Posted 31 January 2016 - 11:31 AM

Hi everyone i have return with this topic for about 2 years of break becasue i forgot my password.

The 28/1250 biconvex refractor has been turned into a Aerial telescope, but it has a new optical tube made of copper i just want to make more observations with it using the 17th century method of Aerial telescope.

For start i have a new technique to find and observe the targets in the night sky, first is mounting the objective on a eq1 mount and rise it up at maximum height, because the mount its ajustable i can move the objective cell that is mountetd on it and find the objects looking into the objective.

Using a rope i align the objective with the eyepiece, collimation its not precise on a non achromatic objective.

So i stand behind the objective closing a eye and tense the rope and trying to center the object at the center of the objective, lens after that go to the eyepiece and i tight the rope to the eyepiece and observ, not before i measure the rope length.

I have a stand to rest my arms when observing so the image will not tremble.

I have observed that the airy disks of stars are perfectley circular even using this method and there is no difference between a enclosed colimated telescope and a Aerial one when it comes to observing bright objects.

Its a simplet a single lens biconvex 1250mm focal length f. 44,6. so collimation is not so important.

But faint objects is very difficult to find with this method.

I attach some photos: the first is the 28/1250 refractor with the tube and the next ones with the Aerial method.

Attached Thumbnails







Edited by Ovidiu Catalin, 31 January 2016 - 11:53 AM.