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About billdan

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    Astronomy, Amateur Radio, Classical Guitar player
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    SE Queensland
  1. This is the backlash I'm getting with the Mesu 200 Mk1, which is very low. You may want to check your DEC balance and make sure its OK.
  2. The major problem you will have to resolve with the camera replacing the secondary is a method of accurately achieving focus. The Critical Focus Zone of a F5 newt is 70 microns and about 90 microns at F6. (The width of a human hair is about 100 microns). Focus is not a set once and forget about it, you have change focus as the temperature drops during the night. Also the Coma free zone of an F5 scope is only 3mm in diameter at the focal plane and about 5mm for F6. So you may be disappointed without a coma corrector attached. If you use a cooled camera, warm air will be pushed out by the TEC cooler fans making the seeing worse than it actually is. My advice, don't bother, stick to conventional. Cheers Bill
  3. Before you commit to buying one, get Lucas to give you all the measurements, just to make sure it will fit inside the Obs and you can still close the roof. Bill
  4. You may have an issue with height as well Davey, my garden shed (Obs) is 9' x 6 ' and 6' tall.
  5. I agree Davey, or at least still make available the original Mesu 200 for those of us who have an existing pier and looking to upgrade. I can't imagine many astronomers would want to dig out their piers to accommodate the new version. This new bended knee pier looks very tall, I don't think my roof in the Obs would be tall enough to use it. I'm glad I have the original Mesu 200 before it disappears.
  6. That should be OK, if the wedge an handle all the weight on top of it.
  7. It looks like the Mesu 200 Mk2 can only be used with the bended knee pier as it has no latitude adjusters.
  8. Looks like another clone of the ZWO-1600MC (now discontinued) or the QHY163C cameras.
  9. billdan


    A 3D printed rack and pinion focuser would be challenging, unless it was a hybrid using a brass rack and a brass pinion.
  10. Not sure what the answer is regarding the focal reducer, you would have to see its spec's to see what the entrance pupil has to be. It's a pity in our hobby we can't rent before we buy, it would make life a lot easier.
  11. Hi John, Your light cone expands at the rate of your F ratio. If you know the length of your drawtube you can work it out whether you will get vignetting. So with a 44mm diag sensor at F7, the light cone will be 10mm wider (54mm) at a distance of 70mm (70mm / 7) away from the sensor, and 20mm wider (64mm) at 140mm away from the sensor. As 2.5inches is 63.5mm wide, if the distance from the sensor to end of the drawtube is less than 140mm ( 5.5") you should be OK. Cheers Billl
  12. Hi Heine, Thanks for your advise about removing the dew shield etc, I will be buying the Kendrick secondary dew heater designed for this 80mm secondary mirror and I'll try the scope without the shroud as well. My concern with removing the shroud is light leakage when doing flats. I will try it first and see how the flats go. The HNA from Hubble Optics looks very promising going by their website, and the 14in F4 astrograph from Altair looks well constructed and designed for mounting on an EQ mount. Cheers Bill
  13. Don't mention anything about astronomy because they won't care. Instead tell them it's keeping you awake at night and you'll complain to the media if they don't shield it.
  14. Hi, I replaced my 8in Newt with a Skywatcher 14 inch f4.65 over Xmas. Its early days but so far everything performs as it did with the 8 inch on board. My guiding is around 0.4 arscecs and increases to 0.7 in bad seeing. The scope and accessories weighs 30Kg and I have 30kg of counterweights to compensate. Time will tell whether I keep it like this or go back to a smaller scope, mainly because a large aperture increases the effects of the seeing and it doesn't handle the wind very well. Cheers Bill
  15. I think the 2/3rds method only applies if you have a lot of field curvature. Like a Frac without a field flattener.
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