Hastings Triplets from Thorlabs

[N1 (Mirko)]

Anyone know how to turn this:

http://www.thorlabs.de/newgrouppage9...tgroup_id=5368

into an eye piece? What's the best approach for mating their mounted or unmounted triplets to a 1.25" barrel? I guess a field stop would have to be installed also, for a tidy view. It comes in 3 focal lengths.

Any suggestions appreciated. Thanks.

[Wavytone]

Why ? At those prices you can buy many perfectly good eyepieces that will work better than those, and complete with a nice barrel to fit your scope.

A triplet on its own will have a very small useable field maybe 30 degrees, and the eye relief is nil. Seems a lot of effort to go to to end up with something that will be inferior to every eyepiece made over the past 100 years or so.

[N1 (Mirko)]

Thanks Wavy for your comments. Depends how well the triplet is executed I suppose. AFOV and ER are non issues for me, I can handle anything that is on the market today. Also I think at the focal lengths they are selling, ER might actually be pretty good.

Originally Posted by Wavytone

Why ?

I have all the eyepieces I want. (for now anyway )
That means it's time for some experimenting.

[Wavytone]

For experimenting... One of these on its own won't be much good but if you were to add a Plano-convex achromatic doublet with the plane side facing the focal plane, you'll have something close to an Erfle or a half a dozen modern 5-element eyepiece designs. That might even be fairly useful.

Not sure where you'd find achromatic doublets this small though, and you want ones that are coated.

[N1 (Mirko)]

Thanks. I shall look into this.