The Admiral

That would bother me. Given that is not normally the case, one reason could be that the Ha filter isn't quite centred on the Ha peak. Or, I suppose it could be that the OIII band is wider than the specification. One would like to think that such an expensive filter is perfect, but without individual calibration one can never know. Of course, this applies to all NB filters. What f-number are you imaging at? A low f-number can really affect how the filter works too. See Cuiv's YouTube video https://youtu.be/VkSvpOLlD2Y. Ian

You should certainly be pleased with that, I know I would be. Lovely image. Ian

Have a look at the ZWO Mount Facebook pages, I'm sure that there are folk who are trying some sizeable optics. I'm sure it would be able to throw it around, but you'd need the cw on, and probably a heftier tripod. The big question would be whether the guiding would be up to it, depends what fl you are talking about. Ian

From another message? Thanks. Yes, early days and it needs a lot more time on it to get the noise a lot lower. Yes I'm using the ASIAir with the AM5, and as you'd expect there are no issues with it working with the AM5. I don't have a vast experience with EQ mounts, but I think it all comes down to expectations. For me, with this lightweight, short fl, set-up, I am very pleased with it. I've been pleased with the guiding results, but then again, it hasn't been subject to poor seeing conditions yet, and it has worked essentially flawlessly (other than operator error ). But set-up is easy, and not having to balance the rig or use counterweights is a big bonus. There a reports of it being used successfully with longer fl scopes (even those beyond the recommended). If one is looking for a high end mount for long fl imaging, then this is probably not the mount. And of course, there are more brands now starting to offer harmonic drives. I have created a thread of my experiences here, if you haven't already seen it. Ian

Me neither! As guiding is based on PHD2, then time to turn to the PHD2 manual. I think this para explains it. "Some guiding configurations can benefit from guiding on multiple stars rather than just one. This results in using a weighted average centroid position of multiple stars rather than just the centroid of a single star. Multi-star guiding is enabled using a check-box on the Guiding Tab of the Advanced Settings dialog. When this option is enabled, the Auto-select function will identify up to 12 stars in the field of view that have adequate SNR. No more than 9 of these will be used at any one time, but the remainder will be used to replace secondary stars that are lost or rejected for some reason. The "primary" star is the single best candidate, the same one that will be selected if multi-star guiding is disabled. As guiding proceeds, some of the secondary stars may be rejected because they are too dim or have drifted outside the field of view. This is of no concern, the multi-star guiding algorithm handles the secondary list automatically. When multi-star guiding is active, the PHD2 image display will show the usual rectangle around the primary star and circles around the secondary stars. All other UI features associated with a guide star - brightness properties, SNR, FWHM, etc - relate to the primary star, not the entire list. Multi-star guiding can be enabled or disabled while guiding is active. However, enabling the feature will force another 'auto-select' procedure. The multi-star algorithm uses the secondary stars to refine the centroid position and reduce its volatility, so there is essentially no way for it to degrade guiding performance." So there you have it. Ian

Does that mean that you are single star guiding, not multi-star? Ian

Sounds all good 🙂. Presumably, resumption of guiding was automatic? It would be very helpful if somehow we could know where in the PE cycle the mount is, as I would imagine that the response to failure of guiding would be very much influenced by the presence of "irregularities" in the shape of the PE curve. One day I might centre the image on a bright star and then let the mount track without guiding, with frequent subs. It should be possible to recreate the PE curve by checking the deviation from the centre position. Ian

Although it's cooled down now, I've had no time to progress further before now. So for anyone who's still interested in this thread, I've just processed IC1396. My firsts attempt at dual band imaging with the L-Extreme filter, and I've clearly got much to learn, besides which it needs a lot more integration. However the results are not the purpose of this thread so much, and the image is posted elsewhere (https://stargazerslounge.com/topic/398677-ic1396-elephants-trunk-in-hoo-false-colour-my-first-dual-band-image/). For this imaging sequence I achieved an overall guiding level of 0.31" rms RA, 0.32" rms Dec, to give an overall rms figure of 0.44", which I'm pleased with. PA was 5.2'. The guide log is attached. PHD2_GuideLog_2022-08-11_215834.txt Ian

This is my first foray into NB imaging, using the L-Extreme dual band Ha and OIII filter. Clearly I've got a lot to learn, and there is a need for much more data and is very noisy. Still, early days experience using my Askar FRA400 and Zwo AM5, so at least I do feel a step forward has been made. I processed with the APP (v2.0.0 Beta 2) Ha and OIII extract routines and the RGB combine tool. Incidentally, does anyone know what the different combine formulæ do? I just used LRGB1, and couldn't see any difference between them. I used Lightroom for much needed image enhancement! Imaging details - Lights 35 x 300s Darks, flat-darks x30 Date 11 Aug 2022 The mount performed well, giving me a combined rms error of 0.44". Ian

Excellent news. I hope it works well for you. Ian

Is it necessary for the log to be sent in before shutting down? I record my session on a memory stick, and not only are the subs all saved there, but so too are the logs and guide logs. Would that be of any help to you? I can't help thinking that the guide-stars were lost on account of the longer guide rate. I don't know what your PE curve looks like but there are some quite abrupt switch-backs with mine, and I would conjecture that if the guide rate is not fast enough then the star could be lost, though I've little experience with guiding. Fortunately I've not imaged under poor seeing conditions, but I guess under those conditions the guide rate has to be a compromise. How much better multi-star guiding is affected by such conditions I haven't a clue. Ian

Sorry Mart, I didn't mean to imply that your post was coming over as negative, in fact I thought it was positive. You seemed pleased with what you were getting, and I was really saying that I too was positive about mine. Just agreeing with you in fact. Perhaps I should have started off by saying: "Mart, I have to say I'm rather pleased with mine too." Ian

Mart, I have to say I'm rather pleased with mine. Coupled with the AAP+ it's made imaging a whole lot easier and enjoyable. Mind you, being able to image in T-shirt and shorts is so much nicer than thick warm clothes and gloves . I was imaging the Elephant's Trunk Neb on Thursday night too, despite the essentially full Moon, using the L-Extreme. I still haven't got around to processing it yet, far too hot where my PC is. I was pleased with the guiding too. Here are the stats courtesy of PHD2 reader: Sorry, I've had to squash the trace into one page width, so probably not ideal to assess, but I was pleased with 0.44" overall. That's with 0.5s guiding. I used dither every 3 frames. PHD2 was reporting an RA error of 5.2'. These guide results are quite typical so far, up to about 0.65". I use multi-star guiding, are you? The aggression settings seem to be the default AAP ones, and that is what I've been using. I started logging my initial thoughts and experiences here. Ian

Thanks Richard. Dead right, my back is thanking me, and to be honest, I just wouldn't have bothered getting the heavy gear out, even if I was able to. Using this gear with the ASIAir just makes life so much easier too. Tempting though it may be, I shall probably bring the gear back in in the early hours. I'm not that brave yet . I've already got a Pelican Nebula taken through a L-Extreme from last night, and tonight I'm having a go at the Elephant's Trunk Nebula with the Extreme too. Where I do my processing is too hot to be comfortable so that'll have to wait a bit. All of these could do with more imaging time, but currently I'm just relishing the opportunity. I can always add more subs later. Ian

I thought I'd update my thread on the latest adventure with this mount. Given the late nights called for when imaging at this time of year, I can't summon the energy very often . Last Saturday (6th Aug) I imaged IC 5070, the Pelican Nebula, in straight colour. I've been having trouble doing the PA on both my imaging runs (which I'll describe elsewhere), but I managed to get 9.1' PA Error, overall RA guide errors of 0.39"rms, Dec error of 0.4"rms, and combined 0.56"rms, according to PHD2 log viewer, with a 0.5s guide exposure. I've posted the result here. Yesterday I got the kit set up and intend to image IC5070 with an L-Extreme wilter (ha-ha, that typo spells out more like I feel in this heat) filter, my first entry into NB. I shall have to see how that turns out. Ian

This was the second attempt at imaging with my new kit, and for this I chose the Pelican Nebula. 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 It was processed in Astro Pixel Processor, with some tweaking in Lightroom. I like bright punchy images, so it won't appeal to those who prefer a gentler approach . I've recently noticed that some stars appear a bit greenish, so it probably deserves some green reduction. It comprised 39 x 180s lights, 30 x darks, 30 x flats, and 30 x flat-darks. Imaged 6-7 August 2022. Ian

Very nice Stuart. Your camera and scope must be well matched, as you seem to get sharp and detailed images. Incidentally, do you use a reducer with the scope? Ian

Just to muddy the waters further, have you looked at the Altair triplet scopes? I had a Wave 102ED triplet and that gave some nice results. I see that there is a new 130mm triplet, which with the reducer gives about 700mm effective FL at f/5.6. Might be a bit heavy though. These scopes might exist as other brands of course (i.e. TS APO range for example). They all come with an optical bench test results sheet. Ian

Welcome Heid from someone in the same county! I got my first telescope at age 66 in 2015, and all I can say is it doesn't get easier as you get older, so you've done the right thing 🙂. Wish you every success with your acquisition. Ian

My set up uses the bog-standard ASI120MM in a 50/200mm guide scope, and I got good results recently with 0.5s guiding, but I believe that the seeing was good. I haven't had an opportunity since. I do admire your stamina for imaging last night(?), I felt too drained by the heat 🥱. Ian

Nice result there Macroscopic. Guiding looks very acceptable, and the PE curve looked quite well behaved 👍. What imaging filter were you using? You say that you are using IR for guiding, is that because you have found visible guiding unsuccessful, or more as belt and braces approach? Have you practical experience of guiding being an issue with poor seeing, with this mount? Ian

Aha! I was beginning to think I was alone . My AM5 arrived at the beginning of July, and I've posted up my experience so far. https://stargazerslounge.com/topic/396654-the-zwo-am5-landed/ So far I've been suitably impressed, but of course this is the wrong time of year to be imaging. I'm not up to very late nighters. Blimey, looks like snow on the ground in your Redcat picture . What guide and imaging exposures were you using? Did you use a filter? Ian

My situation exactly! Ian

In contrast, I gave up on the programme early on because of the constant barrage of music that accompanied it. It really isn't necessary in my opinion. Sorry to be grumpy about it, but for me it spoiled what could have been an interesting programme. Ian