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rickwayne

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About rickwayne

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  1. APP should work your flats to completely defeat vignetting. If it isn't, something weird is going on. Have you tried comparing a sub in different modes in APP's viewer? Try looking at it calibrated and uncalibrated, with a good hard stretch set in the DDP panel on the right (more than you'd ever use to develop the image). Likewise, pull up one of your flats and stretch it till it screams, see if anything jumps out at you. Did you shoot flats for this session, or reuse a set? Are you sure the focus was in the same position?
  2. Since hydrogen is so abundant, hydrogen emission is by far the brightest component in emission nebulae. It's a deep-red frequency that gets knocked down a lot by terrestrial cameras' IR-cut filters. However, if you image reflection nebulae, you'll get much less signal -- they tend to be blue (like scattering produces a blue sky). Really, these "light pollution" filters are a poor man's narrowband setup, so poorly adapted for broad-spectrum targets. For some kinds of lighting (e.g. sodium vapor) you can find filters that knock out just that particular line, but as LEDs proliferate,
  3. Yeah, the trouble is that just about every expensive piece of kit is "Wow, it's so much better now I could never go back". You might wish, after the fact, that you had the money available again to do something else, but your astro-self will never regret acquiring a dedicated camera. Makes so many things easier, and if you go mono, you have a world of new possibilities too. RGB, LRGB, narrowband...I am really glad I dropped nine bills on my 183, tell you that for free. I think I will be glad I blew twenty-five of them on the CEM70, if we ever see stars again.
  4. I was gonna say: Narrowband, homies. Chuck on that hydrogen-alpha filter and you're laughing.
  5. Oh yeah, you're DEFINITELY the first. As we say of retractable-gear pilots, there are two kinds: Those who've made a gear-up landing, and those who will. (When I first checked out in such a bird, the fanged instructor so rewired my brain that whenever I flew fixed-gear a/c thenceforth, I still ran the gear checklist, except that the response, instead of "down and locked", was a look out the window and "down and welded".)
  6. Yep. You've essentially turned your DSLR into a mono camera with 3/4 of its photosites inactive (most Bayer filters have double G sites, e.g. my Pentax is BGGR). So you'll need a lot of integration time to pull up the Ha signal, and only the red channel will contribute anything.
  7. Concur. The number of photons hitting the sensor is the same except for noise effects whether you do a few long exposures or lots of short ones. But longer exposures will help dig signal out of the noise. I run 10 minutes at gain 178 on my IMX183 sensor for narrowband, at least when my guiding is behaving. Five works pretty well. Is there a reason that you're not running at the highest gain (i.e., lowest read noise) available? You're not going get good star color with narrowband so there's little reason to avoid blowing out the stars, and you've got oodles of well depth and ADC resolutio
  8. Lucky you. I cross-connected the DEC drive cable on my CEM25P to the ST-4 port one night shortly after I got the mount...what's all that red smoke? (I had a red LED headlamp.) I pleaded in a letter to iOptron to make the labels readable. I mean, dark grey on black, for a bit of gear used IN THE DARK? Somebody's nephew got hired fresh out of graphic design school for that one. Failing that, at least ship the mount with empty RJ-11 plugs in all the ports, as markese68 suggests. Nada.
  9. When the connections all work, an integrated suite like NINA, APT, or Ekos is a joy to operate. Of course then you can't image without a computer or tablet.
  10. I was going to suggest the same -- unless it's a deep-cycle battery, best not to whang on it too hard or you'll shorten its life. I have one of these little meters wired into the harness for my battery (which is a deep-cycle). Takes next to no current, and it will not only give you the voltage going out, but also how many amp-hours you've consumed since the last reset. Very nice feature is that you can set a voltage-level alarm, which blinks the blue backlight. So you can safeguard your battery from too deep a discharge, when the voltage starts to drop, it will get your attention. Super-
  11. Yep! I bet it feels good to make this much progress. The GIMP is a terrific pixel-level editing program but astro has some special challenges that respond to purpose-built software. I've actually done some deep-sky images start-to-finish in Photoshop, stacking and all. It's possible, but it's like using a hammer to smooth wood before painting it -- just not intended for the task. In addition to calibration and integration, astro software like Siril (or Astro Pixel Processor, PixInsight, ASTAP...) offers functions such as gradient reduction and background correction (to get rid of light p
  12. Perfect technique for reflection nebulae :-).
  13. Flaming Star is my next target, assuming I can get my new mount to behave.
  14. Field rotation is what happens without an equatorial mount. If you visualize, say, Orion on the eastern horizon, then track it overhead to the western horizon, you'll see that unless you rotate the camera, it will have flipped 180 degrees. Or, for a simpler example, if you visualize the Little Dipper going around the pole, keeping your camera pointed perfectly at its center doesn't mean that the constellation won't rotate in the FOV. Equatorial mounts do more than track a target, they also compensate for this effect. Field rotation is most notable at the edges of the field, which is why
  15. Nice! There's always Bracken's The Astrophotography Sky Atlas if you want to hunt for good targets. Telescopius.com will put suggestions up for a given set of search parameters. I find that Stellarium (e.g.) is great when I know what I'm looking for, but having a premade seasonal list to work from means a lot less thrashing about. My other tactic is to subscribe to notifications from Astrobin on photographers whose work I particularly prize (e.g. Kathy Walker, pete_xl) and just shamelessly follow what they're targeting.
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