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hjw

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Everything posted by hjw

  1. Thanks Tomatobro, I did what you suggested and had partial success. Three out of four directions during guiding are working. Tried to find a straight RJ12 cable with 6 wires (6P6C) rarer than hen's teeth :( What did people do before ebay?! Thanks again! Hopefully I'm on the right track!
  2. After years of dutiful service my HEQ5 mount is playing up. It started with the Synscan controller at times claiming that no mount was found when outside. Back inside everything was fine. I did change the power source but that didn't seem to make a difference. During (the Australian) winter there were not too many opportunities anyway. Now it's getting warmer and the skies improve I took the scope out again and the mount connected but now I noticed that the guide impulses through ST4 cable are not having any effect. During calibration in PHD2 the mount is not moving at all besides the normal star tracking. In other words the mount seems to be working but I lost guiding. The place where I bought the mount moved from Melbourne to Sydney and there is no other repairer within 800km. With the 2 issues together I am afraid it is something major. Anny ideas appreciated! Clear skies!
  3. The Helix Nebula (NGC7293) is one of the nearest planetary nebulae to our solar system - about 700 light years away. The nebula itself is the gas blown away from the central star when it neared its evolutionary cycle. The light from the remnant of the star causes the gas to fluoresce, hence the color. Equipment: Saxon 200DS on a SW HEQ5 mount, guided with a SW 80ST scope and a ZWO ASI120MC camera. Imaged with a Pentax K-30 equipped with a GSO coma corrector and a Baader UHC-S filter. 40 images 300sec each ISO 1600, 20 flats and 150 bias frames taken over two nights. Stacked with DSS and processed with photoshop (contrast, vibrancy, color balance and levels) Clear skies! HJ
  4. Thanks! I was hoping I missed something and hope dies last... Well, there is always next year.
  5. Hi, I've been imaging a galaxy (NGC6744) in the constellation of Pavo over the last few nights. The object is rather big (20'x13') but faint (surface brightness 14.79). I started too late on it because I can only get about 1 hour shortly after sunset. So far I've got 2.5 hours of exposure time with 2-4 min at ISO 800 or 1600. The image is still extremely noisy and I can only just make out the outer spiral arms. My question is, how do you improve imaging on very faint targets. Obviously, more exposure time - but seeing the improvements from one night to four, I am not sure it will get me where I want to be. Darker skies later at night would also help but that is not an option until next year. I am just wondering whether there is anything I am missing. Equipment: Saxon 200DS on a HEQ5, SW ST80 with ASI120MC for guiding, Pentax K30 with GSO coma corrector, 120-240sec exposures ISO 800 or 1600, 20 flats and 150 bias frames for each ISO. Thanks! HJ
  6. I started with the ED80 on a HEQ5 mount and yes, it is a very nice setup. About a year ago I bought a Saxon 200DS (rebranded SW 200PDS) and must say I love it. f/5 compared to f/7.5 makes a huge difference. I have a smaller FOV (objects appear larger) and require half the exposure time. With a DSLR noise increases significantly after 180sec exposures dur to the sensor heating up. Collimation isn't all that hard. I use a home-made collimation cap and can do it in a couple of minutes. The draw back is that with the guide scope (SW ST80) attached the mount has reached its limit. Wind does become a problem and a larger mount would be recommended. The ED80 gives a very crisp image but on fainter objects I was always battling noise from the sensor. One day I will get a cooled camera - maybe...
  7. If you are interested solely in observation, I would go for a dobsonian. I found that Astro Anarchy (http://www.astroanarchy.com.au/telescopes.html) probably has the best prices in Australia. Within you price range you can look at the 6" or 8" Skywatcher Dob.
  8. No, not really. Narrowband photography will help a lot, but you will get false color images. Does a good camera improve imaging in a light polluted area - not really. Only filters will. Does a good (cooled) camera improve imaging at a dark side? Yes, because you can get longer exposure times without heating the sensor and causing artifacts.
  9. I would never have thought that the day would come where I say: "The clouds in an astro image look good." It's just not meant to be like this. And yet, this was the only image of the night with clouds and it was my favorite.
  10. Can't always win. The US had the solar eclipse last year - gosh I was jealous!
  11. Thanks! I agree, I have a few images without clouds and decided to post this one.
  12. Like half the world we were treated to a lunar eclipse and a Mars opposition this morning. It was spectacular! I was hoping to get the actual moon set as a blood moon but the light pollution of a 3.5 million city and a sunrise did its best to ruin this idea. Shortly after this shot the moon became invisible. Still, having the eclipse over the city lights made getting up early on a weekend worthwhile! Pentax K-30, 70-300mm lens @70mm, 3second exposure ISO800. Clear skies! HJ
  13. It is the time of the year, where we have a plethora of objects high in the sky but the weather is such, that last night was the first night in almost two month where I could go for a DSO. I decided, from all possibilities to go for M20 because I really like the diversity of colors in this nebula. The Trifid nebula is located in the Sagittarius constellation and is about 5200 ly away. It has a rare combination of an open cluster, an emission nebula (red), a reflection nebula (blue) and dark dust bands. Equipment: Saxon 200DS (8", f/5) scope on a HEQ5 mount, SW ST80 guide scope with a ZWO ASI123MC guide camera, GSO coma corrector, Pentax K-30 camera. 54 x 120sec light frames ISO1600 (I went for shorter exposures because the wind pushed this setup right to its limit), 20 flat frames and 150 bias frames. For the rest of the week, it will be cloudy with rain and then the moon will be in the way should it clear up. All those missed opportunities. Alas, you can't have everything Clear skies! HJ
  14. There is a picture on the APOD website: https://apod.nasa.gov/apod/ap180325.html . It's raining here right now, so no chance to have a go at it Well it might last another few days. Clear skies HJ
  15. I thought I try my luck again. Centaurus A is a strange galaxy and is part of the M83/Centaurus A cluster and therefore is at the right time to be imaged too. The galaxy is between 10 and 15 Mly away and is characterized by the unusual s-shape dust band. In its center is a super-massive black hole emitting relativistic jet streams (unfortunately my Pentax does not pick up X-rays that would be spectacular...) Saxon DS200 f/5 on SW HEQ5, Pentax K-30 unmodified, SW ST80 and ZWO ASI120MC for guiding. 50 light frames 180sec at ISO 1600, 150 bias frames and 20 flat frames (I am new to the reflector and the vignetting drove me nuts so I finally started using calibration frames) The other galaxy in this group is NGC4945 and it is rather boring, so I will skip this one... Clear skies! HJ
  16. Congratulations on the birth of your son!
  17. Very nice image. An all-time favorite! I have to admit I prefer RGB image over the Hubble palette. Bummer about the supernova - it felt SOOO close!
  18. Sooner or later you will need some form of tracking device: a home made "barn door" being the simplest, followed by a SW Star Adventurer or similar to a motorized mount. Otherwise you will be limited to very short exposure times. There are various rules, usually 500 or 600 divided by focal length equals exposure time in seconds before stars start trailing. For example at 200mm your maximum exposure time would be 2.5-3 sec. My suggestion would be to start with the milky way with 18mm and take about 30 sec exposures (quite a few) and practice stacking with DSS and some post processing. Once you get some tracking equipment any larger DSOs come in range. I started out like this and it is good fun! Good luck. HJ
  19. Not quite on the same level as other entries but this will be my first challenge contribution... You have to start somewhere. Clear skies! HJ
  20. I was excited too. It would have been my first supernova (not discovering, but imaging). Well next time...
  21. I hate to be the bearer of bad news, sorry! This is a sub from about 10min ago. I tried to have it on the same scale and roughly the same orientation and the new star is not there. Sorry mate!
  22. How exciting. I imaged Carina two days ago and we have another clear night in Melbourne. I have just started imaging again! By the way, how do you notice something like this?! Good luck - hope you are right. HJ
  23. I bought myself a Saxon 200DS (equivalent to the SW 200PDS) for Christmas and have been struggling ever since to get it to work properly. At the end two things made the crucial difference: I had to rotate the tube so that the camera points to the ground (on the side it twisted the tube slightly and one corner of the image was out of focus while the rest was fine) and I hadn't noticed that the guide scope was slightly out of focus which caused the guiding to be less then optimum (Silly mistake :(). Anyway, got things working now. We had 4 clear nights in a row, so here is last nights effort: M83 M83 is one of the brightest galaxies in the Southern sky. It's 15 Mly away and spans about 12 arcmin. Equipment: Saxon 200DS on a SW HEQ5 with a Pentax K-30 unmodified camera, SW ST80 guide scope with a ASI120MC guide camera. 61 x 180sec light frames ISO 800 stacked with DSS and processed in Photoshop. Clear skies HJ
  24. Hi, I recently took possession of a Saxon 200DS (a Synta twin of the SW 200PDS) and I am struggling to get good images with it. I have a GSO coma corrector and a set of extension rings for it. In general I have trouble to get the star size below FWHM=6 (on the SW 80ED I can get 3.5). On the image the diffraction spikes appear only on one side and it would be fair to call them diffraction "halos". I've tried a few nights now with different objects but seem to get nowhere It's 15 light frames 180sec, ISO 400. Saxon 200DS, HEQ5, GSO coma corrector, Pentax K-30, SW ST80 guide scope, ZWO ASI120C guide camera Any advise welcome! Clear skies! HJ
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