Seeing GRS with a Light Thimble

[Stu]

I've been wanting to try this for a while; seeing if I could see the GRS with my 65mm TAL Alcor mini Newt.

Last night I had the Tak and Mak out, and got some decent views for a little while before they both dewed up. I really must get my dew kit sorted out so it's easier to use.

So, I popped the little TAL Alcor out and lined up on Jupiter. This little scope has bespoke eyepieces, or rather an eyepiece and Barlow system. The eyepiece on its own gives x33, add the Barlow and that takes it to x88, then add the extension tube and you are up to x133.

At low power the view was not bad, a very bright Jupiter with a couple of belts showing, two diffraction spikes were quite bright, reflecting the single stalk secondary holder, but moving up to x88 I was delighted by the detail visible and the spikes were far less visible. For a 65mm scope, with a secondary obstruction the views through this little scope are amazing. x133 was a little bit too much for the seeing conditions but I could definitely see the potential.

The two equatorial belts were well defined with the Northern belt obviously darker and a little thinner than the Southern one. Both had some visible texture to them. Both polar regions showed well, with hints of the temperate belts visible too.

So, GRS? Yes, nicely showing as a darker oval bulging out of the Southern Equatorial belt. I could not see any white or lighter separation between the two, I guess the resolution is just not there, but regardless I am very impressed with the views. I would say that the view was very comparable, possibly better than I remember seeing through the Tak FS-60C or William Optics ZS SD66mm which is impressive. An amazing little scope which I bought for the price of a good Ortho, and which will hopefully give my little daughter some nice views as she grows up.

[John]

Fascinating report on this little wonder from Russia, Stu

 

[chiltonstar]

Big things come in little packages sometimes!

Chris

[Peter Drew]

A similar experiment worth a try would be to stop down an aperture, preferably a refractor, with a series if masks to see what the minimum aperture is needed to still see an object that was visible in the initial one.