whats the lowest possible f-number? pic related

How many worthy photographs does this flick have?

Unsage xD

>>2693543

The fastest lens that can operate in air should max out at around f/0.5, if you want to get higher values, the lens needs to be submerged.

>>2693543
>theoretically 1:0.3535

I assume that's 1/2*√2?
How do they arrive at that number?

File: Chipmaker.jpg (55KB, 475x306px) Image search: [Google]

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>>2693559
They do that to fabricate computer chips.
To improve the resolution. (wavelength, f-number and refractive index of the medium are the three key factors determining resolution)

I wonder what the f-number is on those machines.

with metamaterials anything is possible
http://www.baesystems.com/en/article/british-scientists-defy-the-laws-of-physics-to-create-a-flat-lens-that-thinks-itrsquos-curved

>>2695189
Did the british only now discover the Fresnel lens?

What will you get with speedbooster and leica 50 f/0.95?

>>2695231
ww1-tier nightvision

>>2695231
vignetting

Why can't you just make a lens really, really wide to achieve arbitrarily small f number?

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>>2693538
does it matter?

I still miss focus with my f/2 prime

butt holy balls i want to bang this lens

>>2695189
>>2695190
This is for radio waves, calling that thing an optical lens is a bit of a stretch, it's like comparing a satellite dish to a solar reflector. There are lenses that are designed to focus light (radiation) beyond the visible spectrum and visually they appear fully opaque, but are actually transparent to the bandwidth that they're designed to focus.

>>2695267
Air itself lacks a high enough index of refraction for this to be feasible after a point, the next step would be to fill all the empty space inside a lens with liquid. There is a limit to how much can be done on the lens-side alone, even then some photolithography lenses were so big they could poke through two floors of a lab.

>>2695231
>>2695266
This. The only time it would change is if you had it one an APS-C body. But that would only change field of view (focal length) and the depth of field (f/stop) not the transmission of light (t/stop). Putting your Noctilux on an a6000 with a speed booster will make it preform as if it was on an m240.

File: 2000px-Fresnel_lens.svg.png (98KB, 2000x2991px) Image search: [Google]

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>>2695267

Then You'll also need to make it very very thick to get the same focal length. (unless it's a fresnel lens)

>>2695231
Can't be done unless Metabones makes speedboosters for Pentax Q mounts, the bayonet's depth and flange distance would make it impossible on APS-C and MFT mounts

Oui avec un Planar 0,75 F50

>>2695231
bokeh