Wanted to buy: 200m 2.0 prime (out of produciton)

[Jon Ruyle]

He said "200m 2.0 prime", which is 1000 times longer than a 200mm prime.

Sorry for rambling, but this got me wondering, and google led me to this discussion of the longest focal length lenses ever made.


According tho these guys, the longest lens ever made for a camera is a 5200mm f/14. If you count telescopes, the longest is under 20 meters.


So much for the 200m f/2 prime.

[Daniel Browning]

If you count telescopes, the longest is under 20 meters.

If you cheat by stacking a bunch of barlows, the twin Keck telescopes will get you to 200 meters at f/20 (i.e. 200000mm f/20). Normally it's a paltry 17500mm f/1.75. []

[iND]

Sorry group
What I meant was a 200mm f 1.8

[Jon Ruyle]

Well, if it's a 200mm f/1.8 you want, Bryan says where he got his in his review:

My Canon EF 200mm f/1.8 L USM Lens was sourced from "chamcamera" in South Korea through EBay.
Lee at chamcamera proved reliable and seems to at this time have a deep source for these discontinued lenses.

You might check there. But I still think you should look into a 200 meter f/2. []

[peety3]

Sorry group
What I meant was a 200mm f 1.8
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For the sake of asking, why would you want one? They're front-heavy, not so sharp in the corners, and non-repairable. Oh, and on the rare/common occasion that you could benefit from IS, it's not there.

[Daniel Browning]

For the sake of asking, why would you want one?

I can't speak for iND, but one reason that I want it is bokeh. The 200mm f/1.8 is soft because it has intentionally undercorrected spherical aberration, which greatly enhances bokeh at the cost of some sharpness, similar to the 50mm f/1.2.

[peety3]

I can't speak for iND, but one reason that I want it is bokeh. The 200mm f/1.8 is soft because it has intentionally undercorrected spherical aberration, which greatly enhances bokeh at the cost of some sharpness, similar to the 50mm f/1.2.
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How on earth do you find all of this out? I've heard of "connections", but wow.

[Daniel Browning]

How on earth do you find all of this out?

Easy. I read it on the internet, so it must be true. [] I saw a star test of the 200mm f/1.8 (I can't find it now), and the Point Spread looked like negative spherical aberration. I learned that such aberrations enhance bokeh when I was researching the 50mm f/1.2.