+Graham Posted October 19, 2013 Share Posted October 19, 2013 The picture is of my capture screen after a 300 second sub in HA. Note the 'fog' around the outside and the center. The large stars have a halo round them. I have this in perfect focus according to the bat mask. I am thinking my GT 81 is full of moisture but before I take drastic actions I want to hear your ideas. Link to comment Share on other sites More sharing options...
Brantuk Posted October 19, 2013 Share Posted October 19, 2013 Looks like a build up of dew to me Graham - the atmosphere's pretty "wet" out there right now. Are you using dew bands? Link to comment Share on other sites More sharing options...
+Graham Posted October 19, 2013 Author Share Posted October 19, 2013 Hi Kim Yep dew band running as per normal. This problem has been building up over the past week or so. Probably due to this persistent rain and the fact the scope is permanently set up in the obs. I'll give it another hour to see if it clears up other wise it is going to be an attack of the hair dryer Link to comment Share on other sites More sharing options...
+Graham Posted October 19, 2013 Author Share Posted October 19, 2013 Well the condition has improved considerably over the past hour so I think dew is the cause. Still going to give it a go with a hair dryer tomorrow to remove the moisture from inside the scope. Link to comment Share on other sites More sharing options...
Brantuk Posted October 19, 2013 Share Posted October 19, 2013 Yup - if you have some condensation inside the scope then it may be an idea to bring it indoors, take out the eyepiece (or camera) and dry out thoroughly. I've seen sct's that have a small puddle of water hanging in the tube (though I appreciate you're not using an sct). You could try turning the dew bands up a bit first I guess. Let's hope it's not dew in the camera...... Link to comment Share on other sites More sharing options...
+Graham Posted October 19, 2013 Author Share Posted October 19, 2013 Yup - if you have some condensation inside the scope then it may be an idea to bring it indoors, take out the eyepiece (or camera) and dry out thoroughly. I've seen sct's that have a small puddle of water hanging in the tube (though I appreciate you're not using an sct). You could try turning the dew bands up a bit first I guess. Let's hope it's not dew in the camera...... I checked the Atik the other night Kim and it was fine. Think your right though I will bring it in tonight once I am done and let it dry out thoroughly. Dew bands are home made and run at a constant temp. Link to comment Share on other sites More sharing options...
+Graham Posted October 19, 2013 Author Share Posted October 19, 2013 well I have given up for tonight and have brought the scope indoors. Had a look at it and the problem is worse than I thought. I can see the moisture in between the lenses in the cell. Slow drying out process is now under way. Link to comment Share on other sites More sharing options...
+Ibbo Posted October 20, 2013 Share Posted October 20, 2013 (edited) has the cover slip on the ccd iced up? just read the full thread at least you have found the problem Edited October 20, 2013 by Ibbo Link to comment Share on other sites More sharing options...
dawson Posted October 20, 2013 Share Posted October 20, 2013 Graham how dry or not is your obsy? Is this a common risk even in a reasonably water proof obsy if leaving the scopes out there? Hope it dries out quickly and nicely. James Link to comment Share on other sites More sharing options...
philjay Posted October 20, 2013 Share Posted October 20, 2013 This is why I dont leave scopes in my obs at this time of year and bag with condensation trap the mount, condensation can be a pain. Ive also conformal spayed my motor board. when it gets to this stage graham, i bring everything in and sit it near the radiators for a day or so to dry everything out. Watch moisture on the ccd window also, you may look at it and think its clear at the start of imaging but as things cool the window fogs due to the resident moisture in the camera/imaging train condensing out. If your objective has moisture both sides leave the caps off both ends and keep it indoors nice and snug, check its dry before taking it out again. If the moisture has crept between the elements then its a little more complicated. Link to comment Share on other sites More sharing options...
+Graham Posted October 20, 2013 Author Share Posted October 20, 2013 Thanks Phil Going to leave it sitting with warm air blowing through it today to see what joy that brings. Link to comment Share on other sites More sharing options...
+RonC Posted October 20, 2013 Share Posted October 20, 2013 I tend to open up the obsy when I can if it's breezy and/or sunny just to air it all out, especially this time of year! Cheers Ron Link to comment Share on other sites More sharing options...
+Graham Posted October 20, 2013 Author Share Posted October 20, 2013 I tend to open up the obsy when I can if it's breezy and/or sunny just to air it all out, especially this time of year! Cheers Ron My obsy has a 4 inch vent all the way round to allow for air flow Ron. Mind saying that I have taken your advice and opened the roof as well today. It is pretty damp in there what with all this persistent rain we have been having. Link to comment Share on other sites More sharing options...
Teslar Posted October 20, 2013 Share Posted October 20, 2013 A small 12v dehumidifier might be the solution to your problem. You could leave it running 24/7 and trickle charge the battery. That's my plan when the obsy eventually happens Link to comment Share on other sites More sharing options...
philjay Posted October 20, 2013 Share Posted October 20, 2013 Ive been down that route and personally leaving something running taking power constantly is not an attractive idea to me. My reasoning is i need condensation protection for at least 4 to 5 months in the uk so it needs to be running 24 7 for that time and count the number of times you actually get to use the obs in that time. It just doesnt seem finantialy viable. Therefore a caravan crystal condensation trap by the mount and a cover over the lot is alot cheaper imo and works well provided i check the crystals once a month and a bag of crystals lasts about 3 years so its well cheap. Link to comment Share on other sites More sharing options...
dawson Posted October 20, 2013 Share Posted October 20, 2013 And here's me thinking an obsy was going to solve ALL issues Link to comment Share on other sites More sharing options...
+Graham Posted October 20, 2013 Author Share Posted October 20, 2013 Well if it wasn't damp in there,,, it is now. Dozed off on the sofa like you do on a Sunday afternoon. It was the thunder that woke me and the sound of a torrential rain storm hammering against the windows. :facepalm: Still the obs floor need a wash :lol: I am thinking a good dose of water repellant on all the electrics in there might be a good idea before I power it up again. Link to comment Share on other sites More sharing options...
dawson Posted October 20, 2013 Share Posted October 20, 2013 Oops! Link to comment Share on other sites More sharing options...
+Graham Posted October 20, 2013 Author Share Posted October 20, 2013 Well The GT spent a good 4 hours with a hair dryer up its chuff today and I think we have a result. Same place as last night, same 300 second sub and what a difference. :) Link to comment Share on other sites More sharing options...
philjay Posted October 20, 2013 Share Posted October 20, 2013 Excellent job Graham. Bad luck on the wet obsy, I presume you are wearing your wellies in the obs at the mo We have all done it and Im sure I will do it again Anyrode, how come you have clear sky, its full cloud here building up to rain Link to comment Share on other sites More sharing options...
+Graham Posted October 20, 2013 Author Share Posted October 20, 2013 Excellent job Graham. Bad luck on the wet obsy, I presume you are wearing your wellies in the obs at the mo We have all done it and Im sure I will do it again Cheers Phil. If it hadn't have worked you would have been getting a shout about stripping down a triplet Good job the obsy has a concrete floor with a pre-designed slope in the floor for just such a situation. Link to comment Share on other sites More sharing options...
Teslar Posted November 11, 2013 Share Posted November 11, 2013 Ive been down that route and personally leaving something running taking power constantly is not an attractive idea to me. My reasoning is i need condensation protection for at least 4 to 5 months in the uk so it needs to be running 24 7 for that time and count the number of times you actually get to use the obs in that time. It just doesnt seem finantialy viable. Therefore a caravan crystal condensation trap by the mount and a cover over the lot is alot cheaper imo and works well provided i check the crystals once a month and a bag of crystals lasts about 3 years so its well cheap. A solar charger to keep the battery topped up that's powers the 12 dehumidifier. That's the set up I've seen and it seemed to work well. I'll have a chat with the chap next time I see him as he's had it in for a year now Link to comment Share on other sites More sharing options...
andyboy1970 Posted November 15, 2013 Share Posted November 15, 2013 I have 6 bags of desecant in the Obsy and one inside the end of the scope (reflector). Each bag is 500g and get brought into the house every couple of months and left on the radiator to dry out for several hours. When I go in the Obsy it is bone dry. Cross ventilation also helps. Link to comment Share on other sites More sharing options...
catman161 Posted November 15, 2013 Share Posted November 15, 2013 I have 6 bags of desecant in the Obsy and one inside the end of the scope (reflector). Each bag is 500g and get brought into the house every couple of months and left on the radiator to dry out for several hours. When I go in the Obsy it is bone dry. Cross ventilation also helps. Where do you get bags of desiccant from Andy? Link to comment Share on other sites More sharing options...
andyboy1970 Posted November 16, 2013 Share Posted November 16, 2013 Where do you get bags of desiccant from Andy? Stolen/borrowed from work! Aircraft engines come with about 20 bags every time they come from workshops. Link to comment Share on other sites More sharing options...
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