Jump to content



  • Posts

  • Joined

  • Last visited

Everything posted by RobertCL

  1. That's a really good video. I love the fact you get the horizon in all the way round with your lens.
  2. So I managed to write a small program that subtracts a dark frame from a number of image files in the same directory, so that I could get rid of the worst of my hot pixels. Heres the result from about a week ago: Looks a lot better, though there were still a few stuck pixels on the original - I'm not sure they are visible on the youtube version though.
  3. Nice You've got a much better field of view than I have. I really like the way you get the whole horizon in the image. Internal reflections in the dome do seem to be a problem. I get exactly the same. I left mine out again last night and managed to take some darks, so all I need to do now is work out a nice way to subtract them from all the images it will have taken overnight. It seems that the Philips web canes will generate enough heat to clear dew from the dome, which is handy. Mine cleared itsself again last night.
  4. So I left it out again last night to capture the clouds and here is the result; a few glimpses of the moon and a few stars, but mainly clouds and hot pixels! I started off with 30s exposures, but it wasn't capturing and details on the clouds, just uniform white, so I switched to 15s exposures about half an hour or so in (you'll notice the clouds slow down). Not sure why it's a bit green either. Same timings as the previous video roughly, ran from about 5:30pm -> 7am until it I got complete white out. Interestingly, I'd left the camera out all day but not running and when I first turned it back on at about 5pm the dome was obviously misted up because everything looked blurred and out of focus. However after about 5 mins it cleared, so I don't know if that means that it generates enough heat when running to keep itsself clear or whether it was just a coincidence. Though I've never seen my telescope optics clear themselves when they get dewed up, so I'd like to think the camera running generates enough heat to keep the dome clear. Better go and check that rain didn't get into it now! Edit: Oh, and I turned the camera round so north is now up, south is down, etc. Robert.
  5. So I've been following this thread with some interest because I've had a modified Philips webcam for some time now and it's been sat around doing nothing much and I've always thought that some kind of all-sky camera would be nice to have. So here's my effort made from what I had previously along with the embedded USB hub and USB <-> Serial convertor ideas from SPC900 mod yesyes' thread. Last night I stood it out on the patio and ran a long USB cable back into the livingroom. You can see my rather subtle clingfilm round the plugs approach to protecting the USB connection from the weather. I left SharpCap running overnight (from about 6pm -> 7am) capturing 30s exposures and here is the resulting video (creating using mencoder on linux [ mencoder "mf://*.png" -mf fps=30 -ovc lavc -lavcopts vhq:vbitrate=1500 -o movie.avi ]) : And a single frame - roughly north is left, east is down, south is right. The bright sausage just over the trees on the right is Jupiter just coming into view. So here's a list of issues: - "Forgot" to take a dark frame so there are annoying blue spots on the image. Even if I had taken one, I'm not sure what software I could use to subtract it from all the .png files I ended up with before combining them into a video. Also, there must be some way to take the data I've got and infer a dark from it, it's really obvious which pixels need to go! I think I've managed to create a dark in Photoshop from the frames I took, but I can't think how to subtract it from all the images I've got - doing it in Photoshop leaves black holes in they sky (rather than blue holes!) because the sky background in the images isn't totally black. - Exposure. I set it at 30s, 20 (or 30?) for the gain after some messing around. Really you need some software that allows the settings to change over time, then it could run during the day as well and get all those lovely clouds going over! However to do this, I think I'd need to flick the "long / normal" switch back to normal (which is a physical switch on mine) and switch the camera back to full auto mode - hence "better"(*) software required. (* - SharpCap is already superb but I also think that a sky camera needs some custom software) - Moon. Spoiled it rather last night, but thats not too bad I guess. - Light from the house was reflecting on the dome at the start, until I moved a planter around to block the light - you can see it appear near the start of the video. Could be solved by moving the camera away from the house, but they you need a longer USB lead at which point my camera stops working. So instead you need a computer "outside" (or in the shed), but I don't have power in the shed, so ....? Some kind of very low power PC running from a 12V battery maybe... - The dome has misted up this morning, not sure if it did last night, maybe the camera running all night kept it sufficiently warm. - The field of view isn't "all sky" - it's not bad, but it would be nice if it were more than I've got, but I'm using a (I think) 2.1mm lens that I got from ebay. I've not managed to find anything wider on the few attempts I've made to look. - Water / weather proofing. I've not tested it, but hopefully the copious amounts of glue-gun glue will be enough. I'm not really planning on leaving it out at the minute anyway. - Some of the frames are "spoiled" due to the exposure being incorrect - you can see a few of these in the video where it kind of flashes. I should really have removed them before creating it. - Would be nice if I'd thought to orient the camera so north was up! - Given it was fairly clear last night, as 30s exposure doens't seem to have picked up many stars - though maybe the moon is to blame for that? Probably some other stuff as well! I'll have to have another go with it when the moon isn't full because that spoils in a bit really. Thats all for now! Robert.
  6. That looks like a very nice job. I'm just starting out on the whole pier / observatory building adventure. Where did you get the castors from? Would I be right in thinking that you had to shave some width off the wheels to get them into the Unistrut?
  7. If you're just trying to capture images at an interval then SharpCap already does this. I just realised last night after reading the "all sky cam" thread. Just set number of frames and interval when you start capture - saves png images into a folder I think. I've not tried it in LX mode though.
  8. I'd be very wary of the USB over cat5 device unless you've seen one working. I think in most cases these devices simply send the USB signals over a cat5 network cable. They aren't converting the USB signals into tcp/ip so as such you can't send the signals through a router (be it wired, wireless or powerline) because it won't understand. Certainly things like that usb over cat5 adapter ive looked at before are merely using the cat5 cable to allow you to have a longer cable run than the maximum 5m allowed by USB. It doesn't mean you can plug the cable into your home network. Worth checking before spending any money if nothing else.
  9. Cheers, guys. Stuart, to create the animation I just loaded the frames into GIMP as multiple layers and the did a save as GIF. There is an option when saving to either save as grayscale or indexed colour - maybe you have the grayscale one checked by default?
  10. I'm not aware of anything, but would be interested to know if something exists because I've just gone through the process of lining up 7 frames of Jupiter in GIMP so I could save then as an animated gif. It wasn't really that difficult just a bit tedious as I kept making silly mistakes while I tried to get some text in there as well!
  11. Hi All, It's been a while since I posted anything here because I've not had chance to get out with the scope. Last night was one of the best nights I've seen for a while though. I wasn't really planning on doing this when I went out, but it seemed too good to miss. Celestron C6-N, 4x Barlow, Philips SPC900N webcam, avi's all approx 60sec in length taken approx 15 mins apart, stacked in Registax, then animated in GIMP. Enjoy, Robert.
  12. Nice, I remember having having a wow moment the first time I went to image that as well.
  13. You should only press the stop button when you want to stop! Not before you start. I usually just start with the leftmost button and then work right. So camera, telescope, loop, PHD. Thats it, guiding is running. Only press stop if you want to stop guiding for some reason. It sounds like you didn't managed to get a good star lock at the start.
  14. I did eventually manage to find it again so I think it must have just been a period of bad seeing or something. Managed to get the camera setup and auto guiding running, then about 4mins later a load of low cloud /mist rolled in. Oh well, at least I've got to see it!
  15. I managed to slew right to it about an hour ago using the coordinates from heavens-above and could just about make it out through my 6" reflector. But now, after I've looked at a few other objects, gone to get the camera and slewed back to it and I can't see it anymore. Sky does seem a little less transparent than earlier, but I'd have thought a 10sec pic would show it up anyway. I'm confused.
  16. Sun is out at the minute, so hopefully I might get chance to see comet Hartley.
  17. I have a single resistor stuck on the back of the secondary mirror on my newtonian with some double sided thermal tape of some sort. The resistor itsself is one of the big square White block style ones. Seems to work pretty well, so long as I don't ever want to get it off again! Also I used a Velleman pwm motor controller kit that I think came from maplins to build a diy variable controller kit. Seems to work pretty well. There are various tutorials on the web, I dont have a link for the one I used right now, but it shouldnt be that hard to find...
  18. Yes, I've just ordered one of those adaptors from astonomizer. They're pretty good value compared to the official canon power adaptors. Hopefully it will arrive in the next few days.
  19. I've just ordered the ac582. No real reason except it was one of the cheapest I could find that I could order online that said it was both ir and uv. Some of the cheaper ones (only by a few £) seemed to be ir blocking only, though I'm not sure if that's just what the description said.
  20. Surely nothing is barmy if it produces good results. Who could have predicted that webcams would be so popular for planetary imaging!? Now that's barmy
  21. Yeah, I'd agree with buster - have you tried using the wavelets? You should be able to get much better than that with a 10" scope from what I've seen on here. That looks like a pre wavelets image from my 6" reflector. Just grab the fist few wavelet sliders and move them about half way across and see what happens!
  22. Yes, that's pretty good. What type of scope are you using for that?
  23. Ah, excellent, I didn't know there was a mac version.
  24. You might want to check that you can get software for the mac for autoguiding before you go buying other hardware. Unless you also have a windows laptop of course. There are various software packages available for windows such as PHD (which I use) and Guidedog(?) and I'm sure some others. Don't know what is available for mac though.
  25. Yes, thats a very nice image. Hopefully tonight is looking promising here and I might get chance to have my first go at Jupiter this year.
  • 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.