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jonstarrysky

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About jonstarrysky

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    Star Forming

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    East Herts
  1. Sounding OK so far..... tonight looks to be clear, my friend will be up for that (same pitch). I'll be coming up Friday hoping that the weekend forecasts are actually fibbing. Sunday night forecast looks bit better.
  2. I'm hoping to go up Friday (pitch T352, roughly mid/ upper in the Red area) for some visual observing with a dob. Fingers crossed for the forecast improving a bit !
  3. Or use the Sony A7 SLR camera, which has an hdmi video output....
  4. So looks as I thought: modern video astronomy cameras work exclusively via USB and necessitate a laptop to see live images. Stacking requires software. My own preference would be for a mallincam type camera where stacking and basic image improvements can done on the fly, within the camera electronics. Camera goes direct to monitor. As stated these use old CCTV technology, and unfortunately will lag behind modern video cameras using the latest chips etc
  5. I have an old analogue watec which connects direct to a monitor via a composite video-out socket. My monitor can also take HMDI. I have absolutely no interest in using a laptop or capturing digital images. Live viewing is all I want. Am I correct in saying literally all modern digital video astronomy cameras necessitate a laptop these days? Why don't they have at least an HMDI output as well as USB???
  6. Nice report Helix and great to see some more big dob visual action at Kelling ! That night was special. I need to write up what I saw with the 18" Webster. Certainly got my dose of galaxies, using Argo to rapidly tour dozens of NGC galaxies to the South. Was useful to compare and see which ones stand out (many of the small/dim ones look similar). I guess the winner, probably surpassing M51 and its obvious spiral arms, was NGC4565 - so big, filled the field in my 13Ethos. Greatly elongated edge-on shape + dust lane was stunning. Much better than under my normal light polluted skies. Did you see M5 ? This was stunning, almost as good as M13. It was the first time I saw the M57 central star visually without doubt. At this time is was approaching dawn, I guess with moments of good seeing. To my eyes, a tiny diamond of a star fleetingly appeared, bang in the center of the ring, several times.
  7. Yeah, I liked the un-obscured southern horizon. In summer will be possible to delve down into Sagittarius: Lagoon, Trifid and maybe lower still .....Will be murky, but more transparent than houses and trees ;-) That light was SSW; blocking with cars would be dependent on exact location of scopes and risks blocking good areas of the sky nearby? Wonder if the owner is amenable to tweaking its direction (wishful thinking) ?? Re. the approach, maybe driving up the track with side-lights on is OK, till you get near the hard-standing ?....Be good to know the thinking of folks who frequent this spot; attitudes towards this kind of thing can vary.....
  8. Hi folks, just to clarify, I was at Kelling and know of several folks with stuff going missing this time. This was theft, there is no other viable explanation. Lets forget about dogs or stuff blowing away in the wind, or being mislaid, forgetful owners etc. Not great for the victims to hear this....On no previous Kelling that I went to has a single piece of kit gone missing under suspicious circumstances to my knowledge. And our pitch was scoured afterwards. The thief(s) had a propensity to lift low value items which is odd. As Paul suggests, perhaps local kids doing nuisance. Someone with some other motive other than simply for profit. Our pitch had two planispheres taken amongst other low value gear. You cant by accident just lose two planispheres....The folks I go stargazing with - trips like Kelling -we are careful, we simply don't lose stuff, not even a loose screw or a tent peg.....but this time was different.....
  9. That's all very interesting. But instead I will talk about the Watec camera..... Only kidding... good luck with the project. Don't see the attraction myself. The secondary mirror does a very good job of bringing the focal plane out the way of incoming light, so you can put as much clobber there as you wish and its not casting a shadow. Regarding getting rid of the secondary, quoting Suitor: "as long as the obstruction is kept inside that fraction [20-25%], the image closely approximates that of an unobstructed telescope." And a camera might well weigh more than a secondary mirror. I know of someone who has the kind of setup you refer to. Hoping to take a trip to see his obs sometime, will be interesting how it works out in practise...
  10. Seems an obvious gap in the market. The Mallincam Universe has a 1.12" chip (28.4 mm). http://mallincam.tripod.com/id56.html Claims magazine quality images from live view. But no analogue output for a slimmed-down pure "electronically assisted" visual approach.
  11. Talking pure video astronomy (camera analogue output fed direct to AV input of monitor), it seems these vid cameras are based on CCTV units. These typically have small 1/2" or 1/3" chips. Means equilavence to a 6mm eyepiece i.e. narrow field. Contrast that with full blown CCD imaging or dSLR, with their huge chips and big fields. So has no one developed an astro video camera with a big chip ? Mallincam have their "Universe" that does this. But ....that looks more like an imaging decide for me. Only USB output, and laptop is essential... Seems like to get the big field, you are forced down the digital route.....
  12. thanks Macavity, Good point about capture being asynchronous....Just noticed they do a cheap USB capture dongle at Modern Astronomy. Might be useful for evaluating tweaks and kit options (eg comparing filters and focal reducers) when it's cloudy...
  13. So some interesting feedback re focal reducers. Indeed autocollimation is the way to go for alignment accuracy. I'll be using a Catsete XLK infinity. My Servo-CAT 18" scope with the Watec will be an interesting experiment then..... The 18" will also have a new quartz primary mirror in a few months (of no relevance here, but I just cant wait for that !!!) OK, so equivalence to 6mm eyepiece is really pushing it. Technically and the kind of target objects. It the tracking is up to it, potentially awasome. But I can see my piggybacked 4.5" f/4 Newt getting most of the Watec action, as a worst case. Visual on the 18" and monitor on the piggyback 4.5".... I have several reducers to play with. One from modern astronomy, and two from Mallincam with variable spacers: MFR-3 and MFR-6. The MFR-3 is supposed to be ideal for Newts. And MFR-6 has a modest reduction ratio (0.7x I think). I plan to incrementally increase the redution factor till either there are image quality issues or .....I run out of in-focus. I asked for an inch longer FL for the new primary mirror, so will have more in-focus to spare (focus position moved out by an inch). And I bought a 1.25"-2" camara adapter that in effect buys some in-focus vs using a normal 1.25"-2" focusser adapter - the camera body goes flush against the 2" focusser drawtube opening. See http://mallincam.tripod.com/sitebuildercontent/sitebuilderpictures/2inchadapter.jpg I guess an image capture device may be called for at some point to document some of the results.... (not that imaging is the prime objective).
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