Results 1 to 6 of 6

Thread: lenses

  1. #1

    Default lenses

    how does an electronic lens from a digicam compare to those prime lenses or zoom lenses??

    lets say, fer eg, on the S602z, it has a 6x optical zoom,..... from abt 28mm - 210mm, how does this kind of lens compare to those zoom lenses used on 35mm SLR or DSLR??

    if lenses could be made so compact, y not just make these kind of compact lenses fer all kinds of cameras???? wouldnt it be ezier to carry arun and as well to use??



  2. #2

    Default

    Cos the normal digicam got small sensor... so can haf small lens lor...
    dats why thier short lens like 6mm-40mm can be equivalent to 200mm on slr....

    dats y slr have to use big lens, cos thier sensor is big ...
    like the oly e-1 lens is mucho smaller den thier competing slr's cos thier lens design for smaller sensor, others design for 35mm film size...

  3. #3
    Member
    Join Date
    Nov 2003
    Location
    Northeast
    Posts
    1,226

    Default

    huh? then how does film compact with zoom lens compare with zoom lens on SLR? I mean the sensor size (aka 35mm film) is the same what....how come the disparity in lens size?

  4. #4
    Deregistered
    Join Date
    Dec 2002
    Location
    Singapore
    Posts
    6,601

    Default

    dee, the effect is just like that:

    a smaller lens usually has a shorter focal length, which translates to using a smaller exposure area or imaging circle... while for slr's, the lenses have a much longer focal length, so that there is a distance big enough for the light through the lens to fall onto the film/sensor.

  5. #5

    Default

    Quote Originally Posted by justarius
    huh? then how does film compact with zoom lens compare with zoom lens on SLR? I mean the sensor size (aka 35mm film) is the same what....how come the disparity in lens size?
    Ah... u mean like on the compact cameras with zoom ar?
    hmmmm .........
    correct mi if i am wrong, but i think its to allow for the accomadation
    of the lenses...
    to allow the interchangeable lenses they need to have a large enuff daimeter to ensure its structural integrity so haff to be bigger....
    also on compact film camera's i think they are usually not as bright ... hence can use smaller daimeter lenses ...

  6. #6

    Default

    From THIS FAQ that NorthernLights posted ....

    I think this is why SLR lenses are SO much bigger....

    the popularity of SLR cameras caused the creation of many "retrofocus" lenses, lenses that have "virtual" exit pupils much farther away from the film than you would expect from their focal lengths. This was done to increase "back focus" (the physical distance between the rear lens element and the film or sensor) so that the rear elements of the lens would physically clear the swinging mirror in the SLR cameras.

    .....

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •