catman161 Posted May 22, 2012 Share Posted May 22, 2012 Hi guys, Sorry of another Barlow thread. However I wanted to be specific. What's the difference between say a Televue 2x powermate and the significantly cheaper Televue 2x Barlow? I am thinking both the difference that might be seen visually and or simple planetary imaging with my SPC900 webcam. Is it worth spending the extra for a powermate? Also is it better to get a higher strength powermate like a 4 or 5x rather than a 2x? Thanks in advance for your thoughts Felix Link to comment Share on other sites More sharing options...
Guest Kheldar Posted May 22, 2012 Share Posted May 22, 2012 On the dob a 4x or 5x is going to be completely unusable, I suspect you will struggle to track on a target at 3x! Even EQ mounted it was a rare night when I could use a 4x let alone a 5x. The Powermate is in a different league to any Barlow due to the way it's constructed. That's why it costs so much more For planetary imaging, you simply can't do better and I guess this is going to be true of visual as well. However, what exactly are you going to use it for visually? You've currently got the zoom so have 150x at the high power end. Stick 4x on that and you are well beyond the useable visual magnification. I would recommend a 3x TAL max for your planetary imaging, and remember that it's going to take some practice to use that really Link to comment Share on other sites More sharing options...
catman161 Posted May 22, 2012 Author Share Posted May 22, 2012 Awesome thanks Stephen thats really good (and comprehemsive) advice-exactly what i was looking for .I was wanting to use it mainly for the webcam imaging of planets. So I thought maybe the 2.5x powermate. Does that sound like a reasonable idea? Link to comment Share on other sites More sharing options...
Guest Kheldar Posted May 22, 2012 Share Posted May 22, 2012 If you got the cash that sounds like a plan to me Link to comment Share on other sites More sharing options...
Brantuk Posted May 22, 2012 Share Posted May 22, 2012 A powermate is a pure magnifyer - you just can't see it either visually or imaging. It gets right out of the way and just magnifies. Ordinary barlows (including TV) make their presence known one way or another Link to comment Share on other sites More sharing options...
catman161 Posted May 22, 2012 Author Share Posted May 22, 2012 Goo stuff thanks Stephen. Much appreciate your more learned opinion. Astronomy seems to turn up new questions for me everyday! Nice one thanks Kim. I think I will go for the powermate-maybe post wedding though, she's already highly strung as it is Link to comment Share on other sites More sharing options...
Brantuk Posted May 22, 2012 Share Posted May 22, 2012 Slap it on the wedding list (and invite some rich buddies lol) Link to comment Share on other sites More sharing options...
catman161 Posted May 23, 2012 Author Share Posted May 23, 2012 Slap it on the wedding list (and invite some rich buddies lol) Ha ha I don't think I would get away with that! Link to comment Share on other sites More sharing options...
Guest Eddy Posted May 23, 2012 Share Posted May 23, 2012 I'm just going to steal a question in this thread, Kim what do you mean by they make their presence known? Does the FOV get reduced or something? I can't say I've noticed much Link to comment Share on other sites More sharing options...
Brantuk Posted May 23, 2012 Share Posted May 23, 2012 You'll get all sorts of effects with barlows Eddy - field curvature, coma, chromatic aberation, etc - all down to the interraction between the scope characteristics and those of the barlow. But a beginner won't notice it too much - it takes a well trained eye and a lot of imaging experience (which I don't have I hasten to add) to really see it. The powermates just magnify and nothing else cos the lens arrangement cancels out all the nasty stuff. Ask me again in 5 yrs when I've had a good go at imaging - I'm just regurgitating stuff good imagers have pointed out to me Link to comment Share on other sites More sharing options...
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