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long_arms

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Everything posted by long_arms

  1. Ha I did google this out of interest, all those crushing/bending penny machines at tourist destinations springs to mind. Can't believe its enforced. However to remove any doubt, it was only paint. I have now cleaned the 20p clean and the Queen looks as good as ever! No tower for me just yet.
  2. Small splodge opposite the focuser of the 200p dobsonian. Pointed at a light source to attempt to illuminate it. The inside of the telescope seems very black until I illuminate it like this. Interestingly I can find an angle where the paint appears "lighter" than this. Its hard to get a photo of.
  3. I've seen mixed things about Black 2.0, apparently it had the usual tendency of getting slightly lighter as it dried. The video I posted shows comparison between Black 2.0 and Black 3.0 quite well I think. From this article: https://www.fastcompany.com/90300113/move-over-vantablack-you-can-now-buy-the-worlds-blackest-black-paint "His first version, Black 2.0, wasn’t quite as black as Vantablack, since it only absorbed 95% of the visible light (Vantablack absorbs about 99%). Now, Black 3.0 is out and available on Kickstarter for about $32 per 150ml tube. According to Semple, it is the blackest, mattest, flattest acrylic paint available on the planet, capturing up to 99% of all the visible spectrum radiation. The paint is based on a new pigment called Black Magick, whose exact composition they aren’t disclosing. Black 3.0 is made up of this pigment, combined with a custom acrylic polymer. Semple and his colleagues claim that the polymer “is special because it has more available bonds than any other acrylic polymer being used in paints,” allowing more pigment density. The paint is then finished with what they claim are new “nano-mattifiers,” which remove any shine from the paint. Unlike Vantablack, the resulting paint is soluble in water and nontoxic" Thankyou for your feedback on flaking! Before I paint the drawtube I will certainly check this out. ?
  4. This is a good shout, I have an IR742 Pass filter somewhere, I'll try and get a photo through that. The small amount of dried paint on paper, is now making everything I can find look positively gray!! I'll see how easily it flakes when its dried on the steel tube of the telescope.
  5. Tried to think of a fun quick test to document this afternoon, previous little tester on less metallic object is unbelievable to be honest. So, very shiny coin with grazing light and lit from above also. Whilst drying, as you can see its a thin single coat (not simply "filling" in the shape) Finally, even on a challenging shiny object with light shining on it, it makes it essentially 2D.
  6. Hello, It's been a long time since I've posted in this forum, anyway I've picked up a Skywatcher 200p F/6 dobsonian as a DIY project whilst I continue to work on a new telescope from scratch, (I've started to grind the mirror). I'll be making improvements to this dobsonian as a project and learning experience, I've already got a temperature controlled fan which has a probe that can measure both mirror and ambient temperature. I'll be measuring the primary mirror with my in progress Foucault/Ronchi/Bath Tester when that's finished in the next couple of weeks, may even refigure it depending on results. But I'm most excited about this right now. The blackest Black Paint as an alternative (hopefully better alternative) to flocking! This stuff is seriously black and flat, I backed it on kickstarter and received 3 bottles along with goodies. I plan on painting the area opposite the focuser, area around the primary mirror, inside the focuser drawtube, potentially the secondary mirror holder and edge of the secondary also. It's a shame I don't have any flocking to compare it with but it looks incredible. This video shows just how impressive it is (moreso than my little tester I've done). https://www.youtube.com/watch?v=uJIIzcbRD9w I'll try and get some decent before and after pics. Dan
  7. I need to stop. But I couldn't resist. Last one I swear. This one is of Mr Percy Wilkins and his amazing hand drawn maps of the moon from 1953. Never heard of him but now I have to find his maps.
  8. The British Pathe Youtube channel is incredible. You could quite easily lose a few hours trapped there watching old videos. If you search for telescope or astronomy there alone it comes up with dozens of archived footage. I won't post them all. Here's a bloke in 1942 with his homemade 14" Newt. Even made the screws !! Thats keen. Is it the Earliest footage of amateur astrophotography?
  9. I managed to stumble onto this old film from 1960 on Youtube. It seems "Cox, hargreaves and Thomson Limited" used to grind mirrors in an old air raid shelter ! Funny film. I was curious and found this website about the tunnels! http://thetimechamber.co.uk/beta/sites/deep-shelters-air-raid-shelters/coulsdon-deep-shelter-surrey Be good if one day some ATMs get permission from the council to use them for the same purpose again.
  10. Hello, Unlike me, there are some real experts on this forum and I hope they respond to this thread . I will however, throw in my 2 cents in the meantime. I could be wrong, but the massive difference in the airy disk inside and outside of focus is normally a pretty good indication of spherical aberration. In this case youve got very strong rings inside of focus and for want of a better word; mush, outside of focus. This surely indicates Undercorrected Spherical Aberration. Dan
  11. No problem ! The Normalize Histogram is actually quite useful for finding the best exposure settings to be fair. You can play with gain, shutter speed, exposure etc. I.e Sacrifice some gain for a higher frame rate and compare against regular settings easily because the brightness of the two stacks will be the same.
  12. The 'Normalize stack' setting on the Stack Options side of the main window. Just below the 'Frame Percentage to Stack'. I check this and adjust the percentage to whatever brightness I'm after. Dan
  13. My camera came today also No duty to pay either which was great. Works well with my laptop. It doesn't come with a suitable lens (presumably because of the larger sensor) so I have only been able to see a dark frame (The CS lens that comes with the ASI120's won't focus). First impressions are extremely low noise even with the gain pushed to the max. Certainly seems better in this respect compared to the ASI120's. Finally however it does seem to get warm quite quickly regardless of settings. Sure its nothing to worry about just something I noticed. Dan
  14. I already have the ASI120MC-S and with my relatively new USB 3.0 laptop I have gotten some pretty great frame rates. The bottleneck imo is the Hard disk though. At the end of the day would I get this camera if it was USB2.0? Yes. Definitely glad its USB 3.0 though for those ISS chasing moments ! With regard to deep sky. I took this with my ASI120MM+colour filters. Unguided. Lots of short frames. Through my 200p/heq5. I think it worked quite well. Guided would be better but my guide camera was taking the light frames I reckon the ASI174 will be much better for deep sky so I'll no doubt give it a go. Dan
  15. I ordered one yesterday For me at least, this looks like the camera to beat for Lunar. I'm also hoping to enter the scary, bright world of Solar so I hope its good for that also I know its kind of a niche, but another big strength for this camera will be closeup images of the ISS. I love chasing it myself! Extremely short shutter speeds allows you to make the most of the extreme frame-rates! The ASI120 was good but its not easy with a 1/3" sensor! Much easier to get the ISS on the bigger sensor = loooads more frames + Higher frame rate. Global shutter may help as well. No downsides? Slightly bigger pixels maybe, not an issue imo. Here's an example of what I got with the ASI120. I used a 200p with its stock 2x barlow and around 3ms shutter speed (hence ability to make the most of the ASI174MM frame rates)
  16. Just ordered the brand new ZWO ASI174MM!

  17. Hello, I give in . Looking towards the summer and the amazing h-alpha images on this forum I've decided to invest in a Solar setup. Firstly to be clear...I am purely interested in high resolution imaging of the Sun. Don't care about full disk etc. I've seen some amazing images with the Quark but equally so with a PST Mod. I was leaning towards the latter, partly because I don't like the sound of the 4.2x barlow. But then the quark is probably cheaper and a lot easier. Aaaargh Would a Quark and a SW 150mm f/5 go well together maybe? Better results than a Tal 100rs + Pst mod? I would love some opinions and help! Many thanks, Dan
  18. Hello , I'm starting to plan my first mirror grind/telescope build and I fancy buying some bits (focuser/fans etc) early to keep me motivated. I want to have a good focuser. But I had my heart set on a good Rack and Pinion. Does anyone know if one exists for a Newtonian? The 2.5" feathertouches can't be mounted on one can they? I was looking at this but I can't see a suitable adapter for it...http://www.starlightinstruments.com/store/index.php?route=product/product&path=36&product_id=61 If I go with a crayford, is the Feathertouch actually the better focuser.... or should I get a Moonlite? Love to hear some opinions! Thanks, Dan
  19. Sounds like the First stage certainly made it onto the Barge. Unfortunately the landing was too hard. Not that it matters this time, incredible that they returned it and hit a relatively small target! Future is here. Elon live tweets the launches so delivered the 1st stage news there. https://twitter.com/elonmusk/status/553855109114101760 and https://twitter.com/elonmusk/status/553857574005915648
  20. Hello, My ASI120MM doesnt like my new laptop. Had to use ASI120MC-S. I'll be buying the new mono version now. USB 3.0 comes into its own on the moon...full resolution at 60fps is great! Anyway these were all with my 8 inch newt. (SW200p), Revelation 2.5 & ASI120MC-S. All images converted to mono. Trio of craters with fancy sounding names like Arzachel etc... Sunrise at Maginus. Dramatic shadows coming from the peaks of Montes Apenninus. Always like to imagine what the view must be like from the edge of one. Someone on twitter pointed out that I'd picked up Rima Hadley Rille from Apollo 15! Over the um Sun to get that with my telescope . Finally the customary view across the Southern Highlands. It was a good night Clear skies, Dan
  21. Hello, Tonight I had my first attempt at the ISS with my new camera (and laptop). I've taken images before but with the ASI120MM. I fancied colour and USB 3.0. It took 16,000 frames in around 200 seconds ! I definitely need a new barlow, thinking of either the posh celestron 2x or similar. The next big jump will be with the new telescope I'm going to make though. SW200p. Stock SW 2x barlow. ASI120MC-S. Manually tracked. Thanks, Dan
  22. Answered my own question. Learnt something new today haha. From Wikipedia "The European manufacturer of Pyrex, Arc International, uses borosilicate glass in its Pyrex glass kitchen products however, the U.S. manufacturer of Pyrex kitchenware uses tempered soda lime glass."
  23. I've contacted this supplier after finding a recommendation for them on here. http://www.stathis-firstlight.de/spiegelschleifen/materialeng.htm As far as Pyrex goes, this is what I meant. If the supplier uses the name "Pyrex" surely it must be glass produced by World Kitchen LLC? "For decades, Pyrex was made of borosilicate glass, a special type of glass in which boron oxide is added to the mix. The added boron allows Pyrex to handle heat much better than typical glass, so Pyrex is commonly found in kitchens, laboratories, and in use with aquarium heaters (as the heaters are, necessarily, submerged in much cooler water). But in 1998, Corning, the company which made Pyrex, sold the brand to World Kitchen LLC. World Kitchen decided to stop the manufacture of borosilicate glass, and since then, Pyrex sold in the United States is made of tempered soda-lime glass, which does not handle heat as well as borosilicate glass does." Taken from here. http://nowiknow.com/the-war-against-pyrex/ Food for thought if buying a "Pyrex" branded mirror blank surely? Dan
  24. Hello, Looking for a 12" mirror blank. I originally wanted to splash out on quartz but this is seemingly impossible. So looking for other low expansion materials. Simply put, why is a Borosilicate blank from here £268. http://www.galvoptics.fsnet.co.uk/telescope3.htm But a "Pyrex" blank from here only £75? http://www.scientificmirrors.co.uk/Telescope%20Making%20Supplies.html Is one better than the other? I read somewhere that the "new" pyrex doesnt have the same thermal characteristics it used to. Many thanks, Dan
  25. ASI120MC-S arrived! Now just need to choose a USB 3.0 laptop before the next lot of ISS passes....

    1. HIP3802

      HIP3802

      Before choosing a laptop make sure the camera can take USB 3. I had to return an ASI 120 earlier in the year as it was not compatible (at all!!!) with USB3.

      HTH.

      Martin

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