Carton Optics 60 900 refractor

[lansonlad]

Last night my wife came home with a very large black box, a colleague was moving and did I want their old telescope.

After doing some digging it is a Carton Optics (CoC) scope that has clearly seen better days.

The mount is stiff and there are no slowmo controls in the box, theres only one screw to hold the finder in place (and the finder appears to be a barlow lens as I can't get anything into focus) and finally the focuser is slipping, after stripping it down it appears the teeth on the focus tube are worn.

It also 0.965" eye pieces, there are two on the box but they've seen better days.

I could replace the mount and try and repair the focuser but is it worth my time and money?

Opinions please.

Thank you

[Carbon Brush]

I don't know this particular scope.
However, often these old scopes had a good objective. Performance being let down by poor eyepieces.
Mounts were often a bit wobbly - but so are some new mounts in my opinion.

A few years ago I converted a Prinz (Dixons brand) 0.965" scope to use 1.25". No real money spent and a good long refractor at the end of the day.

As it has cost you nothing (so far) you can spend.

You can bodge a modern eyepiece on there using gaffer tape and live with the dodgy focusser.
If you can get a good result, you know it is worth the money and effort of upgrade.

If nothing else, you have a very good storage case for your refractor purchase🙂

HTH, David.

 

[John]

It looks as if a barlow lens has been put into the finder scope mount. I can't see a finder in the box so that is something that you will need to sort.

The diagonal looks to be one for solar observing - it has that hole in the backplate to let most of the solar energy out. I'm not sure how safe those are considered these days 🤔

You will need to get another diagonal for night time use.

 

[philj]

Carton Optics are well regarded in the vintage scope world and provided the objective is in good condition and hasn't been got at, the scope should do up well.

 

Agree with John, no finder and a Barlow has been wedged in the finder bracket with an eyepiece in it.

The diagonal is a Herschel wedge solar viewing prism and I would not recommend using it without some expert advice.

A standard prism/diagonal will be needed although I'm sure it will come to focus direct viewing but that can be uncomfortable.

 

Looks like the mount slow motions are missing also.

 

A good find I reckon

[Stephenstargazer]

Dont think that diagonal is solar Herschel wedge as the angle looks like 45deg. Just look through it on its own, should work like a mirror or prism (NOT at sun of course).Good luck!

[John]

47 minutes ago, Stephenstargazer said:

Dont think that diagonal is solar Herschel wedge as the angle looks like 45deg. Just look through it on its own, should work like a mirror or prism (NOT at sun of course).Good luck!

I thought it might be one of these, which are described as being herschel wedges:

[philj]

That's what I thought John. I still have one somewhere around.

[Franklin]

41 minutes ago, John said:

I thought it might be one of these, which are described as being herschel wedges:

That is one of the old Japanese herschel wedges, it was intended to be used with those .965 Sun filters in conjunction with the scopes aperture stop cap. I personally wouldn't chance using one these days and will stick with my Lunt. There are folk over the pond who still use these and post on CN about their findings. The design is actually safe to use but the lack of a heat-sink at the rear means that a dangerous laser beam shoots out and it is this that is the danger. They were known as "Tie burners"! Enough said.😁

Edited November 21, 2023 by Franklin

[Stephenstargazer]

Are they set as a normal 45deg prism then?? And is the top/front face set at another angle? Misleading to call it a Herschel wedge which has a back face set at a  much steeper angle to the eye. Fortunately I never came across one of these. If you look down  the top of a Herschel wedge you see your own eye (when it is not pointed at the sun). You see nothing reflected looking from the front. Hence my suggestion to look through it.

My Dictionary of Astronomy did not help on this subject!!

BTW the heat sink on the back of my 'proper' Herschel wedge is safe to touch after even an hour of solar viewing. What 'dangerous laser beam' ??? I think you mean a focused image lile any magnifying glass 🙂, useless for cutting steel, great for killing ants😈.

 

Edited November 21, 2023 by Stephenstargazer

[Franklin]

Not a real laser beam😁but a strong beam of concentrated sunlight no less and if a small child were to stand behind the scope it could end bad!

Not sure if it's a prism, I thought it was a 45deg un-silvered flat mirror and most of the light just passed through?

[Stephenstargazer]

48 minutes ago, Franklin said:

I thought it was a 45deg un-silvered flat

Wow, that explains a lot! Pretty bad to blame it on Herschel then. That would come to a nice focus back about same distance as eyepiece.

I have never found that hot point with a modern Herschel, may have to stick a finger inside? There is an unfocused image on the base of the prism, very handy as a finder🌞

Edited November 21, 2023 by Stephenstargazer

[Franklin]

I've seen an old Unitron herschel wedge that had a metal flap at the back to direct the sunlight down to the ground and it was completely open at the back. This one had a prism inside but not a 45deg, more like a thin wedge.

 

[bomberbaz]

I recently obtained a prinz astral which is a 76.5mm (read 3 inch) F16 and was 0.956 too. I gave it @Peter Drew to clean up and repair the focuser end of things. Now I have a lovely (1.25") scope which still needs some tlc but as it stands is a cracking scope. 

As @Carbon Brush says, the actual glass side of these scopes is often very good. At F15 if the glass is good then it should be superbly corrected, so if you can sort the focuser out you could be onto a fantastic double star buster. 

[Franklin]

I've had several old Vixen 60mm F15 scopes and the optics were very good and I'd try and fix up the Carton and also take apart the Sun diagonal and show us what's inside it😁.

[Franklin]

15 minutes ago, Stephenstargazer said:

Pretty bad to blame it on Herschel then.

Technically they were known as Sun Diagonals and not Herschel wedges and they also produced two Sun filters, one labelled "Sun Filter" and another labelled "Sun Filter for use with Sun Diagonal". I've never seen instructions but maybe the latter was intended to be used before the diagonal and the former on the eyepiece?

[John]

7 minutes ago, Franklin said:

Technically they were known as Sun Diagonals and not Herschel wedges and they also produced two Sun filters, one labelled "Sun Filter" and another labelled "Sun Filter for use with Sun Diagonal". I've never seen instructions but maybe the latter was intended to be used before the diagonal and the former on the eyepiece?

I saw it called a "herschel wedge" somewhere else but I can see now that was a mistaken description. It is intended for observing the Sun and I don't think it would work well for observing at night. Probably not really safe to use for solar observing either, by todays standards.

I still have my old Tasco 60mm F/13.3 from that era (maybe ever earlier ?). It's objective is pretty good. The stock .965 inch eyepieces and the rather wobbly yoke type alt-az mount don't do it justice though.

The Carton that is the subject of this thread seems to have what could be a decent equatorial mount 🙂

 

Edited November 21, 2023 by John

[Stephenstargazer]

You still have to use secondary filter(s) above a Hirschel or it is too bright. Typically nd9 and continuum which also removes uv/ir.

Back to scopes...I can see a gap in my collection, but I do have 90mm f/13  catadioptric for same purpose in a short format 🙂..........but an f/15 with Herschel would make a very nice white light solar. Lots of sunspots just now.

Edited November 21, 2023 by Stephenstargazer
Long scope envy?

[Stephenstargazer]

22 hours ago, Stephenstargazer said:

If you look down  the top of a Herschel wedge you see your own eye

Dohhhhh! That is the reflection from the continuum filter, nothing to do with the prism 😬

[fireballxl5]

I own an 80mm f/15 OTA made by Glen of Lyra Optics fame. This has a Carton objective and star images are text book perfect when the seeing allows. The views are great,  you just want to go on finding colourful doubles on a good night🙂

[Roy Challen]

On 21/11/2023 at 21:52, bomberbaz said:

I recently obtained a prinz astral which is a 76.5mm (read 3 inch) F16 and was 0.956 too. I gave it @Peter Drew to clean up and repair the focuser end of things. Now I have a lovely (1.25") scope which still needs some tlc but as it stands is a cracking scope. 

As @Carbon Brush says, the actual glass side of these scopes is often very good. At F15 if the glass is good then it should be superbly corrected, so if you can sort the focuser out you could be onto a fantastic double star buster. 

The Prinz Astral 660 is a fine telescope indeed. Mine was converted by Richard Day into a Skylight, it has split (once) the double double with a 25mm Zeiss Huygens albeit on a night with perfect conditions. Also very good for planetary, lunar and white light solar. Needs a good mount though.

Edited November 23, 2023 by Roy Challen

[tuckstar]

I have zeiss telementior that is/was.925 but unfortunately it didn't have any eyepieces. Just one adapter from apt and it now takes 1.25 eyepieces. No messing with original scope and now I use a set of Clavè eyepieces with it. 

[MartianHill]

Nice scope @lansonlad and worth doing up 👍

There are some slow mo controls here…

 

Edited November 23, 2023 by MartianHill

[Gonariu]

Nice telescope! About a year ago I bought a used Bresser 60/900 with which I saw the Moon and Castor well. The kit included 5 eyepieces, a 90 star diagonal and a solar and lunar filter which both screw onto the eyepiece. Being an f/15 I thought that the solar filter had to be safe but I trusted it up to a certain point, perhaps now that the sun is at around -20 declination so it doesn't exceed 30 degrees above the horizon even here in Sardinia I could trust you......

[SteveWolves]

Never use an eyepiece solar filter please.

[davidc135]

If the single eyepiece filter were to break in the heat there would be nothing to prevent a serious risk to your eye. At the least, if it were preceded by a Herschel wedge, the rays would have been diluted 20 fold.

David