Daz Type-R Posted February 23, 2014 Author Share Posted February 23, 2014 Interesting replies guys, thanks a lot. Link to comment Share on other sites More sharing options...
Craig Posted February 23, 2014 Share Posted February 23, 2014 Just reading this thread through, I didn't know about the green filters increasing the amount of detail you can see. I'm left wondering whether that works for people with poor colour vision (like me). Link to comment Share on other sites More sharing options...
Perkil8r Posted February 23, 2014 Share Posted February 23, 2014 Just reading this thread through, I didn't know about the green filters increasing the amount of detail you can see. I'm left wondering whether that works for people with poor colour vision (like me). Good question Does red light still make it good for you to see your way about and not ruin your night vision? Whilst not the same thing I know, it would indicate if your eye reacts the same way to red and green light as it does to someone without colour blindness. I always assumed it was (for want of a better description) the wiring being crossed between eye and brain that confused the two colours? Link to comment Share on other sites More sharing options...
catman161 Posted February 23, 2014 Share Posted February 23, 2014 Interesting one Craig-do you suffer with protanomaly or deuteranomaly? Link to comment Share on other sites More sharing options...
Craig Posted February 23, 2014 Share Posted February 23, 2014 I'm not familiar with those terms but I have heard this one used when I've had my eyes tested: Tritanopia http://www.color-blindness.com/2006/05/08/tritanopia-blue-yellow-color-blindness/ I do not recall being hit to the head (one of the causes), but then I might not remember it. Link to comment Share on other sites More sharing options...
Craig Posted February 23, 2014 Share Posted February 23, 2014 Does red light still make it good for you to see your way about and not ruin your night vision? Whilst not the same thing I know, it would indicate if your eye reacts the same way to red and green light as it does to someone without colour blindness. I always assumed it was (for want of a better description) the wiring being crossed between eye and brain that confused the two colours? Honest answer. I don't know? I've not compared using red light with other colours, I simply used red light because that was the accepted method. Link to comment Share on other sites More sharing options...
Guest ecopley Posted February 23, 2014 Share Posted February 23, 2014 I was kidding about the corrector. I'm assuming that the guys who built my scope know their stuff. Thank you for the information though. While I assumed it was necessary I had wondered why. Now I know. Cheers! Link to comment Share on other sites More sharing options...
Brantuk Posted February 23, 2014 Share Posted February 23, 2014 I don't know the technical explanation in terms of wavelengths and stuff - but you'll probably find that dim red light is the least likely to trigger the eye's cones (color receptors) - or possibly stimulates them least. . Link to comment Share on other sites More sharing options...
Daz Type-R Posted March 4, 2014 Author Share Posted March 4, 2014 Well, just got in from an enjoyable few hours in the back garden, and I am shocked at just how much reducing my aperture down from 200 to 50 mm made Jupiter so much better. Granted, it wasn't blow your socks off better but you could see a difference, the glare was massively reduced which enabled better observing of the bands. Had a slight senior moment when I had what could only be described as a defraction spike across the FOV, thought it was just my eyes until after about 5 minutes I realised I had placed the 50mm opening right across one if the veins holding the secondary in place, amazing how it improved the view once I moved it! So the proof is in the pudding (if it was ever in doubt) a F24 is better than a F6 for the planets, I'm just glad it is that easy on my setup. Link to comment Share on other sites More sharing options...
dawson Posted March 5, 2014 Share Posted March 5, 2014 Well i am amazed that it's so much better, but as you say the the pudding doesn't lie. I'll have to give this a go with my newtonian before jupiter scoots off behind the neighbours house, as i think it's also got a little hole in the end cap. Thanks for feeding back daz, Fascinating. You live and learn. Jd Link to comment Share on other sites More sharing options...
Werisit Posted March 24, 2014 Share Posted March 24, 2014 Hi folks. Interesting reading. I tried this with my st 102 (f5) the other night. (Skywatcher's budget short tube refractor). It made the moon a bit less painful to view and certainly cut down the c/a. As for an increase in contrast and sharpness I can't say there was an obvious improvement. It was really still too bright as It was getting towards full. On Jupiter it did cut down the c/a but also dimmed it to a point where there really was no advantage. I wonder if you might gain on your Newt because you'd be avoiding the central obstruction and you have plenty of aperture anyway. Alan. Link to comment Share on other sites More sharing options...
Guest Posted March 25, 2014 Share Posted March 25, 2014 I always thought that if one reduced the aperture, it would also affect the Dawes limit, which would mean that smaller details cannot be resolved visually or photographically. However, if one made two or more small holes, the telescope would work like an interferometer and you would not have a lower Dawes limit. Link to comment Share on other sites More sharing options...
Werisit Posted April 12, 2014 Share Posted April 12, 2014 Don't forget to return to full aperture before you go back to DSO's. M13 doesn't look much through a 50mm F18 scope! Link to comment Share on other sites More sharing options...
andyboy1970 Posted April 14, 2014 Share Posted April 14, 2014 I have viewed the Moon through the small 50mm cap before and it improved the view/dimmed it nicely. If memory serves me isn't Resolution directly linked to apature? Or is that the much forgoten about Daws limiting magnitude? Link to comment Share on other sites More sharing options...
philjay Posted April 14, 2014 Share Posted April 14, 2014 Ok Im gonna throw something into the discussion here, yes higher f ratio will help with planetary and yes this has been known for centuries, however with your newt Daz if you want to improve planetary and double star performance try an apodising screen, see here http://home.digitalexp.com/~suiterhr/TM/MakingApod.pdf These work I used these on an 8.5 newt 30 years ago also Suiter would not write about it if they didnt. Give it a go, this way you are retaining your apeture plus fl but improving detail performance Link to comment Share on other sites More sharing options...
Cazz Posted April 14, 2014 Share Posted April 14, 2014 What an interesting thread, we'll have to try that on the st150, although I'll probably find it too bright still, but I find a pigmy bulb bright lol. :-/ Link to comment Share on other sites More sharing options...
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