Jump to content



  • Posts

  • Joined

  • Last visited

Everything posted by Dangerous-Dave

  1. Thanks for this, saved me from posting my CCD back to Starlight Xpress for a clean and reseal. Distance = 7.4 x 4 x 36 = 1065mm = on the primary!
  2. Uffington NT car park has a reputation for other uses!
  3. Belated headsup for this event. Durham Astro Soc will be holding a public meeting at Rainton Meadows Nature Reserve, Houghton Le Spring on Saturday evening (19:00-21:00). The theme is Jupiter, but there will be a dichotomy moon too. Weather forecast looks OK. Free with voluntary donations to the society. Feel free to bring a telescope.
  4. Hi Robin, how bad is your light pollution? I could just about make out the auroral arc over the streetlights, but we are on the edge of the Tyne & Wear light pollution and have a good northern horizon.
  5. Fantastic display last night! The Kp was only '4 - unsettled' but there was a strong southerly Bz, and I thought I could just make out an auroral arc over the light pollution in our street, so quickly got in the car and drove up to the North Pennine AONB. Initially all I could detect were two strips of green ionized Oxygen along the northern horizon. Admittedly this is pretty darn good for 55N, but at 8.30pm this errupted into pillars of red, at one point the whole ensemble resembling a crown of thorns, with colours easily visible to the naked eye. I then relocated to a darker location up in the wilds near Blanchland and was rewarded with more activity at 10.00pm! All shots taken with EOS30D, Samyang 14mm/f2.8 and 8mm/f3.5, I hope I haven't used up all my astro luck last night!
  6. Derwent Reservoir Broccolitia, Cawfields, Walltown Crags on Hadrian's Wall The coast north of Blyth Anywhere in Northumberland National Park! Kielder Forest
  7. Thanks, that doesn't bode well! Does the flattener include any micro adjuster to assist in this? Thanks DD
  8. Wow, surely not just me who sees flaws in star shapes and CA there? I have been imaging for nearly 10 years and that CA looks as bad as achromat Takumar SMC lenses I have used (not a criticism of the imager I hasten to add). Any thoughts Per?
  9. Any news regarding vendors?. I am too poorly to kip in a tent ATM but have need of some nicknacks
  10. BUMP! Anyone tried the new WO Flattener 6 with the Megrez 72? Being largely unimpressed with reviews of and images from TS apos I have decided to Guide with an OAG and use my Megrez 72 'guide scope' for wide field imaging. I used to own the MkIII flattener but was unimpressed, like others I found the stars misshapen even at the correct spacing. Thanks DD
  11. Hi per, thanks for the review. I have been considering buying the TS 100/f5.8 or 130/5.2. Looking at your pics there are two things that might concern me: a. brighter stars seem a little diamond shaped. I get this with my R200SS, but this is a Newtonian! Is there anything causing diffraction in your image chain? b. some noticeable red halos - possible CA?
  12. Thanks for that folks. Yes, the brand is pretty much an unknown quantity. Not that I would buy any scope without extensively reading forums and reviews first, but you can buy a scope badged Takahashi with some confidence. Although I do feel the 580mm focal length of the TS100 is about as low as I'd want to go with my CCD (SXVF-H16), the FSQ is not much less than that. With regards 49mm image circle, IIRC I am currently getting that from my R200SS and it covers my 4000 chip fine.
  13. Hi folks, does anyone have any opinions on the TS 100mm quadruplet? http://www.teleskop-express.de/shop/product_info.php/language/en/info/p6478_TS-100mm-f-5-8-Quadruplet-APO-Astrograph---FPL-53-APO-Objektiv---100-580mm.html The 65mm counterpart seems to get rave reviews from owners, albeit after issues with pinched optics in earlier models, but I am struggling to find any impartial comment whatsoever on the 100mm. Am I right in thinking 'TS Optics' are made by APM, or is that wishful thinking on my part? thanks DD
  14. Many thanks to you all for your replies. I get a sense that for image quality inch for inch the apo is a no brainer but the jury is out on the light grab issue.The issue of mirror degradation is an interesting one, are we referring to deterioration of the silvering or general build up of grime?
  15. Hi all, does anyone know of a formula to convert obstructed Newtonian aperture to the equivalent unobstructed refractor equivalent? I know my Vixen R200SS has an aperture of 200mm, 800mm focal length and a 37% obstruction. Using pi-r-squared, and deducting 37 percent for the obstruction, the surface area equates to an unobstructed circle of diameter 160mm. Is it a fair assumption, therefore, that a 160mm f5 refractor would have the same resolving power, light grab, field size and contrast as my 200mm f4 Newtonian (assuming both are perfectly collimated and have equivalent quality optics)? Or are there efficiency differences in the two designs to take into account? The reason I ask is I am considering trading in my R200SS and switching to an apo quadruplet, but I do not want to sacrifice f speed as the quantum efficiency of my CCD camera is not that great. Would my exposures need to be considerably longer using the same camera on a 100mm/f5.8 refractor? Thanks
  16. Got one of these too but never worked it out, bit odd the company did not include instructions. I am not sure how you are supposed to make Dec corrections when there is no motor on that axis.
  17. Thanks John. I saw that wiki page but wasn't sure which Hasselblad mount it referred to - there are quite a few, as this page shows http://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html.
  18. Thanks stephen, it is very much second hand (probably over 10 years old!)
  19. Hi folks, does anyone know where I can source a new controller board for the old style EQ6 synscan? I believe OVL used to sell these in the past, but couldn't find them on their website. Thanks!
  20. As I say, I think you may find the SMC's have a lot of CA in the blue channel. Leitz 180mm Telyt apo gives excellent bang for buck for DSLR users. A bit blunt at f3.4 but nice results stopped down to f4 - I use a mask screwed to the filter thread.to avoid iris diff spikes.
  21. Stunning pics Dave, especially of the bat nebula. Your imaging has improved loads (was pretty good to start with). Out of interes, what is the register (flange to chip distance) on the Hasselblad FE 250?
  22. I used Pentax 6x7 lenses with my SXV-H9 for a while and was pleased with the results. Stick to narrowband though, unless you can afford the 3 grand+ for the EDIF, the SMC lenses have too much CA for LRGB. Regarding lenses, I would pretty much agree with dave w, I found the 300mm/f4 and 165mm/f2.8 best. Avoid using AStronomik narrowband filters though, even the 'halo free' produce reflections when used withentax 6x7 lenses. There are examples on my Flicker page http://www.flickr.com/photos/dangerous_astro/. Select Deep Sky set and scroll back to 2010. Also pics of the lens set ups in the equipment set.
  23. Lovely shot, I caught the cat paw in a widefield from SW France the other year, but it was a real horizon scraper.
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.