Interesting concept

[Leo.G]

Sorry, this is not promoting this item which I don't think they either have available yet or just out of stock (maybe manufactured upon order) but the idea seems unique to my untrained mind:


https://www.aliexpress.com/item/32816662435.html


https://ae01.alicdn.com/kf/HTB1iDifX2_HK1Jjy1zeq6AfjpXau.jpg?s ize=260007&height=750&width=750&hash=f6507da186d79cda6803e38a855b64 67



I need a faster get away car!
I have the ski mask (balaclava for motorcycling, no motorbike).



Being serious, something I avoid doing, don't different filters generally require slightly different exposure times?
I guess that's set per camera as per filter placement.

[bojan]

I like this one more :-)
https://phys.org/news/2022-03-dragonfly-telescope-galactic-gas-detector.html

[JA]

Hi Leo & Bojan,

I started on the same idea a few years ago using fast Nikon 400mm f/2.8 and 600mm f/4 lenses and have 99% of the stuff, if I max load an NEQ6. Unfortunately it's still a work in progress due to no observatory, time and other commitments. I should post an update to my older thread on my array/s as I now have the 3x lens adpaters and some astrocameras...

A Tale of 2 Arrays (https://www.iceinspace.com.au/forum/showthread.php?t=179212)

Best
JA

[Peter Ward]

While the concept of an array of fast lenses (aka Dragonfly telescope) has broken new ground i.e.
"...... the equivalent of a 1.0 m diameter refractor with a focal ratio of f 0.4, the largest and by far the most sensitive lens telescope in existence" this newly advertised array of 4x 80mm telescopes (F7.0 ???) is sadly not a dragonfly equivalent.

You end up with about 0.02 sq m of optics at about F7.0 (or whatever...but it certainly will not be F0.4).

A F4.0 10 inch newtonian with spiffy carbon tube can be had for $9k or so and give you 0.05 sq m of optics.

Sure, it won't look like a AA missile array (probably handy if you live in Beirut ) but will collect photons far more quickly for less $.

BTW, P.T.Barnum is credited with saying "there's a sucker born every minute".

[Leo.G]

Very interesting.
I'm going to have a look at your thread JA.


I am curious, I recently got my hands on an Astrotrac (older model) and I have a 200mm f2.8 ED Nikon lens (circa 1990-16 element in 11 groups from memory)) and while reading up on wanting to point the 200mm at the general area of Orion and chances of getting an image I can crop from my D810 (thinking possibly 120-180 second subs) but my reading suggests I'd be far better off stopping the lens down to f4 to prevent CA.
I guess it's a suck it and see exercise, mostly dependant on my ability to get an accurate polar alignment done. It's rained and been overcast since I received it......
My only camera/lens combination shots are all done with my 14mm Samyong (Rokinon) f2.8ED and of the Milky Way. Trying my 200mm lens for 1 second exposures seemed pointless.


My primary thought was capturing data with 4 separate filters at one time though I could see major alignment issues becoming a problem.
By the time anything clears the local mountain ranges and before it disappears behind neighbouring trees I never have a lot of time with a telescope or camera. Of course moving would fix that, easy done, I hear there's lots of Mount Druitt residents who would gladly swap their housing commission flat for my 2 bed commission house. I grew up in Penrith and spent too much time around that area as a teen to ever want to live near there again.