Re: [Utah-astronomy] Where is power needed?
Jim, High power above the maximum can sometimes compensate for resolving power difficulties of a person's eye. There will not be more detail there, but sometimes the high power will make it big enough to see. Also, the seeing on vrareeare occasions will allow a "peek" at higher resolution than you might otherwise think. One word of caution. High power also brings out the defects in the eyeball. You have to be very careful about what you see, and whether it is an artifact or not. Please look up Hershel's use of high power, and his reports of moon creatures. (A famous hoax) Brent --- Jim Gibson <xajax99@yahoo.com> wrote:
Question for Rich Tenny (or anyone else)
I saw the new Televue products (41mm eyepiece etc) you mentioned last night at SLAS at:
http://www.televue.com/WSP2003/NewProdsJan2003/New_at_WSP2003.htm
I dont currently have any hi-power stuff like the 3.5mm or the 2.5mm Nagler. I ran this little program at: http://www.csgnetwork.com/telescopemagcalc.html for a 12 mirror with an f7 focal length and a 2.5mm eyepiece. One of the calculations states that for this setup the Maximum Useful Magnification is 600x; however, the 2.5mm would provide 853x. I also recall from a previous conversation we had that someone told you in reference to the Mars opposition that it could take all of the power you could crank. How does all this square? Does the Maximum Useful Magnification mean that everything over 600x (in this case) will go soft? If (big if) I bought a 2.5mm Nagler, could I use it for anything else? I am thinking that such power would only be good for bright planets.
Jim Gibson
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Great point. Let's not forget Lowell's infamous canals. And I'm still trying to decide why I believed I saw the chevron pattern of Venus with my little 8 inch, years ago. It was either an exceptional situation with just the right kind of cloud cover to cut down on glare (I was looking through clouds then) combined with a freakish condition in Venus' atmosphere, or I convinced myself I saw shapes that I did not, or some optical trick. But it sure looked real! -- Joe
One word of caution. High power also brings out the defects in the eyeball. You have to be very careful about what you see, and whether it is an artifact or not. Please look up Hershel's use of high power, and his reports of moon creatures. (A famous hoax)
Brent
--- Jim Gibson <xajax99@yahoo.com> wrote:
Question for Rich Tenny (or anyone else)
I saw the new Televue products (41mm eyepiece etc) you mentioned last night at SLAS at:
http://www.televue.com/WSP2003/NewProdsJan2003/New_at_WSP2003.htm
I donít currently have any hi-power stuff like the 3.5mm or the 2.5mm Nagler. I ran this little program at: http://www.csgnetwork.com/telescopemagcalc.html for a 12î mirror with an f7 focal length and a 2.5mm eyepiece. One of the calculations states that for this setup the ìMaximum Useful Magnificationî is 600x; however, the 2.5mm would provide 853x. I also recall from a previous conversation we had that someone told you in reference to the Mars opposition that it could take all of the power you could crank. How does all this square? Does the Maximum Useful Magnification mean that everything over 600x (in this case) will go soft? If (big if) I bought a 2.5mm Nagler, could I use it for anything else? I am thinking that such power would only be good for bright planets.
Jim Gibson
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Joe Bauman science & military reporter Deseret News bau@desnews.com (801) 237-2169
If there is sufficient interest, I am willing to hold an "eyepiece seminar" sometime this summer, when my workload eases a bit. I envision a couple of speakers, perhaps, on subjects like lens configurations, field-of-view, terminology, eyepiece history & mythology, etc., then a workshop where everyone gets to assemble their own eyepiece from surplus optics. I will choose the speakers. Then a star-party in the evening to compare commercial products and try-out everyone's home-made eyepiece from the workshop. If I can't procure the eyepiece parts free, there may be a small charge to cover those costs only. Any interest? Chuck __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
I would love to be part of that! I remember John Dobson telling folks at ALCON last summer that his favorite eyepieces were made from old binoculars scavenged from thrift stores and pawn shops... Rich --- Chuck Hards <chuckhards@yahoo.com> wrote:
If there is sufficient interest, I am willing to hold an "eyepiece seminar" sometime this summer, when my workload eases a bit.
I envision a couple of speakers, perhaps, on subjects like lens configurations, field-of-view, terminology, eyepiece history & mythology, etc., then a workshop where everyone gets to assemble their own eyepiece from surplus optics. I will choose the speakers.
Then a star-party in the evening to compare commercial products and try-out everyone's home-made eyepiece from the workshop.
If I can't procure the eyepiece parts free, there may be a small charge to cover those costs only.
Any interest?
Chuck
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--- Richard Tenney <retenney@yahoo.com> wrote:
I remember John Dobson telling folks at ALCON last summer that his favorite eyepieces were made from old binoculars scavenged from thrift stores and pawn shops...
I love that statement! I have a fondness for my own eyepieces also. It comes as a shock to many people that an eyepiece made from "junk" optics can be just as sharp, or sharper, than a mass-produced item. I also like having the option of tailoring things like eye-relief, FOV, etc., to just precisely what I"m after, not having to accept what a nameless engineer decided-on, sitting in his office somewhere. Sounds like we have the makings of a seminar! C. __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
I'd love to participate in that. Greg --- Chuck Hards <chuckhards@yahoo.com> wrote:
--- Richard Tenney <retenney@yahoo.com> wrote:
I remember John Dobson telling folks at ALCON last summer that his favorite eyepieces were made from old binoculars scavenged from thrift stores and pawn shops...
I love that statement!
I have a fondness for my own eyepieces also. It comes as a shock to many people that an eyepiece made from "junk" optics can be just as sharp, or sharper, than a mass-produced item.
I also like having the option of tailoring things like eye-relief, FOV, etc., to just precisely what I"m after, not having to accept what a nameless engineer decided-on, sitting in his office somewhere.
Sounds like we have the makings of a seminar!
C.
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Chuck, I'd certainly be interested in an eyepiece seminar. Put my name on the list. I would be really interested in seeing which eyepieces perform the best on my 10" and my 8". Dave, I hope this seminar by Chuck can asnwer many questions like the one you ask about the Orion Epic eyepieces. Brent __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com
participants (5)
-
Brent Watson -
Chuck Hards -
Greg Taylor -
Joe Bauman -
Richard Tenney