48 replies to this topic

[Peter Besenbruch]

was playing around with mine today and was looking at power lines in the day time about 3 kms away the image were extremly sharp at 81x and that was looking THRU a glass window

you must have had a really bad sample or i have a really great sample?

i will report back as to how high i see mine going moon planetary and DSOs

How we tested also plays a role. I set mine up next to a Pentax 80mm achromat. 32mm Plössl in the Pentax, 15mm RKE in the Edmund, both pointed at M42. What was remarkable was how much more "space" existed between the trapezium stars in the refractor. I kept checking and rechecking the magnifications. Then I played with other eyepiece combinations. By itself, I would have said the Astroscan was sharp at 30x. Then the Pentax came along and redefined sharp.

[izar187]

 

was playing around with mine today and was looking at power lines in the day time about 3 kms away the image were extremly sharp at 81x and that was looking THRU a glass window

you must have had a really bad sample or i have a really great sample?

i will report back as to how high i see mine going moon planetary and DSOs

How we tested also plays a role. I set mine up next to a Pentax 80mm achromat. 32mm Plössl in the Pentax, 15mm RKE in the Edmund, both pointed at M42. What was remarkable was how much more "space" existed between the trapezium stars in the refractor. I kept checking and rechecking the magnifications. Then I played with other eyepiece combinations. By itself, I would have said the Astroscan was sharp at 30x. Then the Pentax came along and redefined sharp.

 

80mm Pentax slow achro, with a high end plossl.

Against a 4" f/4 newt, with three element ep.

It should have.

No coma at all and way less astigmatism.

Pretty apples to oranges comparison.

Just saying.

 

RKE's are/were Edmunds house ep's, very light weight, and what they first offered with Astroscans.

The weight factor, for this scope, was the only real thing they had going for them.

But they are a miserable design for an f/4 scope.

About any plossl or ortho is better, significantly better.

Which is probably partly why Edmund stopped offering then with the scope at one point, and went to plossls.

Edited by izar187, 31 December 2016 - 07:43 PM.

[Peter Besenbruch]

80mm Pentax slow achro, with a high end plossl.

Against a 4" f/4 newt, with three element ep.

It should have.

No coma at all and way less astigmatism.

Pretty apples to oranges comparison.

Just saying.

 

RKE's are/were Edmunds house ep's, very light weight, and what they first offered with Astroscans.

The weight factor, for this scope, was the only real thing they had going for them.

But they are a miserable design for an f/4 scope.

About any plossl or ortho is better, significantly better.

Which is probably partly why Edmund stopped offering then with the scope at one point, and went to plossls.

I found the RKEs comparable in edge correction to a standard Plössl. They accomplished this by adding a lot of distortion. Sharpness at the edge of the field was comparable with orthos and Plössls, but in no way could you call the RKE an orthoscopic design. I'm not sure what gave you the idea that I was using a high end Plössl either. I tested with a surplus Jaegers 32mm.

 

As for coma, yes, it was there, but not in the center of the field. Quality had nothing to do with Edmund switching to Plössls. Price did. RKEs currently sell for $85. Currently, most Plössls sell for far less.

​

​I agree that the Astroscan was a miserable design, badly executed.

[izar187]

 

 

was playing around with mine today and was looking at power lines in the day time about 3 kms away the image were extremly sharp at 81x and that was looking THRU a glass window

you must have had a really bad sample or i have a really great sample?

i will report back as to how high i see mine going moon planetary and DSOs

How we tested also plays a role. I set mine up next to a Pentax 80mm achromat. 32mm Plössl in the Pentax, 15mm RKE in the Edmund, both pointed at M42. What was remarkable was how much more "space" existed between the trapezium stars in the refractor. I kept checking and rechecking the magnifications. Then I played with other eyepiece combinations. By itself, I would have said the Astroscan was sharp at 30x. Then the Pentax came along and redefined sharp.

 

80mm Pentax slow achro, with a high end plossl.

Against a 4" f/4 newt, with three element ep.

It should have.

No coma at all and way less astigmatism.

Pretty apples to oranges comparison.

Just saying.

 

RKE's are/were Edmunds house ep's, very light weight, and what they first offered with Astroscans.

The weight factor, for this scope, was the only real thing they had going for them.

But they are a miserable design for an f/4 scope.

About any plossl or ortho is better, significantly better.

Which is probably partly why Edmund stopped offering then with the scope at one point, and went to plossls.

 

"I found the RKEs comparable in edge correction to a standard Plössl. They accomplished this by adding a lot of distortion. Sharpness at the edge of the field was comparable with orthos and Plössls, but in no way could you call the RKE an orthoscopic design. I'm not sure what gave you the idea that I was using a high end Plössl either. I tested with a surplus Jaegers 32mm.

As for coma, yes, it was there, but not in the center of the field. Quality had nothing to do with Edmund switching to Plössls. Price did. RKEs currently sell for $85. Currently, most Plössls sell for far less.
​
​I agree that the Astroscan was a miserable design, badly executed."

--------------

 

Not comparable to plossls to my eye, GSO or Carton, specifically below f7.

Orthos are better than either, across more of their field in fast focal ratios, in my experience.

Pretty much equal size field betwixt RKE's and ortho's, with the ortho being a just better all around ep, for any scope.

 

You are correct in my error regarding "high end" plossl, which was poorly read on my part.

I am guilty of transposing Pentax, and it's better then average optical reputation, across to the ep.

 

With who knows how many RKE lens elements Edmund may have on hand, as they still sell just the elements, plus the very simple RKE barrel design, only three elements, all aluminum, basic black anodizing inside and out... it's hard to believe there's a cheaper ep to make, from a materials alone standpoint. Certainly little to assembly, in my experience taking mine apart. They retail for 85 bucks apiece, because they retail for 85 bucks apiece, and are not hardly worth it in my opinion. They sold once upon a time for as little as $39, which was a decent price for them.

 

An Edmund in house design, for a less costly to make ep...  than a symmetrical, plossl, or ortho...  that was a bit better corrected than a kellner.

Which they are.

 

I disagree that the Astroscan is a miserable design, nor badly executed.

Portable, self contained, and fun.

It is a neat design, and better then it's mimics.

 

But it is a closed tube, that takes a bit longer to acclimate than an open tube of equal size.

With a widow that must be clean and dew/frost free.

A mirror mount that if cooked too long too often, then will not hold the mirror in collimation.

Focuser and ball mount that were never designed for heavy eyepiece nor ep/barlow combo's.

F4 by design, so best with ep's up to the task of an f4... and not too heavy.

Edited by izar187, 01 January 2017 - 02:24 AM.

[Peter Besenbruch]

Peter wrote:

"I found the RKEs comparable in edge correction to a standard Plössl. They accomplished this by adding a lot of distortion. Sharpness at the edge of the field was comparable with orthos and Plössls, but in no way could you call the RKE an orthoscopic design. I'm not sure what gave you the idea that I was using a high end Plössl either. I tested with a surplus Jaegers 32mm.

As for coma, yes, it was there, but not in the center of the field. Quality had nothing to do with Edmund switching to Plössls. Price did. RKEs currently sell for $85. Currently, most Plössls sell for far less.
​
​I agree that the Astroscan was a miserable design, badly executed."

 

--------------

 

Not comparable to plossls to my eye, GSO or Carton, specifically below f7.

Orthos are better than either, across more of their field in fast focal ratios, in my experience.

Pretty much equal size field betwixt RKE's and ortho's, with the ortho being a just better all around ep, for any scope.

I found the edge correction of a standard (Circle T) ortho about the same as the RKE, but the orthos accomplished this without strong bending of straight lines prevalent in the RKE. I never did like the RKE because of that.

With who knows how many RKE lens elements Edmund may have on hand, as they still sell just the elements, plus the very simple RKE barrel design, only three elements, all aluminum, basic black anodizing inside and out... it's hard to believe there's a cheaper ep to make, from a materials alone standpoint. Certainly little to assembly, in my experience taking mine apart. They retail for 85 bucks apiece, because they retail for 85 bucks apiece, and are not hardly worth it in my opinion. They sold once upon a time for as little as $39, which was a decent price for them.

I remember them selling for closer to $30, way back when. Then again, orthos didn't cost much more.

An Edmund in house design, for a less costly to make ep...  than a symmetrical, plossl, or ortho...  that was a bit better corrected than a kellner.

A lot better corrected than the Kellner. RKEs not only did this by adding distortion, they also used a more exotic glass than the typical Kellner.

I disagree that the Astroscan is a miserable design, nor badly executed.

Portable, self contained, and fun.
It is a neat design, and better then it's mimics.

But it is a closed tube, that takes a bit longer to acclimate than an open tube of equal size.
With a widow that must be clean and dew/frost free.
A mirror mount that if cooked too long too often, then will not hold the mirror in collimation.

Focuser and ball mount that were never designed for heavy eyepiece nor ep/barlow combo's.
F4 by design, so best with ep's up to the task of an f4... and not too heavy.

I am aware of one mimic by Bushnell, and that was pretty bad. Being better than that wasn't saying much. Where to start. It had a ball mount that basically needed a table top, or a tripod to raise it up. Edmund also showed people holding the assembly in their laps, but that never really worked. Combine it with what we typically wear in Hawaii (shorts, flip-flops) and it was absolutely a no-go on one's lap here. Most tripod heads weren't stable enough to hold the scope, and Edmund never drilled and tapped their mount for the heavier duty, 3/8" connections.

 

A Barlow and Plössl combination started to tax the balance of the scope. The rubber focuser roller gave out after a couple of years (people here would "fix" theirs with rubber bands), and the movable tube tended to fall into the scope. Collimation was always a bit off and couldn't be adjusted. The felt pads always got sticky. The peep site finder never lined up with the scope.

 

Eyepieces that could handle the f4 optics? Perhaps a Nagler, or Televue Plössls. Naglers from 9mm at the time were simply too heavy. That said, even eyepieces not optimized for fast scopes should have been sharp in the center of the field. They weren't. An f11 achromat showed a much better edge of field, but it was the center I tested.

 

The Astroscan was what I would describe as a frustrating telescope, never a fun one. It's a scope where form trumped function, and the execution was lousy. There are too many rose colored glasses when talking about older equipment.

Edited by Peter Besenbruch, 01 January 2017 - 09:10 PM.

[eklf]

I have routinely used the astroscan as a quick - and yes, fun- RF scope.  I must have lucked with my unit as it (foucser and mount) handles the weight of a paracorr and 22 LVW without much slop or slippage (a 13mm Ethos was a different story).  My unit is slightly off colimation, but for low power it is not an issue.  I dont go higher power on it - its OK on moon at mid -powers, but nothing else.  I only use it at low power and its fun to do so (used with a green laser).

Attached Thumbnails

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[SteveG]

I wish they still sold those simple, 1.25" Paracorrs!

[SteveG]

so

some of my Eps came in for this scope

i think they are all great EPs in there own right

not sure if i need all

 

thinking of keeping the 5.5 because great EP cheap and 82 AFOV this helps alot since the scope is not tracking

 

the rest im not sure?

Of those, the only worth keeping is the 26 mm Plossl and perhaps the zoom. The Meade is far too heavy for any Astroscan.

 

I would sell the rest and get a GSO shorty barlow ($40 new).

 

For the finder, I screwed a Synta type shoe to mine. In that, I placed a laser finder, or RDF when the laser wasn't practical.

[Mitrovarr]

I'd probably test out the Astroscan before you buy eyepieces for it. There is significant variation from unit to unit, with regard to the optics, the focuser, and the stiction of the mount. Mine is pretty decent at high power (although 200x is extremely optimistic for any Astroscan) but they're definitely not all able to do that.

[izar187]

 

Peter wrote:

"I found the RKEs comparable in edge correction to a standard Plössl. They accomplished this by adding a lot of distortion. Sharpness at the edge of the field was comparable with orthos and Plössls, but in no way could you call the RKE an orthoscopic design. I'm not sure what gave you the idea that I was using a high end Plössl either. I tested with a surplus Jaegers 32mm.

As for coma, yes, it was there, but not in the center of the field. Quality had nothing to do with Edmund switching to Plössls. Price did. RKEs currently sell for $85. Currently, most Plössls sell for far less.
​
​I agree that the Astroscan was a miserable design, badly executed."

 

--------------

 

Not comparable to plossls to my eye, GSO or Carton, specifically below f7.

Orthos are better than either, across more of their field in fast focal ratios, in my experience.

Pretty much equal size field betwixt RKE's and ortho's, with the ortho being a just better all around ep, for any scope.

I found the edge correction of a standard (Circle T) ortho about the same as the RKE, but the orthos accomplished this without strong bending of straight lines prevalent in the RKE. I never did like the RKE because of that.

With who knows how many RKE lens elements Edmund may have on hand, as they still sell just the elements, plus the very simple RKE barrel design, only three elements, all aluminum, basic black anodizing inside and out... it's hard to believe there's a cheaper ep to make, from a materials alone standpoint. Certainly little to assembly, in my experience taking mine apart. They retail for 85 bucks apiece, because they retail for 85 bucks apiece, and are not hardly worth it in my opinion. They sold once upon a time for as little as $39, which was a decent price for them.

I remember them selling for closer to $30, way back when. Then again, orthos didn't cost much more.

An Edmund in house design, for a less costly to make ep...  than a symmetrical, plossl, or ortho...  that was a bit better corrected than a kellner.

A lot better corrected than the Kellner. RKEs not only did this by adding distortion, they also used a more exotic glass than the typical Kellner.

I disagree that the Astroscan is a miserable design, nor badly executed.

Portable, self contained, and fun.
It is a neat design, and better then it's mimics.

But it is a closed tube, that takes a bit longer to acclimate than an open tube of equal size.
With a widow that must be clean and dew/frost free.
A mirror mount that if cooked too long too often, then will not hold the mirror in collimation.

Focuser and ball mount that were never designed for heavy eyepiece nor ep/barlow combo's.
F4 by design, so best with ep's up to the task of an f4... and not too heavy.

I am aware of one mimic by Bushnell, and that was pretty bad. Being better than that wasn't saying much. Where to start. It had a ball mount that basically needed a table top, or a tripod to raise it up. Edmund also showed people holding the assembly in their laps, but that never really worked. Combine it with what we typically wear in Hawaii (shorts, flip-flops) and it was absolutely a no-go on one's lap here. Most tripod heads weren't stable enough to hold the scope, and Edmund never drilled and tapped their mount for the heavier duty, 3/8" connections.

 

A Barlow and Plössl combination started to tax the balance of the scope. The rubber focuser roller gave out after a couple of years (people here would "fix" theirs with rubber bands), and the movable tube tended to fall into the scope. Collimation was always a bit off and couldn't be adjusted. The felt pads always got sticky. The peep site finder never lined up with the scope.

 

Eyepieces that could handle the f4 optics? Perhaps a Nagler, or Televue Plössls. Naglers from 9mm at the time were simply too heavy. That said, even eyepieces not optimized for fast scopes should have been sharp in the center of the field. They weren't. An f11 achromat showed a much better edge of field, but it was the center I tested.

 

The Astroscan was what I would describe as a frustrating telescope, never a fun one. It's a scope where form trumped function, and the execution was lousy. There are too many rose colored glasses when talking about older equipment.

 

Well, they simply were not 80mm f11 scopes.

Which is a very optically friendly, capable scope.

 

At f4, plossl's, ortho's, and RKE's each behave a little differently.

Ortho's are the general winner to my eye.

RKE's are in last place.

 

The felt pads were felt pads, to hold the scope on target.

They were always supposed to stick a bit.

Cleaning the ball helps.

 

The peeps sights do align.

Or you align them.

 

All table top scopes work better on a stable mount.

Best on a platform top tripod.

So they can be used either way.

 

Fun scopes.

Not for everyone, or everything for sure.

Particularly if comparing them to completely different designs.

[halx]

For easy pointing you can get a cheap 2xAAA green laser pointer and lash it down to the OTA in the EP bulge's corner with a string or rubber band. Works perfectly well .
I'm sometimes using heavy EPs with it. Notably my 9mm WO XWA 101. Spectacular views at 50x! But to amend issues with the weight I'm using a special fixed drawtube with it (3d printed custom fit) and either hugging the ball while sitting in the chair or pushing it hard enough into the mount piece while laying on the ground in the sleeping bag

[Peter Besenbruch]

Well, they simply were not 80mm f11 scopes.

Which is a very optically friendly, capable scope.

The comparison was made at the center of the field, where differences of f-ratio are minimized.

 

At f4, plossl's, ortho's, and RKE's each behave a little differently.

Ortho's are the general winner to my eye.

RKE's are in last place.

Again, the comparison was made at the center of the field, where differences of f-ratio are minimized.

 

The felt pads were felt pads, to hold the scope on target.
They were always supposed to stick a bit.

Cleaning the ball helps.

The peeps sights do align.

Or you align them.

All table top scopes work better on a stable mount.

Best on a platform top tripod.
So they can be used either way.

I did lots of ball cleaning, and the felt did more than stick a bit. At 16x it didn't matter much. At 30x it started to matter. As for the peep site, mine had the plier marks to prove I aligned them. My complaint with the mount was that the attachment point was not stable. You could buy another tripod attachment gizmo, but I never tried that, as it was fairly expensive.

 

I think it would be good to compare the Astroscan with current, relatively non-cute compact Newtonians. There is the Astronomers without Borders One Sky (also sold under the Skywatcher label outside the U.S.). It comes with a good finder and a Dob. mount. Even better, the scope connects to the mount by means of a standard Vixen dovetail bar. It also collapses for easier packing and storage. That's good design. If Edmund resurrects the Astroscan, this is the kind of scope it will compete against. I know which one I would recommend.

[Mitrovarr]

The Astroscan is unique and there are a couple of things you can do with one you can't do with a mini-dob, but for most users I'd go for the mini-dob all the way. You can tension a mini-dob to use arbitrarily heavy eyepieces, or attach weights to the tube to balance it. You can collimate a mini-dob. It can be placed on a different mount. A mini-dob doesn't have a optical window to fog up. You can change out the focuser or the finder more easily. There are probably other reasons too.

 

The main advantages to the Astroscan are the high durability (it makes a really good scope for kids) and the extreme portability (I think it's smaller than a mini-dob). I've gotten away with using it as a lap-scope, which you certainly can't do with anything else (you can use it in bed if you have a suitably placed window, which I did a lot in college when I had a nice south-facing window and the winters were brutally cold). But I'd say the mini-dob has more advantages for the average user. Or, maybe some other alternative - the replacement I have for my Astroscan is a ST120, which has more aperture, doesn't have obstruction, doesn't have coma, and has a 2" focuser. Just as far as wide field scopes go, I think either a fast refractor (apo if you can afford it, achro if you can't) or a 6" F/5 reflector (which, crucially, can have a 2" focuser - this both widens up the field and allows the use of a paracorr) is probably the actual best option.

[izar187]

 

Well, they simply were not 80mm f11 scopes.

Which is a very optically friendly, capable scope.

The comparison was made at the center of the field, where differences of f-ratio are minimized.

 

At f4, plossl's, ortho's, and RKE's each behave a little differently.

Ortho's are the general winner to my eye.

RKE's are in last place.

Again, the comparison was made at the center of the field, where differences of f-ratio are minimized.

 

The felt pads were felt pads, to hold the scope on target.
They were always supposed to stick a bit.

Cleaning the ball helps.

The peeps sights do align.

Or you align them.

All table top scopes work better on a stable mount.

Best on a platform top tripod.
So they can be used either way.

I did lots of ball cleaning, and the felt did more than stick a bit. At 16x it didn't matter much. At 30x it started to matter. As for the peep site, mine had the plier marks to prove I aligned them. My complaint with the mount was that the attachment point was not stable. You could buy another tripod attachment gizmo, but I never tried that, as it was fairly expensive.

 

I think it would be good to compare the Astroscan with current, relatively non-cute compact Newtonians. There is the Astronomers without Borders One Sky (also sold under the Skywatcher label outside the U.S.). It comes with a good finder and a Dob. mount. Even better, the scope connects to the mount by means of a standard Vixen dovetail bar. It also collapses for easier packing and storage. That's good design. If Edmund resurrects the Astroscan, this is the kind of scope it will compete against. I know which one I would recommend.

 

I was able to use Edmunds attachment gizmo back in the day.

Perhaps there was some application where it was useful, but observing on a tripod was not the one. IMHO

The only tripod set up worth a toot with the Astroscan, IME, was a raised platform for the ball base to sit on(or in).

On the order of what folks build nowadays for their Star Blasts, where they are keeping the one arm dob mount.

 

Regarding the Astroscan itself:

Most of the other scopes that have replaced it's niche, like the AWB you mention, and the scopes mentioned by Mitrovarr,

simply weren't around at the end of the '70's when the Astroscan came out.

 

In my experience, a 6" f5 newt is a way way more better scope.

And apples to oranges in comparison to the Astroscan also. 

 

From the for what it's worth department...

I pulled a vintage '79 one out of storage the other morning to peek at Jove, because of this thread.

About 5am, 26 F degrees, though an opening in the trees, over a roof, from on a car hood, about 10 min cool down.

3.9mm Siebert SS, Baader Neo filter, approx 114x.

 

Jove was just outside the ep fov in the peep site, as I expected, and was good, because I'd just brought out that ep.

Ganymede, Io and Callisto were out doing their thing, Europa was not.

A bit of differing apparent size and hue to them, but none of them sharp in focus.

I identified them by position, after the fact on http://www.shallowsky.com/jupiter/

 

Jove showed the common layered cake appearance you can get with lower planetary magnifications.

EZ, NEB, SEB, diminishing away to a belt and zone or two more above and below, but not well defined at all.

It was impossible to determine any structure in the EZ.

 

After 5 minutes or so, packed up and went back in side.

I was not dressed for the temp, the car was covered with frost which meant the scope would be too.

In another 15 minutes Jove would be in the trees.

And the image was just not that revealing.

4" on Jupiter is lots more fun, with fine focus adjustment, higher magnification, a stable mount(cars wiggle), a chair...

... and honestly more than 4" of aperture.

Edited by izar187, 03 January 2017 - 02:19 AM.

[Mitrovarr]

On a side note, I've bolted my Astroscan's base to a cheap tripod that came with a Meade DS scope (which I got from a garage sale for almost nothing). It does a fine job, and allows higher magnification than tabletop use. One thing you realize when you start to use a tripod is just how awkward tables are, even if they're stable; they almost always interfere with head positioning and scope rotation.

 

To remedy my Astroscan's lack of finder (I have one of the oldest ones with no peepsight or anything) I double-sided taped a red dot sight to the ball. Works great.

[halx]

Mounting the Astroscan on any mount type or making one (attaching to the base or to the OTA directly) is a no-brainer, as it provides three sturdy 1/4x20 attachment points. To convert it into the dob - one could make a usual fork stool with round windows / dimples in the sides accepting the ball with a tensioner / clamping rod underneath.

I've made a very convenient and compact chair attachment for it in the matter of a couple hours: 

 

[aatt]

I have found my Scan, after the secondary fell off and I rehabbed the scope, to be a better scope than I first thought.I think it is a China scope. I just used it the other night to look at The Rosette nebula with an UHC filter in yellow zone skies and saw the best view of it ever. It is not wonderful for planetary viewing, but for wide field DSO it is a fun scope and, like binocular astronomy, provides a perspective that you cant get otherwise. My Scan has been able sustain magnifications of over a 100x and still get decent images. With some exceptional seeing in Florida last year I got somewhere in the upper 100s.The  Scan was starting to show the strain at that mag, but I stuck with it because the seeing was so good that the optics issues did not matter.The other night I found that using an ES 24 mm 68 degree eyepiece and an ES 11mm was a bit much for the focuser.I had to actually pull on the focuser tube to get it to travel right.Not a big deal to do, but not real convenient either.It likes lighter eps for sure. It is not my goto scope as a rule, but if I am traveling with limited space or feel like a quick wide field peek, I have found it to be a capable, fun and valuable tool in my astro kit. M82 and 81 looked pretty good this last weekend nesting amongst a pretty wide field and it is nice to see the Veil in its entirety too. Cant do that in either of my dobs!

[Peter Besenbruch]

I was able to use Edmunds attachment gizmo back in the day.

Perhaps there was some application where it was useful, but observing on a tripod was not the one. IMHO

Bummer! I always wondered whether those things worked, or not.

​

 

Regarding the Astroscan itself:

Most of the other scopes that have replaced it's niche, like the AWB you mention, and the scopes mentioned by Mitrovarr,

simply weren't around at the end of the '70's when the Astroscan came out.

​

Speaking of a blast from the past, do you remember the Coulter CT-100?

​I never got a chance to look through one, but that was a very different approach.

​

 

In my experience, a 6" f5 newt is a way way more better scope.
And apples to oranges in comparison to the Astroscan also.

From the for what it's worth department...
I pulled a vintage '79 one out of storage the other morning to peek at Jove, because of this thread.

About 5am, 26 F degrees, though an opening in the trees, over a roof, from on a car hood, about 10 min cool down.
3.9mm Siebert SS, Baader Neo filter, approx 114x.

 

​

​A 6" is a lot better in terms of light grasp and resolution. I used the OneSky as an example, because it is smaller, and packs down smaller still. As for the Astroscan, mine would not have tolerated 114x even in warm temperatures. The Baader M&SG is another thing that wasn't there in the 1970s.

​

[izar187]

 

 

I was able to use Edmunds attachment gizmo back in the day.

Perhaps there was some application where it was useful, but observing on a tripod was not the one. IMHO

Bummer! I always wondered whether those things worked, or not.

​

 

Regarding the Astroscan itself:

Most of the other scopes that have replaced it's niche, like the AWB you mention, and the scopes mentioned by Mitrovarr,

simply weren't around at the end of the '70's when the Astroscan came out.

​

Speaking of a blast from the past, do you remember the Coulter CT-100?

​I never got a chance to look through one, but that was a very different approach.

​

 

In my experience, a 6" f5 newt is a way way more better scope.
And apples to oranges in comparison to the Astroscan also.

From the for what it's worth department...
I pulled a vintage '79 one out of storage the other morning to peek at Jove, because of this thread.

About 5am, 26 F degrees, though an opening in the trees, over a roof, from on a car hood, about 10 min cool down.
3.9mm Siebert SS, Baader Neo filter, approx 114x.

 

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​A 6" is a lot better in terms of light grasp and resolution. I used the OneSky as an example, because it is smaller, and packs down smaller still. As for the Astroscan, mine would not have tolerated 114x even in warm temperatures. The Baader M&SG is another thing that wasn't there in the 1970s.

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Back in the day, the best boost I found for one was a 2.8x Klee.

For adding focal length, correcting astigmatism, increasing eye relief, with the least moment arm added to the focuser.

Though not perfection, still a very usable 150x for planets and doubles, within the limits of a 4" short newt.

[Peter Besenbruch]

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Back in the day, the best boost I found for one was a 2.8x Klee.

For adding focal length, correcting astigmatism, increasing eye relief, with the least moment arm added to the focuser.

Though not perfection, still a very usable 150x for planets and doubles, within the limits of a 4" short newt.

In addition to mine, there were two others in use in our club in the mid 80s. All were a bit fuzzy at 50x. You got lucky, it seems.

[Mitrovarr]

I think mine can make it to about 130-150x. It's kind of hard to tell exactly how far you can take an astroscan because they have real problems focusing and tracking at very high power, and unless you go out of your way to get eyepieces and barlows specifically for that you are unlikely to have the right stuff to get to those powers anyway.

I mean, to take an astroscan to 200x, you need either a 2mm eyepiece (yikes) or a 4mm eyepiece (still pretty uncommon) and a 2x barlow that actually works with the astroscan.

[izar187]

I had a Klee 2.8x just for the Astroscan.

With light weight ep's it worked well for me, to get to something higher magnifications.

A specialized tool, for a specific use.

 

You're right about the tracking.

It's most often necessary to line up the scope, and wait for the target to enter, cross and the exit the fov.

Consecutive passes, while you accrue target details.

 

As with all table top scopes, stability of table is pretty important.

Or it gets tedious fast at these kinds of magnifications, in this kind of scope.

Car hoods frequently aren't up to the task, due to wind shaking the car, and the person too, leaning against it.

Which you don't realize until you get up to higher magnification.

 

The only 4mm I've used in this scope is my 3.9mmSS3, where it works very well.

http://www.siebertop...rtho page).html

But it is too much moment arm in the focuser when with a barlow( 2x or 1.5x) for this scope. IME

There is a 1.9mmSS3, though I have no experience with it.

 

There are some 4mm plossl's out in the world.

Perhaps someone has tried one with a 2x shorty barlow, in this scope.

Edited by izar187, 08 January 2017 - 01:07 PM.

[skycreep]

I have an older made in Japan version.

Excellent little scope.

It's actually perfect for what it does.

Grab and go outside and sit down at the picnic table. 

I use my radians from 4mm to 18mm.

On really good nights (not that often), I can use the 3mm.

Mr favorites are the the 6mm and 8mm.

They seem to work really well no matter what the seeing conditions.

I've never had any of the problems mentioned above.

Not just perfect for kids...

Every now and then, I'll throw in the 28mm RKE.

Something magical about the 28, but just not enough power...

[StreamedOnline]

You got to admit.  Its an icon of a telescope, Great learning, Easy to use and lots of fun.    Bring back the ASTROSCAN I say.