Searching scope history.

[mikeDnight]

 I'm hoping someone can shed a little light on the history of my 6" refractor. It was advertised as an Edmund Scientific 150mm F10 achromat, but other than that, the only thing I know about it is that the Edmund's objective is mounted in a home made tube assembly with a Celestron rack & pinion focuser by someone in the UK. It's a hefty tube assembly, and the scope may possibly have been moved on in the past due to presumed poor optics. 

 My immediate impression while looking at terrestrial targets in daylight was of an objective having very good colour correction. It was only later that night that I realized there was a real problem with spherical abberation. It turned out that the objective had been fit back to front, and after carefully removing the glue dabbs holding the retaining ring in place and reversing the lens, the the problem disappeared completely. The scope shows very little CA on bright stars, and virtually nothing around the limb of the Moon, which to me indicates a very well thought out objective. 

 It may be a long shot, but if possible I'd like to hear of anyone having experience of this scope or from anyone knowing anything about the age/date of the objective or its history. 

Edited March 11, 2022 by mikeDnight

[F15Rules]

Hi Mike,

That objective looks uncoated to me? If so, I'm wondering if it might have been made by AE scopes of Luton?

Someone who might be able to shed light on it is Es Reid, who I believe did work for/with AE and Jim Hysom..

HTH..and that's a cracking looking scope!

Dave

[wookie1965]

Now that is a really nice 6" refractor 

[mikeDnight]

Thanks Dave,

 When I bought the scope I met the seller at a carpark and it was raining lightly. I didn't look at the lens but asked if it was coated, at which he said "yes". It was only after getting it home and looking at it properly that I couldn't see any coatings on it. I wasn't too bothered by that as long as the optics were fine. I know Edmunds used to give the option of coatings or not on their lenses, so it could be an Edmunds lens as the seller claimed. Whatever it turns out to be, its a superb figure and dead sharp optics with great colour correction.  The fact it appears to be uncoated though did have me wondering about its age. May be Peter Drew might have had dealings with similar lenses in the past?

[F15Rules]

I had an AE optics 4.5mm F14.4 achro some years ago, and its' lens was uncoated (quite common in the 70s)..but very good polish and figure.

Here's a link to my old thread re the AE frac..

Dave

 

[JeremyS]

Will be interesting to find out the history of this fine scope, Mike. The maker clearly knew what they were doing.

The only thing I can say is the diagonal is definitely a Tak 1.25-inch prism 😊

[F15Rules]

5 minutes ago, JeremyS said:

Will be interesting to find out the history of this fine scope, Mike. The maker clearly knew what they were doing.

The only thing I can say is the diagonal is definitely a Tak 1.25-inch prism 😊

...and scopes didn't have handles "back in the day"...😁

Dave

[mikeDnight]

1 hour ago, F15Rules said:

...and scopes didn't have handles "back in the day"...😁

Dave

If any scope needs a handle, this one does! A big one!! Perhaps Jeremy has a few spare?😂

[JeremyS]

8 hours ago, mikeDnight said:

If any scope needs a handle, this one does! A big one!! Perhaps Jeremy has a few spare?😂

Think you might need something more substantial 🤔

[Pete Presland]

13 hours ago, mikeDnight said:

 

 My immediate impression while looking at terrestrial targets in daylight was of an objective having very good colour correction. It was only later that night that I realized there was a real problem with spherical abberation. It turned out that the objective had been fit back to front, and after carefully removing the glue dabbs holding the retaining ring in place and reversing the lens, the the problem disappeared completely.

 

WOW, makes you wonder how they were using it. It does look a beast of scope, it might make a very good Solar white light imaging scope 🙂 

[Louis D]

You might try cross posting this question on CN's Classic Telescopes forum as well since you suspect it's an Edmund objective.

[mikeDnight]

2 hours ago, Louis D said:

You might try cross posting this question on CN's Classic Telescopes forum as well since you suspect it's an Edmund objective.

Thanks Louis,

I'll need to try and resize the images before I could post them. CN isn't as forgiving as SGL, but I'll certainly give it a go. ☺

Edited March 12, 2022 by mikeDnight