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schmeah

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Everything posted by schmeah

  1. Thanks guys! Rob, binning refers to a CCDs ability to combine adjacent pixels on the chip to make a "superpixel", in this instance effectively combining 4 pixels into 1. This increases the signal to noise ratio and thereby reduces the total imaging time needed. However, this also reduces the resolution which is related to pixel size. Many imagers bin their RGB subs because the detail in the image is not provided by the color subs, and can keep the detail by combining unbinned luminance subs. Binning luminance subs can make sense if your image scale resolution would be wasted if your atmospheric seeing conditions are not good, and therefore less resolution is acceptable. Derek
  2. This is a prototypical flocculent unbarred spiral galaxy in Ursa Major. Forty six million light years distant, apparent magnitude of 10. Shot over two nights with a QSI 540 wsg on 9.25 Edge and Avalon M Uno. Thanks for looking. http://www.pbase.com/dsantiago/image/162030077 Derek
  3. Thanks for all the kind comments! Derek
  4. Thanks! This was at native FL f/10. There still is no reducer for the 9.25 Edge. Derek
  5. Thanks Herra. I agree processing is a far greater challenge. Imaging properly positioned targets is important as is excellent cooling. I have not had much success with LP filters (IDAS). I seemed to lose too much faint signal, and so have done better without, but with more and shorter subs. Derek
  6. NGC 891 is an edge on galaxy, 30 million light years distant in Andromeda. This was shot through the dense light pollution in northern New Jersey. It required a lot of gradient reduction, but otherwise the data was relatively clean. A total of 8 hours LRGB. Thanks for looking. http://www.pbase.com/dsantiago/image/161622733 Derek
  7. Congrats Jarno! Looking forward to a first light report and some great images! Derek
  8. i agree. My mount, possibly related to the belts, has an uncanny ability to generate round stars regardless of the conditions and guide tracing. Its the FWHM that really matters in terms of resolution. You can still get round (but big and bloated) stars on a night of poor seeing, but you can't get a low FWHM no matter how your mount responds, nor can you get a low FWHM when your mount is tracking poorly even with perfect seeing. Derek
  9. Congrats Jarno! The Linear is a great mount. There are some fabulous images being produced on it. Look forward to hearing your report. Derek
  10. This is a center crop of an image of NGC 7319 I took this past week. It is at FL 2350, 9.25 Edge at f/10. It is from a single two hour long Ha sub and two one hour long OIII subs. I could probably image with a single sub over the entire evening if I had perfect polar alignment. The full image is here:http://www.pbase.com/dsantiago/image/161216013 Derek
  11. Yes Jarno, that is the thread I recall reading. So one disgruntled user (who kept the mount anyway because he still liked it), and some creative math and physics furmulae by his friend don't make a convincing enough argument to condemn the mount (and was the Linear not the M Uno if that matters) in windy conditions. I think Luciano's reply and example were cogent and at least as convincing. Unfortunately there is not a large enough user base to form a conclusion one way or another with this issue. Torsinadoc has the right idea, in building a sturdy wind shield, accepting that most light weight portable mounts will have wind issues. Derek
  12. Hi Jarno. Who are the people saying they are having problems in windy conditions? I think most mounts have problems in windy conditions. I think the only way to judge objectively would be to compare different type mounts performance under the same conditions, ie at a star party. Assuming that belt elasticity will equate to worse tracking/guiding under windy conditions is a stretch (no pun intended). I think if I imaged in such windy conditions, I would be looking for a personal observatory, or at least some other form of wind blocking solution, rather than hoping that I picked a wind resistant mount. But again, I've had no problems in moderate wind. And even when my PHD RMS measurements are somewhat higher, the stars still come out round and tight somehow. Perhaps the belt elasticity has some positive effects as well, more rapid corrections, as Olly had alluded to earlier in the thread. Derek
  13. Hi Jarno. There was a thread somewhere, perhaps on Cloudy Nights, where there was detailed discussion regarding the possibility of flex in the avalon mounts due to belt elasticity. I don't want to call it a myth, but I haven't found any users who have substantiated this claim. I can, however, say that the only night in one year of frequent imaging where I lost subs due to out of round stars was on a windy evening, steady 15MPH with stronger gusts. I rarely set up on windy nights though, and I suspect that few mounts would perform well under those conditions. However, if you truly are going to be imaging under frequently very windy conditions, perhaps you should be looking for a tank that you KNOW will hold up better in the wind, Mesu perhaps? Overall I absolutely love this mount. Hour long subs at FL 2350 f/10 are now routine with tight, round stars always. Derek
  14. Thanks for the update Mauro, that's great! I am really looking forward to seeing how you gents get along with this. With no encoders or homing sensors, I never really thought of my M Uno as a remote capable mount, but perhaps... Derek
  15. But you mean RA "tracking speed" not "guide speed", correct? This may be very helpful for me and my Avalon M Uno. I've also noted the my mount tracking speed is slightly off in RA and I get westerly star drift consistently, even after accurate polar alignment. Although it still guides very well, it has always bothered me. There is a tracking rate adjustment slider in my Avalon Stargo software that I have played with that significantly reduces this drift, but I didn't know how to calculate the amount of error. Thanks! Derek
  16. That's great Elio! I'm really interested also to see how you progress with this. Two questions. What about a dew shield? Doesn't seem like it would fit on the Edge SCT inside the Merlino with the roof closed. Does it have the motorized polar alignment feature that I've seen on the Avalon site? And if so, how automated is this? Derek
  17. Any update on this? Anybody have one and can comment on useability? Derek
  18. Great stuff! Keep it coming. Derek
  19. Hi Olly. Yes, it would appear that the corrections are so quick, the guide star snaps right back on pixel. There doesn't seem to be much if any difference in my results whether my total RMS is 0.4" or 1.2" (typically in the 0.5-0.6 range) at an image scale of 0.65" per pixel. My stars are never out of round (flatness typically less than 0.05 in Maxim) and FWHM typically in the 2.5" (seeing dependent) range regardless of the guide trace. So many focus on the guide trace and tracking/guiding numbers when buying quality mounts. But it doesn't seem to be strictly applicable to these mounts. Regarding customer service. Truly stellar. When I was having issues with StarGo initially, it seemed that Luciano was down the street rather than across the Atlantic. My experience was similar to Phil's. Why was his thread locked, BTW? Derek
  20. Hi Aaron. I am very happy with the M Uno, and now that I am imaging at longer FL (2350) and am still not wasting any subs due to poor guiding/tracking, I am convinced that I made the right choice. If you have any questions, feel free to ask me here, or PM me. Derek
  21. Thanks! I was suprised at how many tiny fuzzies are in this field, and also that the PN showed up in such short exposures ( though couldn't really see it on any of the individual subs ). Derek
  22. I imaged for years on a fork 10" LX200R @ f/10 with subs as long as 20 minutes. Getting an OAG made all the difference in the world with my setup. And piggybacking a refractor turns it into an all around setup. In fact my one and only APOD was on this fork mounted setup. Although there are challenges with the fork mount, the simplicity, no flip etc, is what led me to get a single arm fork variant (M Uno) when I upgraded. Derek
  23. Perhaps the largest known sphere in the universe, Abell 39 is a faint planetary nebula in Hercules. This was taken on my Avalon M Uno with a QSI 540 and Edge 9.25 @ F/10. LRGB subs were short (3 minutes) and binned x 2 due to wind and poor seeing. Thanks for looking. http://www.pbase.com/dsantiago/image/159862427 Derek
  24. Hi 4X. Glad to see a new M Uno owner! I never need to recalibrate after starting a session. In fact, with the M Uno I get to sleep through my entire sessions To my recollection PHD suggests calibrating near the equator (dec 0), but I do fine calibrating on a star near my intended target. Good luck! If you haven't already, consider joining the Avalon Instruments Yahoo Users group. Derek
  25. Thanks much Mike. I browsed your website. Very impressive for someone new to astrophotogaphy. And wonderful photogaphs in general. Derek
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