John

The "african continent" shaped darker area may well be the Syrtis Major. It has a rather triangular shape. The airy disk / star test is done on stars rather than planets.

I think the lesson is clear with these "T" type mounts - balance is the key to getting the best from them and that needs some experimentation to get "just right". Even more so than I originally thought.

That might explain why the put one on the EQ mounted newtonians but not the dob's then ! Thanks Tim

One of the members of my astro society. Eddie Carpenter, has an asterism named after him - Eddie's Roller Coaster. It is a nice binocular target in Cassiopeia and included in this BAA list: https://britastro.org/journal_item/22500

There should be a rubber O ring around the finder tube sitting in the narrower of the two grooves - towards the front end of the finder body. Without it the finder simply will not stay in place in it's mount.

Good point about dual scope setups Stu - when I want to do that my Skytee II copes with it quite well or even the Ercole. I don't use two scopes that often though. When I was beta testing the AZ100's I found that I needed two of their 3.7kg counterweights on the other side of the mount to get smooth slow motions with my 130mm F/9.2 triplet. This would have led to a rather heavy set up had I decided to go for the Rowan mount. The T-Rex, as I'm sure you know, needs no counterweights at all.

My first dob was one of those. Mine was white and branded "Revelation" but it was the same scope. I bought it for just £100 used and was rather surprised when it performed as well if not a bit better than the 8 inc Celestron SCT I had at that time.

The GRS was quite clear at that time with my 90mm refractor at 80x magnification. Just where @CraigT82's pic shows it. Well done for getting it !

Not all eyepieces reach focus at the same point by any means. Not even in the same eyepiece range in some instances.

Agreed 100% Skywatcher uses these back plates on some of their newtonians and not others. Don't know why they put them there but they can be removed and left off to be honest with you. They actually slow down the cooling of the scope as well as getting in the way of the collimation screws.

I use my refractors without a diagonal when I want to remove that component from the light path, eg: for star testing, collimation checking etc. I've tried to get a collection of diagonals that have minimal negative impact on the image quality because I much prefer to have one on the scope when I'm actually observing though it !

Where did those 11 years go ! I actually purchased one of the semi-circular ones instead from Astroboot and it has served me very well:

10mm eye relief is pretty good for a 3.4mm eyepiece. An ortho of that focal length would have about 2mm. But if you wear glasses when observing 10mm is usually not enough. I think glasses wearers would find many of these "top tier" short focal length eyepieces very challenging to use. Luckily the DeLite's, Delos's and Pentax XW's are in the next tier down (so still very good) and have a lot more eye relief

Getting at the azimuth bearing of a Giro mount is not easy ! There is a trick to it - I'll try and find a link to the method.

Using a barlow often requires a re-adjustment of focus and if this is quite substantial then you might run out of focuser travel.

Slow motions are very useful I agree. I can cope OK without if the mount motion is smooth on both axis. I'm delighted with my T-Rex which suits my 130mm F/9.2 perfectly. The Ercole and the Skytee II carried it OK but the T-Rex showed me what a top end alt-az mount can do. Unfortunately the T-Rex is out of production and getting on for AZ100 in terms of pricing if you can find one:

Hello and welcome to the forum I agree with the above - stick to using the 20mm and 12.5mm eyepieces with the barlow lens only being used with the 20mm. The 4mm and the barlow lens used with the 12.5mm eyepiece produce too much magnification to get a clear and useful image with a 50mm aperture scope.

It is a "bird-jones" design on a rather flimsy mount. The 2nd review is the accurate one. Have a search on here to find more about them, eg:

The Ercole specs say lubricant-free bearings. "The GIRO-Ercole mount differs through the new radial/axial bearing without lubrication. Inside their are high quality plain bearings which counteracts the rotation and a lateral load. Furthermore the support points and length of bearing has been extended significantly. So the mount can carry more weight."

They work well

I'll say it again, there is still a niche for a good capacity alt-azimuth mount, with slow motion controls, that is priced somewhere between the Skytee II / Ercole and the £1K plus units like the AZ100. I'm glad that I hung onto my Skytee II. Far from perfect but it does what it does competently and has a good capacity for it's price once the saddles are replaced and it's on a stronger tripod.

I very nearly bought the 3.3mm TOE a little while back. Like Mike, I've not had a great Tak eyepiece experience to fall back on though. Anyway, I'm happy with what I've got eyepiece-wise now "There will always be grass that looks a little greener"

Interesting report The seeing here last night was pretty poor - I could not usefully use more than 120x on either Saturn or Mars and Jupiter was more like 80x. Amazing how much difference 40 miles or so can make. They both sound like superb instruments

Shame. I guess they were a "niche" product but at least they were available unlike most of the now "legendary" planetary performers. They will soon become very expensive items and very hard to get like the ZAO's and Pentax XO's have become. Unless .............. something else is found / launched that performs in the same way

I observed the pair quite close together at 2:30 am this morning. Seeing was not up to much but Mars showed some detail even at 100x with the 90mm refractor. Nice pairing but could have done with steadier seeing.