Quote:
Originally Posted by Paul Haese
Yep 3x is more likely the best solution to this problem. I use the 2x regularly, with the filter wheel acting as an extension and this gives me very large image scales. The 3x with your native focal length would be fine and get you up to near 4x meaning a focal length of 7315mm. With a small extension you could get it up near 10,000mm. I could loan you a 3x to see if this will work and it not at least you would know without spend more money than necessary.
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Thanks very much for the offer Paul, I really do appreciate it, however this afternoon I rang Micheal at Bintel and he is quite willing to let me change the 5x powermate for a 3x TV barlow. Looking at the Televue data graph for the 3x at 70mm from the top surface of the barlow it is producing 4.5x add another 30mm and it delivers 5x. My filter wheel and DMK give me spot on 70mm from the chip to the top surface of the barlow. The FL of my scope is 1,827mm, with my DMK and filter wheel on the 3x TV barlow at 4.5x my FL would become 8,221mm and if I turn up a 30mm extension with my lathe, at 5x my FL would be 9,135mm. It looks like this will be the best way to optimize the DMK for my optical system.
I see on the TV that the Clayton weir is being built. When completed we will be able to cruise down to Clayton with our boat which hasn't been out of the storage shed at The Marina H. I. since Oct 2007. Will have to catch up with you some time.
Quote:
Originally Posted by bird
Trevor, the 3x TV sounds like a good option if you can get it up to 4.5x.
I think it's also a 3 element barlow (from memory) so one less lens than the 4 element powermates, a slight plus.
cheers, Bird
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Thanks Anthony, checking the data sheet for the TV barlows it seems there are only 2 elements in them, have attached the Televue data graph, the 3x TV does seem to offer the best solution for my needs. It would be great to upgrade my CCD but the upgrade is not really within my means at this stage. I wonder why Al Nagler has not put out a 3x Powermate.