Ok, I admit, I still don't get it!

[FLO]

66mm astro scopes, you know the ones, from GSO but sold in various guises. Their owners really like them but I can't see beyond the small 66mm aperture.

I had an 80mm refractor a while back. It was good fun and great for holidays but ultimately (for regular observation) it was a '1 hour scope'... After an hour, I'd used up all the targets that were worth looking at.

Perhaps it is an imaging thing? Perhaps its an astro 'Spotting scope'? Perhaps if I could better understand their attraction, I might sell more of them!

What am I missing, please?

[GordonCopestake]

I dont think you are missing anything Steve, you've got it in one: They are 1 hour scopes. For those nights when you only want to be out for an hour and you dont want it to take you more than 5 mins to setup. Grab and go for the masses.

Plus theres the imaging thing too, nice wide FOV and all that.

That being said I had an ED80 and whilst I loved it, the change to a 12" dob was like going from being blind to having 20/20 vision!

[GazOC]

As a visual obsever, 80mm is absolute minimum and at least 100mm is prefered IMO.

I know a lot of people use the 66mm scopes to pull double duty for birding and taking on walks to look at scenery as well as astronomy.

But, no, for astro work I don't 'get it' either.

[Tinkerbell]

The answer is a dark site. Looking through any scope from a moderately light polluted site can be hit or miss and the 66 and 80 is more miss than hit.

After being introduced to an 80 at a very dark site I bought one as it was astounding what could be seen, I must admit that an 80 was going to be acquired for the 350D anyway but the views were amazing just using the Mark 1 eyeball. Now I can get those views from a not so dark site with the 350D :shock: I also agree with the one hour thing as well

[Jamie]

Steve its just MHO here but 66mm scopes are only good for

guiding and imaging not observing.

Like i say just my opinion....

[Kaptain Klevtsov]

Steve, it's got to be an imaging thing I think. I am even struggling with the bigger chip Atik camera as the bit of sky that I can aim it at in the big 'scopes is still tiny. I grabbed a baby ST80 f/5 as it was really cheap a while ago, and while the DSLR images are poor, the narrow band performance is outrageous. It's still only pointing at a little bit of the sky, but I can almost get it in my pocket! Even a short focal length "proper" 'scope like the ED80 has just too much magnification for a lot of the stuff up there.

I imagine that one of these baby proper 'scopes would be fantastic with a mid-range CCD like the 16HR as it would allow me to bag loads of the fuzzies. Shame I just blew the dosh on the camera, or I might be looking for one myself. In fact I'm toying with replacing the (visually otstanding) OMC140 with something with a shorter FL and faster f/ ratio for imaging.

Guiding with a little 'scope seems such a waste, as these exotic ED 'scopes are much more spendy than an achro, and you don't need an APO as a guide 'scope.

Captain Chaos

[GordonCopestake]

You on the look out for a Tak 60 then CC hehe

[Kaptain Klevtsov]

Could be tempted by an ED80 with a better focuser plus some pound notes to replenish the back pocket Gordon.

My biggest problem is that I wouldn't dare stick the Mak. in the post, even though it arrived that way.

Captain Chaos

[GordonCopestake]

You'de be suprised how well optics survive the post. I always hate sending glass via royal mail but have had no problems so far. The worse that seems to happen is collimation goes. Although a C8 i had never lost collimation despite 2 journeys with Parcel Farce.

The ED80 with a WO Focuser is a thing of beauty. A big beast though for an 80mm scope.

[MartinB]

Agree with the 66mm comments. I am very pleased with my ZS66 doublet but even that needs a 0.67 reducer to fully frame M31 and the Rosette for instance. Imaging at short focal length is a joy - very forgiving and you can capture some of the best targets up there. I've rarely actually looked through it accept for alignment. Moon looks nice with excellent colour correction..

I just don't get this phobia about the Synta crayford though. The big problem has been that the bearing surface to the drawtube isn't always flat which means some have had problems slipping when loaded with a heavy camera at the zenith. I have never had any problems with this despite loading it with chunky camera, reducer and filter wheel. Sure it's not as nice as the dual speed WO jobby but in practice I have no difficulty nailing the focus.

[John]

I just don't get this phobia about the Synta crayford though.

It's more of an issue with the ED100 than the ED80 I have found - that maybe because the drawtube in the ED100 is much longer.

John

[MartinB]

Guess the longer focal length will show up any coarseness of movement more as well.

[Macavity]

I suspect those "posh" 66mm scopes are fairly accurate in their spec. I feel the odd (well my) ST102 is more like ST ninety-something? I once tried to "draw it out" on paper. I did sense e.g. the internal baffles were in about the right place. I did occasion to wonder about that draw tube though. Did it intercept the light cone as it moved inwards? Still, the idea of "dramatic surgery" never really grabbed me...

[Greg]

Although I wouldn't go for a 66 Apo myself there's obviously a market for them in the imaging department.

Saying that you wouldn't bother with them visually depends on where you live. A 66mm APO in a dark sky (As a compact grab'n'go). Would give better views than an 80mm Apo in the city...

Don't knock it till you try it I suppose...

Now if someone was to give me one........

[John]

I did occasion to wonder about that draw tube though. Did it intercept the light cone as it moved inwards? Still, the idea of "dramatic surgery" never really grabbed me...

I started a thread about this a while ago - I wondered the same thing. I'm not sure we ever reached a statisfactory answer. As I see it the internal end of the drawtube in a refractor is a kind of movable baffle, the question being, as you say, does it intercept the light cone from the objective when it's within it's normal range of movement ?. I suppose you could work it out by tracing the optical path.

I'm getting an ST100 shortly - I might just try that.

John

[Rob]

As a new 66 owner. I'm in a fairly dark site (Home), with the New Forest 35mins away!. The 66 Petzval has beaten the 80mm Sentinal on colour correction and magnification... also I can bung it on my Bresser 6000 camera mount for 45mm grab n go!. It also compliments my C8 in the FOV dept.

Its well built, nice dual focuser, great colour correction, suprised on DSO performance for 66mm!!. Large FOV. Goes on the camera mount, fair on planets, great on the moon.

Win,win,win as a second grab n go scope. Would not have it as my only scope. And at a £150 inc del it beats a Achro 80mm!!!

[FLO]

I guess the scope you have with you is better than the one left at home.

And if it has jewel-like construction and APO optics, even better 8)

[AndyH]

"I dont think you are missing anything Steve, you've got it in one: They are 1 hour scopes. For those nights when you only want to be out for an hour and you dont want it to take you more than 5 mins to setup. Grab and go for the masses."

"As a new 66 owner. I'm in a fairly dark site (Home), with the New Forest 35mins away!. The 66 Petzval has beaten the 80mm Sentinal on colour correction and magnification... also I can bung it on my Bresser 6000 camera mount for 45mm grab n go!. It also compliments my C8 in the FOV dept.

Its well built, nice dual focuser, great colour correction, suprised on DSO performance for 66mm!!. Large FOV. Goes on the camera mount, fair on planets, great on the moon.

Win,win,win as a second grab n go scope. Would not have it as my only scope. And at a £150 inc del it beats a Achro 80mm!!!"

I agree with the above posts. I have the Astro-Tech 66mmED in anodised green (mmm) and use it 70%/30% daytime/astro. Colour free when viewing raptors etc against a bright background. Tiny case and fits on a tiny manfrotto tripod. Great for squeezing into an already packed out car when going on holiday etc.

Great secondary astro scope, but would steer a newbie away to a bigger scope for a first purchase, unless he/she is also a birder. My dad has the mega expensive Leica birder. I don't have the heart to say I don't see any difference between it and my A-T.

Andy.

[FLO]

I really must try one 8)

[Rob]

A good example was tonight Steve... 10.45pm suddenly a nice clear sky, I'd already downed a nice curry and a bottle of shiraz!!.

Jumped outside with the 66 on the Bresser tripod and took in 30mins of light targets!.

Saturn was nice through the scope using a 9mm Ortho & my 2x Orion ED Barlow... fair bit of detail available there!!!!

Rob

[Greg]

Jumped outside with the 66 on the Bresser tripod and took in 30mins of light targets!.

Nice one Rob..

Sometimes we get a bit carried away with imaging, GOTO and the complexity of sometimes a very simple and rewarding hobby....

Grab 'n' Go..How about Get out 'n' Look

[Rob]

Jumped outside with the 66 on the Bresser tripod and took in 30mins of light targets!.

Nice one Rob..

Sometimes we get a bit carried away with imaging, GOTO and the complexity of sometimes a very simple and rewarding hobby....

Grab 'n' Go..How about Get out 'n' Look

Indeed mate!

[MartinB]

Sometimes we get a bit carried away with imaging

:shock: no not me guv. Must put an eyepiece in mine sometime

[Brass n glass]

This has been a fascinating thread and here's my two penn'orth. Observation for me ranges across wildlife, astronomy and the world of the microscope. The only reason why I forked out the terrifying sum demanded for my TV76 is that I believe it's probably the closest thing there is to a true crossover scope, powerful enough for useful observational astronomy and tough enough to survive a bit of unkind weather and the occasional knock against a rock when watching wildlife. Also, like other small fast refractors, it can focus on fairly close objects. I was out in a field recently looking at Mercury when a fallow buck appeared in a gateway about 100m away and stared at me for a short time. I just managed to get the scope onto it and caught it full-on for a few seconds. A truss dob would have been useless at that moment and wouldn't have done much more than the little frac with Mercury, either.