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Lead_weight

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About Lead_weight

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    Nebula

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  • Website URL
    Www.macobservatory.com

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  • Location
    Houston
  1. Lead_weight

    Imaging with the 130pds

    Is there an equivalent version of this scope in the U.S.? I would love one of these smaller fast scopes, but can't seem to find an equivalent, and SkyWatcher doesn't carry it on the U.S. site.
  2. Lead_weight

    ASI 1600 and Gain

    I'll provide my own observations here...no science though! I typically image narrowband at around 200 gain. Since most of the light is filtered out, it takes more exposure time to get signal onto the chip. I also don't have amazing equipment, but stuff that is suitable for the weight and focal length of my scopes. That said, I can't run longer exposures (5min+) without starting to see more issues with tracking. So I image narrowband in my bottle 6 sky 200 gain, 3 min exposures. For LRGB, I typically set gain to 76, this was a number someone on Cloudy Nights came up with as a better option than unity for a little more dynamic range and less noise. I usually expose for 60s to keep under my light pollution ceiling. Anyhow, these settings have worked great for me. All options are a trade off. And no one setting works best. But you should experiment a little with your skies to find some settings that work well for you. One final observation that I've learned after doing this for the last two years is that more integration time is always better. I'm now regularly spending one night's imaging session per filter. And, when I started, I was imaging multiple objects in a single night, giving no more than 1-2 hours per object. What I do now has had a huge impact on the overall quality of my images.
  3. Lead_weight

    Celestron AVX Mount.

    I've had really good luck with my AVX. All my photography is done with it. But I've taken particular care to stick under the rated weight limit, and a focal length of no more than about 900mm. For visual you can go above that, but for imaging, you'll find it's not precise enough (even with guiding) go do longer focal lengths or heaver imaging setups (above 20lbs).
  4. Lead_weight

    Astro Pixel Processing

    I just recently spent some time writing a tutorial for processing a bi-color image in APP. Here's a link. I find that it's way easier, and produces really good results without a lot of effort as far as integration and calibration go. I also find it's light pollution removal feature hands down better than Pi. All that said, Pi has some very nuanced features that cover modifying your images in ways APP just isn't up to par with...yet. I like to do all preprocessing in APP, then touch up in PI and Photoshop.
  5. Lead_weight

    Mounted vs unmounted CCD filters?

    They are, however, there are brands that have taken steps to aid in putting unmounted filters into the filter wheel correctly. Some use a tape label around the rim of the filter indicating the direction, or some put anti-reflective coating on both sides of the filter so it doesn't matter which direction they face. But just do a little research so that your decision is sound. Definitely do a forum search for the type of filters you're looking into, you might find they have other issues that would warrant choosing a different product anyway. You can also use the filter size calculator at Astronomy.tools to check your scope and camera configuration to ensure you get filters large enough to accommodate the FOV available to you. You may find you need unmounted filters.
  6. Lead_weight

    Really strange subs and calibration files

    I've never used DSS, but that order sounds correct. If you want to supply a download link to all your data (lights, flats, bias, darks), I'd be happy to give it a go on processing to see if I can produce some decent results with what you have. Might also reveal where the issue is.
  7. Lead_weight

    The Mac Observer says Hello!

    Hi Andrew :). Very cool. I bet you could also use Astro DSLR, PHD, and EQMac (a port of EQ Mod to the Mac) all natively on the Mac.
  8. Lead_weight

    Deep space scope recommendations

    You can't go wrong with the 6 or 8SE. I started with a 6SE. It can't be understated how important GOTO was for me as a novice. When I hand held binoculars, or used a manual telescope, I hardly ever saw anything. I would mostly view the moon, maybe a planet, because they were easy to find. Though it sounds like your wife might already know the sky. But having the GOTO, and the ability to just tell it to point at an object, and there it was for me to see...wow, it was amazing. Now I own 4 telescopes, two mounts, and tons of expensive gear! It's a slippery slope to be sure. Enjoy!
  9. Lead_weight

    Really strange subs and calibration files

    I don't think you can correct out the light data if you are doing your calibration properly. What does a single frame of your HA data look like (stretched)? If the Veil nebula shows up, then you are probably not doing something correct during the calibration process.
  10. Lead_weight

    Can you use a 4k TV for flats calibration

    Gotta agree here too. I used to do this regularly, and probably 1 in 3 sessions, bumped something in the image train, or a piece of dust moved, and my flats were worthless. But 2 out of the 3 times it worked! Haha. What I now do is cover the scope with a folded over white t-shirt, and aim at a clear part of the dusk or dawn sky, and take my flats. The FOV is so small that this is a really effective "light box". And there is plenty of light available to expose to the correct ADU value for your flats. Most times after an evening of imaging, I wake up, head over to my scope and point it up at an open spot of the sky, put the white shirt over the front, and capture a few flats. The white t-shirt diffuses the light sufficiently to capture the flats with even lighting across the front lens. I've had no issues doing it this way, and flats are perfect every time.
  11. Lead_weight

    First Attempt with Pixinsight

    You might try Astro Pixel Processor. It's also got a free trial, and is a lot more straight forward for processing. The steps to process are linear, order in the interface 1-9, and you just follow the steps to process your images. I've been finding I can do all my calibration and integration way easier in this program, and the results are really good. I also find it easier for removing light pollution and calibrating the color for the image. But I still do a few steps in PixInsight occasionally as it's got a more robust and varied tool set. But also, APP is a fraction of the cost.
  12. Lead_weight

    Really strange subs and calibration files

    Not sure if it will help or not, but I literally just wrote a tutorial for processing the Veil Nebula with Astro Pixel Processor. I realize it's not Photoshop, but the program is free for 30 days. You might try it out and follow the tutorial to see if that works for you. As for your issue in Photoshop, is it possible you didn't stretch the histogram? This would certainly show a dark image after integration if it wasn't done.
  13. I use those tables, and the math is sound. The short exposures are to ensure you don't overexpose the stars...not necessarily the object you're imaging. But in most images after stretching you'll see you have a few clipped stars, so you can expose longer so long as you're willing to blow out (pure white centers) a few of the larger stars in your photo. I've experimented in doing short exposures of 30 seconds (almost double the recommended setting for my light pollution and F stop), and I did 750 images, which took about 4 hours of processing time just to calibrate the frames an an 8-core iMac Pro. My conclusion was that I was willing to go no less than 1 minute per sub exposure and would probably never again do 30s exposures. I'm in a red zone and tend to do Gain 76 for LRGB with 60second subs. And Gain 200 for narrowband with 3 minute subs. You will really struggle to get good narrowband results without upping your gain and exposure time...especially for OIII and SII. You can see some of my images on Astrobin. I post all my gain and exposure time for all my images.
  14. The Lum filter is Luminance, so it's just capturing the brightness of the object, and it's typically used for adding to your RGB captures to bring out details not captured by the filtered light. With narrowband, the desire is to only image certain wavelengths, then assign them a color when processing. You don't need Luminance for this. You're already ahead of the game by not using the ZWO narrowband filters. They produce some pretty bad star halos on bright stars. (I have this same camera.) Eventually, not happy with the halos, I changed to Astrodon filters, which have better anti-reflective coatings on them, and all the halos were eliminated. I have seen some instances of halos with Baader on OIII, but some people have had no issues. My scope is an F7 reduced down to F5.7, and I still see minor vignetting on 31mm filters. But I can correct it all out with flats. Astronomy tools has a calculator to check the size of filters for your scope. That might help you decide.
  15. More and more I've been relying on EKOS/Kstars for imaging. Even if you tear down and re-set up each night, it will automate the entire nights imaging process without intervention. It handles the meridian flip, requires a guide star, and plate solves to be sure your object is in the same position as it was before the meridian flip. I believe your equipment is pretty well supported by it, and it's free to try. Might be worth exploring. All this automation helps eliminate the "human" error factor. Haha.
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