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    Photography, and Astro Imaging
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    South Suffolk. UK

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  1. Water under the bridge now Martin, but it came across as a bit of P*** Take, and that didn't go down well at all. My apologies if I misread it 🙂. Onwards and upwards 👍
  2. If that is what some folk are foolish enough to believe, then that is up to them. If we going from logical discussion to frivolity, then I'll leave you to it, but in terms of ridulous exaggeration, I would say that there is a "big difference between scratching your backside, and tearing the skin off". For a man whose intelligence, and knowledge, I have much respect for Martin, you surprise, me.
  3. Theory is devised under controlled lab conditions, and can only estimate the multitude of variables that could impact on it under "Real World" in use conditions. Where laboratory testing is involved, unless the test equipment used is calibrated to traceable national standards (UKAS in the UK), the results carry very little standing. Then of course there is Measurement Uncertainty, which usually follows a mathematical distribution, The uncertainties can either be systematic or operator induced, but they are real, and must be taken into account . Hey, I been retired for some 19 years, and didn't think I would be discussing theory v practice, and measurement uncertainties, revolving around an amateur level Chinese CMOS based astro camera, for what is a hobby pass time 🙄 We have probably bored other members to tears. ☚ī¸ If I find out why this 294 camera is giving me poor results, I will let you all know.
  4. Yep, that is the theoretical result,/prediction, probably taken under Lab conditions, but to quote an old English saying, "the proof of the pudding is in the eating", and theory doesn't always play out in practice. I had a 40 year technical career, the last 20 of which were in R&D (Radio Frequency Engineering, and Electromagnetic Compatibility), and If I had a ÂŖ for very time practice didn't align with theory in the real world, I would be a very rich man. The only theory that was never wrong, was good old Ohm's Law. 🙂 BTW Vlaiv, your command of the English language never ceases to amaze me 👏. I can get by with some German and French when away on holiday, but fluent, absolutely not.!!
  5. QUOTE:- Martin B "Could the issue be that you are comparing OSC with mono Dave?" Perhaps I should rephrase my question to read "Am I expecting too much from a OSC CMOS astro camera" Martin. There has never been any doubt that mono is more sensitive than OSC. Back in the day, I moved over from OSC to Mono, because I wanted to image in NB, and LRGB. For this purpose I used a 7 position motorised, and usb controllable filter wheel, with L,R,G,B, Ha, Olll, and S11 filters installed. I am not that serious about astro imaging this time around, and see it very much as a sideline to my photography. After reading user comments on various astro forums that CMOS was so much more sensitive than CCD, I thought I could get acceptable results with a CMOS OSC camera, but I have yet to see this. The image quality I got with my SX CCD OSC asto cam (H9C), I have yet to see repeated with this 294c camera. I chose the 294c because of the 4/3rds sensor size, and 4.63x4.63um pixels, as opposed to the smaller sensor 183, with its very small 2.4x2.4um less sensitive pixel. My SXVR H16 had 7.4x7.4um pixels, and very good sensitivity, but of course that was mono. I accept that I am now using a relatively budget imaging setup, comprising a ÂŖ1200 APO Refractor, with a ÂŖ900 294c based camera (I paid ÂŖ2000 for my H16 back in 2011), but its not at the real budget end, and as such would expect better than I am getting with a supposedly more sensitive CMOS camera. However, that is what I have, and I will persist with it, and maybe as I get to better understand its quirks, I will get better results. Time will tell. I do understand that the IMX294 is old CMOS technology now, and am told that the later generation of CMOS cameras are much improved, and more ccd like, such as the 2600 I believe. However, I am not prepared to invest any more money in what what is very much a secondary interest now. I really enjoyed the 12 years (2002-2014) that I spent astro imaging, before a medical intervention prompted me to give it up, and move house. This time around it has been one frustration after another, and as yet, little to show for it, and I have come close to walking away from it. I have nor ordered a 2" Optolong Enhance filter, which will reduce the sensitivity even further. 😅
  6. I have now ordered a 2" Optalong Enhance filter from FLO.
  7. At least its not just me Stuart. If I hadn't imaged successfully for 12 years, with a variety of SX CCD cameras, I wouldn't have known any different. But I have experienced what CCD can produce, and I have yet to see it from this CMOS camera, and its re-purposed sensor. However, its all I have to work with now, and having paid ÂŖ900 for it, I will persist, and maybe one day it will either impress me, or go in the bin. At which point I will either grab one of the last remaining SX CCD cameras, or retire again from astro imaging, never to return. I have seen some good images taken with CMOS astro cams, but I have seen many more that are very 'lack lustre'. Back in the CCD days, it was the other way around.
  8. If I can get somewhere near this with a CMOS camera, I will be both convinced, and happy. I this took this image back in January 2012 with a SX SXVR H16 CCD, (Kodak sensor), with a 110mm f/7 refractor, albeit separate LRGB. All in one evening, and not one night per filter, as someone mentioned on another group, that is how he uses his CMOS camera to get decent results. Comment: for some obscure reason it displays excessively bright posted here, but not on my calibrated PC monitor, or on my website.
  9. 121 in what capture package? As I said, the same gain setting is referenced differently in different software packages, even by different camera manufacturers. For example, a gain of 900 in Sharpcap, is the same as a gain setting of 9 under ASCOM control. Its all done to make life uncomplicated for the end user, đŸ¤Ŗ.
  10. Thanks for that input Vlaiv, comprehensive, and informative as always 👍 Are you saying that I should be processing my 14bit captured images at a lower bit setting, say 8bit? I am learning that CMOS astro imaging, and processing, is a very different 'ball game' to CCD. I guess that many of today's imagers came into the hobby with CMOS, and no past experience with CCD astro cams. I would love to have kept one or more of my SX ccd cameras, so that I could make a direct comparison, using my current setup. But hindsight is a wonderful thing, and when I gave up the hobby in 2014, I had no intention of returning to it. Out of interest, I will try GIMP, and compare the results. I have always been happy to pay for quality software, and as such, never bothered with the 'freebies'.
  11. Some of the results can be seen on my photography website. The square format ones were taken with an SC SXVR H16 (Kodak ccd sensor), with a 110mm APO at f/7, and no filter. I no longer have any of those ccd subs, as I deleted them back in 2014 when I left the hobby, after 12 successful imaging years. I used to pre-process (debayer, align, stack, and calibrate) in either Astroart 3,4, or 5, or Maxim DL 4. Now it is done in Astroart 8. I never had any problem in doing this with hundreds of CCD images, or with the sensitivity of the CCD cameras. There is no doubt the CMOS presents a whole new set of challenges to the CCD imager, now turned CMOS imager. I guess its very much a case of, as the guy working down a hole in a New York street, said to the lady who asked "can you tell me how I get to Carnegie Hall" to which he replied "you have to practice" 😅
  12. Indeed they did Vlaiv, but it was preset by the camera manufacturer, and it worked absolutely fine, and no 'faffing' about with settings. I guess it is what happens when the astro camera manufacturers, grab readily available CMOS sensors, that were designed for use in DSLRs, and Smart Phones etc, and re-purposes them them as astro cam sensors.
  13. The gain was 9 in Astroart (ASCOM), which is equal to 900 in Sharpcap. I set this based on a sensor analysis, at the best crossover point between read noise, and gain. I would be interested to hear what gain settings other folk are using with the IMX 294c sensor. Its not easy to quote gain, when different software uses different gain setting numbers to represent the same setting. Ascom is x1, whereas Sharpcap is x100. Never had to play with the gain conundrum with CCD. I think its called progress 😅
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