kitsuna
06-04-2011, 09:13 AM
Hey all, just thought I'd give a little impromptu report on my first ever 'premier' eyepiece.
Those of you who've been following some of my earlier threads will know that I recently bought a 10 inch Skywatcher Black Diamon dobsonian (f4.7). I'd been using the standard issue plossl eyepieces, and had been enjoying my new scope immensely.
Last night my new Televue 24mm Pan turned up.
I'd been reading about various eyepieces on the web (and on this site) and I'd been hearing that it was an exceptional eyepiece (at least, when it first came out).
Now I must confess that I'd never actually used this eyepiece before (either in my own scope, or checking it out in someone elses), so I basically took a punt.
I got home late last night, so I didn't have time to set up my scope properly. I basically dropped it on the lawn outside, spent maybe a minute collimating and brought out my 25mm plossl and the Pan. I didn't have time to wait for the scope to cool down. I knew that I wouldn't be getting the best viewing, but considering both eyepieces would be subject to the same mediocre conditions, it'd still be a fair comparison. It'd also be a blind test because the plossl is the only eyepiece I've ever used in my scope. So it's my only basis for comparison.
I knew it wasn't going to be a fair fight, because the plossl is a budget item issued with the scope, whereas the Pan has Televue and Al Nagler behind it. Nevertheless;
Seeing was quite good last night. I have no doubt that if I had time to properly collimate and wait for the mirrors to cool, it would have been excellent.
I took a look at Omega Centauri thru the plossl. Still nice, if a little dim in my light polluted area.
Then the Pan.... :eyepop:
I suddenly came to understand what people meant by "the spacewalk experience."
Just amazing. The stars were more sharp, more easily resolved and as far as I could tell, coma had effectively been eliminated across the FOV, even with my lazy collimating.
I couldn't believe what I was seeing, so I put the plossl back in, and found Sirius to do a coma comparison.
Keep in mind, I'd done a lazy collimation job and hadn't let the mirrors cool. When I've bothered to do it properly, I know the plossl can do better than what is written below;
In the plossl, Sirius was a sharp pinpoint of light. I pushed it to the edge, and found that there was noticable coma at about 1/3 of the way from the edge of the FOV, and quite bad coma 1/4 of the way from the edge.
I barlowed it (2x) to make it more obvious. I had noticable coma probably 4/9ths of the way from the edge, and quite bad coma 1/3rd of the way from the edge.
With the Pan, and no barlow Sirius was sharper, and I couldn't readily identify ANY coma even right to the edge of the FOV. I SUSPECT there may have been SOME, perhaps in the last 1/10th or 1/20th of the FOV, but as I said, I couldn't readily identify it.
I barlowed it to try and find some flaws. Even under barlow the image was sharp. At the very edge of the FOV, it was still quite sharp, though it did look as if Sirius had developed a small blue tail pointing towards the centre of the FOV.
I should also point out that this was just a generic 2x barlow of perhaps dubious quality, rather than a specialty item.
My incredulity grew when I put Saturn in view. I did this on purpose because I figured that as the plossl was punching outside its weightclass anyway, I might as well point it at an object that the Pan isn't really designed for. I'd had quite good views in the plossl of Saturn, so I thought it might be a bit more of a close match. Right? :shrug:
Wrong.
With the barlow or without, the Pan demolished the plossl. Saturn stayed in view longer, so I didn't have to do the "dob nudge" as much (that alone made it infinitely more enjoyable to look at). The rings were more easily resolved, and I saw far more colour and atmospheric detail. There was much more colour contrast in the rings and disc. The other thing was that the 68 degree FOV meant that not only could I see Saturn better, I could see it with the background stars and objects in view, making it much more of a celestial object, rather than a disk painted on a black background (as with the plossl).
The conclusion I've come to is that I'll probably never use the plossl again except as a paperweight. It was seriously outclassed. I can't recommend it highly enough.
I'm so pleased with it, I've now put in an order for a Televue Radian.
Happy watching all. :thumbsup:
Those of you who've been following some of my earlier threads will know that I recently bought a 10 inch Skywatcher Black Diamon dobsonian (f4.7). I'd been using the standard issue plossl eyepieces, and had been enjoying my new scope immensely.
Last night my new Televue 24mm Pan turned up.
I'd been reading about various eyepieces on the web (and on this site) and I'd been hearing that it was an exceptional eyepiece (at least, when it first came out).
Now I must confess that I'd never actually used this eyepiece before (either in my own scope, or checking it out in someone elses), so I basically took a punt.
I got home late last night, so I didn't have time to set up my scope properly. I basically dropped it on the lawn outside, spent maybe a minute collimating and brought out my 25mm plossl and the Pan. I didn't have time to wait for the scope to cool down. I knew that I wouldn't be getting the best viewing, but considering both eyepieces would be subject to the same mediocre conditions, it'd still be a fair comparison. It'd also be a blind test because the plossl is the only eyepiece I've ever used in my scope. So it's my only basis for comparison.
I knew it wasn't going to be a fair fight, because the plossl is a budget item issued with the scope, whereas the Pan has Televue and Al Nagler behind it. Nevertheless;
Seeing was quite good last night. I have no doubt that if I had time to properly collimate and wait for the mirrors to cool, it would have been excellent.
I took a look at Omega Centauri thru the plossl. Still nice, if a little dim in my light polluted area.
Then the Pan.... :eyepop:
I suddenly came to understand what people meant by "the spacewalk experience."
Just amazing. The stars were more sharp, more easily resolved and as far as I could tell, coma had effectively been eliminated across the FOV, even with my lazy collimating.
I couldn't believe what I was seeing, so I put the plossl back in, and found Sirius to do a coma comparison.
Keep in mind, I'd done a lazy collimation job and hadn't let the mirrors cool. When I've bothered to do it properly, I know the plossl can do better than what is written below;
In the plossl, Sirius was a sharp pinpoint of light. I pushed it to the edge, and found that there was noticable coma at about 1/3 of the way from the edge of the FOV, and quite bad coma 1/4 of the way from the edge.
I barlowed it (2x) to make it more obvious. I had noticable coma probably 4/9ths of the way from the edge, and quite bad coma 1/3rd of the way from the edge.
With the Pan, and no barlow Sirius was sharper, and I couldn't readily identify ANY coma even right to the edge of the FOV. I SUSPECT there may have been SOME, perhaps in the last 1/10th or 1/20th of the FOV, but as I said, I couldn't readily identify it.
I barlowed it to try and find some flaws. Even under barlow the image was sharp. At the very edge of the FOV, it was still quite sharp, though it did look as if Sirius had developed a small blue tail pointing towards the centre of the FOV.
I should also point out that this was just a generic 2x barlow of perhaps dubious quality, rather than a specialty item.
My incredulity grew when I put Saturn in view. I did this on purpose because I figured that as the plossl was punching outside its weightclass anyway, I might as well point it at an object that the Pan isn't really designed for. I'd had quite good views in the plossl of Saturn, so I thought it might be a bit more of a close match. Right? :shrug:
Wrong.
With the barlow or without, the Pan demolished the plossl. Saturn stayed in view longer, so I didn't have to do the "dob nudge" as much (that alone made it infinitely more enjoyable to look at). The rings were more easily resolved, and I saw far more colour and atmospheric detail. There was much more colour contrast in the rings and disc. The other thing was that the 68 degree FOV meant that not only could I see Saturn better, I could see it with the background stars and objects in view, making it much more of a celestial object, rather than a disk painted on a black background (as with the plossl).
The conclusion I've come to is that I'll probably never use the plossl again except as a paperweight. It was seriously outclassed. I can't recommend it highly enough.
I'm so pleased with it, I've now put in an order for a Televue Radian.
Happy watching all. :thumbsup: