I thought I could push the limit of 85FL scope so I got a 5mm baader hyperion eyepiece, normally as a rule of thumb, the hightest mag for a 85mm scope should be no higher than 85x, I assumed this is high grade lens and should be ok at 100x, but actually I don't think anyone else should try this any more, not hleping in relolution, brightness is not the big issue, but simply can't get a sharp image, maybe it's my scope though.
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85FL and 5mm baader hyperion to get 104x, not a good idea (1 Viewer)
- Thread starter zone8848
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John Russell
Well-known member
A similar constellation has been used with success.
My dealer in Bonn has a customer, who uses an 85 mm Diascope with a modified 5 mm Vixen LVW (shortened barrel, I believe) to inspect the vanes on wind machines for damage.
He uses a heavy tripod and Manfrotto 501 head and can apparently detect 0,5 mm cracks at a distance of 100 m. It saves a lot of time and effort compared to a direct inspection.
John
My dealer in Bonn has a customer, who uses an 85 mm Diascope with a modified 5 mm Vixen LVW (shortened barrel, I believe) to inspect the vanes on wind machines for damage.
He uses a heavy tripod and Manfrotto 501 head and can apparently detect 0,5 mm cracks at a distance of 100 m. It saves a lot of time and effort compared to a direct inspection.
John
Kevin Purcell
Well-known member
That's about 1 arcsecond wide cracks. Interesting as it's a bit lower than the (supposed) Dawes limit for an 85mm objective at 1.6 arc seconds.
But he's not splitting stars (and cracks have length) so perhaps it's not valid in that circumstance.
Still it's pushing the scope to it's limit (and perhaps a bit beyond!).
henry link
Well-known member
The trick here is "single line detection" which can be done with much finer lines than can be separated for line pair resolution.
I got interested in this a few years ago and tried to do some measurements using strands of my wife's very fine hair. I don't remember the exact results now, but I was amazed at the tiny angles involved. An 85mm scope should be capable single line detection to a very small fraction of an arc second, maybe 0.1 or even less.
I got interested in this a few years ago and tried to do some measurements using strands of my wife's very fine hair. I don't remember the exact results now, but I was amazed at the tiny angles involved. An 85mm scope should be capable single line detection to a very small fraction of an arc second, maybe 0.1 or even less.
Fernando np
Well-known member
Hi,
My experience with the TeleVue Radian is more positive. When birding in group and looking at long distances, a 100X among the scopes has sense. I remember a glorious day in the Ebro Dam in northern Spain when some identifications were posible in this way, overpassing the resolution of the 88mmKowa at 60X, the king of the hill. A previous post of mine didn't wake up interest in this forum
http://birdforum.net/showthread.php?t=114068
Fernando
My experience with the TeleVue Radian is more positive. When birding in group and looking at long distances, a 100X among the scopes has sense. I remember a glorious day in the Ebro Dam in northern Spain when some identifications were posible in this way, overpassing the resolution of the 88mmKowa at 60X, the king of the hill. A previous post of mine didn't wake up interest in this forum
http://birdforum.net/showthread.php?t=114068
Fernando
