34 replies to this topic

[jragsdale]

I just received a Zeiss Travelling Telescope from the mid-1920s today off a FB marketplace ad. It's an AS (short focus) lens, 63mm achromat, 830mm focal length (f/13). Brass construction almost top to bottom. Very heavy for the size. This one didn't come with the tripod or tripod hub (sadly that includes the azimuth slow motion mechanism). But did come with the complete OTA, almost perfect condition lens, an era-accurate Tinsley finder scope, two Tinsley 1.25" eyepieces, the exceptional Zenit Prisma, Porro prism, brass extension tube, 3 brass visual backs, altitude slow motion knob, tripod extension column, Zeiss 40mm Kellner 21x eyepiece, wooden case with keys (but missing all the partitions oddly). I think I got a great deal considering all the accessories that it came with and the great condition of all the optics. This will be a long restoration project, hopefully which I can finish close to the 100 year anniversary of this scope's build. Photos attached below.

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Edited by jragsdale, 15 July 2022 - 07:17 PM.

[jragsdale]

Lens and mount

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[jragsdale]

Zenith prism, Porro and Tinsley Finder

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[jragsdale]

The whole shebang of accessories.

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[tony_spina]

Beautiful!    Congratulations on your new acquisition 

[Piggyback]

Wow and congratulations! This is a beautiful Zeiss refractor. Looking forward to follow up on your restoration efforts.

[Kasmos]

Super Cool!, nice move Jordan. From the FB ad I didin't think it was going to have the box or any other goodies.

 

The only downside, if you can find them, Zeiss parts are going to be pricey.

 

Maybe Dave Trott can give some pointers

 

https://davetrott.co...ling-telescope/

 

Didn't you post a still (in another thread) from his video?

 

https://www.youtube....h?v=FuT3TpdTBp8

[jragsdale]

The only downside, if you can find them, Zeiss parts are going to be pricey.

Yeah, I've already consulted Dave about making a tripod and hub. I'll try to duplicate his efforts if I can find similar parts. Luckily it appears I don't need much to make this a finished complete scope.

[jragsdale]

First order of business was to get this rusty porro prism back into operation. It had a lot of rust on the eyepiece side and the whole inside was fogged over with moisture, dirt, and rust, there was no seeing through it. I managed to get the screws off without too much mangling (I'm terrible with flat heads, they call me the stripper). I cleaned the whole unit inside and out with gentle soap and warm water with a gentle toothbrush first. Rusty screws were treated with rust treatment and I used a little bit on the prism base inside the unit as well. I gave the inside of the unit a very light coat of flat black to darken everything back up and stop any future rust. The prism took like 50 cotton swabs with methanol to get all of the hard water and rust stains off. I was surprised it was salvageable honestly. But it's 99% clear, there's a few prominent air bubbles in the glass though which is surprising in a prism unit. After putting it together I gave the rubberized armor around the outside a rub down with some leather conditioner, and the main metal cover was a little dull, so I gave it a very thin coat of boiled linseed oil to bring back the shine and protect. Now it's back in business and is clear to view through!

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[jragsdale]

Dew shield missing paint on the end but it's a clean line and the brass steps up. Maybe made after the fact? It's not magnetic but the main OTA is.

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Edited by jragsdale, 16 July 2022 - 07:40 PM.

[Kasmos]

First order of business was to get this rusty porro prism back into operation. It had a lot of rust on the eyepiece side and the whole inside was fogged over with moisture, dirt, and rust, there was no seeing through it. I managed to get the screws off without too much mangling (I'm terrible with flat heads, they call me the stripper). I cleaned the whole unit inside and out with gentle soap and warm water with a gentle toothbrush first. Rusty screws were treated with rust treatment and I used a little bit on the prism base inside the unit as well. I gave the inside of the unit a very light coat of flat black to darken everything back up and stop any future rust. The prism took like 50 cotton swabs with methanol to get all of the hard water and rust stains off. I was surprised it was salvageable honestly. But it's 99% clear, there's a few prominent air bubbles in the glass though which is surprising in a prism unit. After putting it together I gave the rubberized armor around the outside a rub down with some leather conditioner, and the main metal cover was a little dull, so I gave it a very thin coat of boiled linseed oil to bring back the shine and protect. Now it's back in business and is clear to view through!

Amazing transformation. That was some fast and well done work! 

 

I've never heard of using boiled linseed oil for something like that.

[Terra Nova]

The tube seems awfully short for 830mm f.l.? My Telementors were 840mm and much longer and all the Zeiss Traveling Telescopes I’ve seen were much longer and they had f.l.s on the order of ~830 to 840mm. Maybe it’s an optical illusion of seeing it without the dew shield and tail piece? Cool telescope. I’ve never seen one close up.

Edited by Terra Nova, 17 July 2022 - 09:15 AM.

[Kasmos]

The tube seems awfully short for 830mm f.l.? My Telementors were 840mm and much longer and all the Zeiss Traveling Telescopes I’ve seen were much longer and they had f.l.s on the order of ~830 to 840mm. Maybe it’s an optical illusion of seeing it without the dew shield and tail piece? Cool telescope. I’ve never seen one close up.

I thought the same thing.

 

The ones shown in this link do look longer....

https://www.cloudyni...zeiss-traveler/

 

...But the short focus models that Dan has look more like Jordans

https://www.cloudyni...eiss-traveller/

[Piggyback]

The tube seems awfully short for 830mm f.l.? My Telementors were 840mm and much longer and all the Zeiss Traveling Telescopes I’ve seen were much longer and they had f.l.s on the order of ~830 to 840mm. Maybe it’s an optical illusion of seeing it without the dew shield and tail piece? Cool telescope. I’ve never seen one close up.

There is the E-version featuring 850mm f.l. I have seen these pop up in adverts at insane prices on my side of the pond. Never had a chance to see one with my own eyes, though.

[jragsdale]

The tube seems awfully short for 830mm f.l.? My Telementors were 840mm and much longer and all the Zeiss Traveling Telescopes I’ve seen were much longer and they had f.l.s on the order of ~830 to 840mm. Maybe it’s an optical illusion of seeing it without the dew shield and tail piece? Cool telescope. I’ve never seen one close up.

I think that's just the perspective trick with the extension and dew shield removed. The drawtube with extension gives a staggering 292mm of extra backfocus.

[Kasmos]

I think that's just the perspective trick with the extension and dew shield removed. The drawtube with extension gives a staggering 292mm of extra backfocus.

Go back to the links posted in #13.

 

There are definitely different lengths of OTAs.

[jragsdale]

Go back to the links posted in #13.

 

There are definitely different lengths of OTAs.

Oh, yeah, the A and AS were definitely different. The AS being the short focus lens. I thought she meant short for an AS.

[jragsdale]

Ack! Problem #1: the electrical tape holding on the broken finder ring left a super nasty dry residue, any advise on how to safely remove from the tube without damaging the paint?

[Kokatha man]

...citrus oil...acetone...methylated spirits...white spirit - or one after the other with soapy water to finish off. (orange/citrus cleaner/oil is pretty good for most residues )

[jragsdale]

...citrus oil...acetone...methylated spirits...white spirit - or one after the other with soapy water to finish off. (orange/citrus cleaner/oil is pretty good for most residues )

Acetone and magic eraser for the win! Thanks! That came off really well, and didn't even remove the faint yellowing of the original paint.

[jragsdale]

As I'm working through the focuser, I keep finding the number "12" stamped all over. Also noticed the porro had the number "20" stamped inside under the prism housing and the mount has the number "14" stamped under one of the top mounting brackets. Anyone have a hunch on these? Could it possibly be a date stamp? Or just something to help during assembly?

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[jragsdale]

Got the OTA all finished. Fully disassembled, deep cleaned, oiled and put back together. Left all the character of coarse. Focuser works nice and smooth. Mounted it on some rings so I can use it until the mount/tripod is finished but that'll be a while. Here it is at infinity focus, not a great pic, but interesting to see how far out the drawtube needs to be to focus!

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[Bowlerhat]

A fine addition to zeissitis thread, congrats!

[RichA]

Ack! Problem #1: the electrical tape holding on the broken finder ring left a super nasty dry residue, any advise on how to safely remove from the tube without damaging the paint?

Goo Gone.

[jragsdale]

Goo Gone.

Tried that first and it didn't touch it. Magic eraser and acetone with vigorous scrubbing did the trick.