Stefan73

Well INDI should be running on the pi if your hardware's connected to the pi so there shouldn't be any need to connect to a remote server. It was a while ago I set this up but I don't remember it being at all complicated. I think I just started a new profile, selecting ZWO CCD for the two cameras, EQMOD for the mount, PHD2 for the guiding, chose suitable telescopes and then started it with everything else default. And it just worked[tm]. Maybe restart kstars, start a fresh profile and try that?

Shouldn't you be in local mode then?

It looks like what you're doing is correct and I've certainly got a ZWO camera and guide camera to work fine with astroberry. If you type "lsusb" at a command prompt do you get an extra listing appear when you connect the camera to when it isn't connected? (Mine don't identify themselves as ZWO, it's just a hexadecimal number) Are you using the extra 12V power supply with the ASI 183? If not it's possible the pi just doesn't have enough power from the USB port to make it work but the Asiair does. Does the ZWO mini connect ok on its own?

You can look at various graphs for read noise vs temperature for cameras and cooler is better (although with a law of diminishing returns) but I'd say the biggest plus is being able to have a darks library. You don't have to waste potentially over an hour of imaging time (to make 20 x 3 minute darks for example because you need to shoot them at the same temperature as your lights). You know the lights were at -5C or whatever and the camera can reproduce that temperature at your convenience during daylight or cloud cover!

That effect on the lights looks very like what I had on a very dewy night when the various mirrors of my 130PDS ended up pretty sodden. Could it be dew?

Is there no hope of getting the OAG between the camera and the reducer? You may end up too far away from the camera to be successful if you're the telescope side of the reducer. I had success with the 9mm TS optics OAG sitting between a canon DSLR and a coma corrector in the 55mm of back focus.

There's certainly lots of theory about how long each sub should be to make sure it swamps the noise of the sensor but doesn't get overwelmed by light pollution which you could work out based on your light polllution and camera sensor but, given you're not guiding and are using a DSLR, I'd go for as long a sub as you can get away with as many as you can manage before you want to go to bed or the clouds roll in! 30s subs ought to be fine if that's all you can manage; it's better to have lots of short good quality subs than long marginal ones. You can always stack sessions across multiple nights to build on earlier data as long as you've got calibration frames (flats) from each session. There's a law of diminishing return with adding more and more subs but you'll see more detail emerge as you add more.

another vote for astroberry which nicely packages kstarts, INDI and most other things you might need. Your biggest problem would be actually gettng hold of a pi-4 at the moment.

Ahh the penny drops! I'd never realised it could do that.

You must have a very different CC to me. I use this one from FLO https://www.firstlightoptics.com/coma-correctors/ts-10x-gpu-superflat-4-element-2-coma-corrector.html and I can't see any M48 thread on the telescope side, just on the camera side. The telescope side looks just like a smooth nose piece. The Bader one might work on 130PDS if you're CC moves the focus position outwards like the one I linked, otherwise you're right there wouldn't be enough inward travel. Easy enough to measure if you've got 30mm and there's always FLO's returns policy...

I'm not sure you could directly attach a GPU coma corrector (at least mine wouldn't) as they seem to be designed to be used as a nose piece. Maybe something like https://www.firstlightoptics.com/adapters/astro-essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html or https://www.firstlightoptics.com/adapters/baader-2-clicklock-m54-clamp.html would make it less wobbly though? Do you mean the draw tube needs nearly maximum extension to reach focus? My existing PDS adapter measures about 12mm. The first claims an optical distance of 10mm and the second 30mm so I guess using the second would enable the draw tube to be in further to reach focus. Or you could presumably use the first with some spacers.

Both astap and siril have basic tilt measuring functionality, are free and multiplatform. Siril has the tilt command and astap has it as part of its image inspection functionality.

You're right of course... the kstars log would have been more helpful! Although it doesn't look massively useful; it logs the last dither as successful at 21:22:29 which PHD2 sees requested at 21:21:51 and then it's never mentioned again although it looks like the star was lost just as it was downloading the next image and presumably about to do the next dither. Anyway if no-one else has seen this then I guess I'm just tickling a new bug in kstars and it should resume dithering or it's a pretty unusual circumstance. I vaguely recall some option somewhere in kstars or ekos about allowing a certain number of dither failures but I can't find it now. log_20-29-20.txt

I've always looked at the histogram of the image; as long as that isn't clipped then I think it's OK. Mine usually peak aroune 1/3 of the way along.

I've got PHD2 and dithering working quite happily now but the dithering seems to stop for the imaging run if there's a lost star about the time it does the dither. The guiding and imaging run carried on but it just didn't dither any more. Obviously I get why that dither wouldn't work when the star is lost but subsequent ones might if the guiding is still going. This is using EKOS/INDI on an Astroberry. Am I missing an option or something to tell it to have another go after the next sub is taken? Guide logs attached... PHD2_GuideLog_2022-10-07_200832.txt PHD2_DebugLog_2022-10-07_200832.txt

You can upload it to https://nova.astrometry.net/upload and that will show you where the area you've photogaphed is in the sky so that helps with orientation then you can see how the star trails line up.

Ok that's really interesting. I'd downgraded ages ago to 1.09 to use magic lantern (which I don't need any more due the wonders of EKOS and INDI). Time to upgrade again I think. No dark frames and already using sigma 3,3 so that's OK. The fixed bias offset is really useful as well, I was going to investigate what value to use there at some future point. I'll see if the banding reduction can improve what I've got too but other than that it's really useful to have an idea of the minimum dither I should be doing for the future. Thanks.

Hi all, I've just started guiding with PHD2 and there's appeared two black horizontal lines on the resulting stacked image (see 16_09_2022.fit). They're most easily visible in blue with maximum stretching (like in the screenshot of siril I've attached). Does anyone know why? It doesn't look like the pictures of "walking noise" I've seen and before guiding I didn't seen anything like this. The stack was created from 120 1 minute subs using a Canon 550D, 130PDS, OAG for guiding and no dithering. I think the individual subs have a very faint black line there too but hard to be sure. The 17_09_2022.fit was the same set up (although 90 subs I think) but I tried dithering 5 pixels every 4 frames (in a spiral) which has improved it a bit and the black lines look more smeared so it looks like more dithering is the answer but I've no idea what values I should be using and the ones I did use were just plucked out of the air. What do people use? Or am I barking up the wrong tree here and something else is amiss? Any insight appreciated! 16_09_2022.fit 17_09_2022.fit

Had exactly this when I was polar aligning my new EQ6-R. Ended up nearly 60 degrees on the scale when it should have been 52 going by location. I guess it just isn't that accurate as the software polar alignment seemed happy with that value. That digital angle finder looks cool though. I might get one to check nothing else has gone wonky I haven't noticed...

Thanks all. It did just need a bit more oomph.... your answers gave me the confidence to give it a bit more oomph! Looks sorted now according to lasers and cheshires so I'll see if the stars agree. Allegedly secondaries hold their position well but, if not, I may well replace the grubs as suggested.

I'm trying to slightly adjust the secondary to get the collimination spot on (and as a learning exercise). As far as I know it's the three little allen key bolts at the front I need to turn gently to move the laser dot around the primary (one of which has an allen key in it in the photo). The problem is I can't shift them at all. Applying force does move the secondary but it just moves back when I stop so I think I'm just bending the spider slightly rather than actually turning a bolt. I'm presuming I'd start by slightly undoing (anti clockwise) one bolt? Is there some sort of locking screw I need to undo first? WD40? Just more force?

Hi, What do you use as a rain sensor / rain alarm app? I've never quite plucked up the courage to leave everything out from a rain point of view but it does feel like I'm missing a lot of imaging time from not ever doing that.

Ok that was way nicer than I managed! Was that just with Siril?

Here's what Siril gave me. I did spend ages trying to bring out more red but, given it's an unmodded 550D, it might just really not be there. I'd certainly be really interested in what better processors can squeeze out of it. It's still high in the sky so I'll definitely be adding on future clear nights and see if it evolves... That stack was only from 45s subs unguided and while, I'm close to getting guiding reliably working now, 8 minutes on my overloaded eq-3 might be pushing it! I'll try some longer subs when I'm happy with the guiding and see how that improves things. Thanks for the pointers. result.fit

The level of detail in the centre is amazing! I've been trying this one over the last few weeks and have got nowhere near that. Do you need a UHC filter to have a hope? Or just more skill and/or better equipment than I've got 😀? Here's what just under 3 hours of integration got me with my unmodded Canon 550D, Explorer 130-PDS and a bit of Siril.