Ouroboros

@Rattler. Now I’m seeing there in your two versions exactly what I’m seeing in my recent attempts at processing a wide-field image of the Cygnus Loop. On the one hand I like the delicate detail I see in your original images. On the other hand it’s good to see the bolder, far more colourful and impactful aspects of your more recent version. I seem to have the same ‘issue’ and am finding it difficult to balance those two extremes. I guess I just have to accept a compromise. Maybe I can’t have delicate detail and impactful in the same image!

What do you reckon made the most difference?

Great picture. I like the visibility of the weak stuff. I know how difficult it is to pull up and separate from the background.

Oh, I agree. And “lounge” is so fwightfully non-U, don’t yer know. 😉

I don’t know. That situation goes beyond my level of physics understanding.

I regret not realising in the early days that the mount is at least if not more important than the telescope for deep sky astrophotography. I bought an EQ5 mount, motor driven, but no goto or guiding. On the other hand as an apprenticeship in basic astrophotography it taught me a lot about finding the target, learning the night’s sky, and good polar alignment.

That really is a very nice image. Is that blue OIII? I might have a go at that myself.

In the absence of any initial angular momentum or external forces the two stars would only be attracted towards one another and eventually collide.

It took me a while to realise how critical stretching is. I was misled by the simple dropping the STF stretch onto the Histogram Transformation tool so frequently demonstrated in introduction to Pixinsight videos.

Very nice @AstroGS. Were you using GHS to stretch?

I wonder if this is related to a known USB connection issue with the GEM45s solved (as you have, @Jerry Barnes) by using an additional USB hub between the mount and controlling computer or ASIair. There are references to this problem and workarounds here: https://www.cloudynights.com/topic/778610-new-ioptron-gem45-and-asiair-issue/ Because of this issue I returned a GEM45 during the supplier’s grace period. I do not consider this satisfactory. You should not have to implement this sort of workaround in a product designed to be controlled by an external computer.

I was going to say just that. I imagine Bodmin skies are not dissimilar to North Cornwall coast and up to Hartland Point in west Devon, where I have done most of my astronomy in recent years. Much of it Bortle 2, though Bortle 3 where we are. When clear the skies can be pretty good. Able to see M31 with naked eye good. But as geography teachers used to say the West Country is known for its warm, wet, westerly winds. It can’t ’alf rain and be cloudy. Having said that, when the weather is coming from the east it can be beautifully clear down there. It has to be said that living there would make a considerable difference. You can then take advantage of clear skies when they occur. Visiting as we do does mean we take pot luck and you all know what Sod's Law says.

Thanks so much, @Oddsocks and @symmetal for both your informative responses. It never ceases to amaze me how knowledgable and helpful members are on SGL.

Yes, I zipped forward to that bit actually. I have also found a video which describes how to add filter profiles including the Askar ones to SPCC process. I’ve yet to do that. https://youtu.be/bAwK5Isk-U8?si=qIbadumopWHr8izn

Prior to Oddsock’s post I had wondered that. In fact I looked around for one. The answer is no apparently.

Hello @Oddsocks. Thanks for that. After a quick skim read of that link can I take it that: After doing a crop we still need to run Image Solver before using a process like SPCC that needs the WCS*? The WCS data is stored somewhere in the XISF file. Can I see that WCS info somehow? * WCS - World Coordinate System …. I had to Google!

Having watched this I discovered I was using SPCC more or less in the way in the way recommended. I then decided to experiment by trying various different settings: narrow band or OSC, photon flux or spiral galaxy etc. I tried it three quite different ways and d’you know what …… it made absolutely no discernible difference to the result. 😀 Weird huh?

There's a weird little problem I have noticed using Image Solver script with my new MacBook. Image Solver chunks on through and produces a solution in the process console. However, what it is not doing is writing the solution into the FiTS header of the file. Weirder still is that SPCC seems quite happy to provide a solution - graphs and everything. How is this possible? It shouldn't work should it? PS. The plate solving result shown in the process console is confirmed by Astrometry Net. PS is definitely solving the image. Just not saving it to the image header.

I'll watch that. Thanks.

Thanks. Just tried it. That's a good trick, @symmetal

Yes. I always use SPCC now. I selected the narrow band filter setting and input the 6nm bandwidth. I am not really sure what SPCC tries to do with narrow band one shot colour images anyway. I assume SPCC tries to 'recalibrate' as it were the colour of stars according to the data in the Gaia data base corrected, presumably, for the fact that the data was filtered by the two wavelengths passing through the dual band filter. I assume it then applies the correction factors to the entire image. The resulting colour is often somewhat underwhelming at that stage, which is why of course we like to push up the saturation a tad. However and strictly speaking perhaps we should accept those initial colours as closer to the 'truth' of what's really there.

Last night I managed to get a couple of hours of acceptable subs on the Heart Nebula (IC 1805) in Cassiopeia. Captured using an Askar Colour Magic dual band filter (hydrogen and oxygen). It appears to have given a reasonable image despite the full Moon and only a couple of hours data. This was also (kind of) "first light" processing with PixInsight with my new MacBook. I have had my old MacBook for about ten years and it was really showing its age. It was so slow that it would take over night to process files in WBPP. This new one took 30 minutes to process 64 lights, 60 flats and 60 darks flats. I would prefer a slightly deeper red on that hydrogen. Not quite sure how to do that. All I've done is to turn up saturation basically. And the background could be slightly darker I think. Telescope: Askar FRA300. AM5 mount. OAG. Askar dual band Ha+OIII 6nm filter. ZWO ASI2600 OSC. ASIair Plus. 64x120s subs. Processed in Pixinsight only.

OK. Have you tried googling that error message you showed above? I just did and it came up with lots of links some of which might be helpful.

When I used a polar scope I found it sufficient to kneel or sit behind the mount looking north and up to make sure the mount was pointing in more or less the right direction. I usually found that good enough to see Polaris through the polar scope. Yes, Polaris is by far the brightest star in that vicinity and pretty unmistakeable. You’ll know it when you see it.

Isn’t there an inherent problem here? Even if you did calibrate your laptop screen, images might look different on your iPhone and tablets anyway.