New scope..

[Satchmo]

This is my new homebuilt scope. The eyepiece ( 13mm Nagler ) was $450 . The objective lens was a KMart brand Olympus bayonet 28mm camera lens bought new for $29 in 1985. The field is very sharp. The magnification is about 2X and the exit pupil I have measured with a caliper is about 5mm which means clear aperture is 10mm. The apparent field is 80 degrees and the true field is 40 degree.

Its awesome how much you an see in the night sky with minumum aperture and wide field . I think the fact that you can focus, thereby solving the problem of night time Myopia which most people suffer from, is a big factor. Numerous star clusters and wide doubles are resolving and Eta Carinae has the classic shape. And I can often see many different classes of deep sky object in the one view.I'm taking in more of the Milky Way under sharp resolution than ever before . I can see the whole of Scorpius and more at once.

Some times you've got to step back from the big scopes and remember that they narrow down your field of view greatly, and give you a good dose of train spotter ' fever, and you can forget the bigger picture. Fellow binocular enthusiast Paul Shopis has a binocular version in the pipeline :thumbsup:

[h0ughy]

looks very innovative Mark!

[Tamtarn]

Very ingenious Mark.

I hope this isn't a silly question but what type of adapter holds the EP adapter to the lens ??

Barb

[Starkler]

Its surprising what can be done with old camera lenses. I know a fellow who has made a 40mm eyepiece from an old camera lens and off centre aberrations are amazingly well corrected in his f3.8 scope.

I also enjoy wide field viewing. My 130mm f5 newt comes with me when I travel for work and with the 31mm nagler in it I get a nice 4 degree fov :D

[erick]

Where does the EQ mount connect? :D

[Satchmo]

Barb, The eyepiece holder is is a plastic bayonet fitting rear lens cap. The 1.25" EP holder is from an old focuser. i simply drilled a hole in the back with a hole saw, and then eposied in the EP tube, using a bubble level to make sure it was square with the focal plane.

The cool thing is that you can use the lens focus ring to focus if you lock th eyepiece in the right position. I must try this eyepiece on the 70-200mm zoom that is gathering dust :) .

[Tamtarn]

Thanks Mark

That sounds simple enough. I'll have to get David on to that one :D



Like you I was wondering about whether it would work with a zoom

Let us know on this thread if you do try it with the zoom :thumbsup:

[Ric]

That looks great Mark and from your description it sounds very effective as well.
I look forward to your report on the zoom lens.

Cheers