Quote:
Originally Posted by PSALM19.1
All's well that ends well Knightrider!  I hope you don't mind me asking Alex a question via your thread: I am also in the market for a new EP for my 8" Dob; I use my 6mm Orion Edge On and 32mm Bintel Plossl ALOT and that's pretty much it (my other EP's are a rarely moved out of the case!); the reason to get another is to either get a 3mm or 9mm EP and your recent talk about Long Perng and their similar look to Orion's Edge On series has got my interest! Due to the fact that they differ in price significantly, it would be a bonus to get the cheaper option! Now, my 6mm Orion works REALLY well in my scope; it is clear as a bell across the whole FOV - to go to a 9mm would be for those nights where I need to pan back a bit; and then, to buy a 3mm would be for those cracker nights - I wonder though, how well a 3mm would go in an 8" Dob...? Welcome comments from anyone, not just Alex! |
Hi Shaun,
The 9mm LP is a nice eyepiece, and works well in my f5 scope- so it is certainly a well-priced option for you. I agree that 3mm is pushing the boundaries a bit. I am assuming your scope if f6? If you are getting really clear views in your 6mm then you might be able to go to 4mm, but it would be pretty rare that you could go further. Have you tried a barlow on the 6mm?
I find that there is always a limit beyond which you are simply magnifying the fuzziness of the object, and reducing the contrast. For planets this is usually around 150-200x unless you have exceptional seeing: and that would equate to your 6mm.
The other way of thinking about it is that it is not very often that you can go smaller than 1mm exit pupil: and for an f6 scope this is your 6mm eyepiece. A 3mm eyepiece will give 0.5mm exit pupil: and everything has to be just right for that to work well.
All the best,
Dean