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Post by nemesis on Jan 19, 2009 11:24:15 GMT
Graham...getting an observing session is hard at the moment for exactly the reason you state...the weather! However, this week is a good time if it breaks, so we'll get one together given half a chance. PM me your telephone number and I'll give you a call if one looks possible. Just wrap up warm!
Tim.....the eyepiece versus eyepiece+ Barlow is an interesting question. Technically the eyepiece alone should be better. However, last year when viewing Saturn I used both a 7mm Nagler eyepiece and a 15mm Televue with x2 Tal Barlow, which would have given me a 7.5mm equivalent. The Nagler cost three times the Televue and Barlow combined, but was beaten soundly by the combo in my view. There was more detail and a lot more light. There'll be people who say that's rubbish, but in my opinion I can only go on what I actually viewed.
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Post by bob on Jan 19, 2009 11:48:08 GMT
Hi
What size of eyepieces would you recomend i start of with if i was going to build up a set of 4 or 5.
Thanks
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Post by nemesis on Jan 19, 2009 12:44:45 GMT
Again, depends to some extent what you will be mainly looking at. However, as a general set. With your scope I'd look at a extra wide field 30-35mm, a 12-15 mm and 17-24mm for general work, and a 5-8mm for high power.
So, say 30,17, 12 and 7.....something like that. However, if you're looking at 5, then 35, 25, 17, 12 and 7. That'd give you magnifications of x58, x81, x120, x170 and x290 with your scope.
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Post by NeilP on Jan 19, 2009 13:11:17 GMT
Eamon if it was the 15mm plossl and barlow this combo has lessglass than the nagler so probably should be sharper, naglers are not really designed for planetary work and the Televue plossls are regarded by many as the best planetary eyepieces around.
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Post by nemesis on Jan 19, 2009 14:33:33 GMT
Aha....that makes sense then, Neil, and you're right about the Plossl, it gives very good contrast. However, I'll still hark back to the strange fact that the Plossl was rubbish in my Tal 6" refractor, but great in the Dob...unless the fact that the Dob is much faster plays a big part in it. I find the 7mm Nagler almost intolerably dim, and rarely use it. If it isn't for planetary use, then what could you use it for, as it certainly seems way too dim for DSOs? (deep sky objects for the beginners....galaxies etc)
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Post by NeilP on Jan 19, 2009 15:09:55 GMT
That is because your focal length is toooooooooooo loooooonnnnnnnnnng, I think they were orginally designed to give more mag to short focal length refractors.
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Post by bob on Jan 19, 2009 15:46:04 GMT
Thanks Eamonn
After spending some time searching the interweb i have given myself a headache. When i comes to eyepieces, is there any one make that is best, should you stick to the same make for all or it it based on your scope and what your mainly using it for?
Thnaks for any help given.
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Post by irishbloke on Jan 19, 2009 15:59:20 GMT
I don't know your buget but I have heard the Baader Hyerpion eyepeices are going up by 30-40% soon. So if they would be around your price bracket better order soon. They're on First Light Optic's site.
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Post by bob on Jan 19, 2009 16:01:31 GMT
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Post by irishbloke on Jan 19, 2009 16:18:38 GMT
I have a 13mm on order. You can add 14 and 28 mm filler parts to change the focal the length. The Baader site has a pdf explaining it.
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Post by stevie on Jan 19, 2009 19:00:13 GMT
I'm not surprised the Hyperion's are going up in price, they are superb eyepieces. I'm going to order an 8mm soon, along with the two fine-tuning rings Brian mentions, to complement my 17mm. The rings are only £6.85 each from First Light Optics. They come in two sizes, 14mm and 28mm, and will change a 17mm eyepiece into a 13mm and approx 11mm respectively. You can even use them together to make the 17mm approx 9mm, if I remember correctly. The equivalent changes in the 8mm eyepiece are to 6mm and 5mm. Here's the link. You will need to expand it a bit to read it clearly. www.baader-planetarium.com/pdf/hyperion_visuell_e.pdf
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Post by stevie on Jan 19, 2009 19:17:12 GMT
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Post by bob on Jan 19, 2009 21:35:02 GMT
Just orderd the 8mm and 17mm with the two rings. Better get some overtime soon Thanks for all the help guys
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