68 replies to this topic

[LukaszLu]

Great idea! My second Towa - 60/900 - gives perfectly sharp images but with a bit o CA. If I could get rid of it and increase slightly contrast (perhaps by painting lens sides with black paint?) this scope would be really great. I'll have to try replacing plastic ring spacer with foil spacers!

[jkmccarthy]

Here is a 60mm f=910mm  F/15.2 Carton lens.  The spacers are all single slab pieces 0.005" thick. Each spacer is precision placed and glued to the flint.

I did purchase the Carton 60mm F=910 refractor kit that jragsdale found on FB Marketplace (see:  https://www.cloudyni...2#entry12029203), but when I first used it at night for a star test I found it had rather severe astigmatism.   Looking at the objective lens under CFL illumination, its Newton's Rings were farther off-center in the lens aperture than apfever's images in green monochromatic light.  Under magnification I could see two of the three lens spacers were wrinkled / crinkled.  I disassembled the lens and replaced all three spacers with ones of uniform thickness (matched to the measured thickness of the one smooth+flat original spacer, which was 0.004-inches thick).  This nicely corrected the far-off-center Newton's Ring interference pattern:

 

 

... but although the star test then showed better images, at 180x magnification the images did still show astigmatism, looking at best focus like plus signs  +   with interference fringes in the arms, rather than round Airy disks surrounded by concentric rings, and inside/outside focus like tell-tale short orthogonal lines.  I've subsequently ruled out the possibility that the Carton lens cell might be distorting (warping) an otherwise good lens, as well as ruled out the possibility that the telescope tube might not be square between the top (where lens cell attaches) and the bottom (where focuser attaches) -- a Vixen 60/910 lens installed in the Carton cell and used with the Carton OTA performs very well, while the Carton lens installed in the Vixen 60/910 cell and OTA remains disappointingly astigmatic.  What I haven't done is experiment to see whether the Carton lens could be improved by changing the clocking between its crown and flint elements; there was no index mark on the lens edges when I disassembled it (yet there were two wrinkled/crinkled lens spacers as already noted), but I made my own index mark prior to separating the elements, and I reinstalled the elements in the same clocking orientation as found.  But its present degree of astigmatism is far from subtle, so at this point I'm not optimistic that finding the optimum clocking relationship between the elements (if other than their orientation as I found them) is gong to change this Carton lens from a dud to an excellent performer ... but I've been wrong before (like when thinking the centered Newton's Rings were a good omen after I'd replaced the lens spacers ...).

 

* * * *

 

My question for this audience is -- when did Carton change their logo from that shown in the label on the left (the FB Marketplace refractor) to that shown in the label on the right ?  During the 1980s, or earlier ?  And more importantly to me at present, is the company's reputation for optical excellence typically exemplified in small refractors of either vintage ?

 

 

((I'm debating whether to acquire a Carton 60/910 OTA whose label appears at right above, in order to be able to swap-in a genuine Carton objective lens into the Carton refractor kit from FB Marketplace, rather than leaving the Vixen lens installed ... but is that silly ?   I'm not eager to "throw good money after bad", certainly, but speaking for myself one of the main draws of the Carton 619-A refractor kit was to experience the views through a genuine Carton objective lens ... of course maybe a previous owner already swapped out that refractor's original [optically excellent?] lens to use it elsewhere, and swapped-in a dud --- I have no way of knowing --- but a Carton refractor kit with a Vixen lens isn't quite the same, is it ?  Agree or disagree ?))

 

Thanks much,

 

       -- Jim

Edited by jkmccarthy, 01 August 2022 - 12:25 AM.

[DAVIDG]

 The astigmatism is most likely not going to go away by clocking the elements.,  I would view without the diagonal just to rule that  out .If you have laser collimator that fits the focuser, I would  use that be sure the beam exiting  the front of the lens is in  the exact center, then point the scope at a wall about 6 feet away. If the lens is collimated you should see one spot on the wall. If you see more the lens is out the collimation and you need to adjust the the tip/tilt  to bring all the spots together. That usually means elongating the screw holes for mounting the lens.

   If you have it aligned and you still see astigmatism then it is in one of the elements of the lens. It is not uncommon for these small lens to show problems. They are not precision optics that are  accurately tested, just mass produced one that if they pass simple tests and are sold. 

 

                - Dave 

Edited by DAVIDG, 02 August 2022 - 08:47 AM.

[LukaszLu]

My question for this audience is -- when did Carton change their logo from that shown in the label on the left (the FB Marketplace refractor) to that shown in the label on the right ?  During the 1980s, or earlier ?  And more importantly to me at present, is the company's reputation for optical excellence typically exemplified in small refractors of either vintage ?

Mine was bought by the first owner in 1976

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[jkmccarthy]

Mine was bought by the first owner in 1976

Thanks ... yours appears to be of a style intermediate between the two in my post -- yours has the earlier "{ C.O.C }" logo replaced by "Carton" although not yet switching to the later label's (right side in my post #52) more narrowly-spaced fonts for "Carton" and for "ASTRONOMICAL TELESCOPE".  The later label also includes a 4th line for the model-number + serial-number.  
 

[Universe XY]

A very rare bird has just arrived ... Courtesy of Dietmar from Germany, I have just received a shipment containing the Carton 60/910 refractor. Thanks a lot Diddy! This beautiful, elegant telescope, the design of which is definitely ahead of its time, seems to be in pretty good condition. The copy comes from 1976, it is most likely the Carton 619-A model, although the manual signed by Neckermann is silent about it. I have already started cleaning, I have repaired larger paint losses on the tripod, I have cleaned the mount (although I decided not to change the greases because they still seem quite functional). The work progresses quickly and everything would be fine if it wasn't for the lens.

 

The lens was clearly disassembled. On this occasion, the spacers were damaged. One has survived, and the other two are in a rudimentary form. In such a state, it is not possible to maintain the correct distance between the lenses, perhaps they even touch each other, which is dangerous for the lens. I'll find out soon when I take it apart. I will then be faced with the question of how to recreate the spacers. This is the question I would like to ask my more experienced colleagues. How to make new spacers, so that they do not become a source of scratches on the optics or a habitat of fungi and molds? How to stick them to the surface, and maybe stick them not to the face but to the sides of the lens - even with adhesive tape?

 

Thanks in advance for any advice. Do you recognize this model? Is it 619-A?

Cool, to have tracked down this Carton. I have a similar one I am trying to figure out & hoping it's a good example of the scope. I will have to try to clean the inside of the big lens but I can't easily unscrew the dew shield & was not sure how these came apart. Looks like they both unscrew?

 

My grease on the mount is fine but I am in So Cal so it won't see any freezing temps & it came from Virginia. I'd really be interested in how to go about accessing if the objective is a good one. I don't think my lens was disassembled but you can never tell. Really don't think my scope had much use & was stored pretty well but the big lens area did have a musty mildew smell.

 

I rechecked bringing the scope close to a light. The photo I posted was about 6 foot from a light. It's hard to get a photo but the rings go to the outer edge 7 they are very finely spaced. 

 

Not sure what it means. It's good I suppose from what I can see doesn't rule out a astigmatism? How do I check that in a scope?

 

Cloudy again as it been for so long.

Edited by Universe XY, 12 March 2025 - 09:54 PM.

[Universe XY]

It is missing a lot of stuff and has fatal issues that I think can be overcome in a practical manner.  Questions welcome before I put it away, it will not be on a top burner yet. The mount moves smooth, controls work, grease is typical slow motion stuff now. Many parts abused, many parts like new, the light works perfect and looks like it was never touched.  

 

That is all for here unless asked. I look forward to checking back. 

Nice box & that's how mine was laid out. My box is plywood & the top & bottom is very thing. It's separating & delaminating but it's better than a cardboard box. I plan to strengthen & help restore the box some day. I like the wood on yours. We both have the Styrofoam so guessing early 70's?

 

I have the same blue japan stickers. Definitely the same scope. I've been through the parts & these earlt Carton are an exact match even the long visual back. 

 

 

Edited by Universe XY, 12 March 2025 - 10:47 PM.

[LukaszLu]

Congratulations, yours looks great and I hope it produces equally great images! I recently did some simple comparative tests with the T-620 described in this thread: https://www.cloudyni...i-kogaku-60910/

They have confirmed that it is an instrument that stands out very clearly among other F/15 60mm refractors.

Edited by LukaszLu, 14 March 2025 - 04:27 PM.

[davidc135]

Cool, to have tracked down this Carton. I have a similar one I am trying to figure out & hoping it's a good example of the scope. I will have to try to clean the inside of the big lens but I can't easily unscrew the dew shield & was not sure how these came apart. Looks like they both unscrew?

 

My grease on the mount is fine but I am in So Cal so it won't see any freezing temps & it came from Virginia. I'd really be interested in how to go about accessing if the objective is a good one. I don't think my lens was disassembled but you can never tell. Really don't think my scope had much use & was stored pretty well but the big lens area did have a musty mildew smell.

fitting CN 20250303_152735.jpg

COC 20250222_143144.jpg

mono bullseye 20250310_210129.jpg

 

I rechecked bringing the scope close to a light. The photo I posted was about 6 foot from a light. It's hard to get a photo but the rings go to the outer edge 7 they are very finely spaced. 

 

Not sure what it means. It's good I suppose from what I can see doesn't rule out a astigmatism? How do I check that in a scope?

 

Cloudy again as it been for so long.

The Newton's rings look to be off centre, but that may just be the angle of the photo. I'd check that they are centered, as being off means there is wedge in the air space.

 

Astigmatism is easy to recognise, as a star image at high magnification will expand in directions mutually at 90^o either side of focus. The test is not very sensitive to seeing. Or you could use a reflected glint in the daytime.

 

David

Edited by davidc135, 14 March 2025 - 04:54 PM.

[Universe XY]

Congratulations, yours looks great and I hope it produces equally great images! I recently did some simple comparative tests with the T-620 described in this thread: https://www.cloudyni...i-kogaku-60910/

They have confirmed that it is an instrument that stands out very clearly among other F/15 60mm refractors.

I had it out last night with my 80 X 480 looking at the moon.

 

Really white clean color with no color around the moon. The 80mm showed some green on one side I've never noticed before.

 

The COC 60 X 910 was a gut buy & I probably should not have but we all get enamored. It is in very good shape. except for the box & the seller losing the weight shaft.

 

It's harder for me to use it wo the weight shaft but I can. The mount is stable wo the weight but I am being very careful.

 

View in a 80mm with 1.25 nice ep's really is so much nicer than the old .965 ep's but it seems it take take a 1.25 Vixen back. anyway leaving that until I figure out the weight shaft situation. I will be getting a partial refund on it so will put that toward something

 

There should be a long screw & bolt that goes in the bottom side of the mount that helps with fine tuning it. Dave Trott has a video of a 85 Mini 5 Carton that shoes the bolt. I have the bolt in there but never knew that's really where it went as it's not in the manual.

 

When I got it the weight stop was screwed on the mount. I had to get it off. There is a special nut with a handle for that which makes it easier to use/adjust.

 

https://youtu.be/z7-eybgOzTY

 

I will be saving your thread & a few others on this scope in  the hope to get it back to the sky & hopefully not so many cloudy nights.

 

I hope I got a good lens as some have had duds. 

 

[Universe XY]

The Newton's rings look to be off centre, but that may just be the angle of the photo. I'd check that they are centered, as being off means there is wedge in the air space.

 

Astigmatism is easy to recognise, as a star image at high magnification will expand in directions mutually at 90^o either side of focus. The test is not very sensitive to seeing. Or you could use a reflected glint in the daytime.

 

David

Hard to get a photo & that was taken at a angle with a light source that was very far away. I never saw them before or I guess I may not have noticed.

I did put the scope out on the balcony in the sun as there was a musty smell & might be some mildew. I thought that might at least help the lens before I figured out how to take it off & clean it. I ordered a strap wrench.

 

I took the photo looking down on the lens & from the side. It's hard to get a shot head on. The radius of lines goes to the edge but they are very fine & thinly spaced together.

 

Out of focus is just a round globe...I'll have to play with it more.

 

Thanks

[Universe XY]

Congratulations, yours looks great and I hope it produces equally great images! I recently did some simple comparative tests with the T-620 described in this thread: https://www.cloudyni...i-kogaku-60910/

They have confirmed that it is an instrument that stands out very clearly among other F/15 60mm refractors.

Got a craftsman rubber strap wrench today & got the dew shield off but it came off with the lens cell which was fine with me.

 

There was a lot of mildew or fungus on the inside & with access to the other side I got to clean it.

 

Can't wait to see if it's better. Should be...Least I hope waytogo.gif

 

Before

 

After

 

Edited by Universe XY, 18 March 2025 - 10:28 PM.

[LukaszLu]

Great job! I'm not sure what you mean by the long micro-motion screw? Your picture shows two original slow-motion knobs - one of which is flexible. What I don't see in your pictures is the counterweight and counterweight rod.

[Universe XY]

Great job! I'm not sure what you mean by the long micro-motion screw? Your picture shows two original slow-motion knobs - one of which is flexible. What I don't see in your pictures is the counterweight and counterweight rod.

I have the counterweight & weight lock but no shaft.

 

There is a screw that goes in the bottom. Dave Trott showed it on the mini Carton video I linked. Mine had that screw & bolt. Not really sure how to use it but it's supposed to be good for making small mount adjustments & also it seems to lock it.

[LukaszLu]

You mean this screw? In this version of the mount it is not there.

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[Universe XY]

You mean this screw? In this version of the mount it is not there.

Yes,

I have that screw. My COC was made with a Monolux label & is earlier than yours if yours in 1976? Mine is probably about 1970.

 

I also have a silver ring on the bottom with numbers that I have not seen on others.

 

Edited by Universe XY, Yesterday, 03:49 PM.

[tturtle]

This thread motivated me to take my 60mm f15 Carton out earlier this evening and I was not disappointed. I haven’t had it under the stars since I bought it last year so couldn’t really remember whether the star test was acceptable or not. I was thrilled to see pinpoint stars, no astigmatism at all and extra and infra focus nearly identical with textbook patterns. This scope is such a classic in every way, optically, mechanically, and aesthetically. 

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[apfever]

This picture from entry #56 above is not bad at all. The rings are fairly centered. I wouldn't try to adjust anything this close.  I've found spacers and Newtons Rings to be extremely sensitive. 

 

 

Cheap kitchen aluminum foil is 0.0005" thick. That is 1/2 of 1/1,000 of an inch. That much adjustment on one shim can send Newton's Rings half way across the lens. Any Newton's Rings well within a half radius of the objective would give me pause for tinkering. My challenge would be to see if anyone could tell the difference between the posted rings and perfect centered rings on a blind test. Not happening in my book but YMMV. 

 

I can see where changing out wrinkled shims might have a micro adjustment. 

Edited by apfever, Yesterday, 09:24 PM.

[Kasmos]

This picture from entry #56 above is not bad at all. The rings are fairly centered. I wouldn't try to adjust anything this close.  I've found spacers and Newtons Rings to be extremely sensitive. 

 

post-506905-0-13439900-1741831007.jpg

 

Cheap kitchen aluminum foil is 0.0005" thick. That is 1/2 of 1/1,000 of an inch. That much adjustment on one shim can send Newton's Rings half way across the lens. Any Newton's Rings well within a half radius of the objective would give me pause for tinkering. My challenge would be to see if anyone could tell the difference between the posted rings and perfect centered rings on a blind test. Not happening in my book but YMMV. 

 

I can see where changing out wrinkled shims might have a micro adjustment. 

I couldn't get the rings centered on my 60/700m ATCO 1252 but it appears to be slightly sharper than the two Manon and Mayflower objectives I have in that class.