Critical Lens?!?!!??! HELP!!?
493564
"He had never been jealous of me for a second. Now I knew that there never was and never could have been any rivalry between us. I was not of the same quality as he." Gene realizes that Finny never really wanted Gene to get bad grades. \n"I lost part of myself to him then, and a soaring sense of freedom revealed that this must have been my purpose from the first: to become a part of Phineas." Gene realized that he real purpose was to be Finny because Gene always did what Finny said.\n"Because my war ended before I ever put on a uniform; I was on active duty all my time at school; I killed my enemy there." Gene realizes that the real war Gene had to fight was the one with himself. He really didn't know who he was until years later when he comes back to Devon.
44487
Something is wrong with this question. I see it is 2 months old and would write directly if you allow email.\nI think the question should be about the object not the image. If the object is at the focal length of the lens, then the rays are parallel and easy to see with the eyes. The only image is on the inside of the eye.\nIt doesn't make sense to have length anywhere.
501273
Didn't got the question do you want the solution for all the problems of goodman's Introduction to Fourier optics book? Well I do not think I have them any more if you want a specific problem I can help you. I can even try to get a chapter solution for you. Just tell me each one, I can try to get it for you, I do not garantee but I think I may have a way to got them just send me an email (I have a yahoo email). If you have the solutions and you don't understand tell me each problem I can do it in more detail probably, not garantee at 100% but at a good 90% .
439819
As someone else already said, *never* buy a telescope that markets itself primarily based on magnification.  This is a sure sign that not only is the manufacturer playing on common assumption, but also that the scope itself is probably junk.\n\nThat said, I used--and still use--such a telescope that I got for a present as a kid.  If you treat it well, it will work well enough.  A few pointers, though:\n\n1.)  Do not use the telescope above about 120x.\n2.)  The tripod will almost certainly be jittery in the slightest wind; you may want to weigh it down with something.\n3.)  Don't use the Barlow.  You should probably ditch the eyepieces as well, which I'm guessing are cheesy Ramsdens or Huygenians; even mine at least came with a decent Kellner.  If you see an "SR", "R", or "H" symbol on the eyepieces, save your strength--order a few basic eyepieces from a reputable dealer (Orion, Meade, Celestron, etc.), perhaps with an adapter as well, from .965 to 1.25 for a better field of view.\n\nUnfortunately, ordering this extra equipment will put you well above $100, making it almost worth returning the scope and buying a more expensive one.  I leave that judgment to you, though--as someone else already wrote, this telescope could at least whet your appetite for something better.\n\nI'm sorry I can't be cheerier, but good luck.  For what it's worth, there are a few excellent, but relatively cheap scopes that can be had from Orion for $200 and under, namely their XT 4.5, which has had nothing but stellar reviews.
155010
You need an achromat, which is a compound lens (doublet) designed to have the same focal length at multiple wavelengths.  Take a look at this on from CVI lasers:http://www.cvilaser.com/Catalog/Pages/Template1.aspx?pcid=196&filter=0
481431
Dump laser impulse canon in trash.\n\nStart over with new toy.\n\nBTW, I like the subliminal resume you put in your details.  Nice touch.
572895
I just purchased a years supply of Acuvue 2 lenses for $189. Keep in mind that I was told to dispose of my contacts every two weeks!
1001012
Some liquid to contact  on your lens. It's saline. Go for laser correction.
510528
Hey, I tried to find lenses like that for ever, but never did.. I recommend getting a pair of contacts and dive with them\n\nas long as you dont blink too much or take of your mask they wont fall, I've been doing that for one year and have had no problems
984647
wellllllllllllllllllll a nice and easy question with an extra easy answer\n\nuse the formula \n                \n             1/f=1/u - 1/v \n\nwhere according to sign convention f,u will be negative. since it is left to the lens v=-8.2cm
310947
I agree with the lens cleaner thing!!  but you  need to run it a couple of times and get a air can to clean to out!
161880
I'm doing it right now. \nSee the large, thick appendage? \n\nThat is why I had to get the wide angle lens.
881120
My suggestion would be to order your frames online, and then have the lenses put in elsewhere. Just check around; somebody will have a reasonable price. The frames are what really cost; they cost only pennies to make. \nAlso, I learned (accidentally) that there is a significant price difference depending on the optometrists office. They are privately owned, so they can charge what they want. I saw glasses that I wanted, this store was in the mall, in a trendy area of town. Their price for the same frames was nearly $75 more than what I had seen at a different office. In my experience, the prices online cannot be beat.\nAlso, if you have the lenses put in elsewhere, go someplace reputable. Some years back, I had lenses put in my sunglass frames. As it turned out, the lenses were of a very poor quality; I guess that's why the price was so good!
160744
I suspect that the focal length would change sign.  That is, a convex lens would now act like a concave lens and vise versa.
766701
If you have a *real* lens......hold it a good distance away from a prominent light source. For instance, try to stand in a dark room with a shadeless lamp far away and hold the lens up in front of a piece of paper. Move the lens in toward and away from the paper until you see a clear image of the light source on the paper. Measure the distance from the paper to the lens and this will be your focal length (fl). It's tricky to measure this by yourself, but as  long as you get the 'idea' you can probably find a creative way to do it.\n\nIf you need to do this mathematically the formula is:\n\n1/f =1/d + 1/s\n\nWhere the "d" is the distance from the object to the lens, and "s" is the distance from the lens to the image. Of course "f" is the focal length.
672532
Did you take off the lens cap? Or does your video card have the most up to date drivers.\n\nPut you video card name, followed by Drivers, into a google search\n\nSearch *video card name* drivers\n\nTry that.
406370
More light is needed as the magnification is increased since the size of the hole of the objective lens decreases. Try it!