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buzz

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Everything posted by buzz

  1. I think the comparison is very close. The hyperstar is not really an interest to me at the moment - I would use one of my three refractors for that. I have found very different views on the ability of a GSO Truss RC to maintain its collimation after careful handling. I will be assembling / disassembling my rig each nightand and carefully storing the RC in an unheated building. Some views suggest it will be OK, but if left on the mount and others that the truss is rigid enough to not distort with handling. I have seen other views that suggest that 3 mirror supports are insufficient (especially in the 12" version) to prevent mirror pinching at all orientations. Certainly GSO did use 3 (judging from pictures from SGL forum posts) but I don't know if that is one of the improvements that GSO have made. I did talk to Altair - mentioned my concerns and that I would simply return the telescope if it does not work without continual collimation. They were not concerned, they have existing customers with temporary setups and said they were not aware of issues.
  2. The frequency is not a function of the LED, but of the power supply. I was thinking of a PWM controller with a frequency of about 25KHz. I have some LED's and shall do some experiments and report back.
  3. Has anyone tried one of these devices as a flat panel? Some run off 12V and could be dimmed with a simple PWM controller and seem to be bright enough. They are available in very large sizes, from about 500mm square. They seem to be bright enough but I do not know if the light is uniform. for example: http://gb.auroralighting.com/Products/Indoor-Luminaires/Commercial-Lighting/LED-Flat-Panels.aspx
  4. IKI checked with Altair - GSO have since revised the rear cell and say they have resolved all the issues on the 12" Truss RC. I think I will take a look at the 10" (Ian has them in stock) and then work out if the 12" will be just too heavy to lift into place each time I want to use it. Luckily the Paramount MX has a 41Kg payload, so this 20Kg scope is well within the normality limit. Graham - I tried the TIFF file, but had no luck. I am not certain but I think CCD inspector needs an image before stretching.
  5. Per - I have tried and given up on using Temperhum devices (with sequence generator pro). I'm not getting consistent results and their supplied drivers crash on my Win 7-64 bit platform. There also seems to be two distinct calibrations in an otherwise identical package, which throws it entirely. Some of the Arduino projects look promising - there is one with pressure, temperature and humidity and can take wind/light too. Is the intent to propose an Ascom interface?
  6. update: My friends report the issues from early 2014 have been fixed now. The firmware has moved on since last year and according to them they are tracking with either no guiding or minimal 'safety net' guiding. Judging from the forum, they are now going after even longer sub exposures, enabled with frequent weather and web based clock updates to account for atmospheric conditions and clock drift.
  7. I would not discount 10 Micron. The issues that I related to from 2013/14 are now history. The distributer did take my unit back and the firmware has moved on since. Operationally, those with difficulties similar to mine have resolved their issues to the extent that my colleague, who had to wait several months for a GM2000 to be replaced has just bought an additional GM3000 for his observatory. He wouldn't sink that kind of money into something if it did not perform. I'm happy with the MX and today, I would be happy with a 10Micron too, especially if I had a permanent setup which could make the most of its accuracy.
  8. Thanks Olly. I think this might be it...http://stargazerslounge.com/topic/187671-gso-12-rc-dissambly/ I know that the truss designs now have a revised backplate to alleviate the issues of the focuser hanging off the mirro assy. Adverts refer to a V2 design. I need to find out if these issues are post or pre 'fix'
  9. Yes Olly - I noticed the same. A google search does not find many images taken with Edge 11's, let alone compelling ones. I think the best RC images I found to date were the ones on IKI's site that he and Nik took. I think I'm leaning towards the RC - I might try some planetary but my aim is to image small galaxies and nebula. I passed on the used Edge 11 and you will see it on Astrobuysell in the near future. It belongs to a mate of mine and it has been kept in an indoor obsy and it is fully kitted out with moonlight focuser and accessories. He has just bought an Officina Stellare modified DK. Drool. I did some further digging into the effect of the central obstruction, the differences between the Edge and RC are not as significant as some adverts would leave one to believe. I might even stretch to the 12" RC. 20Kg is about my weight limit. The PMX can handle more, but I can't, trying to slide that into the dovetail every session.
  10. Thanks Graham - for some reason CCDInspector could not handle the JPEG. Could you send me a link to a full frame FITS file and I can measure it for you.
  11. Thanks Graham - I would be using this with a KAF8300 sensor - once you had good focus and collimation, did you get good flatness to the corners on your sensor? Olly - I will check out the Orion. thanks for that.
  12. Hi - I have just found a technical report with some scientific basis. A 10" f/8 RC is really a f/9 and apparently, even with theoretical perfect optics, has a diffraction limited resolution equivalent to a 5" refractor. This report also suggests that the baffles in the closed tube designs are better removed and replaced by black flocking and that the cooling fans need to be reversed in direction to reduce turbulence. Then there is the see-thru condition.... this report suggests a design that has not been fully thought out. I need to find something on the Edge rather than Celestron's blurb. http://interferometer-tests.blogspot.co.uk/2013/06/2542000-10-ritchey-chretien-gso.html
  13. I have a portable setup and my longest refractor is 916mm FL. I need something longer. I'm considering a new Altair Truss 10" RC or a used 11" Celestron Edge HD for about the same money. Both will have high quality motorized focusers on them. I'm imaging with a QSI 683 on a Paramount MX, so the peripherals are up to the task. The scope is stored outside, so it is approximately at the ambient temperature at all times. My initial investigations suggest the RC has the better imaging potential but I am concerned that I will be forever collimating it when I put the system together for a session. On the other hand, the Celestron is a closed tube, so more friendly to handle but with potential cool down issues. Any strong views on pros and cons to consider?
  14. Sorry - just seen the thread reply- you don't pull the knobs off! - they are held on by grubs crews. On the WO, (I don't know about the TS) you have to remove a grub screw on the baseplate to reveal a hole. You turn the knob until you see a second grub screw in the shaft of the knob. You completely remove this and the knob will slide off. If you just loosen it, the screw fouls the housing and the knob will not slide off.
  15. Here are the pictures of the final assembly. You can see the felt pads holding the tube over the existing dew shield. It is quite secure and will slide off when not required.
  16. Update - this scope continues to perform but the dew shield is just too short. I am getting flare from a street lamp so I decided to make my own. For £10, I fashioned something I'm rather please with. I bought a 100mm (4 inch) x 500mm white PVC tube - on Amazon and sold as a 'PVC round ducting for extractor fan'. I sawed off 200mm. I then got some sticky back felt - the sort used for putting under furniture legs for wooden floors, which is about 5mm deep. I sliced off slithers - 15mm x 5mm and stuck them on the inside at 120 degree intervals - 3 near one end and three in the middle. I painted the inside matt black (emulsion). I chose to stick the felt pads directly onto the plastic and paint round them as I was unsure if the pads would stick to the painted surface. The assembly eases over the original dew shield, held in place by the slight compression in the felt pads. This adds about 100mm to the original dew shield but not too much to vignette the off axis guider chip (you sight along the telescope and see what visually clips the sensor first) I can upload pictures if you want.
  17. For some reason 7 timer has been unreliable for some time. I have moved over to Scope Nights. Yes, it has annoyed some with its add-in costs but it consistently delivers the goods and is a tiny fraction of my overall outlay. I also correlate with Weather 14-day and Metcheck. The nice thing with Scope Nights is that it will notify you of a good night and its ranking can be tailored to your needs - ie. humidty, moon phase and wind values.
  18. I like it - that whole setup probably weighs less than one of my counterweights. I'm really intrigued - does the ball and socket come with the mount?
  19. It is not that difficult to make your own - all the modules (focus, USB over Cat5, hubs, dew heater and power conversion) are attached inside with Velcro, fused and fully customizable. The only cable running external to the Paramount and its Versaplate is the dew heater cable, to avoid any chance of interference. The box is an audio projects box off eBay. No metalwork required. It makes my setup a breeze, just 20 minutes including alignment to the beginning of the first exposure.
  20. Just seen this thread. Back to the original post - I actually own a MX and Skyfi. I tried to use my USB skyfi with my PC/MAC - but the prototcol would not work and I could not establish a connection. No luck from the SB forum to find a way through. You have to buy the WiSky adaptor for the ME/MX to be controlled via WiFi as far as I can tell. Having said that, - you can use your ME/ MX without a PC/Mac. You can use it with an ipad/iphone and the iOS version of TheSky. http://www.bisque.com/sc/shops/store/All+Products/Hot+Products/MK5KWiSky.aspx Interestingly my MX, in a portable setup, with an initial T-Point calibration and a 20 point re-cal on each occasion I re-assemble, is pointing and tracking more accurately than my 10 Micron 1000HPS did. I think the T-Point model is more robust. If I ever do just visuals, I'll get the WiSky - it avoids the trip hazzard of my comms cable.
  21. Actually - the Star 71 is just an ordinary lens - when it is in focus, it is at the optimum distance - just like a camera lens. All the elements move together, unlike a traditional field flattener that moves with the focuser. The 55mm distance is kind of irrelevant - if the camera happens to have it, the focuser will be 5mm extended to achieve focus. If it has 45mm, it will require 15 mm extended. Simplez I finally processed my image after acquiring some RGB last night. It is more or less there now. Stars are round and uniform to the edges and nice detail throughout.
  22. I looked for a 48mm to 1.25" adaptor and came up blank. You could use the t-thread adaptor and then fit a t-thread to 1.25" adaptor but I do not know if that would take up too much back focus. What is the distance from the sensor to the shoulder of the 1.25" nosepiece? I have a good solid T-thread to 1.25" adaptor which might work.
  23. Those corner shots look very good. I have been playing with the processing (still need another 5 hours OIII and RGB for the stars) It is amazing what you can get from narrowband, these are just sketches to evaluate different processing options in PixInsight. The main difference between them is one has pure green pixels replaced by neutral pixels (The SCNR tool in PI). Certainly some food for thought. (I applied LocalHistogramEqualization to the separate NB files to emphasize the structures before combining them into the RGB image.) The magenta stars will be replaced by RGB stars in the final version and the plane trail will also get removed with a different SD setting during image integration. I think if I get a more portable mount - this little scope will be a wonderful holiday package too.
  24. Paul , it appears to be 25mm from the back of the focus tube cylinder to the shoulder of the 48mm thread. There is a drawing on IKI website that shows the exact dimensions too I believe. I'm going to buy some stainless grubscrews and replace the nylon ones on the knurled ring on my model. By the way - have they increased the dewshield at all? The white bit on mine is about 100mm long.
  25. All I can say is that if you run the FITS file I posted earlier through CCDInspector, (using the ligher-weight cone shaped adaptor) the tilt is very slight and I could not detect anything in the star shapes. One of the other forums suggested that they were getting pinched stars, that they fixed by repositioning / slackening the tube rings. I took my scope apart and am puzzled by that remark since the main tube in the middle is not really connected to the optics, the optics are suspended inside an inner tube. Looking at the design, unless the optics themselves are not right (and this new adaptor allows WO to tweak the outcome in manufacture), the main source of tilt will be the focus mechanism. I could not detect play in my adaptor, only overall in the focus tube. With a little care, the two brass adjusters on the top can be tuned and the play is perfectly reasonable with my QSI 683 WSG on the end. If there is play in the focuser, it would not be the best solution to change the settings on the adaptor plate, as the play will change with pointing direction.
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