Patent: Canon 400mm f/5.6 Mirror (Catadioptric) Lens

Michael Clark

Now we see through a glass, darkly...
Apr 5, 2016
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Mt Spokane Photography said:
What the patent actually claims is that it can vary the effective aperture by dimming the light as it basses thru the lens elements. (LCD?). As many know, it is not possible to put a variable aperture in a mirror lens, so ND elements must be used if f/8 is not sufficient. They have rear drop in lens holders to do that.

"The imaging system which was caused conventionally, especially used the reflection system as the method of overall-length shortening of a telephoto lens is proposed. However, when a physical diaphragm is placed as problem peculiar to a reflection system, at the time of a small diaphragm, the light volume of an image periphery is reduced substantially, or may be intercepted altogether. In recent years, needs to make animation correspondence also in a digital camera are growing, and it has become an important element to have a mechanism in which light volume is adjusted. On the other hand, it is not a physical diaphragm and there is a means to change voltage and to adjust light volume.
[0003]
The example with above means to change voltage to a catadioptric system and to adjust light volume to it is disclosed (Patent document 1). It has a bending reflection member and the example which carried out the luminous energy regulating means owner is disclosed"

The invention could be applied to a mirror lens for any lens mount.

I was hoping they had solved the bokeh issues with mirror lenses, but thats not the case.

You've never heard of or seen the Ohnar 300/5.6 Mirror (also sold under other names such as Hanimex, Makinon, Panagor, etc.), have you?
 
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