LandyJon

I've had very little practical time with my hyperstar since getting it collimated (more by fluke I think!). I was going to fit the guide scope but read it didn't need it, although the longer guided exposure makes sense I'd have come to that conclusion eventually I guess, need to figure out a detachable clamp so the OTA still fits in it's bag. Totally agree with you on the f6.3, I was exposing 3-5 mins with 200mm guiding. To be clear those pics were 4.5 hrs imaging time unfiltered OSC (one shot colour sensor if OP isn't sure as opposed to mono) it was at a dark sky site and 1 pic is about 3 hrs of the data, the other about 2 hrs ... and I'm sure I could process it better these days but I've still a lot to learn on that side, I enjoy the capturing and tinkering more than the learning how to use editing software lol, I'll get round to it !

I had a William Optics I got 2nd hand from a nearby members advert on here, but any 200mm would suffice, as long as it's fixed securely. There's a golden ratio between pixel scale of imaging to guiding, about 4 if I remember and I seem to remember with the tiny 183 and a 385 I had in the guide, I was about on the limits of recommended, but it worked, I got some good pics, I'll try find on the NAS and post a couple. Hyperstar is a whole different ball game, I'm only just getting in to. You don't need guiding, you don't even need an equatorial mount apparently, f2 is that quick you get good subs in seconds rather than minutes and at super wide FoV field rotation is negligible. I've wondered about putting the guide scope back on but the couple times I've had it out I'm not sure it's worth guiding at all. Yeah that was my point, stick with the DSLR for now but when you start thinking about a dedicated camera, bear in mind the tiny 183 I had just emphasised the problems you're already starting with with these long focal length optics. Personally I love them, the 3 scopes in 1, add in a Barlow and put the guide cam in, you've got a planetary imager you can try, again it's on my long list for few clear sky opportunities lol

I started out with a 6SE and the reducer is a must, don't remove it until you're up to speed on everything else, the narrower FoV is good for smaller targets but introduces much greater need for accuracy in pa, guiding etc. and needs much longer total exposure times. With the reducer I was happy with what I was getting after 4.5 hrs, at F10 it'd take days worth. On PA I can't fault Sharpcap, the routine is simple, expose at park position, rotate 90° and expose again, then it guides you to adjust the bolts. I can get down to 5 arcsec on the EQ6 in <2 mins provided the laptop is in view from the mount (often it's in the kitchen and going back n forth makes it harder). It's a premium feature on Sharpcap, but the £10 ish per year is a small price to pay for the PA alone. I find the software great for capture and the focus aids and calibration frame routines all work with ease. I had a guide scope on mine which worked fine, since upgrading to 9.25 the OAG is invaluable but more to learn and unnecessary at 6" I'd say especially starting out. The other thing I'd mention is look at the field of view differences the camera sensor size makes. I started with a very small 183 sensor which made things more difficult, stick with larger sensors if you can, to keep that FoV wide and minimise the headaches.

Are you using a filter of any kind ? I've had some patterns produced by reflections between the sensor and filter, it was mostly visible on bright stars and solved by adjusting the distance between sensor and filter. Try an image without the filter to see if that removes the pattern. Fault finding with astrophotography usually involves stripping back to basics, other things to try may be ensuring binning is 1x1 and as has been suggested the bayer matrix, have a look at the raw image before bayer pattern is applied or try the 4 different bayer patterns to see if the pattern is still there. Is it on the individual light frames or only after calibration frames (darks/flats) have been stacked.

Thanks Derek hope you're feeling better, shame people choose not to honour the deposit, perhaps it should be taken at booking and refunded if cancelled over a month before, but that could be more of a headache for Lesley I guess. Hope we get a better turn out this time, I'll be there for a break if nothing else, fingers crossed for clear skies, see you there.

Remember the corrector, primary and secondary are all matched at manufacture and oriented for best performance so try to use all 3 from the same scope and maintain their orientation through any dismantle and reassembly. Hope you get something that works well at the end, I liked mine, they're a good little scope.

I didnt think the secondary screwed in to a thread ? Is it held in place then ? I had a 6SE but don't recall removing the secondary, the Edge 9.25 has the same as pictured above, the secondary slots in with a peg to achieve correct rotation position, then the retaining ring screws down to hold it in place. A photo of what you've got would help, there may be earlier versions which were different to the above image, certainly fastar compatibility would have changed the way the secondary mounted if yours is pre-fastar. As for buying spares a quick Google found nothing, but a quick call to FLO or Rother Valley, one or other may help you find the part. Edit : Oh and collimation will need to be checked either way once you've sorted it, these SCTs hold collimation pretty well, I work on the idea mounting and dismounting and carefully packing away etc is all good but take it for a drive and you should check its still aligned. Also cleaning the corrector is easy enough, even if it needs removing, just be sure to mark the orientation so it goes back in exactly the way round it came out from.

Indeed, you need a finder scope of some sort ... Mine have cameras in there rather than eyepieces, but the small white scope (or a red dot) you'd use once aligned with the main scope to find the star you want, then looking through the main scope it shouldn't be too far out of your view, hopefully in it but if not you may see some glow that'll indicate which way you need to move. My main reason for comment tho ... Have you got your location set properly in the synscan handset ? using the right format, ie. decimal or deg:min:sec ... to be honest I forget, its been that long, software does it all for imaging so I haven't used the handset in a long time, but if your location is off your goto and star aligns will all be off. Just a thought.

Yes, I need to put some time in to learning the processing now I've got some good data collecting kit. Was at this point 2 years ago with the 6", now I've finally got everything I need for the 9.25 and got it working I can start concentrating on learning photoshop techniques.

Thanks Damien, something to work on, I'd forgot to remove the filter so should get something better next autumn, was thinking collimation would take all night but it went well, then I didnt fancy dismantling it all in the field to get the filter from inside the hyperstar. But happy with results 🙂

Got the caravan away back to storage finally and had chance to process my images. Think I had the screen brightness up so they looked faint once transferred to phone 🙄 Stu done a proper job for me ... Quite pleased with the collimation.

Yes, I've only had 1 opportunity to try it since and had trouble with it not reaching focus, so I had to wind it out a bit and forgot to not do it on the bright star I'd focused on. Just done it on a star field and happy with the result, maybe a little tweaking could be done but left it on M42 for an hour on live stack and this is the "save as seen" result. Its got an hour of horsehead now too, but we're in the warm room for a chat, I'll go pack it up shortly.

Indeed, we're getting some good clear skies with the occasional patch hazing up. Got my hyperstar collimated pretty good and some good data on M42 and now horsehead coming in. Would be good to see you but I'm hoping to get underway before lunchtime to get back home at a reasonable time since I'm back in work Monday. Glad to hear your friend is getting better, hope you're on the mend too.

Ment to include this in previous post, but the process of putting polaris in the crosshair then adjust alt only bolts to move it to the outer ring puts it at 00:00 ... then rotating RA so the circle is on polaris has set your polar scope to 00:00 which is where you need to be able to set these green rings to 00 ... if they can't be fixed to the axis, I dont see how you are supposed to accurately dial in a polaris time.

Those green rings should allow you to dial in the polar clock accurately, provided the RA ring rotates with the RA axis, which I'm not sure from reading above if that is happening properly on this mount or not. The way I've used it in the past, before laptop software took over the process, was to set polaris to the 00:00 position by centering the star on the crosshair using alt az bolts, then adjust just the alt bolts move polaris vertically to the top of the (clock face) ring. Then rotate the RA axis so the little polaris circle is centred on polaris and set your green ring to 00:00 Now your green ring can be used to dial in an accurate time from one of the polaris timing apps eg ... This shows a time of 08:31 but your dial has a 24 count ... no problem just double the 08:31 to 16:62 obviously we're on clock base numbers so 60 is an hour (just being clear for everyone) so we have 17:02 to dial in on the RA axis and we simply adjust the alt az bolts to put polaris back in its circle, now at the 08:31 position. Realistically by this method the 00:01 is impossible to pinpoint on the green dial where 1mm is about 00:06 The only way to do it more accurately is by having software make the rotation to exactly 08:31 Hopefully this mounts RA dial can be used this way as I understood it to be the most accurate way to polar align without computer control. Edit : just to warn, be sure these rotations aren't going to cause a clash between scope and tripod ! ... the process can be adapted to rotate from polaris at a 6 o'clock position only needing a <45° rotation to 08:31 ... 02:31 clockwise so 05:02 on the dial ... or you could go anticlockwise from a 9 o'clock position 00:29 or 00:58 anticlockwise on the dial ... which is why the ring counts in either direction. 3 and 9 o'clock require an az only adjustment to polaris from the crosshair obviously.

Is that an angry surcharge ! 🤣 Thought I'd try out the water top-up bits I got from Dads van, see how it works. I'm away Sunday, hopefully see you before I set off. Hope you're on the mend and got some good pain killers.

Setting off now too, see you 3 ish

Not something I've ever done but I believe drift alignment is what you need. Someone might be able to help further with it, or start researching it yourself. Its different to plate solving which just centres you on a target.

Get well soon Derek, be good to see you if you're in the area even for a drive through visit, if not see you in the autumn.

I think this might be a good next step, take the filter and CC out of the equation. Try another short stack, forget the bias too, just lights, don't worry about spacing, just get the camera direct on to the scope and see what happens, if it's still there you've ruled everything out, if it's gone you can re-introduce things one by one. Reason I suggest is I've just done a crazy stretch to your first image and the banding looked more of a grid and the only time I've seen anything like was due to reflections from a filter being too close to the sensor. Worth a try before looking to return it.

Offset basically pre-fills each pixel with a small amount before starting to capture light, I dont think its really necessary with these CMOS sensors, but your 1 or the OPs 10 out of a full well of 47,000 are a minimal amount. More importantly with your sensor like many others they have a HCG on the gain at 252, so be sure to use gain there or above as there's a dramatic reduction in read noise. You don't mention darks, have you done them ? does it show on them ? remember darks need to be done at the same temp as your lights, particularly with an uncooled camera you'll want to do a few darks for each imaging session as the camera can't be set to a temp it'll be running slightly warmer or cooler dependant on the ambient temp of the night.

Don't worry, we'll have the initiation bat at the ready 🤣 Damien brings The Hubble's twin sister and uses a tent for storing it through bad weather etc, he sleeps in his van. See you there 🙂

Looking forward to it, hope the mods keep the water out this time. Fingers crossed these storms blow out and we get a week of calm clear skies. See you there.

Welcome, nice to see you know how to spell Jon ! 🤣 I'm from Manchester too, lived all over and eventually settled down the M56 a bit, close enough to see family but far enough to not have them dropping round all the time ! Sure you'll get up to speed quickly, the only silly questions are the ones you don't ask and waste hrs of precious clear skies figuring out for yourself. Have fun.

Sorry to hear that Peter, wishing you a speedy recovery, hope you've still managed to enjoy Christmas and New Year, see you in October.