Simone_DB

The usual! 😉

Well, I think he'd be curious about 30 Doradus! 🙂 Hi to Malc & Fliss.

Something happened to me a couple of years ago, or so. I was out on my balcony smoking. I looked up more or less at the zenith and I saw a bright point increasing in magnitude, it was not moving or that was my impression. For a fraction of seconds I thought of a supernova (😄), because I couldn't think of anything that my astronomical knowledge could lead me to think about, but the brightness began to dim after a few seconds. The only think I can think about is a satellite flare, but as I said, It didn't seem to move, and besides it was very bright for a polluted sky, that's why I was somewhat startled. I stayed with that idea anyway, for lack of others.

You made think about the sci-fi novel "the three body problem" by Liu Cixin, that I've read a few months ago. One cool depiction of the story was (SPOILERS !) about this inhabitated planet in a pseudo-stable orbit somewhere around Alpha Cen or another star of the triple system. People from there were biologically adapted to recurrent extreme conditions, which included periods near one of those stars, during which they completely dehydrated and rendered to some kind of "hibernated" dusty carpets, and epochs, at the contrary, when they were far from all the stars and had to cope with long glaciations. Very cool! I think he won both Nebula and Hugo awards.

😆Oh my, I'm sorry! You're not pompous at all, my friend! About the SD, of course we cannot explain everything, I guess this concerns electronic engineering! Thanks for the heads up and the clarification about the "offset". OCIH (Of Course IT Helps 😄) Alnitak.tif

Hello @alacant, thanks for your thoughts. I'm sorry I didn't rename the files in order to easily distinguish them, anyway you guessed it right. I'm really having a hard time with the software, both because I'm trying to get to know all of them together, instead of focusing on one or two, and because they're all a bit tough, at the beginning at least. My second main issue is about identifying or distinguish the various sources of problems (the alignment, the camera, the moonlight, and so on...) and I suppose this is the reason of your suggestions here. So speaking about them: - I'm taking the bias that way. With the cap and my hand covering the viewfinder of the camera. However, I don't know how to verify the actual achieved "darkness". - I think I need to understand what you're talking about here (I don't know what the offset is, in this case) and I don't know what WHY is. I'll investigate those things. - From your link, I get that darks and biases can lead to additional problems if not used (or produced) correctly. I'll investigate that. - This concerns the point above, I believe. I'll check that out in Siril. - Yes, my camera is some 12 years old and I never had it cleaned 🙄. Since we're here: there is something else I should check, should I bring it to a shop for maintenance? - My camera has negligible built-in memory and I don't know how to shoot directly on an external device. I'll check that. I'd like to ask, tough, how come is it different, since you have a physical connection anyway. Wouldn't noise be produced anyway, just elsewhere? Thanks for the link! On a side note, just for sharing, Saturday I took some shots of Alnitak surroundings with quite disappointing results. I forgot I was willing to try the built-in automatic shooting tool, which it can maybe be used in "bulb" mode, but I'm afraid I have to figure how to follow objects more precisely. I still have no ideas how do you make several minutes exposures. If I got it right, there is some software that visually follow objects. I made maybe 85 pics 30'' each, and my horsehead was a black silohuette on a blacker background 😄. The Flame Nebula turned out better, tough. I wish I had used a D3100 modded camera I borrowed for that, there's a lot of red in that zone, and in fact, in Siril I have the red channel almost black, only stars are visible. Maybe I'll post a pic of my results. It was a very cold night, about 1°C, and after shooting Orion, I would have taken one shot of that beautiful moon and Jupiter, but I realized my hands were so cold that I could barely use them, and I struggled to pack things. I'm now thinking that I should take a break in bothering you all with questions*, and exercise on what I learned so far, study and read. Thanks again, have a great week you all! *If I manage to do that 😁

hI @alacant, Thanks for your time! I'll attach one sample of lights and calibration files hoping that it can help to understand what I did right and wrong. I shot my flats trying to get a centered histogram, with a white shirt on the scope and a tablet shining a white light. I always have these circular noisy coloured rings, which, if I recall it right, appear as I use the "extract background" function in Siril, and indeed I wondered what they were caused by. I'm glad you offered an explanation which I have to get, though. I used an old SD with old batteries. Are you saying that it could be the problem? In any case I just bought a new SD card and original Nikon battery. I can't remember how I processed the image because I've not familiarized with Siril enough, so far, but I followed step by step this video. Unfortunatly it's in italian, but it shows which tools I used. Can I ask you (and @AstroMuni as well) how did you manage to obtain that result? As you said, there's alot of information I couldn't extract, and besides you got rid of those awful rings which I made them disappear as well at the expense of said details. The same happened with the Pleiads. Thanks again the image is very neat! 😍 I'm attaching one of each files I worked with. DSC_0081.nef DSC_0001.nef DSC_0470.nef DSC_0484.nef

I agree! 😁

Hi Paz, thanks a lot! Luckily things are going better, at least with the alignment. Of course I still do awkard things*, but slowly I feel more confident about the basic operation while I exercise. thanks for the suggestion about the chair, I'll see if I can get one! *A couple of days ago, for example, this happened: I had just finished with the alignment, which took me half an hour or so, so I took the eyepiece off in order to put the dslr in. But I didn't tighten AC and/or DEC levers properly so, the mount moves because of the weight of the camera...😬So I proceed to swear to all the Gods I know of, and started off, swearing along for all the time needed! I'm pretty sure this little story awoke memories of some people here...🙂

Ops, I think my reasoning was wrong: I thought you needed the original files, but I think I know why you don't. Here it is: M42_DSLR_fin.tif P.S. In the rush, I uploaded the .tif instead of the .fit I'll do it again as soon as I get back home from work! 🫤 M42_DSLR.fit Added the .fit file!

🤩Wow, I'm impressed, and a bit confused! I was expecting, of course, that any of you could make a better job easily but...didn't I upload a jpg pic? I always thought that very little could be done with such files!

Hi, grazie! 🤗 Well, the Pleiads was actually my first attempt to take some subs, but there are no flat files. One day I'll get back to them! I managed (I hope), to copy M42 files in Dropbox, for @AstroMuni or whoever wants to give them a look! I included Lightroom metadata because maybe I edited them a bit, but if it's the case really a bit, like a tad of "remove haze". https://www.dropbox.com/scl/fo/coit00d6b6ztawedm1vjp/h?rlkey=1i3lx0rn2wntmy0o3p38txcp9&dl=0 Thanks in advance to anybody willing to play around with them! 🙂 Edit: I hope Dropbox's right. If you all use another site, please let me know!

Thank you! ☺️ I'll drop the file somewhere and post the link, I'm terribly curious! 🙂

Hi Wes, thanks a lot for your time and your thoughts! In order: I don't use NR, glad that you confirm that it's addressed in post processing. I'm using Siril and I also find it a bit tough, but also more detailed than others, according to my very limited experience with this kind of software, at least. But you're saying that you use photoshop; I didn't even know you can stack exposure with that, so I'll dig into it! I take light frames in RAW, No NR and WB on "Auto". I'll check the metering mode (which I'm not sure if I know what is it). Now I'm still using 20 or 30 sec of exp, but I'll try to use "Bulb" mode as soon as I can. 1 - I think I'm on the right track here. At the moment, considered my sky and skills, I'm working with 20-30 secs of exposure. 2 - Just one question here. I suppose the temperature we talk about is the sensor's. So if one put the cap on the telescope right after the lights (with no delay to allow the sensor to cool off too much, I mean), and keep on shooting, shouldn't he have the same conditions? 3 - Flat frames are the most mysterious to me, at the moment. So far I used two methods: the first one with a white shirt and a tablet. To have a centered histogram I had to do very short exps, 1/400th of sec or so). When my tablet decided to leave us forever, battery gone, I shot a yellow wall (i didn't know what else to do, I was in session 😅😞 it needed 3'' secs or so. I was shooting a faint target (M101), so I don't know how to judge the work at the moment. Besides, I could do too few shots of Whirlpool galaxy, so I have to try again. 4 - 🆗I haven't taped the view finder, tough. I'll figure something out! No worry pal, you (and the others) already gave me a lot of help! I'm watching tutorials, especially about the software. I'll improve my knowledge in time, I hope. 🙂 Lastly, ehm, a question that I'm a bit reluctant to ask, because I'm afraid it's somehow intrusive or cheeky: I'm very courios to compare my work, say for example with the image of M42 above, with someone else's starting from my shots. Is a common practice here on the forum to exchange source files to do such? If you or someone else is willing to have a try, let me know. I'm very courious about such a thing, because I don't have a means of comparison on the results. Thanks again and have a great day!

Hello, this is my first serious attempt to shoot M42. These are 80x20s ISO 200 shots. I used Biases, Darks and flats. Lightroom, Siril(ic) and some photoshop for stacking/editing. What do you think?

Hello, following the suggestions of many members, I managed to process my first image with Siril/Sirilic. I took 39x20s shots of the Pleiads at ISO 200. I used Darks and Biases (15-16 of each type), but not Flats because I still have to figure out how. The image is very dirty and I think that I'll have the sensor cleaned, because I've never done that in 12 years 😶. Any technical comment is welcome. Thanks! M45_DSLR_exp.tif

Hello @Kilohertz, nice Avatar! ☺️

Hi Simon, thank you! Yes, it makes sense! I don't know either how NR is handled by the camera, that's, if it's a metadata that can turned on and off. Anyway I'll try not to use it. I'm not sure to have the experience to see the differences with or without darks, but I'll try for sure! 🙂 Yes, that's my idea, too. I think it's ideal to work with unprocessed RAW, I think it could also help to better control and understand the processing with softwares. Plus, I have a gut feeling that denoising works better with external programs that with the embedded software of the camera. Thanks Atromuni! I stumbled upon Sirilic just yesterday on a Youtube video. I was looking for Siril and I didn't notice it was talking about the other one☺️I quit watching it, because I thought it was a plug-in or something, but due to what you told me, I have to try it! 🙂

Hi @LandyJon, thanks for your suggestions! An actual example of timings is handy for the next session out! And yes, I think I'll go with DSS, I just saw a video about it, and it seems easier for a newbie. Also, thanks a lot for the clarification about the flats, now I got better why I should take those shots! 😉 I'll check the video as soon as I can. I thank you for your time!

Oh, Amedeo The Great, king of moles! ☺️ Great, thanks a lot. I got a Nikon D5100, so that should be it! And should I keep NR on long exporus on? Sorry for the insistence, that's a feature that doubles exp times, and I'd be glad to avoid it, if the calibration in Siril has the same purpose! Ok, thank you! As a matter of fact I was contemplating a cooled cam as next purchase, but since I see they don't exactly give them away, I could ignore it for now. All I want to do now, is getting acquainted with the tools. Ok 👌! And do I want to put the histogram centered, as the article that I linked says, or should I put it like the light frames? 👌 I'll try "Deep sky stacker" and see how it goes. Simon, I thank you for your time! I hope to be able to show something new soon.

Hello, after a weekend of reading, doing some activity and accomplishing nothing, this morning I woke up with the dilemma about wether hassle you all once again. Jokes aside, since I suppose you all remember how difficult this thing is at first, you understand how I need a "push" to get past the first hurdles. While I was working, 1.62x10^5 questions came to my mind. I selected a few (all the following questions concern DSOs): - Light, Bias, Dark and flat frames (so far, I've read this article): 1) Light frames, as I get it, are the RAW shots. Am I suppose to get visually individual good shots, or can I use longer exposures to save clicks even if results are withishier? Should I keep my ISO low, since I have to stack a lot of shots? Should I use NR reduction on long exp (this in particular is important because it doubles exp times). 2) Can dark frames be shot just with the (capped) camera? They must match the ISO and exp settings of the lights, so I can make a set a library for different settings that I can use (almost) indefinitely, but the important thing is that they must be shot at the same temperature of the shooting site. Is all that right? 3) To take Flat frames I can put a white shirt on the telescope with a light source above it, and take shots that match light frames exp, but they have the histogram quite centered. Sky shots often have the histogram crammed on the left side, so how I achive that? I read that the camera orientation matters, hence do I take them every session or I find a way to align the camera always the same? 4) I've got no particular doubts on Biases. Same temperature and ISO as lights, fast shots. Can they be taken with the capped camera? - Software: I lived a nightmare. I tried to use Siril, but without light, daks, etc. it's useless. I've tried to download and use some scripts that should allow its use without said files (just to practice), but no luck. So let's just leave it for now. I then tried to use Lightroom together with photoshop, but when I try to export them in the latter, LR says that it failed because "photosop wouldn't open" (same using panorama, photoshop levels or whatever). Is it a common issue? Dispite the message, in a couple of occasion it succeded in creating new frames in LR, but I probably don't know how to use it or they're just too bad. They are some 25 frames of Alnitak surroundings taken at 800 ISO (maybe too much), 13'' exp with NR on long exp on. I hoped, not too much actually, to see a glimpse of nebulas, but no luck. I understand those are quite a bunch of questions, and I'm aware enciclopedias were written about what I'm asking, but while I study, if someone wants to comment, share advices, point me to a direction, seen what I have done so far, I'd be immensely grateful. Consider that, for frustration, I ate a lot of spaghetti, played a lot my mandolin and gesticulated a lot more than usual, which denotes a stressful condition for an italian. Thank you!

Great, noted! 😀

I'm checking it out now. I must say the guy is nice and very thorough! 😉Thanks!

🙂👌 I'm going to! I must say this mount is really neat! I am impressed by its precission. I was expecting worse, because of my inexperience. But I must have improved somewhat with alignment, because I had some issues on previous days, but recently everything worked fine. I use an app called "Polar clock". Thanks!

Oh, ok! It's giving the software a reference to subtract undesired elements kind of technique, I guess? I'll dig into that, thanks a lot!