9 replies to this topic

[The_Vagabond]

Greetings, Star Hustlers!

Does anyone know the barrel diameter of the original CRICO eyepieces?

Much Obliged!

[strdst]

These came with a 1958 Criterion Dynascope and are 1.25" diameter.

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[The_Vagabond]

These came with a 1958 Criterion Dynascope and are 1.25" diameter.

Thanks for the reply.
I'm wondering if they may have had a smaller size for the really early Dynascopes, which I think in addition to being a smaller aperture also used weird eyepieces. 
It's possible I might be getting them and later SkyScopes (3" f/12) confused.

[strdst]

I had a skyscope that I sold with a few eyepieces which weren't a standard telescope barrel diameter. IIRC smaller that .965. Microscope eyepiece size perhaps?

[The_Vagabond]

I had a skyscope that I sold with a few eyepieces which weren't a standard telescope barrel diameter. IIRC smaller that .965. Microscope eyepiece size perhaps?

There is a brass fitting inside the draw tube that, if you could remove it without breaking the delicate old Zymac casting would bring it up to 0.965". I mean, it's just barely there.

Amazingly, my SkyScope actually survived my disastrous move. I need to stiffen up the draw tube, but it is still usable.

 

[John Rose]

I just measured an old Criterion 16.3mm Erfle.  0.945". I expect the old Crico are the same. 

[The_Vagabond]

I just measured an old Criterion 16.3mm Erfle.  0.945". I expect the old Crico are the same. 

Ah, thank you!

[The_Vagabond]

Going to bump this up.

I purchased the CRICO eyepieces, a 9mm AR and 18mm H, and they worked perfectly in the old SkyScope. The 9mm has a small clam chip, but is still amazingly clear. Also, a number of small eyepiece parts arrived with them.

[98105dude]

The 4" Dynascope from the '50s that I bought recently has a green tube and came with an 18mm eyepiece that is 0.945" in diameter. It's the model that is mounted on a GEM. I hope it's not inappropriate to say this here, but I'm looking for additional Crico eyepieces of this vintage as well as the counterweight it is missing.

[apfever]

It seems OP has found his matching .965" Crico eyepieces. There are also multiple comments about the 4" Dynascope having a .965" focuser.

 

I have three Crico eyepieces I know of and they are all 1.25" barrels. They are the AR 30mm, AR 9mm, and 18mm H.  All three are very old compared to the regular "CRITERION" labeled ones. 

 

I've restored two factory original 4" Dynascopes.  One with drive, one without.  One of the scopes has documentation from the original owner about how the scope was never modified. Both of those have 1.25" focusers.  Here is a LINK to the restoration with some details on the unique focuser casting.