The Admiral

I've only just started using the Air+ since changing all my gear over from a GEM45 and Altair 102, using the MGEN with my Fuji XT1, to a lighter weight kit, ASKAR FRA400, ASI533MC, and ZWO AM5. Not being a previous user I am still getting used to the way it works, but it all seems pretty seamless in operation and works like a charm. As a new user, it would be useful to be able to familiarise myself with the app screens, but it only works when the ASIAair is running. Ian

I've just read a review by Simon Lewis in New Zealand, and one of the beta testers. He's obviously very positive about the mount, but worth a read. https://www.amateurastrophotography.com/zwo-am5-harmonic-mount-review?fbclid=IwAR281QD1y7gidltcH9Z8SracANGwljnhQOTNhXyKtdAAuBuLXZbjn_ZDpV4 To be honest, I'm feeling very positive about it too and it is such a pleasure to use when coupled with an ASIAir. Ian

Yesterday I spotted this on the tripod. I had assumed that the locking knob on the tripod was just a simple screw arrangement, but I was impressed to see this design. Obviously they'd given some thought to making a non-marring design. Ian

Thanks for your comment. This is first light for scope, camera and mount! So I can't really say. I think that the seeing was particularly good that night too. Ian

This is the end product: https://stargazerslounge.com/topic/397076-m13/. It was processed in APP and the FWHM was consistently between 2.3 and 2.5. Presumably they are pixels, so this is equivalent to about 1.94*2.4=4.7 arcsec, where 1.94 is the resolution in arc.sec/px. I can't help thinking this is a fairly naive calculation though . Ian

This is essentially first light with my new light-weight gear, including the newly delivered ZWO AM5 harmonic mount. It took me a while setting up, as all of the equipment was unfamiliar to me. It was also my first experience with a cooled astro camera, rather than a DSLR. This was the set-up. ZWO AM5 ASKAR FRA400 f/5.6, at native FL. ASI533MC camera Astronomik L2 UV/IR filter William Optics 50mm/200mm Uniguide ASI120MM guide camera ASIAIR Plus 60x60s lights, with flats, flat-darks, and darks. Processed in APP, final polish in Lightroom. Slightly cropped. Taken on 09 July 2022. IC4617 is a Seyfert 2 galaxy, but I haven't managed to find out what its distance is. Ian

Thanks. I'm sure you are right! Ian

Not a problem, I'm interested myself. That is my intention when we get back to more sociable imaging hours . I think there are a few things worth remembering. This endeavour had reasonably good seeing I believe, but it's when the seeing gets rough that problems could arise I think. In fact there is a new thread on the Facebook ZWO mount site which refers to the issues of the more transient behaviour of the harmonic drive, rather than the overall PE. [Note. I'm not a member of Facebook, nor intend to be, but I have been able to read their pages using my Android tablet. The text isn't obscured by the flag telling me to sign in, as there is with Microsoft.] There is mention of this document relating to the Rainbow mount, https://www.firstlightoptics.com/user/products/large/Supplementary Manual V16.pdf, where on page 16 the author notes that some units may display transient tracking error rates which change by up to 0.7 arc.sec/sec. This is a characteristic of harmonic drives apparently, and so would be common to all such mounts (without encoders?). As you can see from the PE trace for my mount, the curve has some definitely sharp kinks, and I guess this is where the guiding could fail, and where a 0.5s exposure comes from. That said, there are owners of the Rainbow astro on this site and appear to be pleased with their mounts. Interestingly, I have seen reference to a 9" SCT (with reducer) being carried by an AM5, and apparently with guiding of 2 seconds. Can't quite see how that works, but there you are. I'm certainly no expert on guiding, so I'm open to any correction here. Naively, I can imagine that should the guiding not keep up with a transient, it will catch up further down the line when rates of change are more reasonable, just so long as the mount hasn't moved too far on, and the overall tracking error remains acceptable. Since I was imaging for at least 8 PE cycles, it does seem that under my imaging conditions, given that all subs looked fine, these transients caused no issue with 0.5s guiding, and with the mount lightly loaded. Of course, I don't know where those 8 cycles sit in the whole 24 hour PE period, and how similar they are over all cycles. A lot of unknowns to be sure, but that doesn't indicate that the mount is not up to the job! Ian

Proper First Light for the camera, scope, AM5 and Me! As the weather's been so decent recently I felt compelled to get out and image, despite the late finish . I chose M13 as it would provide a decent contrast against the light summer sky, and was conveniently situated. This is the first time I've imaged since the Spring of 2020, so essentially all the gear was new to me. I have to say it took a good long while to get imaging, largely due to unfamiliarity, but got there in the end. At least it's the first time I've started off in shorts and T-shirt (not a pretty sight )! I did have trouble using the PA routine, sometimes the circle would move with adjustment, and at other times seemed quite oblivious to my inputs. And of course, the ASIAir won't let you go any further until you get the smiley face, so no option but to continue . It could all be down to operator error, so I shall need to investigate further. I have to say that the iPolar is a cinch in comparison, but then I was using a different mount and not the imaging camera. We'll see. This was the set-up. ZWO AM5 ASKAR FRA400 f/5.6, at native FL. ASI533MC camera Astronomik L2 UV/IR filter William Optics 50mm/200mm Uniguide ASI120MM guide camera ASIAIR Plus I took 60x60s lights, gain 100 at -10°C (at 80+% power, it was a warm evening!), 30x previously recorded darks, 60x flats (0.2s), and 60x Flat/darks (0.2s). Guiding was multi-star at 0.5s. For this exercise, dither was off. I haven't processed the image yet, but really that is secondary to how the mount performed, and will post later, though once done I shall be able to assess the star shapes and sizes. Here are a couple of guide plots from the evening. Here's a single full-frame sub. Centering was bang on. I'm certainly not complaining about these results . I hope this has been useful. Ian Postscript. Interrogating the guide log using PHD log viewer, I get an rms of 0.38" RA and 0.5" DEC for the whole shoot. PA error is given as 29.6', so that needs to be improved.

Thanks knobby, but until the stats come in I can't be sure, even though in my water I feel it will come good 😀. I think if one is very demanding over performance then these harmonic drives, of whatever manufacture, are most likely not to satisfy, but for fairly wide-field applications there is much to like. I guess those with encoders might be a different story, at a price! Ian Ian

But note that ZWO selects it's harmonic drives to be within a specified PE (40 arc.sec total). Ian

So am I Ciaran, but I don't do very late nights! Ian

I have read that of some rancour expressed on the ZWO Facebook site, but this may have been at a time when ZWO were unable to ship through the ports and had decided to distribute 'off-list', within China. Also, I get the impression that America is less well served than we are, but may be wrong on that front. Ian

I ordered mine on 13 Jan. If you've not received yours yet then I suspect that you'll be in the next batch. Glad I'm not alone in ordering one! Good luck with it when it arrives. I've started a thread recording my findings, though imaging at this time of year just ain't going to happen . Ian

Today, with the mount on the tripod, I used both the handset and the ASI Mount software to control the mount. This was through the wi-fi hotspot created by the hand controller. All appeared to work fine, within the limits of what I was able to test. I then took the assembly outside and mounted my intended scope for testing with the ASIAR. I'm pleased to report that the mount is sufficiently light, when mounted to the tripod, for me to carry both ready assembled. That's 5.5kg for the mount and 2.3kg for the tripod. For most this would be a very easy carry. Incidentally, there is now an 'official' manual for the mount (https://astronomy-imaging-camera.com/manuals/AM5_user_manual_V1.0.pdf). The rubber feet of the tripod can be unscrewed and replaced with the supplied spikes. I've been more than happy with the quality of finish of both the mount and the tripod. Both operate smoothly and feel of high quality. Not dissimilar to the iOptron GEM45 I had before. Now for some pretty pictures . To my mind that's a decently robust dovetail clamp for both Vixen- and Losmandy-style dovetails, with decent sized knobs that don't hurt the fingers when tightening. I think this area is a bit vulnerable on account of the long azimuth adjustment bolts, which presumably has come about because early testers found that the original knobs were too small and the only way to accommodate larger ones would have been to extend the bolts. I can see these getting bent inadvertently. The elevation adjustment is smooth and easy, though this is with a lightly loaded mount. On the plus side, the barbell arrangement would give a decent amount of leverage. Now loaded with an ASKAR FRS400, ASI533MC, William Optics 50/200mm guide scope with an ASI120MM, and the ASIAIR Plus. That's 4.6kg, so the load on the mount is only ~1/3 the maximum unbalanced load for the mount. As an early adopter I got to choose whether I wanted the front faceplate to be blank or be embossed with the "bunch of galaxy balloons" emblem. I chose blank. I power the mount and ASIAIR separately. As ever the power blocks never have long enough output leads, so they're conveniently sitting in the weight bag. I used the USB connection from the ASIAIR to the mount, not the wi-fi link. I used the ASIAIR via my Android tablet to control both the direction and speed of my mount by means of the direction 'buttons', to assess whether or not a mount/tripod collision was possible. I concluded it was! As a first step I shall need to increase the distance between the tube mounting rings and the dovetail, which is something I'd have to do anyway if I ever mounted an EAF. I used the 'send to home' function too. I'm pleased to report all worked without a hitch. Note that today there has been some feedback on the ZWO Mount Facebook site that says if the mount is switched off without it being at the home position, then the next time power is re-applied, it assumes that the position it is then at, is the home position. So it is important that the mount be returned to the home position prior to shutdown. I guess that there could be an update in the pipeline for this. Until I can get a chance to do some imaging, which I assume won't be for a while yet, I'm unable to report beyond these rather simplistic checks. But overall, I'm happy with my mount. Ian

I've now received my tripod , so I can move forward! Ian

It does seem that the early testers guide at 0.5s, though I'm not clear why 1 second guiding shouldn't give satisfactory results. Time will tell. At these sub-second guide exposures concern has been expressed that it'll guide on the seeing rather than the star, so it'll be interesting to check how much multi-star guiding can ameliorate this. Another option would be to use an IR filter on the guide camera. Note that I'm no expert in guiding, having done Alt-Az imaging for a number of years before recently switching EQ, so this is as much a learning experience for me. Ian

My comment was really directed towards manufacturers in respect of their harmonic mounts, where we know that the PE curve can be quite hairy. I agree that it is good to wait for real life test reports and reviews, but I my case that would have been a luxury. I'll have to take what comes, but I believe that the harmonic mounts have a place, with known limitations, and for me, it should meet what I need. As for ZWO, I do feel that they are going into this venture with their eyes wide open and they're keen to get it right. They may not totally succeed, but good enough for what I want. They have got a small bunch of amateur astronomers to put these mounts through their paces during the development phase, so they are listening to needs of the community. I can't ask for any more than that at this stage. Ian

Cheers Richard Ian

Thanks for your kind comments. It will certainly be interesting . Ian

Ah, true! Thanks for the heads-up. Doh, I forgot about that. I'll do it now . Ian

Thanks, though the middle of summer is not the best time to check everything out. Results may be a while coming 😉. Ian

Imagine my surprise when I received an email saying that the mount would be delivered yesterday afternoon, rather than tomorrow. Indeed it did arrive, but alas sans tripod . I'm hoping that the tripod will be delivered tomorrow, but I've contacted FLO as well to advise them of the situation (which they'll see when they open for business tomorrow). Anyway, I've made a start on documenting what I can, as a separate post. When the tripod arrives I shall be able to reveal the whole mount. Without a tripod, it would just fall over! Ian

Why the AM5? I've had serious back problems from before the start of this year, so I was looking to downsize my Altair 102ED refractor and iOptron GEM45. These are not overly heavy by most standards, but there was no way I'd be able to shift those lumps about, particularly as I have to build up and strip down my gear for each session. The fickle British forecasts didn't help my state of mind either, and a general malaise had set in. Someone else now has the benefit of my gear, and as a lighter weight replacement I've gone with the Askar FRA400 coupled with an ASI533 (my first astro camera too, and not really seen first light yet!) and all driven by an ASIAir Plus. Except of course I've had no way to use it without a mount. Until now! At about the time I was downsizing the ZWO AM5 harmonic mount appeared, and seemed an ideal mount for my needs. Not too heavy, no need for counterweights or balancing either, and therefore easier to set up and tear down. I'm not by nature someone keen to be a first adopter, and there were a lot of unknowns, but with the expected lead time and promotion price, it seemed to fit the bill. There was no way I would be prepared to shell out for a Rainbow mount! So, that's where I'm coming from. Open the Box! On Friday I got a message to say that the mount would at last be delivered tomorrow, but as it turned out I got a further message yesterday that it would be delivered that day. Well, I was somewhat disappointed to find that only the mount had been delivered, not the tripod . Hopefully that will be delivered tomorrow. So today I thought I'd show some photos of the mount itself. The mount was delivered in the original ZWO outer packaging, well protected by cushions. Here's the mount in its presentation box. Inside there is a nice padded semi-rigid case with optional carrying strap, introductory guide and the all important PE curves for this particular mount. Opening up the case this is what will confront you. That is the mount, hand controller and connecting cable, two Allen keys, and a USB A to B cable. There is room for the counterweight bar, should you have purchased one. Sadly, that's as far as I can go at the moment, until I receive the tripod. The PE curve What we know about harmonic mounts is that the PE curve is not regular, and furthermore, each manufactured harmonic reducer is unique. Hence the provided curve is specific to this mount and identified by the serial number. According to ZWO, manufacturers of harmonic reducers are unable to control the PE within reason, and for industrial uses they can far exceed the accuracy needed for astro imaging. ZWO requires their suppliers to undertake PE testing and they select only those for which the PE is <±20 arcsec. How many other mount manufacturers provide the PE curve? Details of what this means is given here: https://astronomy-imaging-camera.com/tutorials/10-things-you-need-to-know-about-the-custom-am5s-pe-test-report-provided-by-zwo.html So what does this mean for my mount? For the worst case PE: 18 arc.sec drift would occur in 0.6°. Since 360° takes 24hr, 0.6° will take 144s, so the PE max drift rate will be 0.125 arc.sec/s. Hence, with 1s guiding, the error should be no more than 0.125 arc.sec. In reality of course, guiding errors will be worsened, but even so, it looks as though performance will be more than adequate for my needs. I'm pleased that it would seem I have a relatively good sample. When the tripod arrives I shall continue this post. Ian