Results 1 to 4 of 4

Thread: Why different size and wt for the same range of lenses?

  1. #1

    Default Why different size and wt for the same range of lenses?

    Hi guys

    Was just wondering for the same range of lenses of different make (eg Canon 24-70 f/2.8, Tamron 28-75 f/2.8, Sigma 24-70 f/2.8), why are the filter size, weight, etc different despite having the same f stop?

    Was thinking of bring one of these lens for travelling and now, the Tamron lens seems to win hands down in terms of weight and size.

  2. #2
    Senior Member
    Join Date
    Sep 2003
    Location
    In this small world
    Posts
    3,142

    Default

    They can always make the filter size bigger (why I dunno maybe to reduce vignetting). Also the design of the lens (Tamron here) which can give a small filter size. I also dun understand why since I am not an engineer and I dun really care.

    Not all lens are what they are listed (for example a 300mm prime may be only 295mm as there are some allowance of 5% tolerance in difference).

  3. #3
    Senior Member
    Join Date
    Feb 2002
    Location
    Perth Australia
    Posts
    2,548

    Default

    Quote Originally Posted by code
    Hi guys

    Was just wondering for the same range of lenses of different make (eg Canon 24-70 f/2.8, Tamron 28-75 f/2.8, Sigma 24-70 f/2.8), why are the filter size, weight, etc different despite having the same f stop?

    Was thinking of bring one of these lens for travelling and now, the Tamron lens seems to win hands down in terms of weight and size.
    The reasons for the differences are many, however here's a few of them:

    * Different optical designs between lenses from different manufacturers.
    * Different materials used internally and externally by different manufacturers
    * Different glass used in the lenses from different manufacturers

    Get the idea? Each manufacturer has their own set of design criteria (optical performance, weight, physical size, durability, cost etc) and achieves the design goals in their own way. There are however marked differences in the lenses, not just in size and cost, but also in optical performance for example.

    Ian
    The Ang Moh from Hell
    Professional Photography - many are called, few are chosen!

  4. #4
    Senior Member
    Join Date
    Mar 2004
    Location
    singapore
    Posts
    2,522

    Default

    Quote Originally Posted by code
    ... (eg Canon 24-70 f/2.8, ..., Sigma 24-70 f/2.8)...
    Probably because they use different design & technology to make their compound lenses. Else what's the difference in purchasing Canon over Sigma if they are the same everything except price?

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
  •