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  2. I feel I have a scope here that would help you no end a 180mm Mak by SW, sadly in rarely gets used at all now shame I am not in the UK it would be a great scope for you. Alan
  3. Result! So it was just that the big nut was a little over tight then. I'm sure it will be fine now, but I wish you all the best for when you get it out under the stars.
  4. As usual on a project, not much happens at the start, while we think about what to do and organise all the stuff... Then the bits arrive and little happens for a while, then things happen quickly and progress looks amazing... Then the big stuff is up and the fiddly, technical bits have to be done... The last couple of days I have poured the extra height for the pier base and connected some of the electrics. The warm room now powers both domes and I am close to completing the second dome controls. Stuck on the first dome as I can't really progress until the concrete hardens enough to drill it out for the new pier studs. I knocked off the shuttering and the base does look pretty good. I am missing the big vibrator the builder used to get the air out of the concrete, but did my best. The second dome only needs the motors to be installed and connect the ethernet cables (still need to terminate the cables...) and the PC, install software and test. But having neglected the garden (2 acres in total) I need to catch up a bit there too so I am guessing another week. We have 2 weeks of clouds and rain forecast, so no hurry. I am a believer in the theory of new stuff = clouds so I am bracing myself for a terrible summer in SW France and everyone can blame me... Gordon.
  5. hmm so as the sky is clearing, the focus might not be soo bad as the v high cloud looks reasonably sharp compared to the dark low clouds when I first fitted this version up. Some flare from the sun hitting the lens plus a reflection off the lens onto the dome but there's not a lot that can be done there - not like I can fit a lens hood on a v wide angle lens under the dome after all No doubt the flare and reflection might worsen once the wider 150-180 lenses arrive which may well be later this week as they're in the country already and the 5MP board is imminently departing china on its way here too. Light rain earlier hasn't affected the rig and so far being toasted by the sun its still working fine too. The black dome structure the module fits to is metal so could be a double-edged sword tho, shunting heat away from the module but also getting hot from direct sun and cooking it. hmmm will have to see how that goes over summer as temps rise...
  6. Thanks John. Not trying to be picky, just dont want people thinking they can see it at low power! I've seen it in my 4" on a good night so with good seeing I should think a 130 could do it, providing well cooled and collimated. Nice shot btw
  7. There's a bunch of trees to the south that rise to 15° above horizontal so I would really wants planets to be above that.
  8. All gone quiet again, after the excitement of two active regions at once.
  9. Give it a try. I have found though that budget camera = budget results. Start with the Moon. It is harder to get a target on-chip and in focus than you are probably expecting. Sounds like snake oil. Nebulae usually look monochrome to the eye but colour shows up in a colour photograph. M82 looks lurid in many images but to a visual observer is just a faint grey bar.
  10. I'm looking to sell my Zenithstar 66ED petzval which I now rarely use. It was bought in 2005 from Ian Kind Imaging and has spent a lot of that time in storage. I've recently used it as a guide scope. It comes in a padded carry case which is very portable and light. Looking for £150 which includes royal mail insured delivery.
  11. Anyone got one they are not using. Possible part ex for AZ Gti head. Thanks
  12. I guess that is true if you live in Sweden. It is not so bad from the southern UK but still not great, with Jupiter currently at an altitude of 15 deg or less. An ADC is really essential for planets at an altitude of 15 deg or so. At least one can get one's kit together and practice the techniques while waiting for a better opposition. I expect he's right. My results with a C8 usually seem limited by poor seeing.
  13. Hi Peter, I think one resistor will be fine - perhaps Alan could confirm that? Do you have a multimeter with an ohms range? If you do, you can check to see if there is a suitable resistor already fitted on the relay board. With the board not connected to anything else, measure the resistance between IN1+ and IN1- with the red multimeter lead connected to IN1+. Then swap the meter leads over and measure again. If one reading is a few thousand ohms and the other very high then there is a suitable resistor on the relay board and you don't need an external one. Just connect all the IN+ terminals to your 12 volt supply. If you don't have a multimeter I do recommend you get one - it will be really useful when you build your dome driver. This one from Amazon looks OK and not too expensive. https://www.amazon.co.uk/Pocket-Digital-Multimeter-Ranging-Multimeters/dp/B015Z451ZY/ref=sr_1_9?crid=2TO2WULPN4THF&keywords=multimeter+tester&qid=1558353050&s=gateway&sprefix=multimeter%2Caps%2C188&sr=8-9 HTH, Regards, Hugh
  14. It won't be as effective as you hope, I'm afraid. As Gina said, the luminance channel will not be parfocal with itself across the spectrum it covers so stars, in particular, will be bloated and soft. Also, your thinking would probably be sound so far as red and green are concerned but blue would almost certainly be a disaster. The short wavelengths of the blue end of the spectrum are the hardest for the opticians to control, the more so as they head towards violet. The bandpass of a blue filter is wide enough to pass a range of wavelengths coming to very significantly different focal points so the blue channel would be soft and bloated, probably with large blue halos. Again, as Gina said, you might find that your theory would work for narrowband imaging because the NB filters are more nearly monochromatic and so effectively exclude all but parfocal rays. In theory, at least, you might also need to use a program which not only aligned your three channels but which resized two of them to match a third because a major refocus might have a perceptible effect on image scale. Whether it would be significant or not I don't know. I began imaging with a very early TV Genesis corrected for visual use in the pre-CCD era. It gave predictably bloated blue and L stars but was excellent in NB where it was as tight as the Tak FSQ which replaced it. Also Ha/OIII/SII imaging keeps well away from the problem blue end of the spectrum. Olly
  15. Just for completeness - look up parsec as unit of measure, it is about 3.26 light years and it represents distance that produces PARallax of one arc SECond. Amateurs can determine stellar position down to about 0.05" (and in some cases even less) which means that even with small amateur scopes, parallax distance measurements up to ~20pc or about 65ly are possible.
  16. Thanks for the camera settings. Evidently the ASI224MC + IR850 filter does have significant sensitivity in the infrared, but less than in the visible region. The Sun emits a lot of energy in the infrared - around 50% of the total output. However I found a spectrum of Jupiter: https://darklondonskies.com/2015/04/15/first-spectra-methane-on-jupiter/ which indicates that the amount of light reflected/emitted from Jupiter in the IR850 band is much lower than at 550nm. So taking these together, there seems ample explanation for my IR exposures being 10x longer.
  17. Hi, Can someone who owns this mount please post a side view with the arm angle in the upright setting as I'm curious to see how close to vertical it can get. Currently I'm using a GSO Skyview with the arm set to vertical, which is fine for the C5 riding on it, but the mount is showing its age and I fancy an upgrade. The angle is important as I use my C5 on a small balcony and I find with the Skyview arm at 45º I don't have enough room to get comfortably behind the eyepiece.
  18. Yes, for that reason I'm not in any hurry. In any case I have a lot of other things I want to do. OTOH this could be a good time to buy a secondhand scope. Alternatively, I could simply try a 3x Barlow with my MN190. Of course, a C925 should give a significant increase in photons collected.
  19. Done... One last hurdle to overcome, and where the pins of the old hardware were removed, as the threaded holes of the lock-nuts rose above the ends of the screws... What to do about that? Where there's a will there's a way. I simply ground down one of the six flat sides of the lock-nut until it lowered into position... Also, the diameters of the screws' heads required reducing, and to clear the surface of the braces as they slid into place. You can see there on the right where the paint had been scratched before. Gone is that ubiquitous slack and slop that plagued these older mounts(the current ones as well), and right up to the eyepiece of a telescope... The lock-nut for the larger screw is a good bit thicker. I couldn't find jam-type lock-nuts for that size, only for the smaller as seen. They are available online however; perhaps one day. Lock-washers instead of flat-washers were integrated with the lock-nuts, and for peace of mind. Done...
  20. Today
  21. I am the 3rd owner, and the previous owner said nothing about a warranty. Before dismantling, I noted that so far as I could see there was clearance for the fork assembly to spin on the fixed base, if the latter was placed on a flat surface with the AZ clutch loose. But it wouldn't. I dismantled the assembly following the Nexstarsite pdf. When I got as far as loosening the big nut by a fraction of a turn, I tried the rotation and found that it now moved freely. I continued dismantling and found the specified number of nylon balls, looking clean and lubricated with a light grease. So I reassembled everything, leaving the big nut slack enough so that the base would spin a little way under its own inertia - I tightened it and then backed it off by about 1/6 turn. No evident play. I didn't renew the Loctite, figuring that these parts seemed stiff enough not to undo themselves anytime soon. With the cover on, I connected handset and power, giving it a spin at max speed. It sounds better - will have to see how it performs when imaging.
  22. It holds Starguiders well but I never became friends with it For what you want I feel Baader zoom would be much better.
  23. It would be helpful if you would expand on your question - why do you want it answered, what sort of explanation are you hoping for, etc ... As it is now, it just looks like homework assignment that you need help with, and that is also fine, but it would be much better if you did say that you need help with that sort of thing. From your post, one could possibly conclude that it's a "pop quiz" for members, or something like that, and I'm not sure how many will be willing to participate. On the other hand, I'm almost certain that people will be willing to help if you explain it and ask nicely.
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