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jimjam11

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About jimjam11

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    Star Forming
  1. That's a great result. Where did you get the extra counterweight from?
  2. This is very closely related to my thread from a few weeks back, trying to work out where my FWHM values were coming from especially because I am suspicious of the mirror in my 150p. It definitely appears as though less aperture can keep up with more in all but the best conditions we get here? Having said that, the required fettling of the newt gives you something to do on the 350+ nights of cloud each year...
  3. Did you try this out yet, what kind of results are you getting? Mine is nowhere close to balanced in ra or dec with an asi1600 on the back and it showed up as very rapid drift, especially in dec...
  4. You want to measure your bias accurately but it will be in the realm of 21x16=336 Your median exposures are: Ha=576 - 336 = 240 Sii=608 - 336 = 272 You want to be >= 450 adu above bias so you are somewhat underexposed and are therefore not working at maximum efficiency. -You could extend sub length to 5m and see if that gets you 450 above bias. You could keep increasing exposure up to about 10m until you get to your target adu above bias, I don't think many people go beyond 10m with the asi1600 because glows can become problematic. -You could increase gain to 200 and leave the sub length at 180s. I always use gain 200 for nb with my asi1600mm pro
  5. I think 25k will be fine, you should be nowhere near clipping. What exposure time was each sub? What is your offset, gain for each sub and what is the resulting median adu for a bias frame (min 0.3s)?
  6. In SGP you can just dither the mouse in a dark area and it will give you the value in the statistics panel. It will also show you the whole image median level which is usually close. You then need to subtract the bias. You can get the bias amount by taking a bias frame (0.3s works well for the ASI1600) and doing the same thing in SGP. For flats SGP has a flats exposure wizard. I just tell it to target 15000 ADU and it calculates the correct exposure. (N.B. You need to set the gain manually through the driver for this). In PI you can use the Statistics module to get the background level. Alternatively you can use the readout but you then need to convert the number.
  7. This is a cmos camera? Longer might not be better per sub but more total integration will help if you are already swamping the read noise. What is your median background level per sub above bias? If you aren’t swamping the read noise then you do need longer subs or a higher gain... Very useful thread for cmos: https://www.cloudynights.com/topic/573886-sub-exposure-tables-for-asi-1600-and-maybe-qhy163/
  8. Are you dithering? It looks like there is a lot of walking noise in the image?
  9. 200mm on a 1.6x crop is close depending on the sensor used...
  10. In that case you could try both with the 105mm and see how you get on. That will give you 2 different image scales and should be pretty easy to get familiar with. For reference the SA has a typical PE of 25-50" (I measured mine in the region of 45"). It can be guided down to <1" on a good night, and if your pòlar alignment is good enough. You could then start imaging with longer focal lengths like the ed72...
  11. That seems ambitious to me, the star adventurer is great but it works best with shorter focal lengths unless you are guiding and get excellent PA. The D750 is a serious camera; what lenses do you already own? Something like 200mm works well unguided and <100mm is positively great...
  12. I think the AVX is very similar to the Heq5 in performance...
  13. An update: I am still not convinced the mirror isn't adding a small amount of blur but I havent had the weather to test this very well. However, I tweaked my collimation again and when manually focussed I was getting FWHM measurements as low as 2.4" (so 2.1px) which suggests the mirror is ok? I got beginners luck with autofocus in SGPro and it worked from the first time. However, after tweaking my collimation it would never get back to good focus after it ran the routine. I eventually realised I had manually racked the focuser when recollimating and the skywatcher motor had slipped on the shaft introducing conserable play. This is now fixed so I need some decent sky to see if I can consistently get in the 2-3" FWHM range...
  14. Would also be keen to see some fits files from a 130pds or either of the f4 Quattros.
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