31 replies to this topic

[kqle]

Hi All,

 

I'm just getting into astronomy viewing and telescopes.  I recently purchased the Celestron Omni AZ 102 refractor off of Costco's website.  (Maybe, I'll get a Dobsonian at some point.)  I've been doing some research on eye pieces and such and wanted to upgrade my eyepieces from the basic Kellner 10mm & 20mm that came with my purchase, but not overly spend too much.  I was looking into the SVBNY or Celestron X-Cel LX, so I don't break the bank like with a Tele Vue or Baader.  I am sticking to mostly viewing the moon, and planets with some basic easy to find star clusters & nebulas for now.

 

First off, does my Omni AZ 102 take 2" eyepieces?  I don't think it said in the product description when I made the purchase.  But, I remember a YouTube video review saying that it does take 2" eyepieces.

If so, should I invest in 2" eyepieces? I would also like to upgrade to a 90deg dielectric mirror diagonal.  Again, should I invest in a 2" mirror diagonal if my Omni is able to use one?

 

Second, can I replace the finder scope on this?  Or is the finder scope proprietary on this telescope model?  Does this telescope need an extra adapter in order to replace the finder scope?

 

Third, what are 2 or 3 eyepiece sizes should I get with a low power & high power suitable for my 660mm focal length with 200 max power?  I was looking at perhaps a 6-7mm for high power, and 20-25 for low power or 18mm? 

 

I like the idea of having wide angle field of view up from 57-68 degrees.  I'm also thinking of maybe getting a Zoom eyepiece like the SVBNY SV135 (60-40deg.) or the SV191 (65-42deg.) field of view.  Is a 65deg much of a difference compared to a 60deg?  Could I use a 2x or 3x Barlow with the Zoom eyepiece?

 

Finally, any other upgrades I should consider for this telescope but not as to break the bank, at least for now.

Thank you all for any feedback and suggestions.

[Oldfracguy]

Yes, this scope does take 2" eyepieces.  I used to have one:

 

 

 

The finder scope mounting slot that is cast into the upper left side of the focuser is a Vixen/Synta type, so any finder scope with a Vixen dovetail on its stalk will slide right in.

 

If you decide to keep your Costco AZ 102, then the Baader #2956256 Clicklock visual back is one option you might consider to replace the visual back on the end of the focuser drawtube with those tiny thumbscrews.  Here is the one to get:

 

https://agenaastro.c...56-2956256.html

 

Here is a picture of it on a different Celestron Omni AZ 102:

 

 

 

You will need to move the scope farther up in the mount saddle to balance with a 2" diagonal and a heavy 2" eyepiece.  The stock short Vixen/CG-5 dovetail mounting rail that is screwed onto the side of the scope will need to be moved farther down toward the focuser end, and that means drilling and tapping some holes, or just one new hole if you can make use of one of the existing holes.  I have attached longer Vixen dovetail rails to the side of these scopes before, but on this one I decided to buy a set of tube rings from ScopeStuff.com so I could use a different mount that I already had.  See the top picture.  The ScopeStuff.com #CR40 tube rings fit these Celestron 4" refractor tubes:

 

https://scopestuff.com/ss_rings.htm

 

Using tube rings is a better idea in the long run that simply attaching a longer Vixen dovetail rail to the side of the scope like this:

 

 

 

 

Also, for 2" eyepieces that will do pretty well for the price, High Point Scientific has them on sale now.  I have one of these Orion 38mm Q70 70° AFOV eyepieces myself, and have used it on the Celestron Omni AZ 102 to get almost a 4° Field of View:

 

https://www.highpoin...2-eyepiece-8829

 

As far as 2" diagonals go, any of the 2" dielectric mirror diagonals will be fine for use with the Omni AZ 102, such as these:

 

https://astronomics....-for-refractors

 

https://agenaastro.c...r-diagonal.html

 

All achromat refractors suffer from Chromatic Aberration (CA) to some degree, and on the the Omni AZ 102 it can get pretty bad when looking at some brighter targets like the Moon, the brighter stars and Jupiter.  One thing I found that drastically reduces CA on the Omni AZ 102 is a Baader Contrast Booster filter.  They come in 1.25" and 2" sizes.  You really only need it when viewing brighter targets at higher magnifications using 1.25" eyepieces, so the 1.25" model would be a great addition.  It won't turn the AZ 102 into an APO-type refractor, but the views of the planets, the Moon and double stars will be so much better:

 

https://agenaastro.c...-1-2458360.html

Edited by Oldfracguy, 19 April 2025 - 01:22 PM.

[kqle]

Oh, thank you so much for this info. I did not even consider some of the points you suggested. I didn't think of a 2" diagonal or 2" eyepieces as having heavier weight issues.  I don't want to drill holes in my tube, so I like the idea of adding tube rings.  Will this work on the stock mount and vixen dovetail rail on this telescope?  Again, I don't really want to buy a longer rail, where I have to drill holes.  I might consider a contrast booster filter, but at the moment I already have a 1.25" moon filter.  Maybe this is good for bright objects for now.  Thank you for the suggested links to your other recommendations!

[Oldfracguy]

Actually, this short Vixen dovetail rail attached to the ScopeStuff.com #CR40 tube rings is the one that came on the scope originally:

 

 

 

I just used some small pieces of black electrical tape to cover up the holes in the tube where the dovetail rail originally screwed on.

 

You should be able to use the stock mount, since by adding tube rings that can be positioned anywhere along the tube, you will be able to get the scope balanced.

 

There is a long-running thread about this scope:

 

https://www.cloudyni...view=getnewpost

Edited by Oldfracguy, 19 April 2025 - 02:59 PM.

[jimandlaura26]

Welcome to your new obsession! Some thoughts. Visual views and experience will be limited by lowest quality elements in the series of equipment, sky, object leading to your eyes. My first advice - spend some good money on eyepieces and diagonal; that will likely extend beyond your first scope. Recommend Stellarvue equipment here - where solid value and actual experience at the eyepiece matter. Their 15, 8 and 4 mm 82 degree Ultra Wide Angle low-weight eyepieces and their 2” quartz dielectric diagonal would be good choices for your request. The 15mm EP gives you 44x which is high enough to avoid light pollution loss of contrast (object to sky)and a reasonably large field of view (1.9 degrees) - important for finding things and holding them in focus across the field of view for a manual mount. For planetary and small DSOs, you’ll be needing at least the 165x provided by the 4mm. 200x would be rare given your aperture, local seeing and scope limits. The high quality SV designed and manufactured diagonal is pricey, but worth every penny - not a place to skimp (no light scatter or pinched optics). You would be in really good shape with these items. I own and use them all - and they compare very favorably to the AstroPhysics, Televue and Pentax equivalents (that I also own and use). Separately, a Baader SemiApo filter is another high quality solution for achromatic telescopes - I speak from experience here as well. Good luck!

Edited by jimandlaura26, 19 April 2025 - 03:41 PM.

[Nautilus]

The Omni is a good scope but if you put on rings you definitely will need a better mount/tripod.  I suggest that anyway.

 

Here is the Omni side by side with our Starsense Explorer 102 which has XLT coating.

 

The rings with a handle are great. We use the handle to rotate the scope on the mount. The original dovetail lies underneath it so we did not have to mess around with screws, etc.

 

 

 

 

Attached Thumbnails

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[Polyphemos]

The Omni is a good scope but if you put on rings you definitely will need a better mount/tripod.  I suggest that anyway.

 

Here is the Omni side by side with our Starsense Explorer 102 which has XLT coating.

 

The rings with a handle are great. We use the handle to rotate the scope on the mount. The original dovetail lies underneath it so we did not have to mess around with screws, etc.

The way you’ve approached this still prevents the replacement dovetail from accessing the optimum balance point. If you remove the original dovetail and slide the rings and attached dovetail towards the focuser you’ll achieve balance more easily,

[Oldfracguy]

The way you’ve approached this still prevents the replacement dovetail from accessing the optimum balance point. If you remove the original dovetail and slide the rings and attached dovetail towards the focuser you’ll achieve balance more easily,

That is quite true, and would be the obvious approach to take if one were to use a 2" diagonal and 2" wide-angle eyepieces.  But removing the original dovetail would alter the scope from its OEM configuration, which for some people is an important consideration.

[Polyphemos]

That is quite true, and would be the obvious approach to take if one were to use a 2" diagonal and 2" wide-angle eyepieces.  But removing the original dovetail would alter the scope from its OEM configuration, which for some people is an important consideration.

The original dovetail is held in place with a pair of screws which can be removed or replaced with equal ease in under a minute, so I don’t think there’s much of a downside to remove the original dovetail as it’s a completely reversible procedure. 

[kqle]

Actually, this short Vixen dovetail rail attached to the ScopeStuff.com #CR40 tube rings is the one that came on the scope originally:

 

101_2845.JPG

 

 

I just used some small pieces of black electrical tape to cover up the holes in the tube where the dovetail rail originally screwed on.

 

You should be able to use the stock mount, since by adding tube rings that can be positioned anywhere along the tube, you will be able to get the scope balanced.

 

There is a long-running thread about this scope:

 

https://www.cloudyni...view=getnewpost

Oh ok. Thanks for the clarification.  I'll have to look more into the tube rings and perhaps considering a longer rail like the Agena V Series Vixen-Style Universal Dovetail Bar - 180mm (7.1") listed in your attached thread.

[kqle]

Welcome to your new obsession! Some thoughts. Visual views and experience will be limited by lowest quality elements in the series of equipment, sky, object leading to your eyes. My first advice - spend some good money on eyepieces and diagonal; that will likely extend beyond your first scope. Recommend Stellarvue equipment here - where solid value and actual experience at the eyepiece matter. Their 15, 8 and 4 mm 82 degree Ultra Wide Angle low-weight eyepieces and their 2” quartz dielectric diagonal would be good choices for your request. The 15mm EP gives you 44x which is high enough to avoid light pollution loss of contrast (object to sky)and a reasonably large field of view (1.9 degrees) - important for finding things and holding them in focus across the field of view for a manual mount. For planetary and small DSOs, you’ll be needing at least the 165x provided by the 4mm. 200x would be rare given your aperture, local seeing and scope limits. The high quality SV designed and manufactured diagonal is pricey, but worth every penny - not a place to skimp (no light scatter or pinched optics). You would be in really good shape with these items. I own and use them all - and they compare very favorably to the AstroPhysics, Televue and Pentax equivalents (that I also own and use). Separately, a Baader SemiApo filter is another high quality solution for achromatic telescopes - I speak from experience here as well. Good luck!

Thank you for the recommendation on eyepieces and suggested magnification. Considering my telescopes 4" apeture and 660 focal length, I thought 200x would be the maximum useful magnification?  Your suggested Stellarvue eyepieces look like good options at with 82 deg. view.  I was considering the X-Cel LX eyepieces as something similar in price range.  I'll also look into the Baader Semi-Apo filter as well.  I suppose at some point, investment in a high-quality filter is a must.

[kqle]

The Omni is a good scope but if you put on rings you definitely will need a better mount/tripod.  I suggest that anyway.

 

Here is the Omni side by side with our Starsense Explorer 102 which has XLT coating.

 

The rings with a handle are great. We use the handle to rotate the scope on the mount. The original dovetail lies underneath it so we did not have to mess around with screws, etc.

Yes, at somepoint a better mount/tripod would be good.  Perhaps I'll purchase a better telescope/mount in the future as well as a Dobsonian.  Your tube rings with handle looks like a good option, especially since the original dovetail is still in place and you didn't have to remove it.  Thanks for showing.

[kqle]

The way you’ve approached this still prevents the replacement dovetail from accessing the optimum balance point. If you remove the original dovetail and slide the rings and attached dovetail towards the focuser you’ll achieve balance more easily,

Thanks for the recommendation.

[Nautilus]

The original dovetail is held in place with a pair of screws which can be removed or replaced with equal ease in under a minute, so I don’t think there’s much of a downside to remove the original dovetail as it’s a completely reversible procedure. 

I never indicated that I had a balancing issue with this set up.  It was with my Celestron 80ED.

 

There is no need to go through all that.  The mount uses slip clutches like Vixen and unlike the Svbony and is pretty taunt in holding its position (altitude).I have not encountered any balancing issues with it.

 

As fracman indicated, the original dovetail stops it from going any further .

I find no reason to change it plus I am not a tinkerer.  Everything is fine in my opinion.

Edited by Nautilus, 20 April 2025 - 11:42 AM.

[Polyphemos]

I never indicated that I had a balancing issue with this set up.  It was with my Celestron 80ED.

 

There is no need to go through all that.  The mount uses slip clutches like Vixen and unlike the Svbony and is pretty taunt in holding its position (altitude).I have not encountered any balancing issues with it.

 

As fracman indicated, the original dovetail stops it from going any further .

I find no reason to change it plus I am not a tinkerer.  Everything is fine in my opinion.

You didn’t need indicate you have a balancing issue to see that your rings and dovetail are poorly located, and there’s a fundamental difference between “balance” and a mounts ability to resist unbalanced forces. Have a look at oldfracguy’s post #4 to see a correctly balanced scope and where Celestron should have located the dovetails.

 

As I’ve indicated the removal of two screws removes the obstruction you’ve noted keeps the rings from going further. It’s a project akin to turning a door knob in effort and complexity. Arguably you did much more “tinkering” when you fitted the rings from another scope; you just skipped the important first step.

 

If the system you have works for you and your setup, that’s great, and while my suggestion might not apply to you it might help others, and particularly those who are still struggling with less capable mounts like the one shipped with the Omni AZ102, which is the theme of this thread. In two cases where I moved dovetails back for other owners, doing so made a formally useless mount that wouldn’t hold an altitude setting completely workable.

 

It seems that essentially every inexpensive PRC derived achro with fixed dovetails is fitted with their dovetails too far forward towards the objective to achieve balance. Certainly that’s been the case with all I’ve encountered. I’m beginning to think that the reason for this repeated error in assembly is that the manufacturers for some reason have become accustomed to place the dovetail near to where the scope balances WITHOUT including the diagonal, eyepiece, or finders. I guess they’ve been doing it for so long now that it’s become an inviolable tradition, even if it is completely wrong and demonstrates a failure to understand how their customers actually use their scopes.

[VA3DSO]

I've got the AZ 102 and I love it. I don't use it with 2" eyepieces, but it is capable. I like the red dot finder, but as others have mentioned, any finder scope with a Vixen-style dove tail base will work.

 

200x with this scope is likely getting past what it can properly use. I've used mine at 165x on the Moon and it was nice. One accessory I purchased that has really helped is an svbony SV231 color correction filter. It helps tame the chromatic aberration on the brighter objects (especially the Moon).

 

For the dovetail, I've tried both - I purchased a set of tube rings as well as a longer 8" dove tail bar. My preference is for the dove tail bar bolted directly to the OTA:

 

 

I also 3D printed a solar filter and put some Baader solar film in it:

 

 

For the mount, I am using either my AZ4 mount:

 

 

Or my EQ5 mount if I want tracking:

 

 

Finally, I found a nice carry bag on Amazon that perfectly fits the AZ 102:

 

 

https://www.amazon.ca/dp/B0D3228CH1

 

For eyepieces, I think you want a lower power wide angle eyepiece (ie: 30mm) , then a medium-high power that gives around 80x (ie: 9mm) and then maybe a Barlow to use with them both (giving roughly 20x, 40x, 80x and 160x). I mostly use Plössls and Orthos, so I can't comment about wide field eyepieces. I also don't use zooms, so I have no comment there as well.

 

Overall, I find the Omni AZ 102 excellent value for the money. Mine star tests almost perfectly (indicating well made optics) and the only thing I wasn't too happy about was the mount. But both my AZ4 and EQ5 hold the lightweight OTA easily. The original mount works really well with my 70mm telescope, so overall I am a happy camper.

 

 

Enjoy!

 

Rick

 

Edited by Rick-T137, 20 April 2025 - 03:09 PM.

[kqle]

 

I've got the AZ 102 and I love it. I don't use it with 2" eyepieces, but it is capable. I like the red dot finder, but as others have mentioned, any finder scope with a Vixen-style dove tail base will work.

 

200x with this scope is likely getting past what it can properly use. I've used mine at 165x on the Moon and it was nice. One accessory I purchased that has really helped is an svbony SV231 color correction filter. It helps tame the chromatic aberration on the brighter objects (especially the Moon).

 

For the dovetail, I've tried both - I purchased a set of tube rings as well as a longer 8" dove tail bar. My preference is for the dove tail bar bolted directly to the OTA:

 

 

 

I also 3D printed a solar filter and put some Baader solar film in it:

 

 

 

For the mount, I am using either my AZ4 mount:

 

 

 

Or my EQ5 mount if I want tracking:

 

 

 

Finally, I found a nice carry bag on Amazon that perfectly fits the AZ 102:

 

 

 

https://www.amazon.ca/dp/B0D3228CH1

 

For eyepieces, I think you want a lower power wide angle eyepiece (ie: 30mm) , then a medium-high power that gives around 80x (ie: 9mm) and then maybe a Barlow to use with them both (giving roughly 20x, 40x, 80x and 160x). I mostly use Plössls and Orthos, so I can't comment about wide field eyepieces. I also don't use zooms, so I have no comment there as well.

 

Overall, I find the Omni AZ 102 excellent value for the money. Mine star tests almost perfectly (indicating well made optics) and the only thing I wasn't too happy about was the mount. But both my AZ4 and EQ5 hold the lightweight OTA easily. The original mount works really well with my 70mm telescope, so overall I am a happy camper.

 

 

 

Enjoy!

 

Rick

 

Thank you for the useful suggestions along with your recommendation on eyepiece sizes.  It's nice to see someone who enjoys this telescope and it makes me happy about my purchase as a beginner.  I think I will purchase a SVBONY SV182 right angle finder and get a dual finder scope mount to put along side my stock red dot finder.  

I'm looking into your suggested SVBONY SV231 corrective filter.  I already have an Orion moon filter that I received from a friend.  Would this be just as good for most bright objects other than the moon as well as chromatic aberrations?  

I'd also be interested in the specific tube rings and 8" dove tail bar that you used.  Also, the AZ4 mount you used.  Do you have a link to these?

 

[VA3DSO]

Thank you for the useful suggestions along with your recommendation on eyepiece sizes.  It's nice to see someone who enjoys this telescope and it makes me happy about my purchase as a beginner.  I think I will purchase a SVBONY SV182 right angle finder and get a dual finder scope mount to put along side my stock red dot finder.  

I'm looking into your suggested SVBONY SV231 corrective filter.  I already have an Orion moon filter that I received from a friend.  Would this be just as good for most bright objects other than the moon as well as chromatic aberrations?  

I'd also be interested in the specific tube rings and 8" dove tail bar that you used.  Also, the AZ4 mount you used.  Do you have a link to these?

The Orion Moon filter is likely just a neutral density filter - it just makes the view uniformly darker, so it won't help at all with taming chromatic aberrations. The SV231 (and the Baader Fringe Killer) is designed for that - they filter out specific wavelengths of light that appear as yellow or purple halos around bright objects.

 

The rings I used were standard Sky-Watcher 101mm rings:

https://skywatcher.c...-tube-ring-set/

 

The AZ4 mount I use is also a Sky-Watcher (I bought it used):

https://skywatcher.c...h-steel-tripod/

 

The dove tail I used was an SVBony 8" Vixen dove tail:

https://www.aliexpre...5270260816.html

(I bought the 210mm one)

 

And here's a link to the SV231 filter I bought:

https://www.aliexpre...7007782877.html

Edited by Rick-T137, 21 April 2025 - 02:25 PM.

[jimandlaura26]

Thank you for the recommendation on eyepieces and suggested magnification. Considering my telescopes 4" apeture and 660 focal length, I thought 200x would be the maximum useful magnification?  Your suggested Stellarvue eyepieces look like good options at with 82 deg. view.  I was considering the X-Cel LX eyepieces as something similar in price range.  I'll also look into the Baader Semi-Apo filter as well.  I suppose at some point, investment in a high-quality filter is a must.

200x can be used under favorable circumstances. But such conditions (e.g., atmospheric stability “seeing,” light pollution, contrast between object viewed and surrounding sky ) do not always cooperate. Plus, apart from planets, the Moon and planetary nebulas, most low brightness objects start to dim noticeably at 200x magnification and beyond at this aperture. Eyepiece selection is best served by observing yourself (e.g., at a club star party) or by reviewing first-hand comments by others (such as here on CN). I can vouch for Stellarvue (SV) eyepieces and cited comparisons with other premium eyepieces - because I own and use them and I have experienced SV’s commitment to the customer over 20 years. I will not comment on the alternative Celestron eyepieces you cite, because I have not used them. That said, I have owned other Celestron eyepieces in the past (Ultima Plossls and others). Some were very good, others, less so. Could have been luck of the draw, mediocre design or quality control. Question is what you choose to leave to chance. Regarding filters - Baader makes high-quality filters, as do others; you can even place them permanently installed on the front end of your diagonal without any image distortion. You have to pay some for that quality, but it is worth it. Another fact is that there are design tradeoffs - so the Semi-Apo filter mitigates but does not prevent chromatic aberration, but it lets a lot of light through without shifting colors, which is important when you only have 100 mm of aperture in an achromatic refractor. You cry once when you buy good stuff, but repeatedly at the eyepiece when you buy a low quality “good deal.”

 

P.S. Don’t forget about the diagonal.

Edited by jimandlaura26, 22 April 2025 - 06:26 PM.

[kqle]

200x can be used under favorable circumstances. But such conditions (e.g., atmospheric stability “seeing,” light pollution, contrast between object viewed and surrounding sky ) do not always cooperate. Plus, apart from planets, the Moon and planetary nebulas, most low brightness objects start to dim noticeably at 200x magnification and beyond at this aperture. Eyepiece selection is best served by observing yourself (e.g., at a club star party) or by reviewing first-hand comments by others (such as here on CN). I can vouch for Stellarvue (SV) eyepieces and cited comparisons with other premium eyepieces - because I own and use them and I have experienced SV’s commitment to the customer over 20 years. I will not comment on the alternative Celestron eyepieces you cite, because I have not used them. That said, I have owned other Celestron eyepieces in the past (Ultima Plossls and others). Some were very good, others, less so. Could have been luck of the draw, mediocre design or quality control. Question is what you choose to leave to chance. Regarding filters - Baader makes high-quality filters, as do others; you can even place them permanently installed on the front end of your diagonal without any image distortion. You have to pay some for that quality, but it is worth it. Another fact is that there are design tradeoffs - so the Semi-Apo filter mitigates but does not prevent chromatic aberration, but it lets a lot of light through without shifting colors, which is important when you only have 100 mm of aperture in an achromatic refractor. You cry once when you buy good stuff, but repeatedly at the eyepiece when you buy a low quality “good deal.”

 

P.S. Don’t forget about the diagonal.

Thanks for your added info.  It looks like Stellarvue are eyepieces that have a good reputation.  I'll definitely have more interest in their eyepieces from now on.  Your comments on conditions e.g., atmospheric stability “seeing,” light pollution, contrast between object viewed and surrounding sky), seem appropriate as I do live in an area that definitely has either one of these conditions at least all the time.  I guess I'll know that 200x magnification is something to be cautious about.  I think a 6-7mm eyepiece would work even if I use a 2x barlow. I'll look into some of the higher quality filters like Baader, but won't promise any purchase as I'm still watching my budget at this time.  Hopefully I can limit my crying on good stuff in the meantime.

[kenstyles]

 I recently purchased this telescope for a second time because it was a deal I couldn't pass up. Budget option is svbony 8.26" dovetail bar. If you have access to a 3d printer then just print the rings. 

The Astrotech Paradigm/BST Starguider 60° eyepieces are nice and budget friendly. Sold my Celestron Xcel Lx in favor of these. The 25mm AT has issues but you can read about that. 

The Svbony color correction filter will take away the CA but will put a yellowish tint over bright objects. This seems to be the case with filters to correct for chromatic abberation from researching the topic.

Get rid of the stock diagonal. Both diagonals on the AZs I've had are terrible!

Eventually, you'll want an ED lens if CA bothers you enough and you like refractors. 

[Jon Isaacs]

 

Thanks for your added info.  It looks like Stellarvue are eyepieces that have a good reputation.

 

StellarVue eyepieces are manufactured by KUO. The same eyepieces are available from Astronomics, Cloudy In Nights sponsor as the UWAs and XWAs.

 

Jon

[vtornado]

Hi All,

 

I'm just getting into astronomy viewing and telescopes.  I recently purchased the Celestron Omni AZ 102   ...  I've been doing some research on eye pieces and such and wanted to upgrade my eyepieces from the basic Kellner 10mm & 20mm that came with my purchase, but not overly spend too much.  I was looking into the SVBNY or Celestron X-Cel LX, so I don't break the bank like with a Tele Vue or Baader.  I am sticking to mostly viewing the moon, and planets with some basic easy to find star clusters & nebulas for now.

 

First off, does my Omni AZ 102 take 2" eyepieces?  YES I don't think it said in the product description when I made the purchase.  But, I remember a YouTube video review saying that it does take 2" eyepieces.

If so, should I invest in 2" eyepieces? I would also like to upgrade to a 90deg dielectric mirror diagonal.  Again, should I invest in a 2" mirror diagonal if my Omni is able to use one?

 

A two inch eyepiece would be good.   The big question is can you afford it? 

• It would require a two inch diagonal  might be $75.00
• An mediocre eyepiece is around $100.  A good one $200.
• This will unbalance your scope.  You will need to figure out how to rebalance it.  Could be rings, could be buying a longer bolt on dove tail and drilling the tube. 
• I'm unsure if the mount head and tripod can deal with the extra weight.

I would recommend finding a good used 32mm plossl for max field of view for now.

 

Second, can I replace the finder scope on this?  Or is the finder scope proprietary on this telescope model?  Does this telescope need an extra adapter in order to replace the finder scope?

 

My omni has a build in standard vixen finder shoe where any finder with a vixen foot can be installed.  Once again balance issues.  Even a small 30mm finder is heavier than the red dot.

 

Third, what are 2 or 3 eyepiece sizes should I get with a low power & high power suitable for my 660mm focal length with 200 max power?  I was looking at perhaps a 6-7mm for high power, and 20-25 for low power or 18mm? 

 

The included kellners are not horrible.  The weakest link in the chain is the diagonal replace that first.

 

I like the idea of having wide angle field of view up from 57-68 degrees.  I'm also thinking of maybe getting a Zoom eyepiece like the SVBNY SV135 (60-40deg.) or the SV191 (65-42deg.) field of view.  Is a 65deg much of a difference compared to a 60deg?  Could I use a 2x or 3x Barlow with the Zoom eyepiece?

 

Get the Svbony 7-21 with 6 elements.  Svbony seems to have the same model number with different eyepieces.  The 6 element is good/light/cheap.

 

Svbony redline 6 and 9 are good eyepieces.   They do have blackout issues in the daytime and on the moon. 

 

Astro-Tech paradigm dual ED 5,8,12 are very good eyepieces.

 

Celetron xcel-lx line is very good.

 

Although the telescope is theoretically capable of 200x, It is not likeley.

• 200x would be dim, detail would be hard to see.
• will reveal a lot of chromatic abberation.
• will expose any optical defects
• will expose shakiness in the mount
• will be difficult to achive perfect focus.

For my telescopes I use the rule  Aperture / .7 = 140x for yours.

 

If you want to reach 200x, I would recommend the use of a barlow with a more practical eyepiece.

 

 

[Polyphemos]

 

Hi All,

 

I'm just getting into astronomy viewing and telescopes.  I recently purchased the Celestron Omni AZ 102   ...  I've been doing some research on eye pieces and such and wanted to upgrade my eyepieces from the basic Kellner 10mm & 20mm that came with my purchase, but not overly spend too much.  I was looking into the SVBNY or Celestron X-Cel LX, so I don't break the bank like with a Tele Vue or Baader.  I am sticking to mostly viewing the moon, and planets with some basic easy to find star clusters & nebulas for now.

 

First off, does my Omni AZ 102 take 2" eyepieces?  YES I don't think it said in the product description when I made the purchase.  But, I remember a YouTube video review saying that it does take 2" eyepieces.

If so, should I invest in 2" eyepieces? I would also like to upgrade to a 90deg dielectric mirror diagonal.  Again, should I invest in a 2" mirror diagonal if my Omni is able to use one?

 

A two inch eyepiece would be good.   The big question is can you afford it? 

• It would require a two inch diagonal  might be $75.00
• An mediocre eyepiece is around $100.  A good one $200.
• This will unbalance your scope.  You will need to figure out how to rebalance it.  Could be rings, could be buying a longer bolt on dove tail and drilling the tube. 
• I'm unsure if the mount head and tripod can deal with the extra weight.

I would recommend finding a good used 32mm plossl for max field of view for now.

 

Second, can I replace the finder scope on this?  Or is the finder scope proprietary on this telescope model?  Does this telescope need an extra adapter in order to replace the finder scope?

 

My omni has a build in standard vixen finder shoe where any finder with a vixen foot can be installed.  Once again balance issues.  Even a small 30mm finder is heavier than the red dot.

 

Third, what are 2 or 3 eyepiece sizes should I get with a low power & high power suitable for my 660mm focal length with 200 max power?  I was looking at perhaps a 6-7mm for high power, and 20-25 for low power or 18mm? 

 

The included kellners are not horrible.  The weakest link in the chain is the diagonal replace that first.

 

I like the idea of having wide angle field of view up from 57-68 degrees.  I'm also thinking of maybe getting a Zoom eyepiece like the SVBNY SV135 (60-40deg.) or the SV191 (65-42deg.) field of view.  Is a 65deg much of a difference compared to a 60deg?  Could I use a 2x or 3x Barlow with the Zoom eyepiece?

 

Get the Svbony 7-21 with 6 elements.  Svbony seems to have the same model number with different eyepieces.  The 6 element is good/light/cheap.

 

Svbony redline 6 and 9 are good eyepieces.   They do have blackout issues in the daytime and on the moon. 

 

Astro-Tech paradigm dual ED 5,8,12 are very good eyepieces.

 

Celetron xcel-lx line is very good.

 

Although the telescope is theoretically capable of 200x, It is not likeley.

• 200x would be dim, detail would be hard to see.
• will reveal a lot of chromatic abberation.
• will expose any optical defects
• will expose shakiness in the mount
• will be difficult to achive perfect focus.

For my telescopes I use the rule  Aperture / .7 = 140x for yours.

 

If you want to reach 200x, I would recommend the use of a barlow with a more practical eyepiece.

 

 

 

Excellent post, though I disagree with the scope being unlikely to achieve 200x magnifications.  Having used 200x magnification to observe Saturn on numerous occasions I found Saturn is bright enough, chromatic aberration isn’t particularly intrusive, and the optical defects that were bothersome originated more from my eye than from the scope. 200x magnification might be practical only rarely and for specialized cases, but it’s more than merely theoretical.

 

I completely agree about the mount and little good can come from sticking with it at greater than the lowest magnifications; same with the RACI diagonal. I also agree that focus at high magnification will be difficult with the stock focuser, but there are multiple fine focus solutions available and they don’t necessarily have to be expensive.

[vtornado]

I think the use of high magnification (Exit pupils less than 1mm) are highly subjective.  It may depend upon on eyesight and visual perception  I have a very good Orion 100mm f/9 FPL53 refractor, (Same as skywatcher) and I still find .7mm the "best" view for me.

 

I have use .5mm EP (200x) on the moon.  That is a much brighter target.

Edited by vtornado, 30 April 2025 - 04:25 PM.