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michael.h.f.wilkinson

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Everything posted by michael.h.f.wilkinson

  1. As a mount I cannot fault the iOptron HEM15 (so far). Really nice and compact, only 5 kg including carbon tripod. Not cheap, however.
  2. I am travelling to Texas for the eclipse, and my current rig is: iOptron HEM15 mount plus tripod (5kg check-in luggage) APM 80mm F/6 triplet imaging scope (2.5kg hand luggage) Lunt Ca-K module (haven't weighed it yet, hand luggage) Carl Zeiss 500 mm F/8 mirror lens (1 kg, hand luggage) ASI183MC for white light ASI178MM for Ca-K imaging (120g each, check in luggage) Lightweight laptop for imaging/data acquisition (1.2kg, hand luggage) If you replace the Zeiss telephoto with a guide scope, and my non-cooled ASI183MC with a cooled camera, this would work for DSOs. The Samyang 135mm is brilliant for this kind of work, and it combines neatly with the HEM15. It works even without guiding, as this shot shows (120s subs, just tracking on the HEM15)
  3. I wonder if the star adventurers are solid enough for an 82 mm refractor. I have an APM 80 mm F/6 triplet, usually used with 0.8x focal reducer, and use a more substantial mount (Vixen Great Polaris, although I plan to try out the iOptron HEM15 shortly). I have no experience with the star adventurers, I should add. Just my tuppence
  4. I don't have the ASI533, but with my ASI183MC I need very short exposures in daylight at reasonable gain settings. For example, using the camera on the moon (which is after all in full sunlight) at about F/10 requires just a few milliseconds of exposure time so as not to saturate the camera. The ASI533 can go down to 32 microseconds so you should be able to find a usable setting. You might want to try planetary imaging software and use lunar settings for daylight photography.
  5. It is a spectacular image, and although i also tend to prefer more natural looks, I would not call this overcooked. The amount of contrast and saturation preferred is ultimately a matter of taste, so what counts is what you like.
  6. Lovely image. Great detail in the main target, and some lovely background galaxies captured as well. I really should give this target a go with my Schmidt-Newton.
  7. I think Martin (Budgie1) says makes sense. Going for a slightly shorter focal length makes life a lot easier, I find. My stalwart deep-sky imaging scope I use mainly on my Vixen Great Polaris mount (the EQ5 is a clone of that most cloned mount) is an APM 80 mm F/6 triplet, usually with focal reducer (second-hand Tele-Vue TRF-2008 0.8x reducer/flattener). I only started using longer focal lengths when I got a heavier mount (Great Polaris DX), on which I use with a scope with similar focal length (but lighter weight) as the SVbony without, and Evostar 100ED with reducer (I use a 6"F/5 Schmidt-Newton). I also note that while the SVbony scope is faster than the Evostar, it has FPL51 glass, whereas the Evostar FPL53. This would suggest that the colour correction of the Evostar is better (but that isn't guaranteed). Going for a smaller scope like the Evostar 80ED or a triplet like mine can certainly get great results. The forum is littered with examples. Here is one with the APM 80mm at F/4.8 and modded Canon 550D.
  8. That is lovely. Lots of detail, but nothing overblown. Very natural looking
  9. There are two mechanisms at play: stereo and focus. The stereo mechanism uses disparity of positions of features between left and right images to estimate distance. The muscles surrounding the eyes will rotate the eyes accordingly to put the object of interest in the foveae of both eyes. The difference in orientation gives the estimated distance. At large distances this does not really work. Focus simply changes the curvature of the eye lens to get the sharpest possible image on the fovea. When looking through a telescope, it is best to relax the eyes, so the lenses revert to their infinity setting (or its nearest equivalent for) and changing the focus of the telescope to get the sharpest possible image. Note that the image plane might be close, but the eyepieces transforms this into a virtual image at infinity at proper focus.
  10. Absolutely lovely images of an object I had never heard of. Might well try that at some time
  11. I find open clusters are best viewed in a really wide field. You then see them in context, whereas if they fill most of the FOV you just feel you are looking at a bright star field.
  12. I had a couple of LV EPs (7 and 9 mm) and they were superb on planets. I then moved to Pentax XWs (5, 7, and 10 mm) and they have a definite edge, and far wider FOV, but the LVs are great. If you can pick them up for that kind of money, go for them! I now have some SLVs (5, 9 and 15 mm) in a lightweight travel setup, and can't fault them. The only noticeable difference with the XWs is field of view. Build quality is fine too
  13. Brilliant image! The only thing I might change is making the background a shade darker, but that might depend a lot on the monitor I am using
  14. For really extreme portability, there's this, of course: 😉 Works well on lunar imaging, hope to test it on white light solar soon. Downside: only 62.5 mm aperture, but a decent FOV to capture the corona, should I be lucky with the weather on April 8
  15. The C9.25 is around 9.4 kg, the mount will need a counterweight, but it should still fall well within the limits of the HEM15. I have seen plenty of sparkle in star clusters (especially globulars) with my C8. They are sensitive to collimation, but tend to hold collimation well. The MN190 mentioned earlier is 12.5 kg, or thereabouts, which is probably too much, especially when cameras or EPs are added.
  16. That is a lovely image! Great detail
  17. Really lovely set of images. Great processing too: very sharp, but not overcooked in any way.
  18. Lovely images. The first looks a bit more natural on my laptop. Both are great, however
  19. First quick stack I would call that quite a success, for only 62.5 mm aperture.
  20. In the DSLR category there is this one of the Heart and Soul (modded Canon EOS 550D, Samyang 135mm L-eNhance filter, 12h total exposure over three nights) Or Comet NEOWISE from a few years back (unmodded EOS 80D, Sigma 50-100mm F/1.8 zoom, full aperture f=100mm, stack of 30 images)
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