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.

sgl_imaging_challenge_banner_globular_clusters_winners.thumb.jpg.13b743f39f721323cb5d76f07724c489.jpg

catburglar

Members
  • Content Count

    274
  • Joined

  • Last visited

Community Reputation

54 Excellent

About catburglar

Profile Information

  • Location
    North Wales
  1. Leon I think it’s difficult to answer your questions precisely because each EQ5 and drive set will have been machined/assembled to a different level of accuracy. Also, the size of the pixels in the camera you are using will have an impact because if you’ve got a camera with large pixels the errors in the drive may be less apparent than if you’ve got small pixels. I’m guessing that you’re using a DSLR and that you don’t have a guide scope/camera in your setup. I think you’d be lucky to get much longer than two-3 minute exposures with the ED72 (focal length is 420mm) and probably around half that with the SW150 (focal length is 750mm). if you can get rally good polar alignment and your drives have low periodic error then you may do better, but the only way to know for sure is to give it a try. Good luck john
  2. I don’t think there’ll be much difference between the two options. It really comes down to whether you want to pay £30 so that you don’t always need to colour balance your daylight shots- if that doesn’t bother you then go with option 2- it’s what I did, but I don’t do that much daytime stuff
  3. It’s easy- you don’t just add a hyperstar, it actually remove the secondary mirror, which usually multiplies the focal ratio of the primary mirror by x5, hence you’re left just with the primary which is typically around f/2 in most SCT’s
  4. They’ve got a website so you could by direct rather than from amazon: https://uk.telescope.com/mobileProduct/Telescopes/Reflector-Telescopes/Reflector-Telescopes-for-Astrophotography/Orion-6-f4-Newtonian-Astrograph-Reflector-Telescope/pc/1306/c/1315/sc/1349/116720.uts
  5. I’ve seen the post you referred to- and that’s really what got me thinking about it again. I guess I’ve got two things nagging- first that very few people seem to be using them, and second- are the planetary views really so good? I had disappointing views with a Celestron 6inch SCT- it was collimted and cooled, but never seemed to snap to focus and that also has a 30% obstruction. My ETX90, by contrast, is so sharp it’s almost too good to be true....Is it just the Meade optics or is it the F14 focal ratio.... I’m hoping that the ES will have the focus snap that the ETX has, but the resolution/light grasp of a 6 inch scope....I guess I’ll only know when I’ve tried it
  6. Looking at the ES comet hunter as a good scope for both visual and imaging.....but don't see too many user experiences.... My thought process is that the weight/FL are both relatively low, so not too taxing for imaging on an AZ-EQ5 . Coma will be well controlled on a DSLR with an APS-c chip, and at F4.8 native, I won't need to faff with reducers / correctors to get sharp stars and keep exposure times manageable. The few reports I've seen suggest that it's no slouch visually even on planets despite the 30%+ central obstruction....This figure is similar to the SW maks, so perhaps it won't be refractor sharp, but not half bad..... Does anybody else have any first hand experience? Is there any reason not to click the buy button?
  7. I use a bahtinov mask and take 5s exposures at isi 800 or 1600 depending on the brightness of the star I’m using for focus. It’s much easier to see the relative position of the diffraction spikes than trying to use live view, and can usually get it nailed down inside a minute if you start from somewhere close to infinity focus
  8. Thanks for all the tips- exposure time was approz 0.01s - so will try to dim the panel and increase the time, I’ll also take a look at increasing the distance to the panel and might flock the lens hood- wonder if I’m getting some glancing reflections that might be throwing the flat off
  9. I'm shooting with a Samyang 135mm @ F2 on an APS-C sensor. The raw files have a strong vignette (probably about 2 stops at the extreme corners- but I haven't measured it). I'm trying to correct with flats when I stack in DSS, but I still end up with a strong vignette in the resulting autosave file. I've tried using twilight flats with some white paper over the lens to act as a diffuser and a similar technique with a tablet screen. When I review the master flat, it shows the same vignette that the raw images do, so the flat division should work. I realise I could stop the lens down, but I see many people here using the lens wide open - so there must be a way. Does anybody have any tip/tricks for getting good flats at F2. John
  10. Barry I do understand that there’s always some risk- but most fellow astronomers that I’ve come across treat their kit pretty well and describe it honestly when selling, so I’m not too concerned. I’d just like to make sure that the sensor is nice and clean- could you post a single uncalibrated sub from one of your recent imaging sessions. If it’s too big a file I could PM you a link to my OneDrive so you could upload the RAW file. If that looks OK, we can confirm the details.
  11. There's some good learning in the last message from Antonio. I went down the cheapskate route- got a RPi 3b+, installed Astroberry server (like StellarMate- it's Ubuntu with wifi hotspot, indi, kstars, plate solving and lots more pre configured). I'm reasonably proficient in Linux, but there was still quite a lot of head scratching getting it all to work. It's entirely possible to run kstars, indi and platesolving on the Pi- it may not be the quickest, but it's certainly workable- and it's the way I've setup recently. KStars and EKOS is certainly more fully featured than APT, particularly if you want scheduling of multiple imaging runs, multi panel mosaics etc. However, if your needs are a little more modest, a pretty cheap win10 tablet, running APT and real vnc server (so you can access it remotely) or similar can get you a long way. You don't need a lot of processing grunt to run an imaging session. One last point about KStars on windows connected to RPi as an indi server. in this configuration Kstars won't do offline plate solving- so you need both your Pi and windows PC to be on a network that has internet access, or have your PC connected to the RPi in hotspot mode and another connection to your internal home network so you can platesolve.
  12. There’s this adapter from FLO- if you can unscrew your current nosepiece, it might do the trick. https://www.firstlightoptics.com/diagonals/william-optics-sct-adapter-for-2-diagonals.html
  13. I agree with Olly- I don’t usually bother with darks if using short frames and a relatively low noise camera. There’s the natural dither option, or you can use APT’s internal dithering option which works really well even without guiding.I I set it to dither by up to 5 pixels every frame- it only adds a couple of seconds between each exposure and means it does a pseudo random walk around the centre of the image. It is very effective a sorting out hot pixels and such like.
×
×
  • Create New...

Important Information

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