Beginners first night observing wih Celestron OMNI XLT 120 - report and review

[Wurzil]

Hello all.

After recieving my first proper scope, the Celestron OMNI XLT 120 from FLO (rather promptly:hello2:) I had to wait nearly a week before mother nature allowed me a few hours of clear sky. In a way this was a blessing as it gave me ample time to get used to read the instructions and get used to setting the telescope up.

My initial feeling upon opening the packages was that the OTA looked gorgeous (metallic deep-blue) and felt like it was made of solid iron and would last forever. It seems like a lot of kit for £259. The mount also was heavy and solid-looking and easy to set up with the instructions provided. Moving the rig means taking the scope off of the mount and dropping the accessory tray so the tripod legs can fold in - this is very quick and easy so the scope will get a lot of use!

Things I liked after assembling the OMNI XLT 120 and CG4 mount:

OTA looked and felt very special (not just an empty tube with a shaving mirror in it like the cheapy 3" reflector I was using before!);

Focusser felt smooth and reassuring; Celestron have added extensions to the slow motion controls; once balanced the scope moved very nice and smoothly. The whole thing assembled looks awesome and has a quality feel to it.

Things I didnt like after assembling:

The cap that covers the RA gauge was a very cheap piece of plastic and cracked the first time I touched it (this is not a huge problem as it doesnt serve any real purpose); the RA gauge itself looked like it wouldnt be that accurate and had a tendancy to slip; The bit that comes out when you move the focusser (??) had some sort of lubricant grease all over it which was very sticky and you have to avoid touching it (the sort of thing you dont want when touching your EPs); the telescope seems to stick out a lot at the eyepiece-end rather than the lens-end when balanced which means when looking straight "up" you have to kneel or sit on the floor (i think i might move the tube forward when I want to look up).

First nights Observing

The wind that had blown away the clouds was threatening to blow me away too - but I was itching to use the scope so I gritted my teeth and set up the OMNI 120 XLT on my veranda.

The scope only comes with an unbranded 25mm eyepiece (40x) , so I'd ordered a 10mm skywatcher super plossl (100x) to get a better look at Jupiter which was my first target on this moonless night.

Jupiter: I got him straight in view using the 25mm EP which gave me a crisp, bright view with 3 moons and 2 very feint cloud bands. I switched up to the 10mm plossl and after I got it focussed I had a few short WOW moments (lots of detail) but there was a lot of wobbly turbulence that had me blinking (thinking that it was my eyes!). I put the lens cap on which got rid of all that purple chromatic abberation from the achromatic refractor. There was a little vibration as I was shivering against the EP in the wind - but when i was careful, vibration was not really a problem. I reckon when I get a 6mm EP for nights with more stable air, Jupiter will be stunning! After half an hour I left wobbly Jupiter and moved on to Pleiades.

Pleiades: Using the 25mm eyepiece I went to see the seven sisters and laughed - there are more like 700 sisters. It really was beautiful and so crisp. After using the slow motion controls to scan around for a while I decided Id have a wander down the milky way.

Milky way: With the refractor pointing straight up I was kneeling on the floor (and COLD) which was a little annoying but the stars took my mind off of it. That smudge across the sky is actually a billion little diamonds with tiny constellations and clusters all over the place. I felt like I was really exploring now - and while I was on the floor I thought Id try and find the Andromeda galaxy.

Andromeda galaxy: This took a bit of finding as it was IMPOSSIBLE to use the finder scope with the telescope looking straight up (can you get finder scopes with diaganols??) . I had to point the thing in the general direction (from Stellarium) and then just mooch about with the slow motion controls. I found a grey oblong smudge which was brightest in the middle - this must have been it. I have to say I was a little disappointed that it didnt look more galaxy like - I wonder how much the views will improve with better skies, eyepieces and filters etc. Im going to attend a local club at a dark site soon, so hopefully I will be able to get more out of the telescope with their help. I have to admit that at this point I was thinking -"hmm should I have gone for the 8" dob" I really hope this isnt apeture fever starting ALREADY!!! I got up off the floor and saw Orion rising up out of the orange glow on the horizon.

Orion Nebula: I found this easily using the finder scope and it was more pleasing than the andromeda galaxy. I could easily see the trapezium with the 25mm - the little stars were twinkly and razor sharp. The grey smudge of nebulosity had some definition, but I realise that this is just the bright centre of a much larger DSO. Again I wonder how much better this will look under darker skies, with better eyepieces/filters etc. As Orion rose the grey smudge became more noticable but I was getting COLD. Stellarium said Mars would rise pretty soon but It would have to climb above the orange glow before I could see it - I decided to leave it until another night - I wonder if the 10mm will be enough or whether I will need to get a 6mm to see any detail on Mars??

All in all Im quite pleased with the views on what I have to admit was a pretty poor night for observing. I cant wait to go to a dark site, get my 6mm EP and visit a club. Im also looking forward to learning how use the RA and DEC axis properly and how to star-hop.

Is there anybody out there with the same (or similar telescope) with any tips on how to get better views of the orion nebula, andromeda etc, or will I need a big dob to see DSOs with any clarity? Or will dark skies make the views much much better with my celestron?

Also can anyone suggest more targets (bright DSOs) for me, which will be relatively easy to find - the more impressive the better!!

Thanks.

Warren:D

[Wurzil]

hmmm maybe I should have posted this in the beginners section. copy and paste time!!

[Doc]

No it was in the right section. If you don't get answers straight away it doesn't mean we are ignoring you, it just means people are to busy to answer or haven't been online yet. Eventually you will get alot of responses.

[Scottie]

Hi Warren,

Thanks for the good post. You have given me some heart cause your observation experience matched mine quite closely.

Your scope sounds great. I am kind of adjusting to viewings these days after a long long time away from astronomy. As a personal experience it brings to mind the pioneering spirit of searching the wide black yonder and one has a tough time keeping astro images out of ones mind as one looks through the eyepiece.

Keep searching, good luck

[Astro_Baby]

Great review.

You asked if finders have diagonals too - yes some of them do is the answer. There are right angled ones and also corrected image ones (ie the image isn't inverted or switched left to right).

Wet knees - well thats just what happend with longish tube refractors. Its no much different with a Newtonian on an EQ mount where the EP can end up in strange positions. All part of the joys of EQ mounts really.

Comfy positions are for Dob owners and SCTs on only really

Andromeda is apretty much a smudge in my 8" refelector as well. Under a good sky you can just about makeout two dust lanes but thats the best I have have had.

[rama]

ref, your problem ; kneeling on a cold floor when looking straight up through your 120 refracter. i solved this problem by making tripod leg extensions which lifted the telescope a foot higher. eg steel tubing off old vacume cleaners [sourced at local tip] 2ft long with 1ft of wood secured inside half the length of the tube eg drill+screw. x3. place tripod legs into tubes resting on wooden insurts, job done.

[Talitha]

Great report, Warren. I bought a portable pier for my 120mm f/8.3 achro and it made a world of difference. Now it's tall enough for me to stay seated when it's aimed at the zenith although a step stool is needed to view lower than 45 degrees. Sure beats sitting or kneeling on the ground, though.

Instead of placing the red-dot finder close to the focuser, mine's out at the end of the tube a few inches behind the lens... much easier to get into the ballpark that way. Once in the area, i use the correct-image right angle finder near the focuser.

[Wurzil]

Hi everyone - thanks for taking the time to reply.

I think I may have to get me one of those diagonal finder scopes, the finderscope on the celestron cant be moved up and down the tube as it fits into a clip thing down by the focuser.

Thanks Rama for the suggestion of leg extensions - I might just try knocking up some "stilts" for the mount. Ill keep my eyes open for likely bits of tube. I might look into a portable pier as well or should I start saving for a massive Dob instead hmmm.

PS - I just had the scope out again to look at jupiter through a gap in the cloud and it looked AMAZINGLY STABLE AND STRIPY (4 moons today). My friends were mightily impressed!

I love this new hobby.

Thanks everyone

Warren

[wulfrunian]

Very enjoyable read Warren, always great to hear about a scope's first light Re filters - deep sky filters won't help with galaxies, like M31, but can help with nebulae, like M42. And a dark sky is always a bonus if you can find one of course!

Yes it does sound as if you have aperture fever already. I have cured mine temporarily by buying the biggest mirror I can easily lug around.

Or have I...

[Wurzil]

thanks michael, I think Ill have a look at some deep sky filters.

Warren

[iamjulian]

Great report Warren. Sounds like a nice bit of kit. I think Jupiter is getting quite low now (just going off what other people say - I have a north facing observing site so I haven't seen Jupiter for a while) and the lower something is, the more atmosphere you have to look through, and so it will always look wobbly. Best views are from stuff that is much more over head. Andromeda is well placed at the moment, though perhaps not for a refractor. Knee pads?

[Wurzil]

Ive noticed Jupiter is disappearing over my roof earlier and earlier as winter draws in - Ive only just learned how the stars swap around 180 degrees in winter compared to summer (around polaris) and how they spin 360 degrees in 24 hours.

My viewing site faces northish too!!

[wulfrunian]

Loads of people don't really know that about how the sky moves - neither did I until i got into astronomy 15 years or so ago! Also Jupiter along with all the other planets moves against the background stars. It is however visible for a good proportion of the year at one time or another. Looking forward to Saturn reappearing in the evening soon, it's a morning object at the moment

[Wurzil]

Im definitely looking forward to Mars and Saturn in January I believe from what Ive read on here that I shouldnt expect too much from Mars with my scope, but Saturn should show its rings which will be nice!

[WebSentinel]

Hi Warren,

I have the Omni 120 too and I think it is excellent for the price. I speak from experience as I originally owned a Celestron C11 and EQ6 Pro mount, etc. but I hardly used it because it took so long to setup and take down, plus I wanted a more versatile configuration of scopes and mounts to allow me to get out more and enjoy the night sky. I now have the Omni 120 and a WO Megrez 72 on a WO EzTouch mount and some Helios 15 x 70 bins and I get out all the time (I was out between 1.40 and 3.40 this morning and it was great).

I use the CG4 (with an EQ3 RA motor) and the WO Megrez 72 for wide field imaging along with my Canon D400, which works quite well although the mount is very basic (compared to the EQ6 Pro, etc.) and requires careful drift alignment and lots of short exposures in order to produce anything of worth. For visual use I mount the Omni 120 and the WO 72 side by side on the EzTouch mount and enjoy scanning the sky and switching between scopes. The EzTouch mount and the wooden tripod are rock solid and there is hardly any vibration when using high magnification views of the moon, etc.

I replaced the rack and pinion focussor on the Omni 120 with a nice multi-speed GSO crayford and it makes a lot of difference.

I also have a WO 2" diagonal and use Baader eyepieces.

M42 through an 8mm Baader using the Omni 120 is wonderful and as good as the views I used to get using the C11 (albeit I didn't use a focal reducer with the C11).

My general experience of the scope has led me to believe it performs better on DSOs when used in conjunction with a wide field EP - like a 13mm. You can however crank up the power by using a televue powermate (I use the 5x version) for such objects as planets and double stars but to be honest the view really does deteriorate quickly at that level and if the 'seeing' is poor then forget it - not matter what scope you own.

Overall I think the Omni 120 is one of the best bits of kit on the market today for the price. And don't forget that with a refractor you would have to double the size (in mm) to get the equivalent using a mirror - in other words the Omni 120 is the same as a 8.5" plus reflector (that advice is straight from the mouth of the great Sir Patrick Moore) so, no I wouldn't rush out and by an 8" dob just to see a slightly bigger 'grey smudge' where M31 resides!

Nice report and look forward to hearing more about your adventures with the 120!

[tinvek]

nice report and a nice scope. it helps to be a contortionist in this hobby.

always amazes me how good that celestron 25mm eyepiece is, far better than the standard skywtcher 25mm supplied with their scopes. i got one with my c80ed and it get's used in every scope as a start of the session eyepiece. i picked up a second one off here for my lads skywatcher mercury 705 and it made a huge difference.

[Wurzil]

hello tinvek and websentinel! I didnt think people would still be looking at my old thread!! thanks for reading it!

Its good that other people rate the omni 120 quite highly - it makes me think i made the right purchase! And yes, the 25mm EP does deliver nice views doesnt it! I got given a 6.3mm kellner the other day and its awful having to put your eyelashes against the EP - bleurgh!

New adventures with the scope have been few and far between as the weather has been awful for a month - and tonight the weather really frustrated me as I tried to show my friend and her 2 children Jupiter through holes in the low cloud. "Its out -quick get it in the finderscope....got it...oh its gone behind the cloud again..wait ten minutes....its out..oh no" etc etc you get the idea.

see ya

Warren

[russ]

Sounds like a really nice scope Warren and certainly sound very pleased. I'm hearing a lot of good things about these scopes.

I did read on Cloudynights that someone used one of those ankle weights and wrapped it around the tube at the focuser end. This altered the balance point of the tube and meant they could move the tube right up in the rings. This combined with a pillar extension should make things quite comfortable for overhead views.

Hope you get out again soon.

[Wurzil]

That ankle weight thing is a genius idea!!!

ta

[GlennD]

Hullo Warren

Think you have purchased a very nice scope. Contemplatating the same but still think I have a long way to go. Have listed a few on "short-finals" but must still decide but may end up Sky-Watcher newtonian reflector type of 150mm. The Celestron Omni XLT 120 is also going for a good price here in S Africa and is around the same price for the Sky-Watcher 150. Will let you know how it goes. Oh, yes this will be my first scope but not first at astronomy. Goes back to more than 30 yrs with a Tasco 60mm.

With regard to what you can view, maybe the following will be usefull:

JTB's DSO's by Optimal Aperture (ASTROMETRICS: Deepsky Studies by Optimal Aperture)

Kind Regards

Glenn

[AstroKerr]

On 13/12/2009 at 04:27, WebSentinel said:

And don't forget that with a refractor you would have to double the size (in mm) to get the equivalent using a mirror - in other words the Omni 120 is the same as a 8.5" plus reflector (that advice is straight from the mouth of the great Sir Patrick Moore) so, no I wouldn't rush out and by an 8" dob just to see a slightly bigger 'grey smudge' where M31 resides!

 

Are you ab-so-lute-ly sure of that?

[R26 oldtimer]

I 'll show this thread to my 11 year-old to prove that everything you post on the internet stays there, and might haunt you for decades to come...