chiltonstar

I see M42 as a sort of pale lilac-green. One problem I suppose in judging the colour of nebulous objects is that the Purkinje effect may make things look slightly blue, and also after using a red head torch, colours may be distorted until the eye adapts again.

Chris

Very nice Michael!

Chris

I find it is a good scope for planetary imaging, but it is only 180 mm or 7 inches. You will find that all the best planetary images are taken with larger SCTs like the C14. Aperture is everything....

Chris

Here at least (Oxford), seeing and transparency are often mutually exclusive, ie seeing is best on warm hazy evenings with poor transparency, and transparency is often best after rain - usually nights with poor seeing. 

Must be somewhere in the world with 300 nights + of excellent seeing and transparency?

Chris

As Sissy Haas says, "double stars are among the best kept secrets in Nature". Very true. There are so many beautiful and challenging double and multiple stars that once you get hooked, it is a lifetime pursuit. Such a pity that more of us are not interested in them!

Congratulations for starting down this path...... I am a few years ahead, but still a beginner!

Chris

Hobbies or interests have to be essential in these challenging times (hopefully only temporary - my left arm is ready & waiting). I took up astronomy for serious when we had our first daughter. After an anxious hour at 2:00 am dealing with teething issues, rashes, food intolerance etc etc I found an hour outside with a telescope completely took my mind off things and allowed me to get back to sleep again easily. It helped hugely after a stressful day at work as well, even if it cut down sleep a bit too much occasionally.

Like Pete, it has helped me cope with the winter months, even if decent nights always seem a rarity - something always to look forward to.

Chris

Heinzel is a messy looking crater isn't it, when the lighting is right?! Not an area of the Moon I look at very often.

Mak 180, ASI220 mono camera, 2000/5000 10ms frames stacked in Autostakkert and processed in PS.

Chris

Nice images! On each clear night when appropriate, I've been recording lunar avi's so that I've got something to play with on cloudy nights while we are confined to our homes.

Chris

Extraordinary craterlet detail.

Chris

Very nice detail!

Chris

4 hours ago, Pete Presland said:

I swapped my Mak180 for a SCT C9.25, because i wanted a bit more versatility with my scope. The slightly shorter focal length and abilty to use a reducer have certainly given me this. Planetary imaging wise, which is what i do most, i am not sure there is a huge difference in the two scopes.

The collimation of my C9.25 has been pretty solid, maybe this down to its hardly ever transported anywhere. The mirror slop was much worse on my Mak180, than the C9.25. That said, my Crayford has pretty much removed the issue.

I'm surprised the 9.25 isn't significantly better than the 180 Mak for planets - I would have thought the 30% increase in aperture would have showed??

Adding a decent focuser to my 180 Mak was also very worthwhile (thanks to @johninderby for the advice) - it has made double star and planetary focusing SO much easier!

One point not mentioned so far, don't C8s only have a 1 1/4" back unlike the 180 Mak (I could be wrong).

Chris

2 hours ago, Nik271 said:

As for mirror flop as a 180 Skymax owner I measured mine looking at Mars near opposition, it was almost the width of the planet, i.e. 20 arcseconds. Not a problem visually but for imaging it can be a real pain when focusing.

It seems that mirror flop seems to be highly dependent on individual models, for example my 127 Mak has no mirror flop I can detect visually (of course it also works at smaller focal length).

The high end models from Orion Optics UK for Mak and the Celestron Edge HD for SCT claim not to have any mirror flop, but are quite expensive.

I cured mine by winding the focus knob from one end to the other occasionally to spread the grease out along the bolt. Worth a try.

Chris

An important question is what do you want to do with your scope, whether you choose an SCT, MCT or something else? Each scope has certain advantages and disadvantages and will appeal to different groups. For example, expert planetary imagers often use C11s or C14s (SCTs), double star enthusiasts are more likely to use an MCT or refractor. Some say that SCTs are better "general purpose" instruments (although usually compromises tend to please no one) and certainly when I chose a 180 Mak the runner up in my decision making process was a C8 (Celestron SCT)

Personally, I like the short tube and closed optics of both designs - I live in an area with farming all around, and on many occasions the air is thick with dust which is easy to remove from the front of a corrector, more difficult from the surfaces of the primary and secondary of some other designs. 

Just an opinion.....

Chris

52 minutes ago, Mr Spock said:

The larger the aperture, the bigger the 'flare' I suppose. I know I saw it quite comfortably in the 140mm Mak; never saw it at all with the C9.25. Sirius was just a kaleidoscope in the C9.25... 

I put it down to be most likely due to tube current effects: if the rate of temperature change (dT/dt) is too high for the insulation around the mak to cope with, there are some tube currents visible, whereas the frac is much less affected by ambient temperature change. But of course, you're right - the brighter the view as the aperture increases, the more you will see flaring effects.

Chris

The Pup is certainly an elusive little canine; on occasions recently, it's been relatively easy to spot with my 102mm f13 frac (Vixen objective) but more difficult with my 180 Mak, whereas on other occasions the Mak shows it more clearly than the frac. The flaring around Sirius is usually less with the frac, and this may be a key factor I imagine.

Chris

Always seems to be a lot of detail in this region, even on non-optimal nights. 180 Mak, 1.4x barlow (Baader), ASI220 mono camera. 2000/5000 frmaes (10ms) stacked in Autostakkert and sharpened in PS.

Chris

There are some superb doubles and multiples in Orion. To spot fainter stars like C Sigma Orionis, I find a cheapo zoom (7.2 - 21.5 mm Hyperflex) invaluable. When I've found a good magnification for the seeing conditions, I change the eyepiece for a better quality fixed focal length one, although it has to be said, the Hyperflex performs very well with a long focus mak.

Chris

1 hour ago, John said:

Quick set up and tear down are key to getting much astronomy done in the current UK conditions

It is clear now so I've popped my 100m refractor out on an alt-az mount and can get on with observing practically straight off.

 

I did exactly the same with my 100mm frac as Sirius was in a good position and barely twinkling - nicely split! For a quick roll-out, you can't beat a frac and a simple mount.

Chris

4 hours ago, markse68 said:

interesting image as very often they appear like little triangles to me also- they seem to suffer from poor seeing a lot more than other stars 🤷‍♂️

Interesting too the colours of the e and f stars- is that real?

Mark

I suspect that the colours are an artefact caused by the faintness of E and F and the purple background of the nebula.

 Chris

With a beautifully clear night yesterday after the rain had cleared, I had another try at imaging the Trapezium quartet in Orion using a 180 Mak, AS1224 colour camera, 125 ms frames and processing in Autostakkert and PS. I've stacked the best 30% of 500 frames. The seeing was variable, but mainly poor to average. Afterwards, I spent a happy hour revisiting many of the glorious Orion doubles until cloud set in.

I've inverted and labelled the frame for identification.

Chris

50 minutes ago, Pete Presland said:

I also owned a Mak180 "Planet killer" for many years. Never had to collimate it either, always seemed spot on with a star test.  It had a fair amount of mirror slop, which was little annoying. That said it gave me some fantastic views of Mars back then, just looked it was already 6 years ago 2014 😲

I sold it and bought a C9.25, which i thought might be a bit more of an all rounder, which it probably is. I would not mind betting though the Mak180 would have had the edge on the C9.25 when came to imaging the planets though. I just couldn't resist the extra aperture.

Here is the beauty "defrosting " after a particularly cold winter morning session.  I have certainly learnt a lot since those days, a heated dew shield essential for this weather, look at that poor corrector plate! 

 

That is a sad sight! The insulation on mine reduces dewing and frosting on the scope and front corrector, and avoids the need for a heated dew shield, although I suppose with a very long session, dewing will occur. The mirror slop I cured using the well known treatment - rotate the focuser to its maximum each way occasionally to spread the lubricant on the screw out along its length away from the area of most use. I've recently added an external focuser as well (not in image) which is worth while, certainly for high magnification.

Chris

I've had a 180 Mak for about 5 years and I've never had to collimate it - the star tests are always near perfect and as they say, "if it aint broke, don't fix it". My smaller 127 Mak (10 years in use) has also never needed collimation.

Cooling can be an issue - I've insulated mine to reduce the problem, but even  w/out insulation, leaving it out to cool is usually enough except on nights when the air temperature is dropping very fast. As others have said, viewing Saturn and Jupiter near to the horizon is difficult because of seeing, but there will be evenings (warm, hazy for example) when you will get spectacular views.

The OP raises the question of special filters; IMO a 10% neutral density filter works well with Mars and Jupiter and brings out more detail. I've tried other filters, but I'm not sure they really made any significant improvement.

Chris

23 minutes ago, Mark at Beaufort said:

No problem John. I have also picked up both planets. 3 Moons visible on Jupiter plus surface markings. Saturn also captured but no Titan as yet. Best view is with 13mm Ethos with the 9mm right against the field stop. 

I have also obtained close up views using the 10mm Baader Ortho + Baader 2.25x barlow

I got a good view just now with my ED80.

Chris

I had a view for a few secs this evening - handheld. Let's hope for some decent weather on the 21st!

Chris

Quite impressive this evening even using bins (15x70s). Can't wait for the closest approach, although based on weather at the moment, it doesn't look promising....

Chris