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craigg

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About craigg

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  1. Just ordered Dave Eagle's book too, looking forward to receiving it!!
  2. Yeah, me too!! Great image, I think I like the original version than the darker one too, but could easily change my mind. It seems the darker one loses some of the fainter nebulosity in the middle?
  3. Thanks Radek, however I think the Hitech Astro controller doesn't have a reliable offset - it doesn't have the position offset stored between sessions.
  4. No I haven't, but that's a good shout, I'll do that, thanks.
  5. Hello everyone, I recently bought a Raspberry Pi and StellarMate. Mostly working fine with my Atik camera, ZWO filter wheel, etc. However, I was hoping to get the autofocus working, but having some issues. I'm using a Hitech Astro DC focus with a Skywatcher Auto Focus motor. This seems to be working in terms of manual focus, but when I try to autofocus it seems to get it knickers in a twist. I have tried various INDI settings (suggestion here: https://indilib.org/forum/focusers-filter-wheels/2793-hitech-astro-dc-focuser-problem/26330.html) but what happens, even if I get it fairly close manually first is that initially it steps in and out by the increment I set (50) and you can see it getting better, and better, but then for some unfathomable reason, when nearly focused, decides to step in or out by a massive amount, so much that the focus star is no longer visible. I just wondered if anyone has this same combination working, or if anyone has any suggestions for solving this? My main reason for autofocus is that I currently have a mismatched set of filters so would like to automate focusing when they are switched. Many thanks, Craig
  6. Thanks for all the suggestions. PA could be an issue - I've had it on a SW pillar mount which has been polar aligned reasonably accurately. However, I have assumed it's remained aligned over a few weeks, maybe it's moved a bit. I'll check it next time I can see some stars, whenever that may be. I must admit, the field rotation you describe makes sense, but wouldn't I be seeing significant adjustments in the guiding chart if that was the case? I've temporarily bolted the ST80 rings directly to the side-by-side bar, so no clamp or dovetail bar. It's rock solid, so that should rule out any flex in the guide scope. The focuser seems rigid, there doesn't seem to be any give in it and the focus lock screw is tight - the extender is a skywatcher kit barlow with the lens removed. I don't think there are any issues there either. Fingers crossed it works (and for the cloud to clear). Thanks again for all the useful comments. I'll let you know how it goes...
  7. Thanks for all the suggestions, that's given me a few more things to check. I may be misremembering the focal length, might be 400mm that I have set, for some reason I thought 480mm. That's what happens when you get old. Anyway, I'll go back to verify, maybe it's that simple. StuartJPP - I'll also strip down the dovetail, clam shells, etc and make sure everything as tight as can be. Doesn't hurt to double-check. Looking at the forecast, I'll have plenty of down-time to do this stuff before I get to test it out again.
  8. They're reasonably well balanced I think - I've got the two scopes on the dual mount bar positioned so the centre of balance is around the middle of the bar (i.e. perpendicular to the scopes) with both cameras attached and focus tubes around the same position as for imaging. I've also positioned the bar slightly off centre in the mount's puck as the WO is quite a bit heavier than the ST80, so it stays put when I move the Dec axis with the clutch released. One thing I was thinking was whether to slightly off balance the counter weights so that it's leaning slightly 'into' the gears, if you know what I mean. I read somewhere this can help. Interested in why set the focal length to 400mm? I can give it a try by all means, but just curious what the thinking is with this?
  9. lin_guider seems to be quite good in this respect - in the video settings you just give it the aperture, focal length, sensor size and pixel size and it works the rest out for itself. I'll have another look though, when I have it running again, just in case I've missed something. Thanks for the help.
  10. Hi folks, I've just updated my setup to use a SW ST80 guide scope having previously used a finder/guider setup. Here's what I'm using: Mount: HEQ5Pro Imaging Scope: WO ZenithStar 71mm Guide Scope: SW ST80 (both above connected with an Ambermile side-by-side bar) Imaging Camera: Modified Canon EOS 600D Guide Camera: QHY5II-L-M I'm using lin_guider guiding software (essentially PHD for Linux) which was working just fine before using the 50mm finder and the same QHY guide camera. I've updated the guider settings to give it the 80mm aperture and 480mm focal length of the ST80, also tweaked the gain and exposure to suit it. So, when I calibrate and start the guider, I'm getting reasonably good guiding corrections in the guide chart (I think so, anyway, it seems similar to how it looked before with the finder). Now, here's the issue:- I take around 30 images at about 8 min exposures. If I cycle through the raw images from start to finish I can see each one slightly shifts towards one side of the image compared to the previous one. If I zoom in on the images I can also see a small amount of star trailing in the same direction as the drift. Any hints of tips on what to check would be much appreciated as I'm all out of ideas :-( Thanks, Craig
  11. 20 mins is quite fast. If I don't have the evening available (kids also) I just get the binos out instead. I have recently bought a pillar mount (one on casters) which I'm thinking about setting up on the patio and leave the HEQ5 on it all polar aligned. I've got a garden furniture waterproof cover which fits tight over the caster legs, but not with a scope attached. Setup is quicker, but to be honest, you've still got at least 20 mins or so for the optics to cool down to ambient anyway. The problem I've found in the past is that if you leave the whole setup outside with a cover, it still gets damp due to the humidity in this country. Eventually various bits (counter weight bar for example) start to exhibit surface rust. It's a tough one. Let me know, though, if you come up with a solution.
  12. Yes, easy enough to do. Added one to my SW 200P last year. I used one of these: http://www.ebay.co.uk/itm/Arctic-F8-80mm-2000RPM-Silent-High-Performance-PC-3-Pin-Case-Cooling-Fan/182288768003?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D39839%26meid%3Dbb9e20fdd65b4b24bc0a7fb8a45a8a4f%26pid%3D100011%26rk%3D5%26rkt%3D18%26sd%3D171678430988 and one of these to alter the speed: http://www.ebay.co.uk/itm/Gelid-Solutions-Fan-Speed-Controller-with-Manual-RPM-Control-for-you-Case-Fans-/311047221642?hash=item486bdbf18a However, if you have a 12v PWM based dew controller you could use that to power and control the speed of the fan instead (assuming you have a spare port), which is what I do now. You'll need some cables, connectors, etc also. I then bought some cheap perspex and got my son to laser cut it to size at school (good old design & technology lessons!!). I put it behind the primary and get a good airflow coming out of the focuser when on full power and with the tube cap on, just to test. I normally run it full steam while getting it to ambient, about 1/3 to half power when imaging/observing. Noticeable difference in surface thermals on the primary using out of focus viewing of stars, but it can't do much about the high altitude winds (but at least you can see them with the fan). I tried fixing it on with velcro since I thought that might help as a vibration buffer, but kept falling off in the cold, so now I just have some elastic bands around the primary adjustment bolts to hold it in place. It's very slightly loose which helps reduce vibration, but that fan is very smooth and quiet anyway.
  13. You certainly can! And it works well, even in town. You'll need to extend your exposure times when using it, my first attempt a few months ago was of the Rosette Nebula and I used 10 min exposures, which brought out plenty of detail. You get nice contrasty images. I'm still working on how to merge in the RGB data, but making some progress I think.
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