Endolf

I had stellarmate 1.5.8 running last week with my QHY 268M, did you run an update more recently than that?

I've now got Antlia LRGB filters as well as the narrowband ones. Same issue, so I'm pretty sure it's the MPCC. I think the Antlia filters are an improvement though, to the point where it's just about ok for me to deal with in post processing.

Hi, I've got a Baader MPCC MKIII which I've been using with my ASI1600 on a TS Optics Photon 200/1000 (GSO rebranded as I understand it). I got a QHY269M and was using it fine with my other scope (SharpStar 61 EDPH MKII). I've now tried the new camera with the my Newtonian and found that the corners of the images are not corrected. I've eventually managed to improve it by adding 1.8mm of spacers, but it's still not corrected. The baader MPCC is cheap, so I have been looking for a better coma corrector. I've seen the SharpStar 1x coma corrector, and having already got sharpstar gear I am tempted. Does anyone have any experience with this corrector?, is it a rebrand of something else? Any advice welcome, including alternatives. Thanks

I did the same thing, they all seem to be coming like this at the moment.

Yup, I had issues whichever way I had the filters in until I had done that. I "borrowed" some from my ZWO filter wheel, having replaced the narrowband filters in that with the Astronomik 6nm ones. What I haven't tried is turning them round again now the edges are masked. I did have them in the best way round pre masking though.

I tried that on the other scope I got bad rings, which I assumed was the reflections from the edge of the filters, but I'll give it another go.

It's a MKIII

If I remove the MPCC the problem goes away.....

My scope has been indoors since about midnight, so I don't think so, the camera cooler is turned off, so there shouldn't be any frost. There wasn't a huge amount of moisture last night when I packed up. I've seen things like it in the past, but normally a couple of hours with the fan on the scope blowing air through and it clears up. The broadband filters seem to be fine too. I'll try again tomorrow just to check.

I got a new camera a month or so ago, the QHY268M, along with the QHY FW and the Astronomik RGB and CLSCCD and the Antlia 3nm filters (3.5nm OIII as I can't find the 3nm in stock). I got some images with this setup attached to my SharpStar 61 EDPH MKII with the flattener/reducer and all seemed good. I've now tried this on my TSOptics Photon 200/1000 newt with the Baader MPCC. My flats on the newt are awful. There is a huge bright area in the middle, that I assume is a reflection. This causes my flats to over correct the light frames and I end up with a nice clear centre, but horrid edges. Here is the OIII stack without the flat applied With the flat The flat itself And here is a flat from the SharpStar (it's been cleaned since), but there is no central circle. And here is a flat from my ASI1600 on the newt There is something about the combination of the new camera/filters and the newt/mpcc that is causing these ?reflections? when shooting flats, but I have no idea what at this stage, and it means that I have data I can't really use. Any help would be appreciated. Thanks Edit: Just done some tests with the Astronomik broadband filters and I don't see this issue with those, so I'm guessing it's the Antlia filters combined with something. Maybe the MPCC?

I think it's fine, but, wait till the scope is cooled a bit maybe?, I turn my rig on, which runs a fan on the back of the primary mirror, which means some air flows through the rig, moving any moisture from the night before, give it 10 to 20 minutes (by the time I'm PA, got the camera rotated, target framed etc), then I cool. I'm only going to -10. The camera will have already got to just above 0 by then too as it starts cooling as soon as it's turned up (but remains above freezing)

Kstars crashing, what version are you on?, I'm on the nightly's as Jasem has done some work to stop the crashing with the APS-C sized sensors and above on the Pis. I still get it, but only on the rig with my iOptron mount, the other rig is now stable running on stellarmate nightly builds.

What cloud.... 😁

Both of these images were taken with the QHY268M and the CFW3-US from stellarmate, so it can be done https://telescopius.com/pictures/view/79492/deep_sky/orion-nebula/M/42/diffuse-nebula/by-endolf https://telescopius.com/pictures/view/79746/deep_sky/flaming-star-nebula/IC/405/diffuse-nebula/by-endolf

I've got this same combo and it's working. I've not done any firmware updates on either device. I have the FW connected to the camera via the 4 pin connector. Have you tried updating stellarmate?, I'm running the QHY guide cam too on one of my rigs, and found that the QHY camera stopped working, a quick update seemed to solve that. I've also got the kstars crashing issue with the 268M (same as the 2600MM for ZWO users), which seems to have been at least reduced in the latest nightly builds (update to the beta stream in stellarmate). The filterwheel on the 4 pin plug doesn't show up as it's own device, it shows up as a component of the camera, so you don't need to add it. If it's connected to the camera, and the switch in the FW is set to 4 pin mode, then it just appears in indi as a new tab and you can set up the filters in each slot from there.

Indeed, I thought iOptron were supposed to be better than SW....

I've managed to reduce the end play, but not remove it. It's an improvement though. Found there was a grub screw in the pulley. Loosened it up, moved the pulley up the shaft a bit and tightened it back up. Just need some clear skies now....

So I've managed to fix one axis, the video is from before. There are 2 grub screws around the collar that the gear bolts to, and these grip the tube the polar scope runs through. I just tightened them up and now the gear doesn't rotate, so the whole thing is nice and solid. The other axis looks more tricky, as the issue is the shaft that the belt joins to and runs through the clutch can move laterally in it's bearings, this is where the slop is coming from. I might see if the pulley can be moved along the shaft a little. I'm not sure at this stage. I'll take another look tomorrow.

Especially not in both axis....

Thanks, I've started surgery.... I can confirm that the mesh between the worm and main gear is fine, as is the belt tension. The issue is that the main gear "floats" on the axis. I need to dig more in to the guts, but that gear rotating is exactly where the slop is.

I got the CEM26 at the beginning of the month, the weather being what it is I've only had 1 evening with it. I noticed the guiding (especially in dec) was not great. I took a look at adjusting the backlash yesterday and noticed that both axis have terrible slop in the mesh, I tried adjusting it, but it seems to not have any effect, only making the motor stall if it's too tight (so it's doing something), also, doing it too tight means the clutch won't disengage. The videos attached are *after* I tried to adjust it, but as I mentioned, it's made no difference, this is as bad as it originally was. My first setup uses an EQ6-R pro with my 8" newt on the top, so this mount was supposed to be for the SharpStar, so I didn't need the payload of another EQ6, but I'm beginning to doubt my choice. I've contacted the vendor and they seem to suggest that this amount of slop is fine, but it's certainly not what I get on the EQ6 and it's not what a friend of mine sees on his AVX. If the balance is off center, then the gear would be on one side of the worm, and it would be solid for a bit, but as each axis goes over the top, it would suddenly jump, which would ruin the guiding at that moment.

I don't think so unfortunately, the output from the camera (and so the lens cap they provide) is bigger than the output from the spacers, so it can't be used once the filter wheel is on anyway.

I also got the cheap camera lens cap, I've ended up with a small m48 extension with a slip on cap as a replacement. I'm surprised that m48 screw on dust caps aren't a thing in the UK. Can find one in the EU, but thanks to Brexit I have no idea what it would cost me or how long it would take, so having to stick with the bodge for now. I have a dark cupboard under the stairs where I can take my flats and darks, so all is not lost.

I've finally got an image to show. The stars in the corners are not great, back focus was out, I think I've improved it, but the weather isn't looking like I'll be testing any time soon. Just under 5 hours with the QHY268M on the SharpStar 61 EDPH MkII, with the Antlia pro 3nm Ha and SII filter and their 3.5nm OIII.

I've had problems with the BF even *with* a QHY filter wheel, I've removed the 1mm spacer to get the stars in the corner of my SharpStar 61 roughly round, rather than oblong.