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After some trial and error I'm getting some very good guiding results with PHD2 now. 60mm guidescope and ASI290MM mini camera. The M42 image taken late March was 12 x 15 second exposures taken manually with my dslr / C8 and a stopwatch. Stacked in DSS and played with a bit in GIMP. On the night I couldn't get APT to register the camera - turned out to be the mini USB cable (although later trials point to the socket in the camera being a bit loose too).
Bought an iOPTRON iPOLAR that arrived on Friday and had a play with that which has resulted in near perfect polar alignment. 2 star alignment and an additional 2 calibration stars on my Advanced GT mount means I'm getting very accurate GOTOs now and PHD2 (through the ST4 port on the ASI camera) seems to be guiding very well. Last night after more cable faffing I managed to get everything working together to the point where I felt confident enough to leave it running by itself for an hour and a half (45 minutes of 180 second exposures plus 3 minutes each exposure to save the file - I've since found out I shouldn't have noise reduction switched on in the camera - DOH!) so M51 is 15 x 180 second @ ISO 800 lights and 5 x 180 second darks. A little manipulation in GIMP and I think it's come out very well. Obviously still have a lot to learn and I'm going to have to start taking much longer exposures but I'm quite pleased with these 2 pictures.
I’m hoping a PixInsight guru can help me. I’m a PI beginner, but am having fun learning. My question is about the level of noise in my images. After integrating and performing an STF stretch, the resulting image always looks quite smooth. But it doesn’t take long at all – just a DBE really, maybe then a gentle stretch – for the image to become really noisy. And then a lot of my editing is centred on battling that noise. My camera is an ASI2600MC-Pro, which I cool to -10. For a recent experiment, I gathered 20 hours of data from 120s subs. With that much integration time, and the low-noise camera, I was hoping for lower noise than I actually got. (I am shooting from Bortle 8, however).
So my question is: are my expectations wrong, and actually the amount of noise I have is what’s to be expected? Or, have I messed something up in pre-processing or integration?
In case it’s useful, I ran SCRIPT -> ImageAnalysis -> Noise Evaluation on the image straight out of integration and got the following:
Ch | noise | count(%) | layers |
0 | 2.626e-01 | 18.39 | 4 |
1 | 1.037e-01 | 12.01 | 4 |
2 | 1.636e-01 | 11.10 | 4 |
I’ve also uploaded the file (1.16Gb) for anyone kind enough to help investigate further:
This is another finished target for this season.
I (quite) recently bought a TS Photoline 102 ED with FPL53 which performs surprisingly well for a doublet. So I put it to tests and imaging, in parallel with an older FPL51 AstroProfessional 102 ED doublet.
The blue color correction is much better in the newer TS. I shoot luminance often with both and then take the highlights from the better scope.
For this image I also used some older data that I had available, shot with a 130PDS, but that maybe only made my life more difficult. Not that otherwise I shot data through the refractors in a single panel with reducers/correctors, but also in 2 panels with no reducing correctors. Same about the RGB. Some shorter exposures from the backyard, some from a dark site, most of the G data from a dark site, B and R from home (clouds came in at the dark site) and a lot of other adventures.
But in the end I managed to put them all together and made an image out of them.
You can watch it in full resolution and see other details on astrobin: Great Orion Nebula
Over the past few days i've been gathering data on M31 due to the battery not lasting long and andomeda dissapearing behind a tree, therefore the mulitple imaging sessions. So far i've been out and me being me, only took dark, bias and light frames for the first 2 sessions but for the last one i also included flats... (The lights all have very slightly different settings cause i have been experimenting slightly... that being 45sec @ ISO 400, 45sec @ ISO 200 and 50sec @ ISO 100) Now DSS assinged all the correct bias and dark frames to the corresponding light frames but because i only have flats for my last imaging session it applied those to all the different light frames and not just to the last set...(and due to me moving the telescope / taking the camera off, the dust spots have obviously been moving around and that therefor dont work at all for the other light frames...) So my question: Is there any way in DSS to apply flats to only one set of light frames and if not are there any other apps with which i can do this with?
By Stub Mandrel
Back from a break 🙂
A productive evening was the 22 November. I have a strange field of view at home, so along session means I get data on several targets, and at this time of year I often can't revisit for more data. This means these images need to be seen as 'works in progress' that will need more subs adding in the future. Also, I've used Jpegs because my broadband is playing up some of the subtleties are lost (he claimed!) 😞
All Baader narrowband filters, except the Plieades, ZWO RGB. 130P-DS, ASI1600MM-pro and HEQ5
The Tadpoles NGC1983 in Hubble Palette:
The California Nebula HSO, with the S from an evening a few weeks later. No Oiii under my skies. The FOV is a bit limiting with this setup:
Which do you prefer? Pacman in Hubble (SHO) and HSO, in contrast these are crops from a larger frame:
Finally, the Pleiades in RGB, knocked off at the end of along evening so just 75-second subs and not very deep:
All in all, a worthwhile evening, even if my Witch Head was a complete fail and these do need more data next year 🤞