Skymax Pro's vs OMC

[beamish]

How do these compare ?? Having seen the stunning results of Al's planet killer, a mac is definitely going to be the scope I next go for -something short but with a long fl.

Definitely can't afford new so would like some ideas so as I can keep my mincers peeled

I know there's a cracking 180Pro up for sale at 500.00 but more than my budget and besides I still need to squirrel the cash to one side Ssshhh

Karlo

[alexog]

I've read the skymax pro is really good and 150mm (10mm is 10mm). You may find the OMC has a flatter field, on good nights the moon is crisp across the field of my DSLR at prime focus, contrast is also really good and it's much lighter, longer fl and there also seems to be more about s/h? Don't ask me though, I'm totally biased, lol.

[johninderby]

With the OMC140 it's important to know which optics are in it, the standard 1/4PV (lot of these about second hand) or the Deluxe (much rarer) with 1/6PV & Hilux coatings or the upgraded Deluxe (very hard to find) with 1/8PV & Hilux.

Used basic ones can be had for around £300.00 and Deluxe ones for about £400.00 to £450.00. The 1/8PV do go for a lot more if you can actually find one, and are the most desirable and are incredible performers. It seems that owners of the 1/8PV version just don't let go of them, and they would be out of your budget anyway. The basic OMC140 is about equivalent to the Skymax Pro in optical quality.

John

PS

I have owned a Skymax 150 PRO and now have an OMC140C Deluxe iwth 1/8PV

John

[Dangerous-Dave]

Never owned the Skymax Pro but I owned a blue tube Skymax, and now own the OMC140, and the OMC is on another planet optically. I find it hard to believe that a mass produced, production line Mak could rival handmade optics for quality, especially if you opt for the deluxe.

The field of view is indeed shockingly flat for a Mak. It also has three bolt collimation, versus six for Skymax.

There's an old purple deluxe version for a very reasonable £295 on Buy/Sell. Might need the focuser upgrading, as they weren't too good on the purple models, but otherwise a snip.

U.K. Astronomy Buy & Sell

[alexog]

Glad to hear that about the delux guys, I'm off to edit my signature...<--I've been dying to use one of these little gizmos. Actually, no-one likes a show off, so I'll leave it as is. Nice to know though. I reckon if you found a well priced Skymax pro it'd be a very good performer, that 180... worth keeping an eye on.

[Whippy]

Also bear in mind the Intes Micro Maks Karlo, you may be surprised at how little you could pick one up for secondhand. Arguably, they're better optically better than both the Skymaxes and the OMC's plus fully collimatable. Not sure about the newer models but my old MK66 had a SCT thread on the back which is another bonus .

Tony..

[beamish]

Yes Tony, I recall the temptation when you were selling it , good point.

[Whippy]

Yes Tony, I recall the temptation when you were selling it

Still miss it too ..... <snif>..

Tony..

[FLO]

... now have an OMC140C Deluxe with 1/8PV

John, are you going to the Salisbury Star Party? It'd be great to see your OMC140 1/8th alongside our Skymax 180 PRO

I am guessing they sell for a similar price

[johninderby]

The upgraded Deluxe OMC140C is a fair bit more expensive than the Skymax 180. It would definitely beat the 180 where contrast is more important (lunar / planetary) but the 180's aperture would give it the advantage on DSOs etc. The OMC140 should be regarded as a planetary scope though, don't buy it if you want an all-rounder. As to optical quality it's as good as any Intes Micro with a 0.989 Strehl mirror which to give some reference an Astro Physics or TEC mak is usually about 0.980 strehl.

The OMC140 has the advantage in cooldown time and is less than half the tube weight so it doesn't need as heavy a mount. A much smaller, lighter and more portable setup that can also be used on an Alt-Az mount.

Unfortunately I won't be able to attend Salisbury (other commitments).

John

[FLO]

That's a pity, perhaps another time

[GazOC]

Optical quality aside, the difference between 140mm and 180mm is pretty hard for the smaller scope to claw back on planetary detail.

[FLO]

The Skywatcher's Maksutov spherical surfaces are 'relatively' easy to polish to a very high standard, I would expect both the Skymax 150 and 180 PRO models to exceed the minimum requirement of 1/4pv.

If any other OMC owners are at Salisbury....

[Kevin Ellis]

Karlo

I also have an OMC 140 deluxe with 1/10PV Zerodur glass and 2" back.

I would echo John's comments but would add that even my OMC 140 , with Zerodur glass, can take several hours before tube currents disappear. Although a fan does help. It is not a grab and go scope. This is a problem with Maksutov telescopes due to their thick corrector plate. Larger scopes will have longer cool down times.

My OMC is very very very good, full of contrast, but it is still only 140mm. On axis it does not out perform my £50 second hand home made 20 year old well collimated 6" f6 reflector. It also has a good mirror.

[johninderby]

It could be down to the carbon fibre tube, but my OMC140C does seem to stabilise in about an hour or so with minimal tube currents. Anyway I'm happy with it, although if a TEC140 came up at the right price..........................

John

[beamish]

Crikey Kevin that's quite a while for cooldown time Tho I do understand why. My Cape has a flat optical glass so is in effect a closed Newt, v similar, but that rarely takes more than 40 mins/1 hr to cool at worst, usually quicker cos it's kept in the basement

John, Cape, when they were around, used to offer the range in CF (only the 200 was available in ally tubing, IIRC). The CF models used to have fans built into the rear of the mirror cell- I always assumed that that was because the CF took longer to cool as it dissipated the conducted heat thru slower than the ally, hence the currents would be trapped-probably wrong.

[Kevin Ellis]

I have read claims that carbon fibre tubes offer greater rigidity and focus change over an imaging session and are the best choice for astro imagers. The aluminium tube offers a faster cool down time and may therefore be the best choice for visual use or when the scope is not located permanently outside.

My aluminium tube OMC cools down a lot quicker in the summer when the temparature difference is not as great.