powerlord

looks good to me. yeh - looks like some high cloud or some morning fog. Now you know it's doable though it's easy to have another go. Looks like clear tonight for the first time in ages...

So none of above though (and I'm sure @StevieDvd is on the money) explains why one night asiair can tell me it's within 0.00.20, and the next night it's the same, but I change the OTA to something else and now it's miles out and I need to move to get it nice and low again. That is my process now, as it is consistent in this behaviour - I don't PA unless I change the OTA. I mean sure new OTA, different FL, etc - but its claims of accuracy shouldnt be affected by that really, and anyway.. youd expect that to them result in the sort of 'if I PA with a 1000FL then it'll be good with 250FL sort of deal - and that's not the case at all) The fact it CAN stay the same calculating over several nights with the same OTA suggests the software in consistent, and the fact it is almost always different with a new OTA suggest something about the way it's doing it is affected with this ? I'm afraid asiair is the only thing I can PA with. I tried phd2s drift thing and gave up as it was all over the place. Maybe sharpcap is easier ? but I don't have the paid version of that. So I admit this could be asiair funkyness. Tomorrow night looks good, so going to take the 300PDS outside and mount it on the EQ6r-PRO. So that's always fun....and since I need to move the tripod to centre of obsy to fit it in, I'll definately need to PA then! @tomato - I assume that is the same software (and version of it) that you used originally to PA ? If not might be as Stevie says - different sofware different results ?

Exactly, and it would seem to be that the algorithm that is used may or may not be affected by cone error. As I understand it asiair requires alignment on polaris. it shoots a still at home position, rotates 60 degrees west and takes one more picture. it then calcuates error and leaves you ti fix (you can set to auto refresh picture and watch error go down). There is therefore surely an expectation that there is no cone error. consider that there was, and that it is massive: 10 degrees in ALT. So you're mount is at say the right 53 degrees for your latitude, but the OTA is pointing at 63. asiair doesn't know that - it will surely end up requesting something like a reduction in ALT of 10 degrees till it looks right. But of course, it isn't - you're now 10 degrees off being aligned to the polar axis. I've not tested this btw, I might be talking mince. But for other PA methods like PHD2s that don't need to be PAed to polaris, they might be pretty much immune to cone error ? sharpcap is probably the same ? I mean it might not be that at all, I've not done any tests as I say - it could be that it is something else, but it does seem weird that such a simple thing can not match up between different software. and IF cone error didn't make any difference with asiair it wouldn't need re-PAed for a different mount - but it certainly does. All fun and games.

it's not the distance from the axis, it's how colinear it is with the mount. As Craig says - apparently this is called Cone error (thanks Craig). Imagine something like your OTA mounted so badly onto the mount that it points upwards 45 degrees from the direction the mount is pointing. Clearly you'd have some issues PAing. I think the thing is, with something like my big EQ6r-pro you can basically be miles off, but it'll still guide it out no bother at all. But with something like the AM5, it's already having to 'guide' out all the periodic error, so if you don't have an OTA that is very colinear to the mount, you might end up getting a good PA in software, which is actually off enough that the extra work the AM5 has to do is too much for it while also trying to flatten that periodic error out. At least that's my theory. My AM5 had other issues - massive 5-10' spikes intermittently while generally otherwise running nicely at .5 rms or so... hence its back with FLO to be looked at. stu

Let me see. Can maybe post my affinity pic

I'll give that a go then. I've never managed to get clahe to do anything useful before

hmm, Id say thats debatable. For stuff like focusing, PAing, etc where you want to be taking lots of images, every image on something like an asi2600 will take an age to download every time. And for storage too if you want to use removable storage it would be painful. can't really see the problem they are try to solve tbh. for 100 quid saving, you are getting a very very compromised unit - no usb3, no ethernet, 2 less 12v outs. But hey ho, they clearly have a marketing department and see a market there, so its clearly just not for the likes of me as a user type (got 3 pros but wouldn't be interested in these at all if I was starting out). I'd have preferred to see more enhancements to the existing software frankly - some things still missing there - angle showing in plate solving, better astro map features for browsing and planning, re alignment every X subs like dithering, etc. stu

So.. for us asiair users and more and more maybe, users of other software we are PAing via our main cameras and OTA. And mostly this works great. What I do find though is that when I swap to a new OTA, I have to do it again. At first I wondered why - has the mount moved somehow, etc. Now I realise that its basically just that each OTA and camera as mouted on EQ mount is going to be a tiny wee bit probably not pointing 100% in line ? I suppose questions are - well - ok so we end up PAing the optical path effectively - which is probably not what we should be doing, but it's close enough ? Certainly that's what I've been doing for 2 years and get .4 rms with the EQ6r pro so works fine. With the AM5 though it definately needs to be as good as you can get, and so, I mounted a guidescope I'd made 3d printed brackets for that ensure its as parallel to the mount as possible, and PAed with that. But to be honest, when I then put an OTA and camera on, I found the guiding was not very good until I re-PAed with the OTA. Which just confused me if I'm honest. I mean in an ideal world, you have a 100% accurate polarscope in your mount and you do a perfect PA, and provided the mount doesn't move - you are done for ever (as per a concrete fixed pier) right ? So even if your OTA and camera are a bit squint it doesn't matter - because your mount is aligned to the earth's rotation which is the whole point. One would thing therefore that PAing with some sort of super parallel OTA would be the next best thing ? stu

Alll usb2 - why ? I mean it's 2022.. usb2 ??? useless for cameras. https://astronomy-imaging-camera.com/product/asiair-mini

I have one that looks like same lens. It's trash.

It's electronic aperture - so can't change it. Adam's right I think - it'll be CA. It's just weird that it's never been an issue with the L-extreme. I mean, you'd think red CA would be red CA. 7nm or 3nm . Hell, you'd think less change of CA with 3nm. I wonder if the band is shifting down, but then it is still capturing Ha fine. It's not a big deal really, as the redcat is 250mm so pretty similar FL, and it works fine. I've just previously always found the canon sharp as a tack for astro, so was just surprising.

I think I've screwed colour up again. Siril photometric made it bright green right enough. Here's a go with snapseed on phone.

Redcat and asi2600. 200mins - some 120 second, some 300 sec subs. processed as usual in APP and Affinity Photo. Over the last few cloudy nights - so I'm deleted the really bad subs, but probably left a few imperfect ones in there with a bit more 'glow' than there should be but otherwise would have ended up with only a handful of subs. Running at a total of 17 targets imaged so far this month - not too bad going!

sounds interesting. Certainly I'll be buying a second one soon for my second asi2600. The only downside I've found so far, and one I've not double checked is that my Ha was unfocused with my canon 300mm with it. Oh, and of course - less light so longer subs for PAing, focusing, etc needed. As Lee says, halos non existent really. It'd be intersting to do a target which also has strong sii- and shoot ha/oii with l-ultimate, then sii with an sii filter - so full SHO with an OSC.

An update with colour stars - plus a wee bit of colour editing

An update with colour stars.

Just an update - now with colour stars. A little cropped as my angle not quite perfect for stars - asiair doesn't tell you angle when it plate solves a previous image annoyingly.

Mine is iot which helps. I have it set to go on only when roof on, only when humidity above a certain level, temp above certain amount, etc.

Got a second asi2600 as I'm really liking them - so can image two targets with same camera on same night. I've only once shot The Pleiades not long after I started this 2 years ago, so not done it justice. Here's last night's efforts with the Redcat (don't pixel peep). 300 minutes of 2 min subs.

I have a set myself. Awesome binos. Yes expensive, but I got mine 2nd hand on ebay. Sure I could sell for same price. They really are well worth it.

just my 2c - but I wouldn't try to upgrade that - look on ebay for refurbished laptops - lenova are good. you can get a modern ssd based usb3 laptop for less than 200 quid. And as Malcolm says, once you start stacking or trying to run stuff like affinity photo you'll be glad of the power. i3 min, but ideally an i5 or i7. I got a lenova yoga last year off a company on ebay - 179 quid - 256gb ssd, 8gb memory, reversable 1080p touchscreen, windows 10, usb3, etc. Hardly anyone other than hardcore gamers buys desktop/tower/etc machines these days. stu

I like the colors in that a lot. stu

I'll need to have another go. can you post a jpg of the original stretched stacked image just so we can see how much work has been done ? I think I might give it a go with BigBazooka™. stu {BigBazooka == SW300PDS}

Looks good to me, nice detail in the back of the pelican's neck.👍

my thoughts exactly. I know folk that say "nothing beats a real star check" , etc. And fine, ok I get that - but it's not black magic - centre everything and it's done. if you wanna do a star check after that fine, and it will just confirm what you already know - stuff is centred and it's as good as it can be. I struggled for ages with the C925 for example - 5 mins with the ocal, and job done - it's been perfect since. I should be on commission. stu p.s. I'm not. honest.