Old Prinz Astral 500 - Worth Doing Up?

[Ian McCallum]

I bid on and won this old Prinz Astral 500, from eBay.  I didn't look carefully enough at the advert to realise that there was no tube rings or tripod head.  I've got the experience to clean the front objective lens, etc.  Is it worth doing up?  I know that the circle T Japanese optics are supposed to be really good.

[Mr Spock]

I had a Prinz 550 back in the '70s. Nice optics with very little CA.

[DaveL59]

What's the diameter of the OTA tube?

I have an old head that's no use to me but is small diameter, as per pics. No Slo-Mo just basic alt-az but if its of use to you I'd be happy to send it on.

 

[Ian McCallum]

43 minutes ago, DaveL59 said:

What's the diameter of the OTA tube?

I have an old head that's no use to me but is small diameter, as per pics. No Slo-Mo just basic alt-az but if its of use to you I'd be happy to send it on.

 

It's about 63.5mm in diameter. Would that fit at all? 🤔

[Ian McCallum]

The finderscope is missing an eyepiece, is that easy to fix? 🤔 Also the prism seems to have another lens screwed on to the front of it. Is that an erecting prism? 🤔

[DaveL59]

6 minutes ago, Ian McCallum said:

It's about 63.5mm in diameter. Would that fit at all? 🤔

It may do, is a couple mm over 60. No idea what old scope that came from as it was on an older wood tripod I bought some time back to "upgrade" the handling for the LT70AZ, so I just removed this head and fitted the legs to the Celestron one, which I've also since replaced with a sturdier Y fork type. The celestron won't help you tho as the OTA would need bolts in the sides as well as being a wider tube.

Your finder probably used one of the eyepieces that the scope does, I assume that's a 0.965mm opening/barrel? The one that came attached to my vintage 3-inch the finder has a fixed eyepiece, not managed to dismantle that tho but other 'projects' came along soon after and now back working so even less time.

Edited November 17, 2022 by DaveL59

[Ian McCallum]

14 minutes ago, DaveL59 said:

It may do, is a couple mm over 60. No idea what old scope that came from as it was on an older wood tripod I bought some time back to "upgrade" the handling for the LT70AZ, so I just removed this head and fitted the legs to the Celestron one, which I've also since replaced with a sturdier Y fork type. The celestron won't help you tho as the OTA would need bolts in the sides as well as being a wider tube.

Your finder probably used one of the eyepieces that the scope does, I assume that's a 0.965mm opening/barrel? The one that came attached to my vintage 3-inch the finder has a fixed eyepiece, not managed to dismantle that tho but other 'projects' came along soon after and now back working so even less time.

The wooden tripod legs that came with it have an distance of around 27.5mm on the inside, so should be able to take that head.  Do you think it's still doable? If so, I can certainly pay the postage and anything else...

Yes, it's a 0.965" diameter focus tube.  I've got an adapter coming from eBay to convert my 1.25" eyepieces down to 0.965".

Edited November 17, 2022 by Ian McCallum

[DaveL59]

1 minute ago, Ian McCallum said:

The wooden tripod legs that came with it have an distance of around 27.5mm on the inside, so should be able to take that head.  Do you think it's still doable? If so, I can certainly pay the postage and anything else...

that's spot on for the width of the base segments and checking it could be 63mm on the ring part too. Almost makes me wonder if a scope like yours is what it came from tho I thought most of them were EQ mounted and this was older. Only thing with a long OTA is its a pretty narrow collar, 30mm band, so probably won't be the most stable thing esp compared to a double tube-ring setup, but would get you started till you can find something better.

Probably should take the conversation to PM to sort details, let me know whereabouts you're located and I'll have a look at what it'd be to ship and we can go from there. The head's FOC tho, its just a part sitting around here so if its useful to you I'm happy to send it on.

[Ian McCallum]

6 minutes ago, DaveL59 said:

that's spot on for the width of the base segments and checking it could be 63mm on the ring part too. Almost makes me wonder if a scope like yours is what it came from tho I thought most of them were EQ mounted and this was older. Only thing with a long OTA is its a pretty narrow collar, 30mm band, so probably won't be the most stable thing esp compared to a double tube-ring setup, but would get you started till you can find something better.

Probably should take the conversation to PM to sort details, let me know whereabouts you're located and I'll have a look at what it'd be to ship and we can go from there. The head's FOC tho, its just a part sitting around here so if its useful to you I'm happy to send it on.

I've PM'ed you.👍

[Ian McCallum]

I've discovered that a red dot finder that I have will fit on to the OTA, in place of the existing finderscope.

[DaveL59]

That'd make things a lot easier than swapping eyepieces about.

I'll get that head into the post tomorrow for you too 🙂 

[Ian McCallum]

The telescope is now down in Morecambe, with my friend. It'll be mostly used to terrestrial views across Morecambe Bay now.