Stuart1971

Sorry confused, not sure what you are saying here, you mean I should not guide in one direction, or I can but I will have to either in RA only, as it will not work in DEC due to the setting I have for the DEC guiding…

No, the older EQ8 suffered from terrible DEC backlash due to not absolutely perfect round worm wheel, mine has barely any backlash around half of the worm, and some on the other half, it’s a known issue with them….and one that has had many a thread discussing it, and apparently the later ones are not much better….😮

Yes, that what I said, I can still guide in one direction, and just dither in RA only, and this DOC confirms this….yes…?

This is what is says on the NINA site re dithering in RA only…

I did, and it told me I have 3200ms of backlash and to guide in one direction only, and this has worked really well…..🤔

Yes, under the graph at the right hand end you will see a drop down box, which has three settings, the default is Auto, and you also have North only or south only, so if it drifted north after a few min test, then you select south, but you have to swap it round after a flip.

No, if I have it set on south or North guide only I have to use RA only for dither, well that’s what I have read on the NINA website anyway…

Thanks, so as I guide in one direction only because of DEC backlash and this works very well, I see I can dither in RA only, is this not as good, or is it at least better than nothing…?

Another option, which I do, is to guide on DEC in one direction only, this makes the DEC backlash issue moot, so my PA is about 3 arc mins out, so I watched to see which way the DEC drifts without guiding on, and set it to guide just in the opposite direction, so no swapping from one to another so no backlash issue, it works extremely well with mounds with DEC backlash which my EQ8 has 3200ms of….

Well, thank you very much, appreciated….finally getting some good results with this QHY268c, after a couple of months, thinking I had made a mistake buying it…👍🏼

I have been imaging for a while now, and getting fairly decent results, but have been told I need to dither, now I never have, I image with a QHY268c with the IMX571 sensor, and it’s really low noise, I have noticed a bit of walking noise, I think it’s called, where it looks like streaks across the images, when stacked with no calibration frames, but not in the final calibrated images out of APP, now people say that darks are not needed with this camera, and other say to use them, I do use them, as well as flats and dark flats, and seems to work well, so my question what is dithering, and do I need to do it..??? here is an example of my latest image of the Heart nebula, with the above calibration frames, 5 hours of 2 min subs, 50 darks, 50 flats and 50 dark flats, processed in APP with a final tweak in affinity Photo, so more data I’d needed for sure as it’s still quite noisy, but will dithering make any difference to this image had I don’t it at the time…??

Thanks, I think….🤔🤔😂

The PA figure is, well in my experience anyway, also read it in another forum, but if it works for you….👍🏼

Looks good to me…👍🏼

The PA algorithm in PHD2 is pretty much useless, it just does not work at all, so this should be ignored. I ran guiding assistant two nights ago, twice in pretty much succession, in very close parts of the sky and got 3 arc mins error the first time. And 14.7 the second….it’s just a waste of time taking any notice of it….in Sharpcap I am approx 2 arc mins off the NCP…so the figure above don’t surprise me….

No need for it to be level, close is good enough, PA does the rest….don’t sweat over it….👍🏼

Correct, it makes no difference at all if the mount is level, as that’s what PA corrects, close is good, but that’s all you need…no point in spending time on getting an EQ mount perfectly level….many people just do not realise this….👍🏼

Had another go at the Heart Nebula last night, under full moon with the Optolong L-Extreme Duo Ha, OIII filter, with QHY268c 5 hours of 2 min subs, full image and a crop of the centre region

This was mine from last night 5 hours or 2 min subs of the Heart Nebula, under the full moon with the L-Extreme, and a crop of the centre…. and a brighter version, not sure which I prefer….🤔🤔

Imaging last night and had a go at M81 and M82, in the FOV of my QHY268c sensor the two galaxies were side my side, as I thought they should be, then I guide with an ASI174m which had a decent size oblong sensor, and I noticed that the two galaxies were one above the other, in the image on PHD2, hmmm but both cameras are orientated with the long sides of the sensors right to left, yet the guide camera needed to be rotated by 90 degrees clockwise for the images to match which would mean that it would have the short sides of the sensor top and bottom, this can’t be correct can it…?? I know this makes no odds for guiding purposes, but was intrigued to know why… Imaging scope Tak FSQ85 and guide scope Tak FS60cb Any ideas…?

And there are much cheaper versions, but they all reduce the imaging circle, and with todays large sensor cameras, it will not work very well, as the area that is currently suffering from coma, will just be vignetted out anyway….if that a word….😂😂

Hmmm, if it was below 10 arc seconds, you should get over 5 min subs with no trailing on that scope, I would think it was more like under 10 arc minutes… As long as balance is gold it should not trail, it’s down to PA…👍🏼 My PA is under 3 arc mins, and I can get around 6 mins unguided with no trails due to alignment, but periodic error will also play a big part in star shapes…so good PA and good guiding is what you need…..👍🏼

Don’t worry about it, it’s perfectly normal, just get collimation bang on in the middle and you are good to go, this is inherent of uncorrected SCT’s, especially the older ones, I have an 8” 1997 model, and it’s the same…it’s due to the design of these scopes…👍🏼

Well, after another great session with GSS, I may well be sticking with this…best guiding ever, never went above 0.5 rms, all night, and the best was under 3.0 rms…well happy.. I did have one instance where GSS crashed, but it was while I was messing with the 3D picture, and it crashed, this has been reported and could be an issue when using over windows Remote Desktop, as I do, so I have now turned the 3D plot image off, then it ran all night fine….👍🏼

Wow, great minds…😀 me too last night, but not processsed them yet, had the L-Extrme filter on after shooting the Heart, so gave it a shot, 80 x 2 min subs…looking forward to see if they produce anything…