Xiga

How do people find StarXterminator's handling of Newtonian diffraction spikes?

Looks good to me 👍. I was pretty disappointed with mine tbh. Sadr is ridiculously bright though, so I've just accepted that it's hopefully not going to be a problem for me 99% of the time. But I also have been put off Baader now. When the time comes to upgrade the Oiii and Sii filters, I think I'm going to try Antlia next.

Very well done indeed. Great job on the processing, on what is a very tough target. What are your skies like? I'm guessing they must be pretty decent.

Very nice Emil. Amazing what can be done nowadays with the advancements in camera technology. I'm in a Bortle 5 (veering on 6) area, so I usually don't even bother trying to image anything dusty. What are your skies like where you are?

Unreal data, as always. A joy to process! This was my workflow: 1. Used AstroPixelProcessor to remove what little gradient there was in each channel. I then combined them as SHO to create the RGB image (also in APP). The advantage to this is, APP will scale the channels accordingly to balance them. Before, i used to stretch each one individually and then combine, but this doesn't produce channels that are anywhere near balanced, so you then need to balance the histograms yourself. Once the RGB image was created, i gave it a light DDP stretch and saved it as a 16bit Tiff. I then made a 2nd RGB image, combined as HSO, to use just for star colour later in processing. 2. Open the Tiff in PS, crop off the edges and then extract that S-H-O channels from the R-G-B. Save each one for individual processing. 3. Run Starnet++ on each channel. Clean up any remaining artefacts using the Spot Healing Brush in PS. 4. Denoise each starless image. I used Topaz Denoise Ai at 1% level. Even this was too much, so i recovered some of the original detail using the slider. No sharpening. 5. Create the Tonemap by copying the denoised SHO channels into a new RGB image. Then do Selective Colour adjustments to taste - i like Bob Franke's approach http://bf-astro.com/hubblep.htm 6. Create the Lum layer. For this, i used Topaz Denoise Ai on the original Ha image (not the starless one). Similar settings to above, but this time with some mild sharpening. The small & medium sized stars are now a mess (due to sharpening) so i bring it into PS and layer the original Ha image on top and add a layer mask to only allow through the original Ha stars. This layer mask is created from the Original Ha image and the Starless one using Blend Mode Difference. The mask needs the white point brought waaay in, in order to protect the teeny tiny stars. This is now the base Lum layer. 7. Start a new image in PS, with the Tonemap on the bottom as a Color Layer, with the Lum on top as a Luminosity Layer. Some minor Curve adjustments to both. 8. Bring the HSO image from pint 1 above into PS as a new image and work on it for star colour. Duplicate the layer, set to Color, run HLVG (to remove green) then invert the image, run HLVG again (to remove Magenta) and then re-invert back again. Boost the saturation, being careful not to overdo the Reds and Yellows. This is now the star colour layer. Add it into the main image, set Blend Mode to Color, and add a layer mask (the same one we made earlier containing only the stars). This adds the nice star colours to the stars only, leaving the colours we created earlier in the tonemap alone. 9. Added some contrast using the Clarity slider in PS. Making sure to protect the stars, using the same star mask as before (only now inverted). Then add a small amount of Vibrance. 10. Added a very small % of NR using Carboni's Space Noise Reduction. Only needed in the top portion of the image. 11. Star reduction pass 1. Minimum Filter on just the very largest stars. I only selected the biggest 10 or 15 for this. 12. Star reduction pass 2. Used ImagesPlus to do one pass of star reduction at default settings. Then brought this into PS as a new layer and dropped the Opacity slightly, to re-introduce a slightly soft edge to the small stars. 13. Rotate for better framing (to my eye at least) and done!

Very nice image Steve. I also prefer the HaRGB version, because it goes deeper, but i also like the magenta/pink hues of the plain RGB. I assume you added the Ha to the Reds only (in Blend mode Lighten, and with the stars removed), which is the more correct way of doing it, but as Vlaiv points out, adding a certain % of the Ha as Luminance will also make the reds more pink. Btw, if your intention is only ever to add the Ha to Red in Lighten mode, then you might be surprised just how little of it you need. 8 hrs is definitely overkill in this case, due to NAN being so bright, but even on most targets you should be able to get away with a lot less. In processing the Ha, you can actually take a sledgehammer to it and crank the contrast way up. It will look downright ugly, but because of the way it gets added, it won't really harm the resulting image.

I haven't used it myself Adam, so i can't really offer much in the way of help, other than to say you should post your issue and images over in the CN thread (linked below). Russ is very active on it, and asks for images that don't work the best so he can improve the AI. https://www.cloudynights.com/topic/789257-new-ps-plug-in-for-removing-stars-starxterminator/page-7

I agree, i don't think the algorithm should matter for creating masters. I think it only gets used for the accuracy of star analysis and then obviously when the subs get debayered at the integration stage. If you wanted to be absolutely sure, you could always just test it out yourself pretty easily. Create 2 sets of Masters, each using a different algorithm. Use them to calibrate a stack and see if there is any visible difference. If they look the same, give them a DDP stretch and save as a Tiff, then throw them into PS and Equalize them. That should show up any differences.

You fill it with the orange dessicant beads you should have also received. Then you undo a screw on the side of the camera and screw the chamber on. If you connect to Qhy's capture program (I forget what it's called) and bring up the graph that shows the temperature, there is also a gauge showing the Relative Humidity (RH). Qhy say this should be kept close to 30% ish. Mine was as high as 60% but after 2 to 3 days in a flight case with the dessicant tube attached, it dropped back down to about 35%. Note, it will increase during imaging, but you want it to drop back down again when idle. So worth checking up on it every now and then just to keep an eye on it.

@teoria_del_big_bang thanks for posting your picture above. It made me go and have a look in my box, and sure enough, mine also has the same grub screws 😃 Qhy clearly think it should be possible to adjust the central screws with a Phillips head screwdriver. I'm not using a filter wheel, just a simple filter drawer, and it looks like I can access the existing screws, even without breaking down the optical train. I'll obviously be removing it anyway, to make the adjustments, so Adam @tooth_dr is there any real need to replace the screws with Allen key ones?

Thanks Adam! 👍 I get it now. For some reason, I thought the holes in the faceplate were also threaded, but I see now that when you loosen the central bolt the faceplate is now free to move out, hence the need for the grub screws. Out of interest, how many of the 3 sets did you need to adjust on yours? Think I'll also get some black PTFE tape to cover up any small gaps that appear post-adjustment, just to keep any moisture or dust at bay.

I've just discovered this neat method of testing/correcting for tilt. Very impressed with what you have done there Adam @tooth_dr ! I think i also have some tilt on my 268m. At just ~F6.3 it's not as big of a deal, but it's still noticeable. Adam, do you have a link for where you got your screws from? I'm going to have a go at this myself. On your method of adjusting the tilt, did you leave the small grub screws loose, and only lightly tighten them up when you were done? In fact, what do the grub screws actually do, seeing as there are no holes for them to screw into on the camera itself? I take it the central hex bolt is the one used for actually doing the adjustments, and are the grub screws only there to stop the possibility of the lightly-raised faceplate from ever falling back down again?

Love the Double Cluster. Some absolute corkers on show here. This was my own humble effort from around this time last year. 100 mins of colour from a Nikon D5300 and 100 mins of Lum from an Atik 383l+

Still getting my eye back in after a year out. Had another look at this tonight, and decided the previous version was just too bright. Plus, it was bringing out the noise a bit too much for my liking, so used Curves to lower the midtones a bit. Also, reduced the image size down to 70%. Calling it quits on this one now!

Hi guys Just came across this tonight. It's similar to Starnet++, in that it uses AI to remove stars, but it's all done within PS and apparently it leaves far fewer artefacts behind. https://www.rc-astro.com/resources/StarXTerminator/ Personally, i find $60 to be a bit steep for what basically amounts to just a single action (especially when you can get a whole suite of actions for a fraction of that price) but it certainly seems to be very effective. It's also very early days in the development, and Russell promises that it will only get better as he continually improves it. Here is a video of someone doing some early tests of it.

It's a slider in Camera Raw under the Filters menu. I'm on PS CC 2014 so it's possible it's not on the earlier versions.

That's wonderful Carole, really nicely processed. Amazing what a difference even a Bortle 4 sky can make. The Samyang 135 F2 is a great lens, and one I'd like to get myself at some point in the future. Ps - one small piece of feedback, if I may. The image could benefit from a bit more contrast. A quick blast of Dehaze in PS might do the trick, or even just a small curves adjustment, but either way it's still amazing.

Thanks Richard! I've had the camera since February, and have been itching to put it to use ever since. The camera has definitely impressed me I must say. The sensitivity is great, before with the Atik 383 I could never sufficiently swamp the RN in a Narrowband sub, no matter how long I exposed. No problem in that department now. Only downside is I am currently manually swapping filters. Ok for NB, but for broadband I could quickly end up as a zombie. Maybe next year I can pick up an OSC version of this chip, and leave the mono just for NB.

Thanks Adam 👍 Hope you're keeping well. It does feel good to finally be back imaging again! Although it's been a very frustrating month, as out of about 6 sessions only the last one went without issue. Up to now I've just been lucky to have never had any technical issues with the gear, so this is an unwelcome first for me. I'm hopeful the next clear night will go as planned though, now I've re-jigged the finder-guider. The image above has had no star reduction or manipulation. This is just the Ha stars as they are, and I have to say it's so nice not having to tame them in processing, so I'm very pleased with the 3.5nm filter (even though Sadr did have a pretty big halo). Some of the sessions were ok, and one or two showed what I thought looked like tilt, but stacking them all has kind of hidden most of the effect. I also definitely had diff flexure too so that was also muddying the waters. I really need a good session of guiding on both sides of the meridian to know for sure where things are at.

After what has seemed like an interminable wait, i've finally been able to complete an image again, almost a full year since my last one. I sent the mount off to get 'tuned' but the less said about that the better. Anyways, it's good to be back in the saddle again. Acquisition for this one has been difficult. After 5 years of doing AP, and not losing a single sub, not one (even doing 20 min ones regularly) i'm now having issues with eggy stars (at best) or trailed ones (at worst). I've been blaming the mount during the last month or so that it took to capture this data, but in truth i think it's mostly been down to differential flexure, a problem i never had before. Anyway, i've now got some new rings and mounting arrangement for the finder-guider, and was able to use it on the last data session, and things went a lot better for it, so fingers crossed i'm over the worst of it now. Still need one more good night on both sides of the meridian to know for sure though. So even after ditching a lot of subs, i was still able to salvage most of the Oiii and Sii data for this, as even though the stars were not great, i was only using those channels for tone mapping anyway (and a separate HSO stack just for star colours too). Thankfully, most of the Ha data had ok stars, although i do have some tilt towards the bottom left i think, and which i'm trying very hard to ignore! Details: 53 x 6 mins of Ha (Baader 3.5nm UNB) 42 x 6 mins of Oiii (Baader 8.5nm) 23 x 6 mins of Sii (Baader 8nm) Total exposure 11:48 SW80ED, HEQ5-Pro. Qhy268m. Mode 1, Gain 56, Offset 25, -10c. Stacked in AstroPixelProcessor, processed in PS. Resized to 80% as i didn't think 100% was offering anything more, and it also helped hide a little more noise. C&C welcome, and CS!

Wow, that is seriously good Ivo. Easily the best rendition of this i've come across. Good skills! 👌

@ollypenrice how are you stacking your ASI 2600 subs? Are you using Bayer Drizzle? When you have well-dithered subs, and lots of them (which is pretty much always the case with OSC CMOS) then Bayer Drizzle basically bypasses the need to do interpolation. You might find that fine-scale colour details are a bit more accurate, and it could make a difference when then binning. Worth a shot i would think. Unless you are already using Bayer Drizzle, in which case ignore me! 😄

Congratulations to Bryan and Matt, top work guys! And thanks again to IKI and FLO for another great data set and challenge.

Bit late to the party with this one. Didn't have as much time on it as i would have liked, but i found it pretty difficult to process i must admit. APP used for Gradient Reduction, Siril used for Photometric Colour Calibration, then into PS for everything else. Colour stretched manually in PS using Arcsinh, and the RGB was used for the galaxy cores. Didn't use starnet for a change. instead i just went with old-school star reduction.

Nice one Russ. We have very similar kit. Mount, scope and filter. Only my camera (Qhy268m) is different to yours. I shot Sadr a couple of weeks back and saw halos with my Ha filter, so will be interested to see how you get on.