Celestron Omni XLT 120 or XLT 102

[jdg600]

As I seem to be mostly interested in double stars and planetary these days I'm thinking of trading the dob in for a refractor. I quite like the Celestron Omni XLT 120 or  the Celestron Omni XLT 102, both of which are on offer at FLO at the moment, but I don't really know anything about these scopes. Does anyone have any experience of them?

The CG4 mount looks sturdier than Skywatcher's EQ3-2 but I'm wondering if the 120 is undermounted on it and if I'd be better off with the 102, especially as I'd like to piggy-back my dslr on it.

Any advice on this would be most welcome.

John

[nightfisher]

Hi John, the best refractor in this price range has to be a TAL 100RS, but its getting hold of one, i am not aware of any dealers with any in stock and the secondhand ones seem to get snapped up by pst modders, but if you can find one and get an AZ4 mount this makes a pretty good combo.

Re the omni scopes i would agree the 120 would feel a little undermounted, but it would work okay

[jdg600]

Thanks Jules. I hear what you're saying about the Tal, I've always wanted one but they come in at about £500 on a EQ5 and that's a bit outside my budget. Also I really want an eq mount so that I can piggy-back my camera for wide-field ap.

Do you think the Tal is significantly better than the Omni 102? I did read somewhere that some of the later Tal's have quality control issues? 

[Fozzie]

Morning John..

Agree with Jules about the tal100rs, in this price range, whilst I've not had the pleasure I did alot of research and couldn't find a bad thing against it a few months back when I was looking at a similar dilemma...

I was upgrading from a 3rd hand 102xlt ota that I'd aquired.. It was a nice scope, split the double double with it from less than perfect conditions, that was on my eq5.. i think both would do very similar jobs the 120 might just take more time to settle down after being moved/focused etc.. lovely scopes.

Although it would be interesting to see it along side the skywatcher offering To see if any difference is apparent in the xl coatings..

One question, mischief here too... i notice you have a skymax90 in your sig... why not keep the dob.. (you never know aperture fever will hit you) sell the 90 ota (keep the mount) and get the 127mm skymax to go on the synscan mount.. would be a nice pairing and save a bit too and you can get a dslr mount for the ota too?

[Moonshane]

I cannot see which dob you have but for your budget I would say a 6" f8 dob would a good option.

[nightfisher]

I have to say for doubles and planetary i might agree with fozzie re the 127 mak, these little Maksutovs really do punch above there weight, they hold collimation with ease and are really easy on a mount, i have the 150 mak and its a superb tool

[jdg600]

Thanks for the replies guys. I have thought about swapping my Skymax 90 for the 127 version. I would have to get a better mount for it though, I know a lot of people swear by the Skymax 90/Synscan AZ package but I hate my Synscan AZ: I find it slow, noisy and worst of all wobbly.

I know the 127 OTA is highly rated but somehow it doesn't have the allure of a refractor.

[jdg600]

... but as we're talking about compact catadioptrics, how do people rate the Omni XLT 127 SCT?

[Fozzie]

Agreed.. i bought my frac genuinely on a 70/30 split that it looked fantastic (70%) and it would serve me better as a bit more grab and go and the views I'd get on doubles, planets and the moon (30%) which I'm really starting to like as a target..

Now I simply love it.. but it does need a very tall mount..

Don't know about the omni 127.. but looking at the mount I think the difference be ween the eq 3-2 and cg4 is the tripod.. The head looks the same..

The omni 127 is circa £420, the omni 120 £379 and the skymax 127mm is £385 on the eq 3-2.

On thing to note is the height of the ep on the mount.. point a frac up and your on your knees almost even with the tripod extended... you won't get that with the skymax or omni 127, nor will you get any CA (i think!?)

Good luck in your choice, hope this helps some what..

[orley]

I had the Omni 102 for a while on the CG4. Was okay as long as properly balanced. From experience of this I'd think the 120 would be pushing it load-wise. Bear in mind the CG4 isn't driven and motors etc. cost over £100 new. The scope itself was nice but showed a fair bit of chromatic aberration on the moon and jupiter. Focuser is ok. Kept me happy for a while. Am going to go against the grain and say I was disappointed with my Skymax 127 and offloaded it - nice, compact, well built but looking in contrast and sharpness compared with a refractor. But that's merely my subjective view.

[orley]

'Lacking in contrast' darn predictive text!

[rowan46]

I have a c5 on a portable mount and the one thing it is very good on is doubles as I am pretty sure a mak would be. This is on abs at the moment 

http://www.astrobuysell.com/uk/propview.php?view=90567

I have no connection to the sale

[tjr]

One question, mischief here too... i notice you have a skymax90 in your sig... why not keep the dob.. (you never know aperture fever will hit you) sell the 90 ota (keep the mount) and get the 127mm skymax to go on the synscan mount.. would be a nice pairing and save a bit too and you can get a dslr mount for the ota too?

I think this is a really good idea if you are interested in planets and double stars. The dob would be a great complementary scope too if you wanted to do some deep sky observing.

[keithatrochdale]

No matter how good a scope, if the mount is not good the scope is never going to work well.

I see you are in Lancs, why not pop up and visit us one Saturday night, if you let me know in advance I will throw my XLT-120 in the car.

[Lowjiber]

I've had the XLT 120mm on a CG-4 for a couple of years.  Outta-the-box, it's a very nice rig, and I've spliit many stars with it.  The XLT coatings that Celestron uses are really very nice.

I've added a few upgrades (not always needed, but I can't help it. )

The best thing I did was add the 18" pier extension between the tripod and the mount.  Orion makes it and it prevents strikes, etc.  I also added a polar alignment scope to the mount.

To the back end, I added the following:

2x Crayford focuser (I use 'em on every scope that comes with a rack-and-pinion focuser.

35mm focal extension (Let's me use longer eyepieces without drawing the Crayford all the way out.)

GSO 2" 99% dielectric diagonal (I just like 'em.)

GSO 8 x 50 RACI

I don't really do AP with this scope, but keep the mount aligned and covered 24/7/365.  I have the drive motors, but usually only drive the RA axis when viewing.

I can assure you that the scope is not "under mounted".

There's a pic of the scope below... hanging in it's "gun rack" in the scope room at my house.

Clear, Dark Skies

[jdg600]

Thanks for the offer Keith, I'd love to pop over and have a look at the XLT 120 some time if we ever have any clear skies.

Love the 'gun-rack' Lowjiber. I bet you get some wonderful skies out in Nevada. It wouldn't be worth keeping a mount permanently set up and aligned here in north-west England, we so rarely get any clear skies.

[Lowjiber]

Thanks for the offer Keith, I'd love to pop over and have a look at the XLT 120 some time if we ever have any clear skies.

Love the 'gun-rack' Lowjiber. I bet you get some wonderful skies out in Nevada. It wouldn't be worth keeping a mount permanently set up and aligned here in north-west England, we so rarely get any clear skies.

Thanks.  I have three of them for different scopes.  I can't build an "X" with two popsicle sticks, but my morning coffee-drinking buddy, Jerry, is a master with all things "wood"... He makes 'em for me.