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How do the secondary mirrors compare? The 300PDS is optimized for photography. Is this ever going to be of interest? If so you will need a big equatorial mount, is the GOTO mount equatorial?. Is the GOTO actually useful visually or do you prefer to star-hop? If you are visual only I'd take the one with the smallest obstruction. And the simplest mount...

Excellent result. Assuming an exposure can be made and read out in 10 seconds, that's over 1000 subs to stack and align over the 3 hours!

I have owned several small apo doublet / triplet scopes in the 60mm - 90mm range and my example has the best optics for the aperture of any of them. Quibbles; The OTA is not the lightest and some people complained of slightly wobbly focusers (early versions only?). The tensions are adjustable, and I haven't hears of this for a while now. It's been around a long time in various incarnations. WO have a habit of changing the model with the weather (it's called continuous improvement..) so the fact that the GT81 has lasted this long with the optics unchanged probably says something about the commercial benefits of keeping it in production. I paid £450 for my MK1 secondhand ant it's a keeper.

Over the past 30 years of using guiding eyepieces equiped with these illuminators I've found them to fail fairly regularly; I've got 2 broken ones and a third that is intermittent...it only works if the two halves are unscrewed a fraction of a turn. They might almost be considered a disposable item. I've seen several guiding eyepieces for sale on ABS "illuminator missing" which probably tells you all you need to know on build quality.

Field curvature often gets forgotten as a source of edge distortion. A ST120 with an ethos 21 sounds like the perfect combo for widefield views, but FC really takes the edge off the experience. I have 2 scopes that are designed primarily as astrographs; one is a TS65Q and the other is a Pentax SDHF75. Both have a flat focal plane built-in for the camera. When teamed up with an eyepiece also having a flat focal plane the view across the whole field is just insanely sharp without any need to refocus. Optically they are the perfect match for Delite and the smaller Ethoses . The tragedy is that it only works reliably for 1.25" format eyepieces with a 1.25" diagonal and reducer. Using a 2" diagonal requires too much in-travel for many fine eyepieces......why, oh why can't they make an astrograph that will handle both? A 13mm ethos will focus but the 21mm won't... Similarly on Newts, the better coma correctors also flatten the field as well as sorting the coma, getting the best out of flat-plane eyepieces.

If you don't need the eye relief I'd look at a S/H Nagler zoom 3-6mm which might see a lot more use. I bought one off ABS and have not regretted it; they generally go for about £270 used. But the Delites do really live up to their name....

Well done! I remember the excitement my first attempts on old-fashioned film....40 years later I'm still at it!

I think all Canon DSLRs have some potential, certainly for deep sky stuff.. I would'nt recommend a 300D nowadays but they were pretty much state-of-the art 25 years ago and people got good results. Of all the standard Japanese camera manufacturers, Canon are by far the best supported from the astrophotography point of view. Those later than the 400D all have the live view facility ( I believe) which really makes a difference as far as ease of use goes. Great on wide-field deep sky targets like star clusters and the bigger nebulae; just pick your targets to suit the APSC sensor dimensions and your focal length. . Not so good on planets if you want to go stacking; too many pixels and not enough frames! Still ok on the moon though. I've used an 1100D with APT software for years as a widefield camera and been very happy with the results. Most people who stick with it through the steep and painful learning curve end up moving on to a "proper" astro camera, but the Canon option is still the way in to the subject for many. If you compare the results against the costs for a secondhand / already owned DSLR and a new cooled specialist astro camera with the same sensor size you can see why... You will need spare batteries or better, a 12v power supply adapter. I always found it best to control the camera with a PC since you don't have to crouch behind the thing to focus but you can do it the hard way with just the camera/ lens and a mount. There are some good books: Astrophotography for the amateur (Michael Covington); several editions available. Making every photon count (Steve Richards); rite-of-passage reading. The long exposures needed (5 - 10 mins) will make a tracking (equatorial) mount essential because of the earth's rotation. The mount is generally considered more important than the lens which generally comes as a surprise for newbies. Cheapest useful option is possibly a Skywatcher Star Adventurer. To begin with don't overthink it.. you don't mention the focal length of your lens but I'd just have a go on M42 / Orion with a 10 or 20 second unguided exposure (50mm lens) and see what you get. Any lens much longer will need an equatorial driven mount.

Assuming it's a standard lead-acid battery, I'm afraid they don't take kindly to neglect. Car batteries are not designed for deep discharge use; I would assume a leisure battery would perform a bit better in this respect but it still won't appreciate long periods uncharged. A fully charged good 12v battery will show about 13.5v, maybe a tad more. If you can get this then all 6 cells are at least functional to some extent. The lead dioxide on the plates can get changed into lead sulphate. You may be able to restore it by a few charge-discharge cycles. The total charge lost over a session will be about (1.3+1+1)*5 hours =16.5 amp.hours which should be ok for a 70 amp.hour battery since it's only using 25% of the theoretical capacity. From previous experience, the charging efficiency is only about 60% so you would need to put back in about 30 amp.hours for a full recharge. Your charger should adjust this automatically looking at the terminal voltage, and cut back to a trickle charge once 13.5v has been reached.

I've reversed the fans on my 8" so that they blow on the back of the mirror. The fans are not 100% efficient so the "wasted" power helps put a small amount of heat into the mirror which helps with dew.

I'm wearing glasses. If I tip my head from side to side the CA from my specs is hugely worse that anything inherent in your image. Looks like a good scope matched to good processing skills.

Nice report, enjoyed reading it. There is a sense of achievement in finding both Uranus and Neptune. I know what you mean by "perfect Bortle 4 skies.."

Brilliant shot. It's inspired me to have an attempt at Uranus myself!

Great shots, lovely deep space feel to them. I'd be proud of either. I think I just about prefer the first. Maybe the contrast in the galaxy is marginally better in the second? Can you identify the globular clusters in M31 from these shots? If M31 was pushed to one corner you might be able to get NGC147/185 in as well.

Lovely shot. Nice framing with NGC6939 included.

@Stu Lovely shot there.. I bottled the photography option for fear of missing the whole thing faffing about with computers...

Brilliant! Had the 65mm refractor set to go by the front door last night but come the moment it looked a bit small for the occasion so assembled the 8" Newt 15 mins before the occultation. Glad I did...plenty of detail visible on Mars right up to the occultation itself in spite of frosty poor seeing next to the devil's searchlight . Could have made a better eyepiece choice; the ES 5.5mm was starting to fog up through lack of eye relief. A quick swap before the egress.. I never cease to be amazed by the timing accuracy for these things...don't know why; it's only trigonometry and A level physics but there is something deeply impressive about the clockwork precision of the solar system.

I've heard of Amalthea being seen with an 18". It's not that faint (mag 13 from memory) but really close to the planet. https://astronomy.com/magazine/ask-astro/2014/12/miniature-moons There are a couple of other much fainter (mag 17?) captured asteroids whose names elude me tonight in distant orbits that might be on the verge of detectability with the same sort of aperture.

If you do like the really wide viewing experience (some don't) and don't need glasses then your original suggestion of the APM 13mm is an excellent choice. I've tried or owned most of the 100 degree offerings and in my experience it's the closest to the Ethos in terms of performance.

I've owned both (Newt was technically not a Heritage but same optics) . Startravel 80 has a lot less aperture also but less fiddly (no collimation) and can be used later for guiding should you get the astrophotography bug. Very good for widefield but less hot on planets for all the well-quoted reasons, although far from useless. Really nice widefield views for starfields. Scope sits quite happily on a decent camera tripod. It's Ryanair-compatible as well. The Skywatcher 130mm Newtonians are quite good. Almost a 6" with a lot less weight. Performance on planets was very acceptable. If I knew this was the only instrument I'd intend to have then I'd go for the Heritage, but the ST80 is more futureproof as it can be used either as a big finder or a guidescope if you do decide to move on to something bigger. Both work best with eyepieces that cope well with fast optical systems; you may want to factor this in for future budgeting. The stock 10 and 25mm can be a bit underwhelming. Ease of use and the steadiness of the mount will be a big factor in how often it gets used... Either way you're not losing too much cash if you sell it on later.

That's a pretty high end camera that represents a significant financial investment, especially when the cost of the filters are added on. I'd feel inclined to finish the job and get an 80 - 100 mm apo refractor scope...ideally a triplet but there are many good doublets at lower cost. Newtonians can be very good when set up right and with a coma corrector but there is a lot more faffing about compared to the refractor route, and you have to be able to live with the diffraction spikes on bright stars. You may also have back focus issues combining a filter wheel with an off-axis guider and a coma corrector, although some reflectors designed for photography will be a bit more accomodating. Still, refractors generally have much more focuser travel, and the mechanically fixed optics work better with a simple guidescope.

It will still track. As far as the basic mechanics of rotation goes there is no issue. I've done this quite often replacing the counterweight with a camera assembly. For short focal lengths there should be no problems; if you are using longer focal lengths on your camera then watch out for differential flexure which might happen if the mechanicals are a bit weedy. If you are guiding with or for the main scope and your secondary camera is pointing at a radically different point of the sky then you might see some atmospheric refraction effects with targets close to the horizon, again, this will be worse as the focal length gets longer. If your camera lens is only 50 -100mm then it should very straightforward.

The term DSO covers a multitude of possibilities...from small galaxies a few minutes of arc across to massive nebulae stretching over several degrees of sky. You might need to think about exactly what targets you would like to look at. A small refractor (i.e. ZS61) will work reasonably ok with a Star Adventurer mount unguided for 2 minute subs, or a least it did for me some years ago. But quite a few subs get wasted and the success ratio can vary a lot from night to night depending on how well you do the polar alignment. And you get a field a couple of degrees across because of the short focal length which helps.. But unless you need the portability you are really limiting yourself for the future. The usual advice is to get the mount sorted first. The HEQ5 will cost a lot but it will be a better investment for the future. If you stick with the hobby you will end up deciding to guide at some stage...there comes a point where you will probably find there are too few good nights to justify throwing away trailed subs because of poor guiding. Secondhand laptops are quite cheap..I've had several off ebay over the years for this purpose. It does not need to be the latest and greatest just for guiding and data collection. The 130 and 150 PDS scopes are very affordable and real giant-killers in skilled hands, but you have to be able to live with the cosmetically challenging diffraction spikes and potential collimation issues. Refractors tend to be more expensive but they also tend to be more reliable on the night! For a beginner there is already enough to go wrong without having to worry over collimation and mirror flop. Reflectors also guide better with an Off Axis Guider (OAG) which can be more difficult to set up and use compared with the guidescope commonly used with a refractor at prime focus. If you go the refractor route you will need an apochromat which has better colour correction compared to the cheaper achromat. Look for the letters ED in the specs. The tragedy is that there are no really cheap good solutions...AP can all too easily become a money pit! I've got most of my kit secondhand and it's generally been fine. You can generally sell it on without taking too much of a financial hit. Good luck..it is a steep learning curve but there is plenty of friendly advice here. Hope this helps..

I've always found floaters to be the perfect medical justification for aperture fever...given a magnification of *200 with a 2mm exit pupil they are much less of a problem!