Jim Smith

Off Centre Diffraction Spikes. Some of the brighter stars seem to have off centre diffraction spikes. Any ideas? 130pds - drawtube shortened - mirror clips removed - ZWO ASI 533 MCP - Baader MPCC 60x30s - gain100 - APP - Affinity Photo - Astroflat Pro - Topaz deNoise AI

Thanks. I took a look. I don't think they do a Z-mount one.

Does anyone know of a way of attaching Nikon Z-mount lenses on an astro camera?

Celestron 150mm SCT on AZ-EQ5 in AZ mode Nikon Z50 1500mm f/10 ISO400 25x1/250s

Thank you. When processing I left the colours alone and trusted the camera to have got it right on "direct sunlight" white balance.

Two images from a couple of days ago. Darks only with relatively short exposure time. Skymax 127 on AZ-EQ5 in alt-az mode. The Running Man Nebula. Nikon Z50 1500mm f/12 ISO3200 15x30s The Crab Nebula. Nikon Z50 1500mm f/12 ISO3200 33x30s

I think this is pretty close to the live view through a small telescope... Rising Moon_7.mp4

I will give it a try. Thanks.

I might save plate solving for "phase 2". For now I suppose I will need to do some sort of star alignment at least once.

My Lynx Astro FTDI EQDIR USB Adapter for Sky-Watcher Mounts cable arrived along with a USB splitter cable. (My laptop has only one USB port). I installed ASCOM, EQMOD and APT on my laptop and connected my camera and mount...and...it worked first time! I slewed the mount around, turned tracking on and off and took a series of images of a tree all controlled from my laptop. OK, I know that there is plenty more to sort out once I get dark, clear skies but that's a great first step. Thank you everyone! One question...I suppose I still need to do some sort of star alignment. Now I don't have the handset connected how do I do that? Is it done in EQMOD?

Thanks everyone. This is all very helpful. I'm going to take a look at APT first and see how I get on.

I'm a bit stuck knowing what to try next for my DSO set-up. I have a SW 130pds Newtonian mounted on a SW AZ-EQ5 GT. I use a Nikon Z50. My current method is to start siderial tracking on the mount, find objects with the red dot finder by slewing with the mount handset. I focus with a Bahtinov mask, take a test shot then use the camera's intervalometer to take many 30s exposures. I'm quite happy with the results. But I find the mount handset awkward and difficult to use. Also my ancient body is finding it more challenging to position itself so that I can see through the finder. So I am looking for an improved method. I want to use a laptop to control the mount and camera directly. I imagine using my existing Windows 10 laptop with a USB lead going to the mount and another going to the camera. I would like to point and control the mount from my laptop and see the camera's live view on the screen. Perhaps the laptop could do plate solving and point the scope at the required object? I have started reading about various bits of software that might do some or all of these things but it all sounds rather complicated. I don't mind a reasonable amount of complexity but I would like to start off on the right track. Can somebody point me in the direction of a relatively straightforward solution? Thanks in advance, Jim

Capturing Copernicus...

Well, I'm going to train my mount even though that sounds a bit equestrian. Interesting to see if it makes a difference.

You've reminded me of a video I made a few months ago of the periodic error of my mount. https://ishoo.co.uk/video/mounterrorlow.mp4 I think the cycles are about 15 minutes long. Bearing in mind that the above video is of an APS-C sensor rather than the small sensor of my lunar set-up, periodic error might well be the real problem.

Thanks, Of your suggestions, I think the polar alignment might be the most likely. Although I don't notice problems with dso imaging, I do that with only 30s exposures at about 1/4 of the focal length, so it might not be obvious. I will check it again.

Thanks. Looks like Right Ascension to me.

Thanks. Polar alignment is good. The mount lives on a permanent pier. Yes, I do stack the frames but the stackable area gets smaller as time passes. I suppose it isn't a big deal...but it would be nice if it worked.

My SkyWatcher AZ-EQ5 GT tracks the stars pretty well but when I come to do lunar imaging I can never seem to get the lunar tracking working. See how far Copernicus drifts in 3.5 minutes... First frame from video... Last frame from video... Here is the set-up... 2,400mm focal length. Altair GPCAM 178C using whole sensor. I actually get less drift for the moon when using sidereal tracking mode. I balance the scope on the mount quite carefully. This lunar drifting always happens. It's not just a one-off. Does anyone have any ideas? Thanks in advance, Jim

Messier 78 Nikon Z50 55x30s ISO800

...and finally a clear night. I removed the primary clips entirely and fixed the mirror with silicone sealant. I recollimated. So here is my modified "no triangular stars" 130pds in action. Nikon Z50, Baader mpcc III, extra 1mm spacer ring, shortened draw tube, no mirror clips, no mirror edge baffle. One 30s exposure, ISO800, +3ev in Lightroom, uncropped...

Progress! I searched back through Lightroom and found a shot from before when I fitted the mirror edge baffle. (Also before I shortened the draw tube.) The stars, in the centre at least, are circular! I'm pretty sure loosening those clip screws is going to be the fix. I have ordered some silicone sealant in case I decide to remove the clips. I have a feeling that with everyone's help I am going to end up with decent stars across 90% of the field...which I think is a reasonable goal. Thanks again for all the helpful suggestions.

Why did you do this? Will the mirror be loose if I loosen the clip screws? I suppose I'll find out when I take another look at the mirror cell! I wonder if the 130pds mirror cell is the same design as the 200.

That looks pretty much the same as the one I am using.

Thanks. I'm pretty sure I screwed the clips down quite tightly when I fitted the ring baffle. They were already tight. I will loosen them and see what happens.