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About RyanParle

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    Star Forming

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  1. After a few months of being busy on any possible clear night I finally had a couple of nights where I could get some 5min dithered subs. Things went pretty well and I got 4 hours worth of data each night which when stacked looked very clean but lacked in depth compared with the long exposures, but when combined with the previous data actually turned out looking better than expected although this time I have struggled to get the colour balance right, its all a little too yellow, & I cannot seem to get the blues to show, also the background is still a little noisy which I put down to the noise from the older data but I think its a big improvement on before. I'm still not sure my results are great considering that there is around 18 hours of subs. Anyway here is the latest image, comments and critique welcome.
  2. From the Maxim Dl Manual: Sigma Clip – a compromise between Average and Median. A standard deviation is calculated for each pixel location, and a standard deviation calculated. The pixel with the largest deviation is rejected if it falls outside Sigma Factor times the standard deviation are rejected. The average is then taken of the remaining pixels. SD Mask – a custom variation on Sigma Clip contributed by Ray Gralak. This is an iterative algorithm that more effectively removes outlier pixels while preserving "good" pixels. It is most useful when the number of images available is too small for effective use of Sigma Clip. There are a few settings that go with Sigma Clip & SD Mask, I've not experimented much with them but when I have I've never noticed much difference. I will of course post some dithering tests when I get the opertunity to get some more data, the weather looks good for next weekend so fingers crossed!
  3. So after rebuilding my calibration library I haven't noticed much difference to before, but I've taken the time to make a comparison between SD Mask & Sigma Clip as well as Dark, Flat & Bias vs Flat & Bias Each of the images have exactly the same screen stretch, I think that the Dark_Bias_Flat_SD_Mask file is the cleanest of them all but maybe slightly lacking in the fainter areas. the background noise in the Bias_Flat_SD_Mask file appears a lot less even, I guess this is where the dithering will help out. Sigma Clip seems very noisy by comparison to SD Mask, again I assume that dithering would help here.
  4. OK, Have just run a stack with calibration turned off, and whilst it was a bit messy due to the lack of flats it looked like there was a lot more information above the level of the background noise, so I'm thinking that I have a bad set of calibration masters. I'm currently going through "set calibration" and sorting some settings, some how my default combine when creating master calibration frames had become set to Sigma Clip, and Add pedestal was set to 0. I've now set the combine to average for flats & darks (should i need them in future) and Median for Flats. I've also set a more realistic pedestal value of 3x BG noise level. Maxim is currently creating my Calibration master frames, once it has done I'll try another stack to see if its any better.
  5. I've just checked everything through and it appears that it is correct, i'm not sure why MaximDL has saved those integration times to the fits header, but they are definitely the stacks, I've posted a single 15 min sub as well for reference (It has not been de-bayered yet). The file name is messed up as I had an issue and restarted my CCDC script part way through, this for some reason stopped the "object info" being written to the filename & fits header, i manually updated the Fits header but didnt get around to the file name. _900s_270.0deg_20190411_0048_000000720.RAW.FIT
  6. Ok i'll give it a go tonight if it clears up enough... theres a little bit of a haze out at the moment! Fingers Crossed! Should be able to get 90 x 5 min subs easy enough I've set a Minimum dither of 15 px And a max dither range of 100px hopefuly that should smooth out the background a little
  7. Yeah, I understand why darks with a DSLR can be tricky due to the unregulated temperature, which is exactly why I built up such a big database in the hope that every image should have a matching dark somewhere (combined with Maxims dark scaling feature) I do dither when I image, i am currently using the default dither in CCD Commander which is a set to a mimimun of 1 px and a maximum of 4px how much dither would you recommend? Do you think you could pull out much more details than in my previous posted attempts?
  8. After careful analysis of my .fits images and my .tif images I've concluded that i lost a lot of information in the conversion so i'm going to post the .fits files instead, you should be able to get more out of it this way. these .fits files are the combined RGB files, they will need splitting in to individual RGB files before running through FITS Liberator (or similar) Anyone got any good tips on getting the most out of FITS Liberator? I've also done an additional stack this time with SD Mask algorithm and no darks. I was pleasantly surprised at the quality of this stack so I'm beginning to believe that darks are less important than I first thought. this is posted here as well. M81 & M82_Bias_Flat_Dark_Sigma_clip.fit is the original stack M81 & M82_Bias_Flat_SD_Mask.fit is the latest stack M81 & M82_Bias_Flat_Dark_Sigma_clip.fit M81 & M82_Bias_Flat_SD_Mask.fit
  9. Thanks Tooth_dr I would be telling a lie if I said that I was ecstatic with the image considering the amount of data I have, I thought that my local skies bortle 4 rating was mainly the reason I couldn't get more out of it. I will take the recommendation of larger dither & no darks, I'll try RE processing what I have without the darks to see if that gives better results, I think my dither is set to 2 px at the moment, what sort of dither amount would you recommend for future sessions? I will also try getting a lot more shorter subs on the next session. I'm also beginning to think that my choice of ISO setting could be an issue, is ISO 1600 too much for a 50d? I'm happy to post my stacked data for you and anyone else to have a go at, I'm sure there is much I can do to improve my processing and would love to improve. I am not able to post the data straight away but I'll add it when I am at the PC. The Veloce 200 Mkii has long been one of those "if money was no object" wish list items, but recently I was given an offer that was too good to turn down, the final deal is yet to be agreed but I'm expecting to pay around 1/4 of the trade price, it's all totally legit, no stolen or second quality gear. If all goes to plan then I should have it in my hands at the end of the year. The ED80 is a nice scope to use but the Veloce is so much faster & Sharper.
  10. Ok so I've added in last nights data and got a bit more depth, I also sorted out the an issue I had with the flats not being applied when I calibrated the images, I think I've still got colour balance issues though, the dreaded pinky stars are back! anyway here it is, 23x 15min subs & 10x 30 min subs: Any comments welcome.
  11. Too late they are already deleted & re captured, just waiting for them to transfer over to my desktop pc now.
  12. That did the job, I found an old flat shot at ISO 1600 and it gets applied. I'll shoot some more flats at dusk. it seems to have clouded over here now so it doesn't look like i'll be able to image tonight
  13. Thanks Dave, yes I do create masters & they are all loaded and enabled in the set calibration window. My fits headers are showing that flats have not been applied. Although I have just noticed that my latest set of flats were accidentally captured in auto ISO mode, everything else is at ISO 1600, I think this could be it. I'm about to dig out an old flat from my archives to double check.
  14. Thanks Ole, My guiding has been pretty good since giving the mount a tune up & belt mod back in Feb. I am typically seeing an RMS of 0.2-0.3 arc seconds and a peak of around 1.5 arc seconds My image scale is 1.76 Arc seconds / pixel so i am happy that the stars stay on the same pixel for the whole exposure. I may grab a load of shorter subs tonight if i decide to get more data on M81 & M82, I'm not sure that i'll stop using darks though, I have a pretty extensive library of dark frames containing 60, 120, 240, 300, 600, 900, 1200, 1500 & 1800 seconds, each of those is split in to different temperatures from 5 degrees C up to 25 degrees C in 5 degree increments and each group has a minimum of 25 individual darks, add to this the Bias frames & Flat Frames for every 45 degree of rotator movement bringing the grand total of all calibration frames up to around 1400, of course these have now been replaced by master files to save time & disk space. So I pretty much have a set of calibration frames for any temperature, exposure or rotator angle I may wish to use. You're right about imaging without a flattener, I never got around to buying one, and probably wont bother for this OTA, I'll be getting a Officina Stellare RH Veloce 200 MK2 AT some time this year, considering that it will be around the same focal length but MUCH faster at f/3 it will make the APO some what obsolete!
  15. I'm having a issue with Maxim DL where it looks like it is ignoring flat frames when performing image calibration, if i check the log i can see that the darks and the bias frames are loaded but not the flats, can anyone think why this may be?
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