Xiga

I've had the same experience Adam. What looks best on screen tends to look a bit underwhelming when printed. You almost have to 'over-process' the image a bit for it to look it's best in printed form. Interested to see how you get on with your multiple versions.

Yup 🙂

Hi Steve Seeing as you are cropping in P.I before moving to APP, i presume that means you are using P.I for stacking the individual panels? If so, then i strongly recommend you do all the stacking in APP instead. One of the major selling points of APP is it's mosaic capabilities, and to fully take advantage of that you will need to use it for the stacking too. Once you have the registered Lum and RGB images, you are then free to move on to any program you wish for your usual post-processing workflow. Here's a great video guide, and a summary of the main settings, if you're not sure: https://www.astropixelprocessor.com/part-3-register-normalize-integrate-the-mosaic-of-the-mosaic-tutorial-milky-way-to-rho-ophiuchi-by-mabula/ The really important bit, and it is one that might need a bit of experimentation with the settings (No. of Degrees and Iterations) is the LNC settings in the 6) Integrate tab when you come to create your 4 individual mosaics for each channel (Lum, R, G, B). With the right settings, the brightness of each panel should blend together really, really well. I did a mosaic myself recently, and i used 2nd Degree and 10 iterations for a 6 panel Ha mosaic and i thought it worked really well. I did have some issues at first, but i tracked it down to using LNC on each stacked panel. Once i turned it off, and only applied it at the mosaic creation stage, the results improved a lot. Of course, YMMV! Additionally, i would try using APP's 'remove light pollution tool' (i'm going to abbreviate that to RLP) instead of DBE. A lot of folk seem to think it does a better job. I can't say for sure myself, but seeing as you're in APP anyway i think it makes more sense to keep this stage 'in-house' so to speak. I also wouldn't run RLP on each individual panel. I would only run it on each 4 fully-completed mosaic channels, and then again on the combined RGB mosaic. HTH.

Brilliant post Olly. Plenty of food for thought there! I do wonder though how hard this method would be in reality for those of us not in the same league of PS skills. I haven't looked at the data myself, but it might be a good idea Adam to share the stacks for the two Lum panels. Then we could see if there is a better starting mosaic possible. I know you use APP for stacking. Did you use any LNC (Local Normalisation) settings when creating the mosaic? I recently did a quick 6 panel mosaic in APP. With no LNC, the varying brightness of individual panels was very noticeable. But with the right settings i found it blended really, really well, so much so that I don't need to amend any of the overlaps manually. Olly's idea of using an Equalized stretch to show up small imperfections is a good one. With only 2 panels it will stack very quickly, so you could just do several stacks at different settings (Degrees and Iterations) and Equalize them in PS to see which works best.

Yep. Just pull some Cyan out of the Reds in selective colours should do the trick.

Thanks Mark. Hopefully the weather plays along and I can finish it in good time. Thanks Simmo!

After doing a dry run a couple of weeks back with the vintage Tamron 135mm F2.8 lens i picked up last year, i was finally able to make a start on my Cygnus SHO mosaic project on Sunday night. Conditions were mostly pretty good. No moon about, and i only lost a couple of subs due to clouds. As it stands, this is currently a mosaic of 6 Ha panels, each one consisting of 3 subs of 720s each. So 36 mins per panel, or just over 3.5 hrs in total. I still have to capture a column of 3 more panels on the RHS, with the lower-right panel hopefully including the Veil Nebula. Imaging time is hard to come by for me these days, so I'm only aiming for upwards of 100 mins per panel, but might make do with just 60 mins instead. Haven't decided yet, depends on how co-operative the weather is over the next while. In any case, the overall goal is not for a deep image, but a big one, showing the large-scale nebulosity throughout the region. I've since picked up another vintage lens, this time a Zuiko 50mm F1.8. The plan is to use this to shoot the Oiii and Sii. It turns out that the FOV of the 50mm is almost identical to the 9 panels of Ha at 135mm. I figured, seeing as some people get by with binning their Oiii and Sii data, that i might be able to just capture them at a lower resolution instead, and save myself some hassle by only capturing one long panel of each, instead of having to do 9 shorter ones. Only time will tell if this works out or not, but here's hoping 🤞 I also plan to blend in some higher res NB data from my 80ED on a few panels (NAN, Pelican, Crescent, and Veil) for the final image. Minimal processing done on this, just some NR, contrast enhancement and star reduction. I really just wanted to see how it was coming along, and make sure APP was able to stitch it together ok (it did a great job as usual). In processing this, i have realised that with this setup i'm not dithering enough, as i can see what i think is walking noise in some of the raw stacks. Because the imaging scale (8.4") is lower than the guider scale (6.09") it means that even at the highest Dither setting in SGP, i'm only getting a dither of a few pixels, so next time out i'll have to up the scale factor in Phd2 to 4 or 5 to compensate for this. I probably need another 3 full nights to complete this, so roll on more clear skies, so i can finally put the 383l+ on to the 80ED! Full details: Atik 383l+ Tamron 135mm F2.8 @ F4.5 HEQ5-Pro 6 panels of Ha (2" Baader), 3 x 12 mins per panel stacked in APP, processed in PS Presented at full scale, so it's a big image!

Fantastic image Maurice. Refreshing to see this in natural colour rather than NB, and i really love the colours you've achieved.

Looks even better now Adam, good work!

This looks great Adam. I really like the colours, especially the colour in all the background stars. Just a few small pointers if I may: you need to crop off your edges, the sky background has a bit if a magenta tint, and it could maybe do with a smidge of star reduction to my eye (although I'm only looking on my phone). This is also a target that takes well to Deconvolution, or alternatively, some very careful selective sharpening. Based on this image, I'd say your combo of ED80 colour with Tak Lum is working very, very nicely indeed 😎

Very nice indeed Brendan. Being so faint, it would be very easy to overdo the sharpening on this, but I think you've judged it perfectly.

Astonishing image, and level of commitment. You've made a very faint object look anything but. Congrats!

My first thought was that it resembled a ballerina. I take it you see it too?

Thanks for this! I don't use PI so i just use the standalone version, and this has made a dramatic increase in speed for me. I usually use a Stride of 32, so i'd normally have to wait 20-30 mins for it to complete. I haven't timed it, but it's now more like 5 mins. Sweet! 🙂

Thanks Sam. The drizzle is definitely making a difference for you. Good to know that 20 subs is around what it takes. I'll probably have to forego it myself though. With the 8300 chip being quite noisy, I need to do fewer longer subs, rather than a higher number of shorter ones. I could of course just shoot more subs, but I'm going to have to be pretty strict on limiting the exposure per panel, to have any chance of finishing the mosaic.

Amazing image. Can't recall ever seeing brown dust look as good as this, and I'm only looking on my phone. Bravo!

Funny you should mention Dylan. I'm also an O'Donnell. I've seen a few of his Youtube vids (felt like i had to really, being distant relatives and all, lol). I quite enjoyed them. Made me want a RASA! 😄

Lovely image Mark. I like the framing too. Most seem to present this rotated 90 degrees CW, to show the Wizard in an upright position, but i actually find it too distracting. I much prefer your framing. The only thing that springs to mind is the magenta tinge to the stars. Most imagers don't seem to like this (i actually don't mind it so much, it reminds me of Hubble's images, but i seem to be in the minority here), but a simple solution is to invert the image, then run SCNR Green (or HLVG for PS users) and then re-invert it again. Here is the effect of applying it at 100% in PS (jpg). Although if it were me, i would lower the opacity to something like 70% to allow some of the warmth to filter through to the stars.

That's really something special André, congrats! I also like the Fov that Spacecat gives. I know how hard a target this is, having tried it myself a year or two back, before giving up after the realisation i didn't have the gear or skies to really do it justice.

That's gorgeous Richard. A sea of golden stars, punctuated by the Dark nebula. Subtle, yet striking, at the same time. Can't wait to see what you've got in store for us with your Autumn/Winter project.

I was away at the weekend so only saw this on my phone. Now i see it on the computer monitor, i can fully appreciate it. I like the framing too. The Lum looks awesome Adam. That Tak 180 really does suck down the photons! The plethora of teeny-tiny stars it's picked up throughout just look amazing. Looking forward to the final version.

Thanks Sam. Nice to hear from another local member on here 👋 Great to see someone else trying this out too 😀 I agree, for NB work you don't need expensive glass at all, so there's plenty of opportunities for adding a cheap widefield setup, as long as you are prepared to accept it's limitations. It's early days yet whether or not i'll suffer from differential flexure. I'm just using an arca-swiss adaptor screwed to the bottom of the camera, but the lens isn't heavy, so fingers-crossed. The whole thing is sitting on a manfrotto 'thingy' (can't remember what it's called, lol), but it allows for about 150 degrees of rotation (in one axis only), which should be enough for most situations i hope. I also was thinking about Drizzling. However, my plan is to only capture about 100 mins (max) per panel in Ha (either 5 x 1200s or 10 x 600s), which won't give me enough subs to take advantage of it. Did your stars look significantly better after you drizzled? I'm currently at 8.4" and i was a little worried beforehand that they might come out a bit blocky, but i think they look decent enough. Not the best of course, but good enough for a big mosaic, where the focus will be on large-scale nebulosity. Nice image btw 😎

Thanks Adam. I've been wanting to do some widefield work (just as a change really) for a while now. Cygnus is a veritable NB treasure-trove, so i'm hoping to start a long-term project of doing a mosaic of this area in either bi-colour, or possibly all 3 channels. I did think of opting for a lens with a slightly longer FL, but with my imaging time being so low these days i thought 135mm might mean i actually have a chance of finishing it before retirement! Thanks Richard. I'm really liking mono i must say, although it's still early days and i've only really done one full NB image. At the moment, for broadband imaging the plan is to use the D5300 for colour and the Atik383 for Lum. I can't see me having the time to capture separate R, G, and B channels, but the jury is out until i actually try it.

Thanks Ahmed, you're too kind. The mount is getting on a bit now, and is in serious need of a re-tune tbh. Even still, it can handle 20+ min exposures just fine. My max imaging scale is only about 1.5" (with the D5300) so nothing too strenuous, which plays a major part obviously. Thanks Martin! Not sure how comfortable i am with being called an 'expert' though, lol. Happy to finally get using the camera i have to say. Thanks again for the sale, and the nice chat we had prior to it. 😀 Cheers Mark.

A few months back, i bought my first mono camera, an Atik 383l+ from Martin @Xsubmariner off here. I hadn't had a chance to give it a whirl until last night. I thought about getting the 80ED out, but i've been wanting to do some widefield stuff for a while, so i attached an old Tamron 135mm F2.8 vintage M42 lens i picked up last year for next to nothing. The lens needs to be stopped down to F5.6 (perhaps less, i haven't tested though) to produce acceptable stars in broadband, but i was hoping it could be used more wide open for Narrowband. I used step-down rings screwed on to the end of the lens hood to bring the aperture down to 37mm, which is about F3.65 (i did briefly try it wide open in Ha, and it wasn't that bad tbh, but i could still make out some comet-shaped stars in a few places so i opted to stop it down a bit to play it safe). I have a TS Optics filter drawer in the optical train, so i can still swap out filters without too much fuss. I still have about 3-4mm of extra backfocus space to spare, but i can already find focus as it is, so i'm not sure if it's that important that i haven't fully used it all up. Focusing was tough. I was focusing using a Bahtinov mask on Deneb, and i had to use 10s subs (subframes) at 2x2 bin to get bright enough spikes for Bahtinov Grabber to pick up to the spikes ok. Even then, it was showing the focus error moving about quite a bit, even without me touching the focus ring. In the end i just got it as close as i could and went with it. Conditions were not great. Some clear spells, but there was a lot of cloud passing through. I figures it would be good enough for a test session. The Phd guide graph looked horrific, and was somewhere in the 1-2" range (image scale is 8.4" so not a big deal hopefully). I bodged together a couple of old dovetails to add enough weight to counter-balance the 5Kg counterweight. It just about does. It's not perfect by any means, but hopefully sufficient for this purpose. I would ideally like to shoot 1200s subs, but couldn't last night due to the constant clouds (Phd lost the guide star countless times). I was about to give up, but persisted and aimed for 600s subs. Glad i did, as i ended up with 6 useable subs, even if a couple were affected by some thin cloud. Did a quick stack in APP and a 10 min process in PS, just to get a rough idea of what i can expect from this. I used Flats and a couple of Darks just to do a rough calibration. Didn't do any gradient reduction, was in too much of a hurry after packing up last night. Overall i'm fairly pleased with how it performed. I'm obviously not aiming for Samyang 135mm F2 levels of performance here, but for purely NB bi-colour mosaics i think it can do a job. I've included a picture of the rig below as well, in case anyone's interested. CS. 6 x 600s (1 Hr) Atik 383l+ 2" Baader Ha 7nm Tamron Adaptall2 135mm F2.8 (@F3.65)