Alkaid

6 hours ago, Mr Spock said:

Top view is very similar to what I'm seeing, only with much brighter highlights.

I see from the lower image the bright crater in the south is actually two craters... I need the Hubble for that I think 😜 

Thanks for the screenshots, they’re great. I had a look on the web for the craterlet labelling images and couldn’t find much. I’ll use these next time.

Cold clear night, had both 90mm achromat and C8 SCT out. Started with smaller scope whilst C8 acclimatised.  Initial target was Eratosthenes and spent some time on it, before noticing Stadius close by. Not really looked at this due to its proximity to Copernicus, but was slowly captivated by the sheer amount of interesting craterlets within the flooded crater.  After an hour or so, switched to C8 and had fun exploring the craterlets in greater detail. Seeing tonight supported a steady max of x160. I did attempt x220 but not really comfortable observing.  But the modest power of x160 was quite enough for counting and examining these features.  The stadius craterlets are bigger and easier than say the Plato variety, at 3-6km in diameter and make good observing.

ATB Steve

Looks like a good fit for an old EQ2 I have lurking about  🙂

Fantastic project.  I had a TAL-1 and the optics were very good.  The '2' will be brilliant on the Moon.  Look forward to seeing more!

On the scope....for planets you want aperture and focal length.  

On the mount...agree that GoTo can be frustrating and often stops sessions.  (I stopped using it).  Mountwise, I use a simple driven EQ mount for planets.  Simple, nothing to go wrong, tracks great.

If I were going down the driven EQ mount route, scopewise I'd have a CAT such as a C8, Mak180, Classic Cassegrain etc.

I wouldn't bother with the single arm Nexstars etc...there is too much vibration on planets at higher powers.

If I wasn't going down the EQ mount route, I'd go for aperture and get a 12" dob (provided I was happy getting it in and out, they are cumbersome and heavy).  With a scope that size you still have a lot of focal length for upping the power when it suits.  You'll lose the tracking....but the aperture will give some great detail.

Glad it’s not just me or my scope. The seeing is awful! I get long periods of mushiness, then fleeting views of the shadow transit. The contrast is poor, the shadow is a grey/brown rather than the normal hard black.

The mosaic is one of the finest and sharpest I've seen - hats off Sir!

Can confirm the C8 is a good match with the EQ5 for visual, it’s quite a light tube when pitted against the 7” maks. 

That is great! Any Lunar images coming up? Nice.

These are great little scopes, I owned one for several years. The optics are of very good quality.

I use the 102, totally agree that these ST’s are great bang for buck. At low powers I find mine just great.

I might add that I’m the sort of person who gets irritated when discovering small ‘faults’ that originally escaped my attention. Probably some kind of OCD thing haha. I must admit, I would be annoyed if say my kit was out of warranty and I received a (well intentioned) message advising of it’s defects. Particularly if I was quite happy with it...sometimes ignorance is bliss...

Going back to my OCD and thinking of other purchases (non Astro related), I realised that most things have an acceptable tolerance regarding perfection...nothing we buy is 100% perfect...there will always be that little imperfection in aesthetics that can only be seen if you are REALLY looking for it (a pin prick in the paint job for example)...it’s the same with a lot of things, including optics I feel.

Having spotted the problem with someone's scope, I would...

a) Tell them if I knew them / conversed with them a lot.

b) Not tell them if I did not know them and they haven't asked for mine / others opinion.  

c) If I saw one of the many "what do you think of my image / how can I improve it" threads, I may respond to that as it's a direct question.  But I would do it gently..."bit of astigmatism there, feel free to PM me and I'll be happy to tell you how I arrived at that conclusion" etc.

2 hours ago, andrew s said:

Wedge is when the surfaces of the corrector plate are not parallel and  resemble a weak prism.  As they are thin with near zero power, as said above, they cause little chromatic aberration.  In larger sizes it can be an issue and the UK Schmidt camera has an achromatic  doublet corrector.

Regards Andrew 

Thanks, did not know that.

6 hours ago, Peter Drew said:

The main potential cause of chromatic effects in Maksutovs and Schmidt-Cassegrain telescopes is mechanical "wedge" across the optical diameter of the corrector elements.  If the wedge is severe, the component operates as an objective prism and introduces false colour. 

I'm interested Peter, what is 'wedge'?  Thanks.

Following with interest...

Longshot....could there be a separate setting on the controller for use in the Southern Hemisphere? Just a thought..

Very nice!  Yes, the seeing was truly good last night.  I had a think about it and thought it could be down to it being cloudy all day, meaning that the sunshine didn't warm the ground and there were no thermals coming off the land..then it suddenly cleared.  I had some of the best lunar viewing for about a year and spent some time counting craterlets in Ptolomaeus.

A really nice evening.

Great images Michael.   I like the M13 one, can you tell me what is the galaxy shown at 8 o'clock in the image?  I've seen many pics of M13, but only on yours did I spot that little galaxy!

Nice!

Great read, particularly amusing about having a model twice in some cases....it's hard to get off the merry-go-round!

I had a vision of you standing over the larger Maks, berating them for their slow cooling...

Cheers Steve

For full moon (I’m guessing from last night?) they’re fairly sharp, it’s really hard to get definition with direct illumination. Nice effort!

Very crisp!

I was also going to suggest ED80 or one of it’s variants, maybe also a 72..

Super sharp...great images!

Admittedly no experience of these, so apologies if this is a little woolly. There is a difference in the alignment software and method of alignment.

If I remember rightly, the Celestron is apparently slightly easier to align, with a simpler process.   But I think I’d have the 102 over the 90.