108 replies to this topic

[ericb760]

Here’s a pic of the one I mean:

I have owned the 90mm Firstscope on that same mount. The 80 and 90 share the same sized OTA. Truthfully, that EQ-2 mount (or its equivalent) is vastly underpowered for this size OTA. It shakes in the slightest breeze and takes forever to settle down after the smallest bump. I still have the Japanese made C80 but I use it alternatively on a Vixen Polaris mount on a wooden tripod or a Celestron/Meade AZ-3 mount on the aluminum one. I like the aluminum tripods for their weight and transportability. When paired with a decent mount they work fine. If you do buy this one I highly recommend upgrading to a more robust mount. here is a pic of a Meade 80mm on the AZ mount.

[Look at the sky 101]

ah how I would love to have another one, it was my first telscope.
very good for starting out in astronomy.

[GeneDiG]

Here’s a pic of the one I mean:

That's the Synta made version. While I do not own a Vixen model, I like my Synta made 80EQ. The EQ2 mount does OK, it could be better. Mine is on wooden legs which I think helps.

[Bomber Bob]

very good for starting out in astronomy.

 

Yes, it is.  I started this insanity at age 8 - too young for a C80.  But by 13, I was responsible enough for one - I babied my Sears 60 F15 EQ.  An SP-C80 would've set me up for at least a decade - maybe two.

[LU1AR]

I have owned the 90mm Firstscope on that same mount. The 80 and 90 share the same sized OTA. Truthfully, that EQ-2 mount (or its equivalent) is vastly underpowered for this size OTA. It shakes in the slightest breeze and takes forever to settle down after the smallest bump. I still have the Japanese made C80 but I use it alternatively on a Vixen Polaris mount on a wooden tripod or a Celestron/Meade AZ-3 mount on the aluminum one. I like the aluminum tripods for their weight and transportability. When paired with a decent mount they work fine. If you do buy this one I highly recommend upgrading to a more robust mount. here is a pic of a Meade 80mm on the AZ mount.

A simple, economical and easily reversible solution; It would be to hang a thick chain inside the pier.
The nature of the chain -together with its weight- makes it accommodate vibrations and puts them out of phase. At the same time; the friction between the links, exhausted it.
Those of us who enjoyed those long Japanese refractors in the 60's; We know that hanging a chain from the front, was the solution to those weak mounts.
Hope this can help you.
Edgardo

[sneeds]

I can also run my eq-2 in alt-az mode which tends to help as well.

 

So Synta Firstscope 80 optics are generally good?

Edited by sneeds, 31 May 2024 - 10:33 AM.

[Princess Leah]

A simple, economical and easily reversible solution; It would be to hang a thick chain inside the pier.
The nature of the chain -together with its weight- makes it accommodate vibrations and puts them out of phase. At the same time; the friction between the links, exhausted it.
Those of us who enjoyed those long Japanese refractors in the 60's; We know that hanging a chain from the front, was the solution to those weak mounts.
Hope this can help you.
Edgardo

Good idea.

Inside the pier?

Where is the pier in an EQ2 mount?

[Princess Leah]

I have owned the 90mm Firstscope on that same mount. The 80 and 90 share the same sized OTA. Truthfully, that EQ-2 mount (or its equivalent) is vastly underpowered for this size OTA. It shakes in the slightest breeze and takes forever to settle down after the smallest bump. I still have the Japanese made C80 but I use it alternatively on a Vixen Polaris mount on a wooden tripod or a Celestron/Meade AZ-3 mount on the aluminum one. I like the aluminum tripods for their weight and transportability. When paired with a decent mount they work fine. If you do buy this one I highly recommend upgrading to a more robust mount. here is a pic of a Meade 80mm on the AZ mount.

What is the outer diameter of your Japanese C80? It's usually quoted as 9cm, but I always think it looks bigger than the Meade which is also 9cm. Some sort of optical illusion?

[ericb760]

What is the outer diameter of your Japanese C80? It's usually quoted as 9cm, but I always think it looks bigger than the Meade which is also 9cm. Some sort of optical illusion?

I use the same set of 90mm rings on both the Meade and the Celestron OTA's.

[Princess Leah]

This is also 9cm (the blue Omcon), looks as slim as your Meade. But the C80 looks more chunky to me. Perhaps it's a shorter tube, with a longer rack and pinion?

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[Princess Leah]

Some kind soul, could perhaps salve my unusual curiosity in such matters. One could sacrifice a small percentage of their day, and place a small wooden stick, with equidistant units, portrayed by numbers (also known as a ruler). That said wooden stick, would then reveal to a degree of precision, that would undoubtedly be of goodly satisfaction, the lateral distance involved, from one side of a C80 (Vixen) to the other.

[ericb760]

Some kind soul, could perhaps salve my unusual curiosity in such matters. One could sacrifice a small percentage of their day, and place a small wooden stick, with equidistant units, portrayed by numbers (also known as a ruler). That said wooden stick, would then reveal to a degree of precision, that would undoubtedly be of goodly satisfaction, the lateral distance involved, from one side of a C80 (Vixen) to the other.

[Princess Leah]

Very kind of you Eric. Thanks  

[Princess Leah]

 

Is that the Meade. Or Celestron C80 in blue?

[ericb760]

Is that the Meade. Or Celestron C80 in blue?

That is the Vixen/Celestron C80, but my Meade #310 is the exact same diameter.

[Princess Leah]

Thanks Eric. I've never seen a blue Celestron C80 before. My friend has a black Celestron C90 vixen/firstscope and the tube measures 100mm in width.

Seems to be some variation, as others have reported the C90 firstscope using the same tube as the C80.

The black Celestron tubes of the 80s always look like 100mm wide OTAs to me in pictures. 

[Princess Leah]

I have just measured a black C80 'premium' Vixen made. It also measures 9cm. However it looks wider to me. Some kind of optical illusion.  I would have thought black would have made it look slimmer.

[Kasmos]

I have just measured a black C80 'premium' Vixen made. It also measures 9cm. However it looks wider to me. Some kind of optical illusion.  I would have thought black would have made it look slimmer.

None of the Celestron C80s were Blue. It's the lighting and or the camera making you think it is.

[jacklee]

Hello everybody,

    I just joined this group ( Cloudy night ) &  I saw this forum " Firstscope 80 Celestron ). Yesterday I bought a used 80 AZ, with black wooden AZ tripod for $40 at Craigslist. I am cleaning the dirty objective lens now. I have it out, but I saw 3 small white spacer inside the lens edges. Maybe this objective lens got 2 elements. Got dust inside. Any advice will be highly appreciated. Thanks. 

[grif 678]

The spacers need to be there. If you have to take apart, put pencil marks on the edge of the lenses where the spacers go, also put arrow marks on the edge of each lens, so you will have each lens turned the right way when you put it back. There are posts somewhere here on CN, with photos showing how to mark the lenses before you take them apart. I would find that before I would attempt to take them apart, because if you turn one of the lenses the wrong way, you have a mess. If you can not find that photo, just make a post here on Classics, asking someone to show a picture or photo of how to mark your lens.

[starman876]

I was looking at a celestron firstscope 80 from what I found on the web was I believe model 21075 on the label it said made for celestron in Japan I’m trying to find more specific is it worth getting

there is an old cometron on facebook.  

[Princess Leah]

I've just recently acquired a Celestron C80 that is made in China. It has better coatings/light throughput than my Japanese C80.
Optically it seems somewhat better than the Japanese version which suprises me.
The tube is 9cm wide, but is somewhat lighter than the Japanese equivalent.
Anyone else have an early Chinese C80 to compare?

[deSitter]

I've just recently acquired a Celestron C80 that is made in China. It has better coatings/light throughput than my Japanese C80.
Optically it seems somewhat better than the Japanese version which suprises me.
The tube is 9cm wide, but is somewhat lighter than the Japanese equivalent.
Anyone else have an early Chinese C80 to compare?

Automatically generating nice achromats has become easy it seems. But check the smoothness - the Vixen is probably still much better there. You may just be seeing a brighter image from modern coatings. Which is important after all!

 

-drl

[jacklee]

The spacers need to be there. If you have to take apart, put pencil marks on the edge of the lenses where the spacers go, also put arrow marks on the edge of each lens, so you will have each lens turned the right way when you put it back. There are posts somewhere here on CN, with photos showing how to mark the lenses before you take them apart. I would find that before I would attempt to take them apart, because if you turn one of the lenses the wrong way, you have a mess. If you can not find that photo, just make a post here on Classics, asking someone to show a picture or photo of how to mark your lens.

Hi grif 678, 

           I will follow your suggestion. Thanks for replying and also thanks for that tips. 

[Princess Leah]

Automatically generating nice achromats has become easy it seems. But check the smoothness - the Vixen is probably still much better there. You may just be seeing a brighter image from modern coatings. Which is important after all!
 
-drl

Smoothness? You mean the focuser?
I compared it also with an uncoated Prinz 76mm F16. I rate this scope highly.
However the Chinese refractor gave a much sharper image - it was pretty obvious.
Perhaps it was just luck - will try again another night.