Latest Celestron Omni XLT model ....

[John]

I notice that another Omni will shortly join the clan - an F/5 150mm achro refractor, presumably optically similar to the Skywatcher Startravel 150 albeit using hand picked, aspheric optics with XLT coatings. I think these have been available in the USA for a while but now it looks like they are coming here.

The picture I have seen shows the scope using a CG4 mount which I think is similar to an EQ3-2 but with stainless tubular steel tripod legs 1.75" in diameter.

I've not used an F/5 150mm achro but I'd imagine that chromatic abberation would be a big issue - for those that have tried one - is it a significant issue ?

Also I understand that the OTA is 16 lbs in weight and about 34 inches long - surely it's a bit undermounted on the CG4 ?. I would have thought a CG/EQ5 at least and preferrably an HEQ5 would be needed for an OTA of that size / weight ? (the Startravel 150 is mounted on an EQ5).

The one I have seen listed so far was £750ish. I like the look of the other Omni's and the reviews are favourable but I'm wondering if this new one could be a bit of a lemon

John

[Ben Ritchie]

I don't know about the Celestron, but I used an Antares 6" f/6 achromat out in the states and it was a lot of refractor for the money - certainly not colour-free, but good optics, sharp views and decent light gathering. It was great with a 24mm Pan and the rich summer starfields (especially as I was in AZ, so could browse Sagittarius and the other southern constellations that are out of reach from the UK).

[FLO]

The thing to remember when using these short-tube f5 achromats is that they are low-medium magnification wide-field telescopes. When used in that capacity they are very nice indeed but when pushed beyond their comfort zone they are veritable kaleidoscopes!

The longer tube Celestron Omni XLT 120 is remarkably good, particularly considering its current price, but seems to go unnoticed.

[WebSentinel]

There's a review of this scope here: Astromart Reviews - CELESTRON OMNI XLT 150R

And from the Celestron Omni manual (via the Celestron website):

"The Omni XLT150R is the most difficult to balance depending on the latitude, the accessories used, and which part of the sky the telescope is pointing to. Balance this telescope as best you can."

I reckon it would be quite good on DSO though and a bargain at the price. There's also a 102ED version in the Omni range.

I agree with Steve's comments (above) - in fact I'm thinking of buying a 120 this week.

[John]

I reckon it would be quite good on DSO though and a bargain at the price.

Thanks for posting the review link.

I agree that it would be quite good on DSO's but I'm not sure it's a bargain if the £750 price tag I've seen sticks - you can get 12 inches of dobsonian for that price !.

John

[John]

The longer tube Celestron Omni XLT 120 is remarkably good, particularly considering its current price, but seems to go unnoticed.

Not unnoticed here Steve

What a bargain at the moment

John

[Mark at Beaufort]

Clearly an interesting scope. I agree with the view expressed in the article that Celestron should offer the scope as an OTA only. I also agree with John that £750 is too much when you can buy a good sized Dob for far less.

Mark

[GazOC]

I know pretty much all scopes are a better deal S/H than new but this esp. seems to be the case with these 150mm f5 refractors. Most people who put them up for sale are realistic enough to price them so they are at least in the same ballpark as S/H 8" newts or 6" SCTs and you can usually pick them up for around £200-£250 for an OTA.

[WebSentinel]

It's a fair point re. the dobs and pricing but then again with a refractor you don't have to worry about collimation and it comes with a closed tube (unlike most new dobs).

[Mark at Beaufort]

I accept your point Steve. I love refractors which is why I bought the 4" AstroTech EP. I am sure that if Celestron sold this 6" for about £500 as an OTA only alot of people would buy it as a great portable grab and go for viewing the major DSOs.

Perhaps Adam Hinds should chat with Celestron??

Mark

[Rossco72]

I started out with a 120 OMNI XLT and it was a lot of kit for the money (£257) I think. For visual i thought it was pretty good. I did take some prime focus shots of the moon which had significant blue-violet halo around the bright surfaces, but I guess that was to be expected.

I did feel that the CG-4 was a little light even for the 120 so i would imagine it could be even worse on the 150.

If we're truely talking about £750 against £250 then I'd have to say the 120mm was a better package per £.

Regards

[WebSentinel]

I ended up buying the Omni 120 XLT from FLO mainly because I was going to buy an EQ3-2 mount anyway (same as the CG-4) and getting a 120mm refractor for and extra £100 made a lot of sense and what a bargain it has turned out to be too!

It arrived last Friday and I was able to go out and test the optics the same evening (rare I know). Although, the seeing was awful and there was a strong breeze I managed to place the scope on my WO Eztouch mount (couldn't be bothered with polar aligning the CG-4) and test it on the following objects;

M57 - beautiful, perfectly formed doughnut floating in space - wonderful view

Jupiter and moons - lovely and big using my 8mm Hyperion and although it bubbled away in the atmosphere during the few moments of clarity I could easily make out the bandings and details even without a filter of any kind, the best I've seen of Jupiter so far.

Various double stars - all resolved with ease using the 8mm Hyperion much easier than with the WO Megrez 72FD.

and finally spent almost an hour on M13 which, to put it mildly was spectacular! Clearly resolved I manage to make out the propeller and hundreds of the outer stars (and I didn't have to use 'averted vision') - simply marvelous!

The optics are great and by using the lens cap and the 'stop down' (smaller hole with cap placed in the center of the main lens cover) it removes almost all CA on bright objects such as Jupiter and the brighter stars.

All in all I think the Omni 120 is an excellent purchase and would happily recommend it.

Now, if I can only get another clear night to feed my new addiction to M13 and also test the mount out!

Clear skies to all....