Results 1 to 12 of 12

Thread: Lens/Zoom

  1. #1
    Member desmondnwj's Avatar
    Join Date
    Jun 2008
    Location
    Tiong Bahru
    Posts
    276

    Question Lens/Zoom

    To all Veterans out there,

    Scenario: There's a subject that Peter would like to take a picture of. However, it is too far away. How should Peter decide what lens to buy to achieve the zoom that he need?

    Appreciate your feedback.

  2. #2

    Default Re: Lens/Zoom

    He should decide by calculating which lens will allow him to maintain a positive balance on his bank account.
    Alpha

  3. #3
    Senior Member zac08's Avatar
    Join Date
    Feb 2005
    Location
    East
    Posts
    11,755

    Default Re: Lens/Zoom

    Quote Originally Posted by desmondnwj View Post
    To all Veterans out there,

    Scenario: There's a subject that Peter would like to take a picture of. However, it is too far away. How should Peter decide what lens to buy to achieve the zoom that he need?

    Appreciate your feedback.
    Check :

    a) is it possible to get closer to the subject?

    b) is it possible to use a TC to get the range required at the expense of the aperture loss.

    c) buy a long lens which can allow you to reach the distance required, budget willing...

    d) buy a long lens with a TC to get the range required (cheaper than a full long lens) i.e.
    70-200 f2.8 with a 2x TC would be cheaper than getting a 400mm f2.8. But you lose 2 stops of light and get a 140-400 f5.6 instead...
    Michael Lim
    My Flickr Site

  4. #4
    Member desmondnwj's Avatar
    Join Date
    Jun 2008
    Location
    Tiong Bahru
    Posts
    276

    Default Re: Lens/Zoom

    Rashkae: Can assume "he" is beri rich =]

    zac08: Thanks for your valuable feedback. From a layman point of view, I was wondering if say a pigeon is 50m away what spec of lens can home in on it and cover about 50% of the picture. Is there a formula for this (size of object, distance away, size on picture)?

  5. #5
    Senior Member zac08's Avatar
    Join Date
    Feb 2005
    Location
    East
    Posts
    11,755

    Default Re: Lens/Zoom

    Quote Originally Posted by desmondnwj View Post
    Rashkae: Can assume "he" is beri rich =]

    zac08: Thanks for your valuable feedback. From a layman point of view, I was wondering if say a pigeon is 50m away what spec of lens can home in on it and cover about 50% of the picture. Is there a formula for this (size of object, distance away, size on picture)?
    Let's just average a pigeon at about 40cm long. To get this inside 50% of the image sensor, you'd need to know the sensor size, the focal length as well as the angle of view.

    According to a calculation website I visited, 2796.8 mm would be required to get it fully in view. So Half of that would be 1350mm or so...

    you got the dough for a 1000mm lens?

    PS : this calculation was done on a Nikon 1.5 x crop DSLR. So if you are calculating it on a different system, pls try it again here :

    http://www.cambridgeincolour.com/tut...era-lenses.htm
    Michael Lim
    My Flickr Site

  6. #6
    Member desmondnwj's Avatar
    Join Date
    Jun 2008
    Location
    Tiong Bahru
    Posts
    276

    Default Re: Lens/Zoom

    zac08: You are a serious photographer! Thanks for spending the time explaining. Conclusion, unless you are a fifthly rich, use a high res camera to capture than digitally enlarge from there and crossfingers that you got the details

  7. #7

    Default Re: Lens/Zoom

    Quote Originally Posted by desmondnwj View Post
    zac08: You are a serious photographer! Thanks for spending the time explaining. Conclusion, unless you are a fifthly rich, use a high res camera to capture than digitally enlarge from there and crossfingers that you got the details
    No, never digitally enlarge, you'll make it look grainy. Crop crop crop!

    (yes, this is where megapixels does matter)
    Alpha

  8. #8
    Senior Member giantcanopy's Avatar
    Join Date
    Feb 2007
    Location
    SG
    Posts
    6,232

    Default Re: Lens/Zoom

    Quote Originally Posted by desmondnwj View Post
    zac08: You are a serious photographer! Thanks for spending the time explaining. Conclusion, unless you are a fifthly rich, use a high res camera to capture than digitally enlarge from there and crossfingers that you got the details
    There is a 1700mm prime by zeiss and a 1700 - 1200 zoom by nikon

    Actually there is a limit to having more MP for ur sensor. apart from noise the lens might even be outresolved.

    Ryan

  9. #9
    Member desmondnwj's Avatar
    Join Date
    Jun 2008
    Location
    Tiong Bahru
    Posts
    276

    Default Re: Lens/Zoom

    Rashkae: ahhh... "I must crop, I must crop, I must croppppp....."

    giantcanopy: Thanks for insights!

    Anyone tried placing camera to a telescope? maybe I am digressing

  10. #10

    Default Re: Lens/Zoom

    Yea, astrophotography =P

  11. #11
    Member desmondnwj's Avatar
    Join Date
    Jun 2008
    Location
    Tiong Bahru
    Posts
    276

    Default Re: Lens/Zoom

    I dun mean specialize equipment. Literally, 1 x camera and 1 x telescope.

  12. #12
    Senior Member zac08's Avatar
    Join Date
    Feb 2005
    Location
    East
    Posts
    11,755

    Default Re: Lens/Zoom

    Quote Originally Posted by desmondnwj View Post
    I dun mean specialize equipment. Literally, 1 x camera and 1 x telescope.
    Yes... all you need is a adapter for the telescope to fit the camera.
    Michael Lim
    My Flickr Site

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
  •