Felias

+1 for this: the colour gamut is the most important thing if you are going to process astro pictures. HP monitors tend to be good, I bought an HP laptop that had a fantastic display, but I had to return it for other reasons, and got a Lenovo Legion instead -good processing power, but lacking on the range of colour/brightness with respect to the HP. I don't know about yours particularly, but have you tried to calibrate it (there's a tool in Windows display settings, and plenty of apps in the web) and test printing before you buy a new one?

@MKHACHFE Thank you!

Thank you! I'll definitely have a hard time choosing between the Samyang and the Z61 refractor in the rare nights of good weather now that the summer is ending...

That was close! I'll start stocking batteries while I await the delivery... 😅

Just pulled the trigger on one of the three leftover mounts... A minute after that, there's only one left!

Nice colours! I also imaged this region during the holidays (albeit with a camera and tripod only, no tracking), it was nice to have a better view from lower latitudes. I'm just surprised that remote Mauritius has the same Bortle 4 as Camargue, sandwiched between Marseille and Montpellier! Too much population in a small island, I guess...

Thank you, that's actually great to read... My Lenovo doesn't have the greatest screen dynamic range, so I'm always wondering if I'm overdoing the stretch. I normally check on my mobile phone and my Surface pro that the final result is reasonable, but it's good to know that it works for others!

I have tried it with a photo I took back in July, which I have been reprocessing today, and it works really well. It's a WO Z61, so about 400 mm focal length. The reduction seems fine for both small and large stars, even considering that they are not perfectly round because there's always some trailing with my Star Adventurer.

I have made it work! The problem seems to be that I was copying the background from a layer of my previous processing, into a new file. PS does not seem to recognise it as the background even if you put it at the bottom and lock it. If you open it from a saved file and just add the starless image as a layer, it works! And yes, the curves were there to the right, as usual, I don't know why I didn't see them before. Very useful tool indeed, thank you!

Well, the crop tool is selected because I was cropping a photo before, and never changed it. I have tried selecting another tool, and I still get the same message. I did copy the starless image and pasted it as a new layer, yes -will that make a difference? Oddly enough, I have performed manually the steps that the action refuses to do, and once I get past them, it works until it stops at the 'curves' action. Is there a curves window meant to pop up at this step? If I keep running the action, I get a final photo with too much reduction, it needs tweaking. But I tried to run curves myself, and it did not seem to affect the mask on screen, so I was blind to what I was doing.

Thank you! This could be very useful for us PS users.... but I couldn't make it work. It keeps telling me "The command 'duplicate' is not currently available" , "The command 'invert' is not currently available", and "The command 'select' is not currently available". Any idea what's going on? I'm using the last version, PS 2022,and I'm quite sure that I set the layers as instructed. 🤔

Thank you! Yes, I'm very happy with the lens, and looking forward to pointing it at Orion this Autumn....

I have reprocessed the stack from scratch, enhancing the nebulosity and reducing the stars further. I think it looks better, and there is definitely more detail that was hidden in the photo above...

The star responsible (thought there may be more than one, see https://arxiv.org/pdf/0809.3229.pdf ) was found by Fernando Comerón and Anna Pasquali in 2004 (full paper: https://www.aanda.org/articles/aa/pdf/2005/05/aa1788.pdf ) It's very technical, but there is a more readable retelling of their detective work here: https://www.vaticanobservatory.org/sacred-space-astronomy/illuminating-north-america-or-anna-and-fernando-find-a-star/ -Worth reading!

It will always be a pterodactyl to me...

I have finally been able to test my new Samyang 135mm F2 properly. It was very clear last night, so I took the car and went out to my usual dark not-to-bright spot in the fields. I don't know what's going on later with my Star Adventurer, but I'm finding it difficult to keep it polar aligned after loading it with the telescope, or with the camera in this case. I had to settle for 20-second subs to avoid trailing, but I'm anyway limited by the light pollution (including 40% moon), so it's not as bad as it seems. Anyway, modded Canon 700D, 472 x 20s subs, ISO 1600, F/2.8. Stacked in DSS, colour calibrated in Siril, stretched in PS. I used Starnet v2 to reduce the stars, there are too many in this region. I was trying to make the Crescent Nebula stand out, but at some point stretching started to make artifacts in the larger nebulae around Sadr. Maybe it's all that can be done with these data, but any hints will be appreciated.

A free alternative to removing gradients is Siril. This is what I could do, but it should yield better results with a proper tiff file instead of the jpeg I downloaded: The iPad flats should be fine (I do the same), but a full moon is bad news for galaxies! I would try again on a different night.

I had a few things waiting for me when I came back from my holidays. I had wanted one of these for a while: By a cosmic coincidence, it was on offer in Amazon the day of my birthday, "only" £375 brand new, so I couldn't resist! It arrived only a few hours before I did, and I haven't had much of a chance to test it. I took this photo (Canon 700D) during the full moon, but I messed up with the polar alignment, and I lost my flats! Less than 20 min, so I wasn't expecting anything great anyway, but at least the lens seems to work: These also arrived during the holidays (courtesy of FLO), and were waiting in my lab (they belong to the school). I expect to use them with the Dobsonian and the Lunt 40mm. I believe that a zoom lens will greatly improve the experience with the pupils, since swapping eyepieces isn't practical when you have many teenagers waiting, and they get frustrated that we have to find the target again.

+1 for Siril and its photometric colour calibration, it's very useful. But you should still be able to get a decent stack in DSS... are you using flats at all? They are essential.

My final photo of the holidays. A 16 mm shot of Albi, which I think turned out better than the previous 50 mm shot. Light pollution was still horrible, so the processing (in PS) is quite aggressive, but I'm quite happy that I could show the Milky Way looming massively over the whole Episcopal City of Albi, one of the World Heritage sites in France. Echoes of the Albigensian crusade under the indifferent stars: Canon 77D (unmodded), 109 x 15s shots. Just a tripod, no tracking. Foreground 2s exposure, ISO 800 (the monuments were heavily illuminated until 1 am at least, just bonkers!). Blended in PS.

I was in Cornwall too. As all of us who tried their luck from there, I didn't see a thing due to the cloud cover. But it was still unforgettable, I was in the fields and the birds and insects thought that night had fallen suddenly, so they completely changed their sounds, or became silent. As the moon retreated, they resumed. Quite amazing, even if the sun didn't show up!

And yet more holiday photos! This one was taken from the same spot as above, the oratory of Saint Gens, just before starting the panorama. I tried to capture Scorpio before it set behind the mountains, but again I didn't take into account the significant light pollution. L'Isle-sur-la-Sorgue was just 9 km to the SW as the crow flies, so the glare was strong behind the mountains. Nonetheless, some aggressive processing yields this: The sky is a stack of 35 x 15s lights, again with the Canon 77D, Samyang 16 mm f/2.0. Tripod, no tracking. The foreground is a 120s exposure, merged in PS.

More holiday pictures! I took more than usual this time because I had clear skies almost every day. Anyway, here is a Milky Way panorama from Provence: You can see all from the Double cluster and the Andromeda galaxy on the left, to the Sagittarius star cloud and the Lagoon nebula to the right. It is a composite of 12 photos, each one a stack of 7 to 10 shots taken with a 16 mm f/2.0 Samyang lens. Just a tripod and my Canon 77D (not modded). Finding the place was quite an adventure in itself, and one of the loveliest moments in the holidays. Let me add some background: I was staying in L'Isle-sur-la-Sorgue, and after a 20-minute drive into the mountains, one arrives at the village of Le Beaucet: From there, a narrow road takes you deeper into the mountain, to a place called Sanctuaire de Saint Gens. Behind the church, a path in the woods takes you to the Fountain of Saint Gens, which apparently the saint created by pointing to the rock with his index finger (it could be a most useful skill these days): A beautiful, eerie place, which I could enjoy alone. But it was getting dark, and I had to climb to the oratory of Saint Gents, where he used to be a hermit. A cross (the one in the panorama above) marks the spot, but it was a very steep climb, and it was very hot, more than 30 Celsius. A ridge path finally led to the cross, and the views were amazing: The lights belong to the town of Carpentras, I believe. Sadly, I discovered that the light pollution coming from the N and NW washed away the stars, and although I could see the Milky Way easily, it wasn't much better than my usual spot near Canterbury. Bortle 4, I'd say. Nonetheless, I enjoyed the sunset and took some pictures, including the panorama. It was a night in magnificent solitude, and the photo of the cross under the Milky Way is the perfect souvenir of the moment.

I said above that I didn't go to any region of dark skies during the holidays, but I was nonetheless surprised by the excellent views of the Milky Way while staying in Camargue, somewhere near Saintes-Maries-de-la-Mer. I was in a hotel in the middle of the marshes, with bulls and horses as the only neighbours, and there was very little light pollution towards the sea in the South. Therefore, I couldn't resist taking my first proper images of Rho Ophiuchi, which I had never suceeded in imaging from Kent. I was lucky to have a balcony from which I could comfortably work without even stepping outside the building, and a colony of bats kept the mosquitos at bay (on the downside, I got bat droppings on my head, but I was lucky that they didn't touch the camera). 😅 Only my modded Canon 700D, a 50 mm lens and a tripod. 8-second exposures, and since I didn't have my Star Adventurer, I had to track manually. This ment moving the camara every minute or so, to keep the objects in the frame. Very annoying, but at some point I discovered that it was easier to slide the whole tripod for azimuth correction, and just touch the camera to change altitude. I did this for about 20 minutes, and repeated the process four times for slighlty different framings of the nebulae. Not perfect, but I managed to build a panorama with the four stacked pictures (stacking in Siril, stitching and stretching in PS). Considering the difficulties, I'm quite happy with my first panorama of this colourful part of the sky! Click to enlarge. Again, to put this in context, this is where I took the picture from, in daylight (a 16 mm shot). You can see the marshes in the distance, behind the hotel grounds. Scorpius was right above the marshes seen beyond the fence, and Saintes-Maries-de-la-Mer was about 10 km to the Southeast, so a bit to the left of the photo.

I have just come back from a lovely trip around France, and although I didn't take much equipment (basically just a couple of cameras and lenses, and a tripod -didn't have room for my Star Adventurer, sadly), I took some astro photos. I didn't stay anywhere with particularly dark skies, but sometimes I just like the challenge of light pollution if I can get a shot with an interesting landmark. So here is Albi's cathedral, probably one of the most beautiful in France: I took it the past week, with a Canon 700D, and the flat 50mm f/1.8 Canon lens. Just a tripod and 8-second shots, about 30 min of integration time over two consecutive nights. Stacked in Sequator to freeze the ground (took me a few rounds until I got the settings right), and blended with a shorter foreground exposure in Photoshop. It was a nightmare to process, but you can see M6 and M7 quite clearly, as well as the Milky Way. I tried not to push the curve too much to make the transition to the light-polluted bottom of the image less blunt and thus avoid artifacts. There's still a purple fringe around the 78-metre high tower, but the Toulouse-Lautrec light-and-sound show in the gardens of the Berbie palace went on until midnight. You may think that the bright cross to the left is related to the Cathedral, but in fact it's meant to be the Moulin Rouge! 😅 Do note that the radial shadows it is causing on the top of the nave belong to enormous gargoyles. The red tree is also lit for the show, whereas the green ones are in the foreground, close to my hotel, and therefore out of focus. To give you an idea of what I had to deal with, this is a single shot when they occasionally went wild with the lights: Just crazy, but at least I could see the show for free! All things considered, I'm pretty happy with the final result. I have more pictures, which I will try to process in the coming days. Just for reference, this was the view from my window during the day: