Is something wrong with my skymax 127 maksutov?

[aerohound73]

Hello,im a newbie,can someone explain why the performance difference between my two scopes? I own a Meade DS2102 refactor(102 mm aperture,FL 800 mm),basically its not well built(cheap plastic focuser),but damn....the optics in it are awesome!! I wanted to get something a bit bigger and more powerful for viewing Planets and DSO in detail.Got a good deal on a Skywatcher skymax 127(127 mm aperture,FL 1500).However,my refractor out performs it all the way.Images in the refractor are very bright while the same view in my Mak is much,much darker.But here is where my disappointment is: all ten of my eyepieces(40,25,15,12,10mm Plossl 9,6,4mm orthos) work great in my refractor,but in my Mak the arent very good at all.Example:while viewing jupiter,all these eyepieces give me good views with very good detail.Even when Im pushing the magnification limits of the scope with the 9,6,4mm eyepieces,I can still see with good detail the different gas belts and great red spot.very impressive! But the same view of jupiter with the Mak,not good at all.The 40,25,15mm eyepieces still work great.But at 12mm the image starts getting blurry.Can only make out 2 of the gas belts.At 10mm image is blurred even worse and hard to focus.At 9,6,4mm I just see a bright white spot with no detail at all.Its like it just doesnt want to focus the image.As for collimation of the Mak,its factory set and cant be adjusted.Can anyone explain why its not focusing or what is going on?Any input would be appreciated.I thought the Mak(with larger aperture and focal length) would outperform my refractor,but that is not the case.Im so disappointed with the Mak I just may sell it to fund buying an Orion 8" reflector OTA.

[Moonshane]

the Mak will need a good hour or possibly two to cool I should think before it will perform at its best - this assumes storage inside - if stored outside at ambient then ignore this comment.

because your Mak has a focal length just short of double that of the frac, I'd expect the 16mm in your frac to give the same sized imaged as the 25mm in your Mak. Is this the case? if you are cooled then I'd expect the Mak to be able to generate good images at perhaps 150x so your 9mm ortho or barlowed 15mm Plossl should be OK. It should outperform your frac in all but the very worst seeing.

an 8" reflector would outperform both scopes noticably.

[JamesF]

It would also make sense to check the collimation of the Mak and to make sure it's on a mount capable of carrying its weight. You'll probably need exceptional atmospheric conditions to be able to use the 4mm ep usefully in the Mak and fairly good conditions for the 6mm because of its greater focal length, as Shane says.

James

[ronin]

I have found the same.

My small refractor(s) often (usually) outperforms a somewhat larger Mak or SCT in terms of quality and clarity of image.

I sometimes think that we make too much of the terms BIG and LARGE.

Visually on planets and many DSO's my best views by far have come from a fairly mediocre achromatic refractor. Mars has never been good, although never pointed a reasonable sized refractor at it, but Jupiter and Saturn views have by far been better through a refractor.

You have a 102 and that would mean stepping up to something like a 120 or 150, and with a refractor the cost jumps proportionally more with aperture. So perhaps a possible increase would be the Celestron/Skywatcher 120's. I see TS do a 127. The alternative being similar size but ED, however again a jump in cost.

[Carbon Brush]

Good comments from the earlier posts.

Generally the SW127 is thought of as a good performer. I don't know of any poor reports from them.

Don't forget that with the 1500mm FL of the mak, your 10mm EP gives 150x magnification. You need a good sky to take this. Quite a few nighrs just aren't up to this.

Have you tried a true side by side comparison? That is same night and same object.

This of course needs two mounts, or a dual bar and heavy duty mount.

I have found that 'comparisons' made on different nights mean nothing and even the same night with a time separation can be misleading. An hour or two can make the difference between Jupiter being a blob and seeing good cloud bands.

Hope this is useful.

[Astro_Baby]

There are lots of reasons why you may be seeing these issues, which ones are really at the nub of it its hard to say.

Heres my two penneth in no particular order;

1 bear in mind the MAk doesnt actually have that much more aperture. Its true aperture is about 117mm and on top of that it has a central obstruction so its practical aperture isnst that much greater than the frac you have.

2 The Mak will not a long time to cool depending on ambieng temp and how warm the Mak is when its taken outside. It will need at least an hour to come to ambient. I find my larger MK will be usable after about15 minutes but it needs a good 90 minutes before it can run at full power.

3 Because of the Maks frighteningly long focal length you have to adjust your thinking on eyepeieces. This seems obvious but it often quite inbuilt in us to favour a particular eyepiece irrespective of the scope in use. For instance in my TAL 1000mm frac a 10mm gives (by a strange quirk of maths) a magnification of x100 but in my Maksutove with a do al length of almost a meter the mag zooms up to x284 which on most UK nights is unusable.

4 Diagonals...which one do you use ? The Skymax 180 used to ship with an abomination of a diagonal and that means the 127 did too. Vhangimg that over might just be the best thing you ever did. Obviously your Meade frac might have a dreadful diagonal too. I dont know.

5 The 127 should be forgiving of EPs because of its high focal ratio but hou MAY be suffering focus woes. Sometimes with a MK the focus can be a bit imprecise.

6 Collimation....I'd bet the 127 is collimated. Its takes a. It of a battering to make a Mak go out of collimation. You say its not collimatable........are you sure about that ? I thought they were.

7 Weight, no idea what your plastic frac may weigh or how its mounted. The 127 is quite heavy by contrast. i used to own a Nexstar 4 whixh is a bit smaller but a very heavy little scope. Surpisingly heavy for its size. A steady mount is worth an inch of aperture so it may be a reason planets dont look good. Nothing wrecks a highmag view worse than wobbly mounts.

Thats all I can think of.

[JamesF]

6 Collimation....I'd bet the 127 is collimated. Its takes a. It of a battering to make a Mak go out of collimation. You say its not collimatable........are you sure about that ? I thought they were.

Mine certainly is. I've taken it apart completely, rebuilt and collimated it. Here's my star test:

It's a bit of a pain to do without an artificial star and a garden hundreds of yards long, but it's certainly possible.

As Astro_Baby says though, you need to have kicked it about a bit (or taken it apart to get it out of collimation in the first place.

James

[JamesF]

I have found that 'comparisons' made on different nights mean nothing and even the same night with a time separation can be misleading. An hour or two can make the difference between Jupiter being a blob and seeing good cloud bands.

Have a look at Chris Garry's (cgarry) Jupiter comparison thread today. That shows the seeing going from poor to good to poor again in the space of about twenty minutes...

James

[JamesF]

Here's the thread:

http://stargazerslounge.com/topic/168565-jupiter-seeing-demonstration/

James

[ilove1995]

I'm probably stating the obvious but could it be that your mak may have dewed up when you were testing it? I've got the nexstar 4se and it gets covered in dew so quickly. I've made a dew shield for it now (about to go outside with it as it's clear skies here) but without it I find the scope starts to collect dew in less than half an hour.

[ilove1995]

Would just like to add also that the views from my 4se are far superior when compared to my 70mm refractor.

[Astro_Baby]

Its not obvious actually iLove...........its a good point. Maks are generelly dew prone and a dewshield or btter still a heated dew shield is an essential bit of kit for a mak. Mine will dew up at the slightest provocation.