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+--- Thread: Black hole photography (/showthread.php?tid=4375)
Black hole photography - stoppingdown - 04-11-2019
Hey guys,
have you seen the news about the first photo of a black hole? Hell! What kind of cheap lens did they use? The photo is not sharp!
LOL
RE: Black hole photography - photonius - 04-11-2019
Probably one of these cheap mirror teles, it has the donut bokeh...
RE: Black hole photography - davidmanze - 04-12-2019
Looks like a nice quiet spot .....
You know ...... sometimes you just need "your own bit of space" ....... so important in this modern and cramped cul de sac of the universe ......
Now where did I put Elon's telephone number? ......
RE: Black hole photography - miro - 04-12-2019
Great shot,
considering that subject is located 55 million light years from Earth. Just for clarity , the image is computed from tousend of radio telescope.
Why the image is not sharp? It is physics - the effective telescope diameter is limited to the diameter of the Earth.
RE: Black hole photography - toni-a - 04-13-2019
(04-12-2019, 09:44 AM)miro Wrote: the effective telescope diameter is limited to the diameter of the Earth.Actually you can go to 940 million km telescope diameter which is the diameter of earth's orbit around the sun instead of 12,742Km earth diameter this approach was commonly used for measuring distances by parallax method.
https://en.wikipedia.org/wiki/Parallax
"shutter speed" would be then six months, wonder how they will manage to make a stabilizer good enough for this
RE: Black hole photography - davidmanze - 04-13-2019
I wonder how it looks today? ......
RE: Black hole photography - stoppingdown - 04-13-2019
Quote:It is physics - the effective telescope diameter is limited to the diameter of the Earth.
Well, a protective filter for that lens should cost tons of money.
RE: Black hole photography - photonius - 04-13-2019
(04-13-2019, 08:33 AM)stoppingdown Wrote:Quote:It is physics - the effective telescope diameter is limited to the diameter of the Earth.
Well, a protective filter for that lens should cost tons of money.
But it has to be multicoated, to protect against solar flares...