John

Nice specimens of Sikhote Alin folks. My own bit looks more like Debo's to look at but a smaller piece. I used to have a wonderful 200 gram chunk of SA with reglamypts, a roll over lip and other flight markings. I sold it a few years back to buy more astro stuff though I've been building up another meteorite collection recently - I'll have to post some pics. I'm up to 20 different types now.

Thats good to know Chris. It must have been the earlier ones that were working at less than full aperture. Neil English was convinced that his (branded Orion USA) was nearer to 170mm and referred to it was such in his review of the scope. This is an extract from that review: "It was discovered that the effective aperture of the large Orion Maksutov was nearer 170mm than 180mm. I was alerted to this after performing double star tests earlier in the summer of 2014. When I observed Zeta Herculis, I detected the faint companion to be located on the first diffraction ring of the primary star. Now, the locus of the first diffraction ring from the Airy disk is 185/D where D is the aperture in mm. The latest information on its angular distance from the primary is 1.1″. Something interesting occurred to me when I set the formula to find D for a 1.1″ separation. Thus 185/1.1 yields 168.2mm. Then I remembered a review on a lady’s website from the UK where she talked at length about the same (albeit Sky Watcher incarnation) telescope and reckoned the actual true diameter was nearer 170mm than 180mm; "Subsequent flashlight tests confirm that many of the Synta/Orion Maksutov have slightly smaller apertures than advertised (the 127mm model being closer to 120mm). This is due to the fact that the primary mirrors are the same aperture as the corrector plate which results in slight internal vignetting. In comparison, the older Meade 7 inch LX 200 Mak as well as the Questar 7 have an over-sized primary mirror to correct for this." Presumably Synta must be incorporating a larger primary mirror with the later models ?

Thanks Steve, It was great to bump into you and your other half at the Lowell Observatory. That was another place that I'd wanted to visit for many years

Hi and welcome to the forum The focus on a finder is usually adjusted as per the movie that Knighty2112 has posted. The standard 50mm finder on the Orion XT10 is a stright through unit I think - the 45 degree prism / eyepiece is likely to be a later addition. If the 45 prism / eyepiece has been added to a stock straight through finder then that might be a reason why the finder will not come to focus.

Are the Skywatcher mak-cassegrains operating at full aperture these days ? Their design used to mean that the effective aperture was a bit less than stated so the 180 was in fact a 170 etc etc. I had a Skymax 180 for a short while but found the cool down time too long for my observing circumstances.

You can always experiment with a cardboard mask with a hole the diameter of the clear aperture of a 1.25 inch filter cut in the centre. Put that on the end of the eyepiece barrel and see what the effect on the AFoV of the eyepiece is.

Thanks. There is a nice and newish visitor centre and museum which leads on to viewing terraces on 3 levels and there is also a walkway partway around the rim. To get down to the crater floor is a 2 hour hike in very hot and rough conditions. Only allowed by special permission. As you approach the crater (the pic below was taken from around 3 miles away) all you see are the low crater ramparts, no suggestion of the massive pit of the crater which is 1200 meters across and 175 metres deep. All created around 50,000 years ago in around 10 seconds by an iron meteorite estimated to be around 150 metres in diameter. Must have been quite a BANG !!!

Seems a long time ago already but a month ago I visited this place which has been on my "must do one day" list for many years. Very much worth a visit if you are ever in northern Arizona

I'm going to spray my Skytee II black, pop it in the AZ100 box and hope they won't notice the difference ........

I believe so. I'm expecting this setup when I unpack the packages on Monday. Plus a Berlebach Uni 28 tripod, a power supply and a Losmandy plate to attach the scope that I'll be testing the mount with. What nice people they are

The coatings on the lenses could get scratched and that would notably devalue the eyepiece if you ever want to sell it, although it would still work fine.

Personally I'd not use the encoders or the Nexus DSC unit so I hope the mount functions well without them. I'll find out early next week when the only AZ100 yet in existence (complete with encoders and the Nexus unit) arrives

As long as the filter does not touch the top lens (as Ben warns above) it does actually work. One technique of finding challenging nebula is to move a UHC or O-III filter in and out of the view though the eyepiece and see if the nebula can be spotted "blinking" on and off. An issue that I've found when I've tried this is that the filter gets in the way of putting the eye at the right distance from the eye lens (ie: the eye relief distance) to enable the full field of view to be seen. Also the filter glass seems to attract annoying and distracting glare and reflections from any light sources nearby more readily than the eye lens of the eyepiece does.

If you just want the standard item, here is one on e.bay: https://www.ebay.co.uk/itm/Skywatcher-2-Eyepiece-Adaptor/223692961084?hash=item341523b53c:g:L-MAAOSwavRdl4q5 Edit: Now you have 2 options in 25 minutes. Not bad !

I saw that one. I know the seller - top chap and very knowledgeable I was briefly tempted because the scope will be in good shape and is a little bit of history in its way. Nowhere to put the thing though !

I bought my used Nagler 31 around a decade ago and I expect I could sell it for more now than I paid for it back then. If I decide to sell my Ethos eyepieces (all bought used) I'll get my money back there as well I reckon. Until light pollution gets to the point where nobody can do un-aided visual observing that is, after that they will just be paperweights and curiosities !

This is a combination that I use for high power observing a lot at the moment (photo below). It's a 21.5mm - 7.2mm zoom and a Baader 2.25x barlow. I got both for around £100.00. When used together you get the equivilent of a 9.5mm - 3.2mm zoom eyepiece and the optical performance is pretty good. My other high power eyepieces are Pentax XW's and a Nagler 2-4mm zoom and the above combo, though a lot less expensive, gets a lot of use despite the more exotic stuff in the eyepiece case next to it The zoom facility allows you to instantly try a little more or a little less power to see what works best with the seeing conditions and target. The zoom is also pretty decent when used without the barlow although the field of view at 21.5mm is a little limited in common with most zooms.

There is no controversy over NV and I certainly don't regard it as a threat at all. I think the queries are the usual ones you get when a quite expensive piece of equipment is being discussed, similar to the ones when expensive eyepieces, scopes, mounts or, I assume, imaging devices are being discussed. Discussions like this help people to form conclusions about whether they want to move in this direction, either now, in due course, or that it's not for them. All good stuff

From my short experience of the Sabre mount (a mk II) I don't think it would make a good mount for a C11 in all honesty. It would hold the scope (ie not break) but the long focal length and narrow field of view will make actually using it to observe a chore I think. The new AZ100 might do the trick though

No. I think NV is great but it's just not how I like to do astronomy. No wires, no tech, just me, the scope, a case of eyepieces, a star chart and a dark sky and I'll do the best I can with that. Thats just me though

NV does bring a very large improvement to a range of targets but there are many others that it does not benefit so you will still need a quality set of equipment to view those. I'm not sure that NV is an "either or" type choice. It's a very, very nice facility to have but does not replace all other observing methods.

I've just been thinking - having the 2 Berlebach UNI 28's for a while will make the comparison between my current HEQ5 fitting mounts (Skytee II and Giro Ercole) and the AZ100 much simpler - I can have 2 mounts setup side by side and just switch the scope between them. Thats going to make comparisons easier and quicker than trying to use a single tripod shared between them

I had a custom EQ6 adapter made for a Meade Giant Field tripod a couple of years back. It was very similar to the adapter pictured above. Not a low cost item to have made I found. Anyway, the AZ100 is the topic of this thread and I'm really looking forward to unpacking it next week and having a play

I'd like both fittings on my Berlebach so something that can convert fairly easily between the EQ6 and HEQ5 fitting would be nice

Thanks Dave. Out of interest have you compared the performance of the Intes Micro 815 with a top shelf 6 inch apo refractor ?