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Dom543

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Everything posted by Dom543

  1. Entire Veil Nebula in one capture The moonless clear skies yesterday night gave me an opportunity to complete the Veil project with a capture that has all parts of the nebula in one image. This overview images should probably have been the first one before I got into the details of the various parts. But my attempt last month didn't work out and I had to ask Paul for the setting that I have forgotten. The issue is that there are too many indistinguishably uniform stars in this field. There is no way for the program to select a few, keep track and match them. The trick is to tell StarlightLive not even to try to match stars. One achieves this by setting Max Displacement to zero. This also implies that one shouldn't try to stack too many frames, as one is depending solely on the accuracy of the tracking by the mount. Anyway, here are two versions of the overview image both made from the same stack consisting of one frame only with each of the three filters S-II, H-alpha and O-III. This is not even a genuine stacked image, just the three separate channels assembled together. Accordingly, the detail, crispness and smoothness of this capture is not comparable to those of the genuinely stacked images of the Eastern and Western parts of the nebula captured and posted earlier on this tread. The first image is 1x60sec S-II (red) + 1x60sec Ha (green) +1x60sec O-III (blue) stacked together in StarlightLive and displayed with the linear tone mapping option. The yellow areas correspond to the largely overlapping Sulfur and Hydrogen emissions. The finer graduations are not really possible to distinguish on this image scale and without sufficient data depth (stack size). But there are myriads of uniformly tiny stars reasonably pinpoint and the image can serve as a kind of Table of Contents to organize the captures of the various parts of the nebula posted earlier. The second image is made from the same stack of one 60sec frame per channel but using the x^0.25 tone mapping option. This function smears out the stars, they are not as crisply defined. But a benefit of the less prominent stars is that the finer detail of the fainter parts of the nebulosity comes out better. To me the filamentary texture of nebula is more veil-like on this image and, if for nothing else, it's worth to see the comparison. There is, actually, some faint blue Oxygen nebulosity in the central part of the object, which is the cause of what looks likes some smear or noise in central part of the image. This can be better seen on the full resolution image. Both posted images have been slightly cropped and proportionally reduced in size in Microsoft Paint to fit the posting size limit. SX_825 mono camera was used with a Samyang 135mm camera lens at f/2.0 and the image was captured, stacked and processed with the multi-spectral feature of StarlightLive. This concludes the Hubble Palette Veil project for this summer. Clear Skies! --Dom
  2. Hi All, I am back at home and on the internet again. I can and would be happy toreply to any questions or requests regarding the AstroRed screen red and black theme. Clear Skies! --Dom
  3. Thank you for the initial feedback. I am heading to the airport for a work related trip. I will be away and off the forums for about a week. I will reply to all questions, when I return. Clear Skies! --Dom
  4. A new member at the CN forum asked what tricks we use to protect our eyes from the glare of the computer screen during live observing sessions. I use a Windows theme that displays all elements of the of the Windows display in hues of red and black. I mainly use it, when I observe using Starlight Live but it works with every Windows compliant program. This means that when I look for a file or want to save a file, the directory listing and all message boxes are in the red and black palette. If I want to surf the web, Internet explorer's windows are displayed in red and black etc. (The only program that I found not to comply is Google Chrome.) Here is a sample screenshot that I made yesterday evening when I saw the CN member's question pop up on the forum. You see StarlightLive that I was using being in the active window and Internet Explorer and a Windows directory in their own currently inactive background windows. This is achieved by the use a Windows theme file that I made a couple of years ago and have been using during every of my observation sessions ever since. It works on Windows computers. I prefer this to the red plexyglas screen filter that I have tried earlier because it doesn't affect and dim the image itself. Only the user interface elements, the backgrounds and the text. The zip file below contains the theme file itself and a text file with the installation instructions for those, who would like to try. Installation is easy: The theme file needs to be copied into a particular windows directory. Dom's AstroRed Theme.zip Once installed on the computer one can switch between one's regular, often blue and white, Windows screen theme and the red and black one that I call AstroRed. The AsroRed theme will be displayed in the "Personalization" section screen of the Control Panel. (All this is explained in the Description.txt file that is in the zip file.) Enjoy! Feedback or improvements are welcome. Clear Skies! --Dom
  5. Very nice work! You may also want to experiment with adding an H-alpha filter. It has multiple benefits: Eliminates the chromatic aberration of refractive optics, reduces star sizes to make them nice pinpoint and brings out the large emission nebulae embedded in many star fields. Clear Skies! --Dom
  6. Western and Central Veil in Hubble Palette Narrowband The mix between a tropical bird and a supersonic Concorde in the upper part of the field is NGC 6960, also called the Witch's Broom. The triangular formation in the lower left with the long multi colored tendrils doesn't seem to have an NGC designation. According to Wikipedia, it's called Pickering's (or Fleming's) Triangular Wisp. It is interesting to see its filaments changing their color between yellow, blue and green. It reminds me of the colorful whip that I got at a country fair, when I was 3 years old. It even had a colorful pompom at the end, like this one. (But my personal childhood associations shouldn't confuse anyone. Pickering saw it as a wisp, not a whip. He was probably a smoker rather than a herdsman.) As always in the Hubble palette, red is S-II, green is H-alpha and blue is O-III. The yellow areas on the image indicate a mix of Sulphur and Hydrogen radiation (yellow=red+green) This capture was taken with the Nikkor 300mm f/2.8 ED-IF AI camera lens, Baader 7-8.5nm narrowband filters and a monochrome SX-825 camera. 3x60 sec exposures with each of the three filters were live sum stacked in StarlightLive. The TEC of the camera was not turned on. At 4 am Sirius was rising with Orion already high and felt like winter with no need for electronic cooling. This capture was taken on the same night as the previous two from the Wenas Wildlife Area outside of Seattle. Clear Skies! --Dom
  7. Thank you, Rob! Primary credit for the multi-spectral captures should go to Paul, who created StarlightLive and developed the multi-spectral capability that is totally unique. There is nothing anywhere that would even come close, or would dare to imitate it, in the entire astronomy field. It is fun to sit out with the telescope and with every new frame gain a better, deeper insight in the intricacies of our Universe. It also encourages a constant involvement with the process. During the 30 or 60 seconds, while one is waiting for the new frame to arrive there is a certain excitement of what the new exposure will contribute to the whole image forming and what new opportunities, insights it will bring, what actions, adjustments it will necessitate. I understand that every person is different and there are many different ways to enjoy an night under the stars. Others like to go from one object to the next. Spend the night going through the entire "What's up in the sky tonight?" list of their computer or goto program. I can spend entire nights by just trying to get various insights into the same object Well, we are all different and the skies offer an unlimited number of opportunities to explore and have fun. Regarding the ailing Meade 8" SCT, I have to say that I have some attachment to that OTA. I bought it used and it is not easy to find one of these f/6.3 tubes. I have both this 8" and a 10" one and believe that they are particularly well suited for camera assisted observing. With two simple focal reducers, that can be used with both OTA's, I can have six different focal lengths with three focal ratios, including ones comparable to Hyperstars. It takes a minute to switch from f/6.3 to f/4 or to f/2. The 8" SCT is also the largerst scope I can take with me on airplanes in a backpack. I work in Massachusetts in the Boston area for four months every year and I used to keep this OTA over there in my office. Brought back to Seattle because it needs to be taken apart and re-greased but I never got to actually doing it. A project for one of those gloomy November nights... I said that I can spend entire nights with looking for new insights into the same objects. So hang on, more is coming... Clear Skies! --Dom
  8. Eastern Veil with 400mm Optics and Hubble Pallette This has been taken with an 8" Meade SCT at f/2.0 and the SX-825 camera. 2x60 sec exposures sum stacked with each of the three R,G and B filters. To fit the web page, the image has been reduced to 75% of the original. Unfortunately, the focus is not quite accurate here. I focused with a Bahtinov mask on a nearby brighter star and the mirror has apparently shifted, when I slewed the scope back to the object. This particular OTA has a problem with focusing that I intended to fix but haven't gotten to it yet. I am posting this capture mainly, as this 400mm focal length provides the right framing for the object. I wish I had an 8" SCT with a Hyperstar. I get the f/2.0 focal ratio using an Optec 3.3 reducer on the natively f/6.3 OTA. With this Optec reducer I don't notice a significant vignetting. The stars in the corners are not perfect. But it is not possible to know, if the cause is the extreme focal reduction or the mechanical issue with the mirror. The mirror has a play as it is sliding on the baffle tube and may not be perpendicular to the axis of the scope. The old grease will need to be replaced. Eastern Veil with 300mm Optics and Hubble Pallette This is my current favorite from all my Eastern Veil captures. Has been taken with an old manual focus Nikkor 300mm f/2.8 ED-IF camera lens and the SX-825. Instead of reducing the image to fit the web pace, this time I cropped it to 75%. Interestingly, the same 2x60 sec exposures sum-stacked (with each of the three R,G and B filters) worked, as for the previous capture with the SCT. The old Nikkor lens looks rather odd but it is a dream to work with. Very compact, relatively light weight (4.5" aperture, 1' length and about 5lbs weight) and comes from the glory days of Japanese precision mechanics with still perfect focusing mechanism. It is, actually, on Ken Rockwells list of "10 Best Lenses Nikon Has Ever Made". It's ED, not APO and it doesn't quite get blue focused to the same point as the other parts of the spectrum. For triple narrowband I usually focus it with the O-III filter that's closest to the blue end and always produces the largest stars. If focus is not absolutely accurate for H-alpha and S-II, that doesn't disturb much. Stars with the Ha and S-II filters are small anyway. Even imperfectly focused they are smaller than their perfectly focused images with the O-III filter. This ends the sequence of my Hubble palette captures of the Eastern Veil. Clear Skies! --Dom
  9. Star Colors of M22 My wife worked over the long weekend, including evening shifts. So I drove out of town for two nights to take advantage of the moonless skies. To take a break from the Veil nebula, and motivated by Martin's and Hiten's explorations of star colors, I took aim at M22. The Sagittarius region is always low from the 47th latitude of Seattle. From the deck of our house we cannot see it at all, as it is totally drowned out by the lights of the tall buildings of downtown and even taller constructions cranes building the Amazon Jungle (Amazon, like in Amazon.com, not the Greek female warrior tribe or the river in Peru and Brasil). So this is what I got for M22 with the SX-825, RGB filters and StarlightLive from the Wenas Wildlife Area East of Seattle. 2x15sec red + 2x15sec green + 2x30sec blue exposures live mean stacked in StarlightLive. I use the Baader LRGB filter set. This capture was taken with my Meade 8" SCT at its native f/6.3 with no focal reducer at all. The focal length is 1280mm. This OTA is somewhat difficult to focus, especially, when it's almost in the horizontal position, like in this case. We know that globular clusters are ancient structures created in the first billions of years after the Big Bang. Their old stars stars are shining with tired yellowish light. But as globulars are so compact and densely packed, their stars can collide. Out of these collisions new energetic blue stars are created. I doubled the exposure time with the blue filter to have these blue babies a better chance to show off. To get an even richer view, I also tried different slider settings on the same stack. Stretched more aggressively and selectively increased contrast for the blue channel. This is what I got. I post both versions so that viewers can choose according to their tastes. Clear Skies! --Dom
  10. Very nice captures Errol! Too bad I didn't see your Wizard before the weekend. It's one of the summer skies' gems and I may have missed it for the year. Clear Skies! --Dom
  11. Very nice images Alex! Over the weekend I was wishing I had a C8 with Hyperstar. 400mm is the ideal focal length for many objects, including NGC6992-6995. You may want to explore, if a rotator like this https://www.optcorp.com/teleskop-service-t2-quick-changer-360-rotator-tst2rot.html could be added to your optical train. It's only 5mm of thickness and has T-threads on both sides. The entire NGC6995 fits into the field of the 825 chip at 400mm, if rotated to be positioned diagonally. (The long thumbbolts of the rotator could be replaced by shorter ones to avoid additional diffraction spikes. Other than that, the entire rotator would probably hide in the shadow of the filter slider.) Clear Skies! --Dom
  12. Rob, you are right. When I desaturated the image in GIMP, I found the stars interfering too much with the nebula. So I reduced the brightness somewhat. Stas_old, the reason I made and posted the desaturated image is something similar to what you are also saying. I would formulate it so that the monochrome image brings out a different dimension of the structure of the nebula. I agree that it must have something to do with how our brain processes visual information. When the complexity and 'distraction' of the colors is taken out of the picture, then connections, lines, filaments and other patterns take center stage and became more recognizable. If our eye has different sensors for color and low light monochrome, then, I am sure that our brain also has separate "processing algorithms" for the two different kinds of information. Of course, with the monochrome camera there is a much simpler and more efficient way to take a monochrome capture. I should have done it, when everything was set up. With 9 minutes of total integration time I could have gotten a very nice monochrome image. I might have even be able to average (mean) stack. Thank you for the comments. That's how we collectively figure it out what could be and should be done with this new technique. Clear Skies! --Dom
  13. Finally finally, here is the last capture desaturated of its colors in GIMP. Interestingly, it looks quite different. Clear Skies! --Dom
  14. Finally one more capture from with the SX-825. This is from a different stack than the first one. Here H-alpha was given the same 60sec exposures as S-II and O-III. So there are more green hues. This capture is also stretched more aggressively and with higher color saturation. Looking at closely one can notice the rougher texture due to the lack of averaging. But it shows more of the fainter details and more of the varieties of the hues as the three gases mix in various proportions. As before, red is Sulfur, green is Hydrogen, blue is Oxygen. So, for example, hues of orange, yellow and lime are mixtures of S-II and Ha in various proportions. Magenta and cyan are mixtures of Oxygen with Sulfur and Hydrogen respectively. Although in this particular object, Oxygen stays remarkable separate, it doesn't mix much with the other two components. I assume that this means that they are spatially separated by light years. As you can see from the time stamps, I tend to spend a lot of time looking at the same object in different ways. And enjoying it. Clear Skies! --Dom
  15. Thank you Rob and All! For comparison, here is part of the same area taken with the Lodestar. Same location, telescope, technique and exposure times but mean stacking. This also illustrates how much more sensitive the Lodestar is. I had to add up three frames with the SX-825 to get an image of comparable brightness as with the Lodestar. Mean stacking doesn't increase brightness. Clear Skies! --Dom
  16. Work kept me very busy all summer. I have not had a chance to do any astronomy since early June. Yesterday we had a clear night here in Seattle so I set up on the deck. Here is one result, another part of the Veil nebula in Hubble palette. The Veil is so rich in all three major narrowband components that I cannot stay away from it. The only other comparably rich and balanced object that I know of is the Crab nebula, which will be coming up soon on the Eastern horizon. To have something different, this time I used the SX-825 mono camera to see, if its finer resolution can capture more of the fine detail of the Veil. This time, also for a change, I tried sum stacking. Air transparency is never good in Seattle requiring longer exposures. Sum stacking achieves this goal without the need for guiding or overly aggressive stretching. Also, I noticed earlier, that the combination of the frames belonging to the different channels in multi-spectral does have a somewhat similar smoothing effect as stacking. At least in those areas, that are covered by more than one channel. So here is one concrete example, how it works out in real life. 3x60sec S-II + 3x45sec H-alpha + 3x60sec O-III, Sulphur is red, Hydrogen is green, Oxygen is blue. I have the Baader narrowband filters with 7.0-8.5nm passbands. I used my 10" Meade natively f/6.3 SCT with an Optec 3.3x focal reducer with 60mm reducer to sensor spacing, resulting in f/2.0 (poor man's Hyperstar). The SX-825 was cooled to -15C but I also used three dark frames. Just out of habit. The H-alpha exposures were intentionally chosen shorter so H-alpha doesn't overwhelm the weaker S-II. The software was the most recent version of StarlightLive and this capture would not have been possible without StarlightLive's unique multi-spectral capability. The original capture has been reduced to 75% in Microsoft Paint to fit the webpage format. Clear Skies! --Dom
  17. In visual astronomy they say "Aperture wins". In camera assisted astronomy it's "Focal ratio wins". Faster optics delivers brighter images and allows for shorter exposure times. If the camera is your primary means of observing, then try to get a fast (e.g. f/4) scope. Clear Skies! --Dom
  18. Jason, I don't have a remedy but have a diagnosis. The issue is that when you remove the reducer, you increase the focal length of the system three-fold. Which also means that you reduce your field of view accordingly. A reduction to one third linearly means that the area of your field is reduced to 1/9th. Not only that but your object will also become dimmer by a factor of about 1/8. If it was a diffuse nebula, it may still be in your field but too dim to see. If it was a small planetary, then even the fact that the threads fit differently without the reducer may be enough to move it outside of your field. I am not sure that a more expensive mount would solve this double issue. As I know of no easy remedy, I try to avoid of getting into this situation. My way of doing this is not even to try to do real-time camera assisted astronomy at f/10. I am not saying that it is not possible, others may be able of doing it. Just not me. Clear Skies! --Dom
  19. Brandon, By assigning exposures to more than one color channel simultaneously, you could shave off 3 min from the total integration time: 3x30sec Ha to Green + 3x30sec Ha to Green+Red + 3x30sec Oiii to Blue+Red + 3x30sec Oiii to Blue = 12x30sec = 6min It is interesting that the central body turned purple as a result of adding red to blue but the 'apple core" didn't turn yellow as a result of green+red. In fact, the green didn't seem to have changed at all compared to the Hubble palette capture. I like that the green jumps out better against the purple than against the blue of the Hubble palette. Clear Skies! --Dom
  20. Hi Brandon, I like your Hubble palette version of the Dumbbell very much. As S-II is weak, there is no full spectrum and that way it avoids the grayish-white areas discussed in the last paragraph of the post https://stargazerslounge.com/topic/271785-multispectral-starlightlive-captures-step-by-step/?do=findComment&comment=2978458. But more experimentation is always welcome and I am looking forward to your creative implementations of this object. As for this tutorial thread, I tried to keep things as simple and straightforward as possible. So that first time users can repeat all steps and get comparable results. Or even better ones, if their skies are better, or if they come up with some of their own better tweaks. Clear Skies! --Dom
  21. Hi Rob, The full 6992 in tri-NB should be very nice. The "head" of the nebula, which is cut off from my above capture is also very colorful. Below is a link to my attempt from last summer with a 300mm camera lens. At that time I didn't have a S-II filter, so the capture is only Ha+Oiii. Coincidentally, the false color "Swedish" palette yields colors rather similar to the Hubble palette for this particular nebula. https://stargazerslounge.com/gallery/image/27962-300mm-f28-eastern-veil-aka-network-nebula-swedish-palette/ Looking forward to more multispectral company. Maybe we will hit the critical mass with all the colorful summer nebulae up there. The Veil may be the ultimate target for Hubble palette experimentation. It will still be conveniently located for at least the next two months. The Western part of the Veil (Witch's Broom) is also very pretty. Clear Skies! --Dom
  22. Your company in multispectral work would be very welcome. With my schedule allowing only one or two nights for asto per month, this thread grow only very slowly. I hope that you will ave good clear skies over the weekend. --Dom
  23. Thank you Rob! As you are pointing it out, I also notice that there are more little red stars in the background. That can have several different reasons. One is that with more stacking we record photons that are not caught by a single exposure. A second possibility is that the red channel was selectively stretched more on the 3+3+3 original image than on the 1+1+1 draft mode one. A third and possibly easiest explanation is that the black level cutoff was placed slightly higher for the draft mode capture. I don't have the exact slider settings and I usually save about a dozen of different displays of the same data each with different slider settings. Then I decide the next day at daylight, which one I find the most suitable for posting. I usually stop stretching, when the image stats to fall apart. So it is possible that the 3+3+3 capture had more red data and could be stretched further. What I would do next time knowing what I learned from this exposure? I would probably increase the exposure time for the Sulfur channel to 90 seconds. That would yield a more balanced data file and provide more elbow room to play with the sliders. As I said in the original post, this was the first object that I encountered that allowed to use the same exposure times for all three channels. I was thrilled by this and used equal exposures. But still, Sulfur is a rare commodity in outer space (compared to Hydrogen) and deserves special attention and possibly longer exposure times. The other thing I would do the next time is, I would use my SX-825 (aka Ultrastar Sr.) camera instead of the Lodestar. Both the finer resolution and the 30% larger field would benefit this object. Clear Skies! --Dom
  24. Eastern Veil in Hubble Palette Fast "Draft Mode" As a default, I usually stack three frames, in mulispectral mode three frames with each filter. But this time, before I started with the main capture, I made a fast trial capture to see how the relative strengths of the three channels will work out. This was made of only of single frames with each of the three filters, i.e. every channel is just one unstacked exposure. So this entire capture is only 1x60 Sii+1x60 Ha+1x60 Oiii = 180sec total. I post it here for those, who are in a hurry and prefer to have a complete three component Hubble palette image in just 3 minutes. To help to compare the original 3x60+3x60+3x60 capture and the fast 1x60+1x60+1x60 "draft mode" image, I copied them side by side. I also rotated them 90 degrees and reduced the resulting image to 80% to better fit the web page format. To the right is the draft capture. I believe that slider settings were about the same for both images. The draft mode image doesn't seem to badly suffer from the rough texture effect of unstacked captures. Stacking of the three channels appears to have sufficient smoothing effect to result in images that are o.k. for internet posting. At least for the 1/2" Lodestar image size. If one enlarges the images to 200%, then the difference in smoothness is more pronounced. The most noticeable difference between the two captures is in their color balance. The draft mode image is much colder. This is the result of the fact that the weakest signal, which is the red Sulphur in this case, suffers the most from the lack of stacking. I elaborated more on this on the multispectral step-by-step thread here https://stargazerslounge.com/topic/271785-multispectral-starlightlive-captures-step-by-step/?do=findComment&comment=2978458. There is simply not enough data in a single 60sec Sulphur exposure to stretch it more aggressively. A possible way to get more Sulphur and a similar color balance in the draft mode could have been to combine a 90sec S-II exposure with 60sec H-alpha and O-III exposures. But that's Monday morning quarterbacking... Clear Skies! --Dom
  25. I thought that some of you might find the following comparison interesting. After I was done with all the captures and screen shots for the above step-by-step demo, I also took a new capture consisting of only one O-III frame and one H-alpha frame. My original motivation was to be able to provide a comparison for those of you, who are involved in outreach. One possible argument against multispectral captures might be that the general public doesn't have patience for twice as many or three times as many exposures to be stacked as with an OSC camera. Here are the two images copied and pasted side by side. Left is the 3xOiii+3xHa stack from the first part of the thread and right is the 1xOiii+1xHa quick and dirty version. In my opinion, for purposes of public outreach, the quick version is just as suitable as the original one. When we stack frames captured with different filters, the resulting image still seems to benefit from a similar smoothing effect as when we are stacking frames obtained with the same optical path. At least as long as we are not investigating it with a magnifying glass or try to display it on a wall size monitor. If we look at the two images closer, we notice that they differ the most, where the signal was the weakest. Several of the "islands" of red near the center of the nebula are missing or are smaller in the 1+1 stack image.This is logical.Stacking makes more difference, where the issue is whether a pixel is hit by one (random) photon or by no photons, than where the question is whether by five or by six photons. When comparing the two captures, some might even say that the 1+1 image is nicer than its 3+3 counterpart. Due to its nice clean metallic blue-green core, as opposed to the wishy-washy greyish center of the 3+3 stack. What is causing this difference? It is that the weak red signal is missing around the center of the 1+1 stack. Cyan=green+blue. If red is also present, the we have red+green+blue, which is the full spectrum and is displayed as a shade of boring dirty grey. If the red is missing, then we have the beautiful clean cyan. Sometimes half truths are more pleasing than the full truth... Clear Skies! --Dom
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