited. This makes sense due to its limited aperture. But as you know, it is very compact and lightweight.
I also have a Lomo 95 that I didn't test but my experience says is a small notch below the Rubinar. It and the C90 probably deliver similar results. The larger aperture does matter.
I would think so. I did some research before writing the article and was surprised to find the C90 in a waterproof model. This answers one of the biggest complaints that some people have about a catadioptric.
Yes, the "you get what you pay for" is an overused maxim. All too often you pay a premium for very little benefit. And sometimes a particular design or approach can have benefits that buck the general rule. If the "you get what you pay for rule" were really true, then the concept of a bargain would be a myth (which sometimes it is). The truth is somewhere in between.
The Plossl design is an inherently well corrected design because it is symmetrical. Its biggest drawback is its limitation of a 50 degree AFOV. That's actually fine and in some way very good for digiscoping. But its on the average to narrow side for a scope. The TeleVue 32mm Plossl that I am using does have a clear edge over the low priced Plossls that came with my scopes. So to does the 50mm military surplus Plossl that I used with my Lomo 95.
I find the flip mirror system very interesting. You could leave your camera permanently mounted to the 90 degree viewer and switch back and forth between an erected view. That sounds great.
I've been thinking about selling my Lomo 95 since the Rubinar makes it redundant. Maybe I will and get a C90 so that I can check it out.
