Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.



Advanced Members
  • Content Count

  • Joined

  • Last visited

Community Reputation

1,846 Excellent

About Thalestris24

  • Rank
    Main Sequence

Profile Information

  • Gender
  • Location
  1. Thalestris24

    Polar alignment questions

    Hi The Synscan hand controller has a routine for doing Polar Alignment without needing to be able to see Polaris. Drift alignment is another option if you can see either east or west, and south. I for one can only see east so point the mount north with the aid of a true north compass app. Then I drift align to the east using phd2's drift align tool and adjust alt. It doesn't matter if my Az is out slightly since I'm imaging to the east and a small az error doesn't cause a problem. If you can keep your focal length short and your exposures short, PA errors are less of an issue. The new-ish cmos cameras encourage you take lots of short exposures rather than a relatively few long ones (I must get one!). Louise
  2. Thalestris24

    Anyone tried eyepiece projection for EAA?

    OK - that's a lot clearer now - on both accounts . So I was doing the prime focus configuration Since the interest is in using the EP as a reducer, there doesn't seem much point in trying the 'proper' EP configuration, unless there's something exciting about it?? I think using a simple convex lens in place of the EP might give a better result with the prime focus config but might introduce some chromatic aberration. I'll have a go tomorrow if I can find the time and can rig something up - sticky tape and cardboard tubes, probably ha ha. Louise
  3. I think it's microlens diffraction - a known problem with the 1600 https://www.cloudynights.com/topic/556795-reflection-around-big-stars/ Louise
  4. Should be just SW of 36 Tau just now
  5. Thalestris24

    Anyone tried eyepiece projection for EAA?

    I'm still a bit confused! My 800mm scope is still 800mm between the objective and the camera sensor even though I have a reducer in between. Obviously, the distance between the reducer and sensor is fixed at the 'standard' 55mm. Am I right in thinking the change in physical focal length is small, which is why it's not obvious to me? Back to the EP experiments... : The eyepiece projection I did was from inside the normal focal length of the ST80. As I say, that is 400mm but I focused at ~343mm with the EP in. I'm not sure which configuration that is? I suppose your original post, second configuration has the EP further away than the normal focal point? And that gives the longer distance to the sensor? Louise
  6. Thalestris24

    Anyone tried eyepiece projection for EAA?

    Hi Vlaiv I had a play around with my ST80 and 5Mp microscope camera. I found I could get a real focus point with a 20mm EP and the focus tube racked in as far as it would go. The ST80 normally has a focal length of 400mm and aperture 80mm i.e. f-ratio = 5. With the EP in place the focal length was about 343mm, so f-ratio = about 4.3. I only had the camera (loosely!) connected via a cardboard tube so getting (and keeping) focus wasn't easy. I managed to take a couple of snapshots using SharpCap. The problem is that the focal point seems to be at what is just the eye relief. That was too close to be able to use a qhy5l-ii or gpcam. The way around that, I'm thinking, is to just use a simple convex lens rather than an eyepiece but I'd need some way of holding it in place and holding a camera in place. If I had a 3D printer I could probably make one. I have been thinking about getting one - an Ender3 Pro, maybe. I have to say I'm a bit confused as to how an actual reducer works. I have a x0.79 one on my 115mm apo which has a focal length of 800mm (f6.95). So the reducer should effectively reduce that to 632mm i.e. f5.5. Yet the physical focal length is still the same? I assume that all the x0.79 reducer actually does is change the way the light cone converges? Anyway, it seems to work! Louise
  7. Thalestris24

    Worthless EQ5 goto

    Actually, thinking about it, it probably should be minus after all (it was late when I posted before...). The manual is a little unclear but since the Meridian runs through Greenwich, anywhere to the West is '-' and anywhere to the East is '+'. So if your ~3 deg west of Greenwich then it should be entered as -3 to denote West for Merseyside as opposed to +3 deg which would be in the North Sea! So I'm at about -4.2571 deg (W) /55.878 North for Glasgow. Hope that's clear! Louise
  8. Thalestris24


    One of the IDAS ones would probably be good - which one depends on the type of LP you have. Louise
  9. Thalestris24

    3D Printers

    Ok - thanks. Sounds challenging! I thought I was probably hoping for too much from plastic... Cheers Louise
  10. Thalestris24

    3D Printers

    Quick question for you 3D printer gurus... Would a printer such as the Ender 3 let me make (amongst many other things) custom telescope fittings with, say, 1.25" barrel and either c-mount, T2 or M48 threads? Cheers Louise
  11. Thalestris24

    Worthless EQ5 goto

    I was just referring to the time zone setting: It should be a + for Europe (not the minus I said before, d'oh) ps be careful about sharing your location - I would delete the map in your post above
  12. Thalestris24

    Worthless EQ5 goto

    Yes, but you first have to select - or + depending on western or eastern hemisphere before entering the 00:00. Also, the App takes the time from your Android device - which I assume is correct? Louise
  13. Thalestris24

    Worthless EQ5 goto

    Just looking at the Synscan manual, it looks like you have to put a '-' prefix for the western hemisphere time zone?
  14. Thalestris24

    3D Printers

    Being a compulsive tinkerer, there are (many) times when I could really use one... Maybe in the New Year Louise
  15. Thalestris24

    Worthless EQ5 goto

    If it's doing the same thing and out by the same amount every time, it's almost certainly either a setting or else your PA is way out. What is the mount standing on - concrete? Louise

Important Information

By using this site, you agree to our Terms of Use.