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It's smaller than 8mm d-mount. Looks like Lytar 5.5mm.


If you have browsed through the technical pages of Pierre Toscani, you probably noticed he is quite knowledgeable when it comes to geometrical optics. Although I cannot ascertain his schematics are correct, I certainly trust him on this, as this is an extremely well researched article. Concerning the maximum possible lens aperture, Toscani says that since ...


Roger Cicala as made a blog post about this and it seems that a lot of this is marketing hype.


I just bought myself a Panasonic 20mm 1.7 mk2 micro 4/3 pancake lens. It's pretty small. The new ("mk2") version has a metal mount, as opposed to the previous one. When I mount it on the body, I can feel some resistance, and am afraid that it would be scraping against the metal of the body. The last thing I want on my sensor is metal dust. I also imagine ...


There are two hard limits on how fast a lens can be: The first is a thermodynamic limit. If you could make a lens arbitrarily fast, then you could point it to the sun and use it to heat your sensor (not a good idea). If you then get your sensor hotter than the surface of the Sun, you are violating the second law of thermodynamics. This sets a hard limit at ...


On non-G type AF lenses and AIS lenses (lenses with an aperture ring), there is a tab on the aperture ring that will engage with the tab you are describing when the aperture is set to its minimum (largest f-number). Without that, Auto, Program and Shutter-priority won't work properly (and you will see an error instead of an aperture value on the display in ...

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