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Sign Convention for Geometrical Optics

  1. Feb 17, 2005 #1

    Could someone point me to websites with tutorials on the real-virtual sign convention for geometric optics (and possibly other known conventions too)? I've been googling for some time but the results aren't too satisfying.

    PS--Tutorials with mathematics are preferred...

    Thanks and cheers
  2. jcsd
  3. Feb 19, 2005 #2
    Just a reminder.....
  4. Feb 19, 2005 #3
    Thought these might help:

    http://cord.org/step_online/st1-3/st13eii3.htm [Broken]
    http://cord.org/step_online/st1-3/st13j.htm [Broken]
    Last edited by a moderator: May 1, 2017
  5. Feb 19, 2005 #4
    HI Reshma. Thanks a pile for the links. They are indeed useful (I think I came across the first site yesterday but I'm not sure I saw it properly). I figured that the real/virtual sign convention is well suited for my purpose.

    Thanks and cheers
  6. Feb 22, 2005 #5
    Hi Vivek,

    Just another tip: the sign convention in optics is exactly analogous to the cartesian coordinate system.

    For more in mirror and lens systems, "Fundamentals in Optics" by Jenkins and White is an excellent book(a bit advanced though but worth a read).

    Hope your JEE preparations are going well. Good luck!
  7. Feb 22, 2005 #6
    Hi Reshma

    First off, thanks for your reply. Yes I do read Jenkins and White and I had been using the Cartesian Sign Convention (as mentioned in Ghatak and other Indian books) earlier, but I realized that it isn't a good tool to handle more complex problems---in particular those involving optical trains, silvered lens and combination of lenses+motion, etc. For more complex situations (and even for simple ones) the Real-Virtual sign convention is very straightforward. It has been in existence for several years (the first documented explanation I encountered was in Physics Part II by Resnick and Halliday and appears comprehensively in Resnick/Halliday/Krane) but very few people in India use it.

    I was looking for websites which would address the nuances of sign conventions (which books don't speak of anyway) earlier and I thought I may find some useful information but most websites assume at the outset that objects are to the left of the vertex and then of course the convention is obvious. They do not discuss virtual objects, images etc. in detail using their own convention. Even books like Hecht have used similar conventions.

    IF you happen to come across Krane volume II, you must see the clarity with which the R-side/V-side convention has been described. Eventually it boils down to just four points for ALL kinds of refracting surfaces.

    Thanks and cheers

    PS--This is usefull too: www.phas.ucalgary.ca/phys323/fall/notes/optics.pdf[/URL]
    Last edited by a moderator: Apr 21, 2017
  8. Feb 23, 2005 #7
    Thanks for the link, it is very cool!

    Well, if you see, first of all there isn't a single good book which covers optics comprehensively. I use Resnick, Halliday & Walker(not sure if it is different from Krane). Even in this book sign conventions are mostly assumed or left to the reader(ditto with University Physics).

    If I do come across Krane's book, I will check it out. Thanks for the recommendation.
  9. Feb 23, 2005 #8
    Bingo. I couldn't agree more. At the same time though, I think that we're asking too much for optics authors--in the west (and in IITs too--I dunno anything about other univs) its a general practice not to spoonfeed and to let students do a lot of background reading themselves, get involved in discussions and form their own ideas supplemented with fundamentals from instructors. The situation is quite different for some of us who are exposed to coaching schools for JEE prep (or other exam prep)--we're literally spoonfed...told EVERYTHING and little is left to think (that's a bad thing but not everyone would agree with me...I don't mean to sound ideal but it's bad nonetheless).

    As I come across more optics resources, I'll post them here for the benefit of students new to optics...

  10. Feb 24, 2005 #9
    You could entertain yourself more with this link: http://home.wanadoo.nl/perpetual/radiation.html [Broken]. Press the start button to launch an applet.
    Last edited by a moderator: May 1, 2017
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