Is the Skymax 180 Pro really that good?

[Ags]

On the FLO website the max magnification for the Skymax 180 Pro scope is given as 540x, which is phenomenal (3 times aperture in mm, 50% more than comparable scopes). FLO quote 2 times aperture most other scopes.

Would the scope give brilliant planetary views at more sane magnifications? Is it a good basis for taking pictures of planets, or do you really need a 9.25" SCT or higher? Celestron claim a similar max magnification for the 9.25 SCT (555x). Not that I'm saying those magnifications are practical, but I'm using them as a guide to resolving power and optical prowess of the scopes.

[moocher]

I`ve looked through a Skywatcher 180 and i must admit i was impressed!!! If one came up at the right price i`d be tempted to jump on it..... and i own a cracking and i mean superb C8!!!!

Alan:D

[A McEwan]

Is it that good? Honestly? No - it's better.

[A McEwan]

I got mine for a bargain second-hand price and the times I've used it on Mars and Jupiter it's given staggering detail, sharpness, contrast and colour purity. Hardly any image shift too and good solid build quality. Not exactly luxurious, but a good workhouse planetary scope that's built to last.

[optical thrombosis]

I had the opportunity to do some planetary viewing on a friends 180 and all I can say is I was blown away!

[mark7331]

It may be a good scope but the maximum "useable" magnification will be 50-60 x the aperture in inches - i.e.- 354x to 425x. Magnification isn't everything though.

[A McEwan]

In my experience I tend to now ignore the old "50x per inch" maxim that has been touted around for decades. Improvements in coatings, manufacture, glass types have all been made, to the point now where some scopes can be used at magnification far in excess of this. I'm not saying that it isn't a good reference or general guideline, but I would say that there are now many exceptions to this and that it shouldn't be considered a "rule" any more.

Agreed, magnification isn't everything. Some targets, particularly Jupiter, offer a better, clearer view at moderate magnifications rather than excessively high ones and it's all a matter of balancing sharpness with detail resolved.

[red dwalf]

isn`t the 180 a f15 scope compaired to a f10 sct, therefore it should give better contrast on planet views and images.

[Ags]

I was only using magnification as a guide to optical performance. Anything over 150x is seeing limited anyway. Please let's not discuss magnification but the Skymax 180.

Another odd feature of the Skymax 180 is that it weights 7.5 kilograms. That makes it lighter than the Celestron 5" SCT, which is incomprehensible. I'm tempted to get a Skymax second-hand and try mount it on my NexStar mount.

[mark7331]

In my experience I tend to now ignore the old "50x per inch" maxim that has been touted around for decades.

I do agree but the old measure still gives a good ballpark. Don't rely on manufacturers zillion times magnification. Quality of optics is where it counts not magnification in my humble opinion.

[AztecastroMcJ]

think this is Error poss from telescope company's

e.g SW 180 Pro = x540mag

or SW 190MN = x570mag

shud be

x360 and

x380 these are quoted on Skywatcher Site

http://www.skywatchertelescope.net/swtinc/product.php?id=153&class1=1&class2=108

[A McEwan]

Ok, getting back to the 180, some people say that cooldown is a bit of a problem with all that glass. I usually take two scopes out and use the other while I'm waiting for the Mak to cool. Also I keep it in my shed when not being used so I don't have too much of a problem with cooldown. It's nice too that using a mid focal length eyepiece like a 12.5mm Ortho gives a very satisfying 'planetary' type magnification of 219 while still being comfortable on the eye.

Ant

[dweller25]

I bought a 180 Pro for planetary and kept stored it in the house (no choice) and found it never cooled down enough for decent planetary views when I took it outside. This was because it could not keep up with the dropping ambient temperatures.

[dweller25]

Ok, getting back to the 180, some people say that cooldown is a bit of a problem with all that glass. I usually take two scopes out and use the other while I'm waiting for the Mak to cool. Also I keep it in my shed when not being used so I don't have too much of a problem with cooldown. It's nice too that using a mid focal length eyepiece like a 12.5mm Ortho gives a very satisfying 'planetary' type magnification of 219 while still being comfortable on the eye.

Ant

Ant,

Which is the best planetary scopes in terms of sharpness, contrast and detail the 120ED or the 180 Pro ?

[A McEwan]

I haven't compared the ED120 and Mak 180 on Jupiter yet. Going by the views of Jupiter I've had through the Mak though, I'd have to guess that it beats the Equinox on virtually everything. I think it would even be very close on contrast. It is an extra 60mm aperture after all, not allowing for the small secondary obstruction.

Mars is easier as I've used both to observe Mars. The Equinox gave quite detailed views with high contrast and nice colour. However, it left me wanting to use more aperture. The Mak was the cure for that and the detail it threw up was more plentiful. I suspect that the extra resolution compensates somewhat for any slight loss in contrast, but not having done a true side-by-side I can't say for sure.

Both are great on the planets, but the Mak shows more detail.

HTH,

Ant

[Ags]

This contrast thing is interesting. Contrast is reduced by the diffraction from edges in the light column. Obviously a central obstruction introduces more edges and more scattering, but also the proportion of outside edge reduces relative to light gathering as aperture increases. So I'm not sure what would have less diffraction - the smaller 120mm refractor (with proportionally more diffraction from the lens edge) or the 180 mm Mak (proportionally less diffraction from the lens edge, but a bit more from the central obstruction).

[dweller25]

This contrast thing is interesting. Contrast is reduced by the diffraction from edges in the light column. Obviously a central obstruction introduces more edges and more scattering, but also the proportion of outside edge reduces relative to light gathering as aperture increases. So I'm not sure what would have less diffraction - the smaller 120mm refractor (with proportionally more diffraction from the lens edge) or the 180 mm Mak (proportionally less diffraction from the lens edge, but a bit more from the central obstruction).

Good point and in my opinion a critical one if you really want to see the planets well.

I have a 128mm refractor and had the Skymax 180 Pro, the 180 Pro (32% CO) came nowhere near the refractor on the planets in terms of contrast, sharpness and overall detail. My old C9.25 (36% CO) was just the same.

My 8" F/6 Skywatcher Newt (23% CO) will beat the refractor if seeing is good on the planets but stars are still not quite as sharp as in the refractor.

CO above 25% does have a significant effect on planetary performance in my opinion.

So if you want the best planetary views get the biggest aperture you can manage with the smallest CO.

[Astro_Baby]

I have a Skymax which has only been used once so far. The scope showed some potential for planets but the only time its been used was the last night at SSP - dew was horrendous. The scope seemed to be a total dew magnet.

I found the image shift pretty scary myself and if I were keeping it ( jury is still out on that ) I'd want some dew heaters and a visual back.

The other thing is I am so used to rteaching for certain EPs (ie a 5mm) I had to kind of reclaibrate my head.

Obvious faults I think with the scope are;

1/ It could sersiously do with a cooling fan in the back end and

2/ The supplied finder scope cant be aligned because the Skywatcher quick release finder scope mounting doesnt have enough movement. The findershoe is slightgly whacky as its mounted on the rear cell which has a small slope on it causing the finder show to be slighlt pointed upwards.

If I were keeping it thats another mod I would make for sure.

The views of Jupiter I suspect would have been superb if the dew had been better controlled.

Personally I cant decide whether I need a planetary scope that will give great views but will always need a huge cool down period and will always be super sueceptible to dewing.

[A McEwan]

I have a 128mm refractor and had the Skymax 180 Pro, the 180 Pro (32% CO) came nowhere near the refractor on the planets in terms of contrast, sharpness and overall detail. My old C9.25 (36% CO) was just the same.

That's not the same as my experience! Mind you, your refracotr has 8mm more clear aperture by diameter than mine...

AB, I'm sorry to hear that your Mak isn't more user-friendly for you. I find that changing my timetable slightly or using another scope first allows the tube to cool perfectly well, so no need for a fan for me. Hadn't noticed the finder oddity either - but then I use a red dot and it aligns fine with the view through the eyepiece.

Hope you get some good use out of it when you're happy with it.

Ant

[John]

....Another odd feature of the Skymax 180 is that it weights 7.5 kilograms. That makes it lighter than the Celestron 5" SCT, which is incomprehensible. I'm tempted to get a Skymax second-hand and try mount it on my NexStar mount.

My old C5 weighed in at around 4kg for the OTA - perhaps you mean the C8

I wonder how the Skymax 180 would compare to the Explorer 190MN ?. The mak-newt is more £'s and longer and heavier but does offer wide field possibilities as well.

[Astro_Baby]

Oh I am not downhearted - just realtic these days and I dont expect to use any scope more than 2 or 3 times a year and so far the only chance to use the Skymax was blighted firts by a mechanical failure (mount seized up) and then by dew (it rained for most of the day before night settled down).

For me its a case of do I really want to cough up time and cash to get a fan fitted, shum the finder mounting, get a visual back, heater tapes etc etc. I am waiting for the scope to deliver something to me before i invest in it

[mike bacanin]

Good point and in my opinion a critical one if you really want to see the planets well.

I have a 128mm refractor and had the Skymax 180 Pro, the 180 Pro (32% CO) came nowhere near the refractor on the planets in terms of contrast, sharpness and overall detail. My old C9.25 (36% CO) was just the same.

Don't forget David, you own probably one of the best 5" Fluorite Apo ever made.

anyone taking the 180 out from a warm room into cold winter air is in for a very long wait before the image settles due to cooldown.

Agree with Astrobaby, a fan is very deirable on Maks of this size and bigger

Mike

[Ags]

Part of my original question was whether the Skymax 180 Pro would be any good for photographing planets, or would the aperture of a 9.25 SCT beat it, regardless of contrast? Anyone taken any photos with a Skymax 180?

[michael.h.f.wilkinson]

Part of my original question was whether the Skymax 180 Pro would be any good for photographing planets, or would the aperture of a 9.25 SCT beat it, regardless of contrast? Anyone taken any photos with a Skymax 180?

The skymax should be excellent for planetary photography, though I would expect the 9.25 SCT to beat it (that has a very good reputation on planets) by a small margin, due to its larger aperture, but only in good seeing conditions.

Dew is a perpetual problem on any SCT or Mak, so some dew control is needed for prolonged viewing. Regarding cool-down, the SCT has a rather thinner corrector plate, so it may cool down quicker. However, I always get the OTA outside at least an hour (or two) before I do any serious planetary work. I keep myself amused with DSO-hunting in the mean time (globular clusters in particular in recent times). That is the great appeal of my C8: it is compact so I can take to locations outside the city, works well on planets and on DSO observing. The smaller CO offered by a Mak or Newt is better for planets, but the SCT is a very good allrounder.

Just my tuppence

Michael

[Phil Fargaze]

I am also seriously thinking about getting a Skymax 180 Pro but have similar questions as Ags. I would keep it in my roll off roof shed so that should help with cool down. I have a dew band ready to use, and I have an Heq5 mount ready to use, which I hope would be fine with the weight of the scope. I was told that image shift when focussing can be a problem. As for planetary photography, would it work well with a web cam? Would the scope be suitable for occultation work, which would include asteroidal occultations too?