158 replies to this topic

[LDW47]

It appears as though Celestron offers 2 102 achros on altaz mounts. The 102AZ is on a photo tripod head design and the XLT 102 AZ on the one-arm style with slo-mo controls. I have the Omni one-arm version and it's ok for low power, fair for moderate power and . . . tedious. . . at high powers although the slo-mo controls help a lot. I suspect the photo head style would be more difficult to control.

When I looked they both appeared to have the better Omni mount ! Exactly how high a powers are ‘ tedious ‘ in relation to the recommended max power for that scope ? Also for the price, the size of that scope exactly how big, how pricey a mount should one get ?

[Auburn80]

When I looked they both appeared to have the better Omni mount ! Exactly how high a powers are ‘ tedious ‘ in relation to the recommended max power for that scope ? Also for the price, the size of that scope exactly how big, how pricey a mount should one get ?

I max it out with a 4mm so 160x and focusing for me is a chore. 7mm and longer eyepieces are ok. It's a light weight scope so I'm sure there are many mounts that could work better but I have no direct experience with incremental steps up from this mount. My most used manual mount is a 30 year old Vixen SP.

[LDW47]

I max it out with a 4mm so 160x and focusing for me is a chore. 7mm and longer eyepieces are ok. It's a light weight scope so I'm sure there are many mounts that could work better but I have no direct experience with incremental steps up from this mount. My most used manual mount is a 30 year old Vixen SP.

No wonder it is tedious at high powers, with those eps you are probably extending its visual capabilities beyond its working mag. limits ? Check the math just to know where that scope is at when it comes to capabilities, sure you can go beyond that but it starts to get tedious or just plain lousy performance / views !

[LDW47]

The math says that scope ie 102mm x 660mm has a power range up to 51x which equates to an ep of 13mm. You mentioned bumping up to 160x using a 4mm ep, that is more than 3x the calculated max power for that scope. What does that say in the big picture of life ? You use the word tedious so explain why you think it is ‘ tedious ‘, could it possibly be way overextending its capabilities ? Nothing wrong with pushing its limits but lets be a little realistic ! I would say under normal conditions the Nano or Omni but be great for the scope !

[sojourneyer]

It appears as though Celestron offers 2 102 achros on altaz mounts. The 102AZ is on a photo tripod head design and the XLT 102 AZ on the one-arm style with slo-mo controls. I have the Omni one-arm version and it's ok for low power, fair for moderate power and . . . tedious. . . at high powers although the slo-mo controls help a lot. I suspect the photo head style would be more difficult to control.

Such is not the case Auburn.  Both f/6.5 Omni scopes have the same side mount  and

slo mo controls.

 

I even chatted to Celestron about the mounts by phone in this regard. 

Here is the Costco photo of the non-XLT version

[sojourneyer]

The other strange issue is when researching the scope, everything points to the fact that it is / was mounted on a Celestron Omni mount which is about equivalent to the Nano, I have both of them for my g ‘n’ g scopes ! So why the mount shown, did I miss something along the route ?

That is what I said earlier.. the Nano is no better and perhaps not as good as the current

Omni mount/tripod. "I would stay with your original mount if it is no problem."

[Auburn80]

Such is not the case Auburn. Both f/6.5 Omni scopes have the same side mount and
slo mo controls.

I even chatted to Celestron about the mounts by phone in this regard.
Here is the Costco photo of the non-XLT version
celestron-omni-az-102-telescope-costco-1349499.jpg

This is the other 102AZ:

https://www.amazon.c...79558314&sr=8-1

Not the Omni of course but a Celestron 102AZ nonetheless. One has to be careful when referencing the 4" achros.

Edited by Auburn80, 20 January 2020 - 05:16 PM.

[sojourneyer]

The math says that scope ie 102mm x 660mm has a power range up to 51x which equates to an ep of 13mm. You mentioned bumping up to 160x using a 4mm ep, that is more than 3x the calculated max power for that scope. What does that say in the big picture of life ? You use the word tedious so explain why you think it is ‘ tedious ‘, could it possibly be way overextending its capabilities ? Nothing wrong with pushing its limits but lets be a little realistic ! I would say under normal conditions the Nano or Omni but be great for the scope !

I totally agree with you on the mount issue. 

 

As to magnification, according to Orion, their 90mm f/6.7 has a highest theoretical magnification of 180. 

According to Celestron "There are practical limits of magnification for telescopes. These are determined by the laws of optics and the nature of the human eye. As a rule of thumb, the maximum usable power is equal to 50-60 times the aperture of the telescope (in inches) under ideal conditions. Powers higher than this usually give you a dim, lower-contrast image. For example, the maximum power range on a 90 mm telescope (3.6 in aperture) is 180x-216x. As power increases, the sharpness and detail seen will be diminished. Higher powers are mainly used for lunar, planetary, and binary star observations"

 

I do  not take my  Omni above 150

[Auburn80]

No wonder it is tedious at high powers, with those eps you are probably extending its visual capabilities beyond its working mag. limits ? Check the math just to know where that scope is at when it comes to capabilities, sure you can go beyond that but it starts to get tedious or just plain lousy performance / views !

Nah. That's 40x per inch and filled with CA but can still provide detail on Jupiter if one is very careful with focus. I normally use it between 25x and 75x.

[LDW47]

That is what I said earlier.. the Nano is no better and perhaps not as good as the current

Omni mount/tripod. "I would stay with your original mount if it is no problem."

But you don’t know if it is or not unless you have tried them yourself. Do you always go by what others say, incl. me . What actual experience goes with ‘ That is what I said ‘

[LDW47]

Nah. That's 40x per inch and filled with CA but can still provide detail on Jupiter if one is very careful with focus. I normally use it between 25x and 75x.

Thats OK but just expect some ‘ tedious ‘ thats what I am saying ! We are talking the mount performance not the scope, aren’t we ? At those high powers way above spec. any shakes in the mount will be beyond the normal into the realm of ‘ tedious ‘as you called it, its an excepted fact !

Edited by LDW47, 20 January 2020 - 05:30 PM.

[sojourneyer]

This is the other 102AZ:

https://www.amazon.c...79558314&sr=8-1

Not the Omni of course but a Celestron 102AZ nonetheless. One has to be careful when referencing the 4" achros.

You are mixing apples with bananas Auburn.

 

Lets set the record straight...

 

Celestron has several versions of the OMNI: short focal length f/6.5 and

longer focal length f/9.8.

 

The f/6.5 has two versions -

1)coated with XLT (called the  Celestron 22150 Omni XLT AZ 102mm), and

2)one coated with standard Celestron coatings (the Celestron 22155 Omni AZ 102)

 

The former, I believe, Celestron is not selling because it is no longer on their webpage

 

The latter was sold exclusively by Costco

 

It appears that currently Celestron is only offering the Omni 102 XLT  f/9.8 on an equatorial mount.

 

Celestron has two other 4 inch scopes.

 

1) Celestron - AstroMaster 102AZ Refractor Telescope 

This one probably has the same coating as the  22155

It is mounted on a cheaper mount (Manual altazimuth telescope and with pan handle control for smooth and accurate pointing.)

 

2) Celestron Inspire 100AZ Refractor which has a pan handle mount as well

 

I hope this helps out in understanding their scopes

[Jond105]

If your looking at the nano I’d look at the Orion Versago ii instead. They’re on sale right now and it’s what I use with multiple scopes just fine. 

[Auburn80]

Thats OK but just expect some ‘ tedious ‘ thats what I am saying ! We are talking the mount performance not the scope, aren’t we ? At those high powers way above spec. any shakes in the mount will be beyond the normal into the realm of ‘ tedious ‘as you called it, its an excepted fact !

Yes, the mount performance. Although the focuser is a bit stiff; it's quite useable as is. Wasn't expecting more than it delivers so not disappointed; primarily because I got it on sale a couple of years ago. Glad I didn't pay retail.

[sojourneyer]

Yes, the mount performance. Although the focuser is a bit stiff; it's quite useable as is. Wasn't expecting more than it delivers so not disappointed; primarily because I got it on sale a couple of years ago. Glad I didn't pay retail.

the f/6.5 Omni in either versions is a darn good scope for the price.  I would not call it a "throw down"... It deserves better

LOL

 

And the mount is not that bad.  Remember my counter balance proposition.

 

If your looking at the nano I’d look at the Orion Versago ii instead. They’re on sale right now and it’s what I use with multiple scopes just fine. 

Jon

That option weighs 13 lbs and has a weight rating of 15 lbs

It does not have slo mo , just pan handle control

I think the Omni mount is better

[Auburn80]

@sojourner, I was not confused. I was trying to point out that there were more than one version of the 102 (usually the f6.5) on an alt az mount and others seemed to be getting the various versions mixed up. Several references were made to 102AZ and didnt mention Omni or f ratio or XLT.

Yea, it looks like they've dropped that line altogether.

Edited by Auburn80, 20 January 2020 - 05:52 PM.

[sojourneyer]

If you decide to add a crayford, use a 2" dielectric diagonal, want to use the cell phone with the metal adapter

then you might be testing the end limits of the Omni mount

[sojourneyer]

For information sake, Amazon sells a tripod  called the Celestron Heavy-Duty Altazimuth Tripod

 

I spoke to technicians at Celestron and they said this mount/tripod is inferior to the Altaz mounts on

the f/6.5 Omnis

Attached Thumbnails

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[Auburn80]

the f/6.5 Omni in either versions is a darn good scope for the price. I would not call it a "throw down"... It deserves better
LOL

And the mount is not that bad. Remember my counter balance proposition.

Jon
That option weighs 13 lbs and has a weight rating of 15 lbs
It does not have slo mo , just pan handle control
I think the Omni mount is better

Ha, "throwdown" for me just means an inexpensive lightweight easy gng. Not throw away.

[sojourneyer]

@sojourner, I was not confused. I was trying to point out that there were more than one version of the 102 (usually the f6.5) on an alt az mount and others seemed to be getting the various versions mixed up. Several references were made to 102AZ and didnt mention Omni or f ratio or XLT.

Yea, it looks like they've dropped that line altogether.

The short tube Omni 102mm were a very popular telescope, especially for grab and go.

I wonder why Celestron is being so short sighted on this because it has become a big

trend with amateur astronomers

[sojourneyer]

Ha, "throwdown" for me just means an inexpensive lightweight easy gng. Not throw away.

I thought this was a UFC version for Omni  to challenge Conor McGregor

[sojourneyer]

Auburn, go to post 34, which was in 2015

Note how the mount/tripod has changed significantly

[LDW47]

I totally agree with you on the mount issue. 

 

As to magnification, according to Orion, their 90mm f/6.7 has a highest theoretical magnification of 180. 

According to Celestron "There are practical limits of magnification for telescopes. These are determined by the laws of optics and the nature of the human eye. As a rule of thumb, the maximum usable power is equal to 50-60 times the aperture of the telescope (in inches) under ideal conditions. Powers higher than this usually give you a dim, lower-contrast image. For example, the maximum power range on a 90 mm telescope (3.6 in aperture) is 180x-216x. As power increases, the sharpness and detail seen will be diminished. Higher powers are mainly used for lunar, planetary, and binary star observations"

 

I do  not take my  Omni above 150

I’m stickin with my math and my source, any time you deal with theoretical numbers it doesn’t work in real life, most times, say 99% ! To many real time variables, take some advice take theoretical with a grain of salt not gospel !

[Auburn80]

the f/6.5 Omni in either versions is a darn good scope for the price. I would not call it a "throw down"... It deserves better
LOL

And the mount is not that bad. Remember my counter balance proposition.

Jon
That option weighs 13 lbs and has a weight rating of 15 lbs
It does not have slo mo , just pan handle control
I think the Omni mount is better

Ha, "throwdown" for me just means an inexpensive lightweight easy gng. Not throw away.

[Auburn80]

The math says that scope ie 102mm x 660mm has a power range up to 51x which equates to an ep of 13mm. You mentioned bumping up to 160x using a 4mm ep, that is more than 3x the calculated max power for that scope. What does that say in the big picture of life ? You use the word tedious so explain why you think it is ‘ tedious ‘, could it possibly be way overextending its capabilities ? Nothing wrong with pushing its limits but lets be a little realistic ! I would say under normal conditions the Nano or Omni but be great for the scope !

I'd be curious to learn what math you mean that yields 51x?