Crop Factor - EF vs EF-S lenses

Discussion in 'Digital Photography' started by ftaok, Sep 26, 2008.

  1. ftaok macrumors 601

    ftaok

    Joined:
    Jan 23, 2002
    Location:
    East Coast
    #1
    Hi all,

    I was just reading a review on the new 50D and came across this confusing bit.

    What the heck does this mean? I thought the crop factor was applicable to all lenses, regardless of whether it was EF or EF-S. Or is the reviewer wrong?

    Here's the entire review (well, I skipped to the 3rd page). The section that I'm quoting is about halfway down.

    LINK
     
  2. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #2
    The reviewer is an idiot. EF and EF-S lenses are subject to the same crop factor on crop bodies.

    Canon chose to quote EF-S focal lengths in standard 35mm equivalents even though they can't be mounted to fullframe/35mm bodies!
     
  3. OreoCookie macrumors 68030

    Joined:
    Apr 14, 2001
    Location:
    Sendai, Japan
    #3
    Well, it's not well-formulated, but what that means is the following: if a lens is constructed for full frame, then the focal lengths are chosen accordingly: a standard zoom typically has focal lengths between 24 and 80 mm (e. g. 28-70). On crop sensors, these lenses have a different viewing angle than they were `designed' for: a standard zoom becomes a slight tele zoom (~45-130 mm). So people expecting a standard zoom get a tele zoom.

    If the lens was designed for crop sensors, then different focal lengths were chosen, e. g. 17-50 mm for a standard zoom. This corresponds roughly to 28-80 on full frame or film.

    In any case, the paragraph is very confusingly written.
     
  4. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #4
    To me that's not what the paragraph says. It says "This expectation-defeating effect doesn't happen with the EF-S lenses, as they have the multiplier built in". That is simply untrue. My EF-S 17-85mm does not shoot as though it was a 17mm lens on a standard 35mm camera. It shoots as though it were a 27.2mm lens. So the multiplier is not built in.
     
  5. ftaok thread starter macrumors 601

    ftaok

    Joined:
    Jan 23, 2002
    Location:
    East Coast
    #5
    OK, that's what I thought.

    I have decided that I'm getting the 50mm f/1.8 and this review was about to throw a monkey wrench in my thought process. I have been using my 18-55 lens at 50mm to help me decide between the 50mm lens or the 35mm.

    If there was something funky with EF-S lenses and the 1.6x conversion, I'd have to re-think.

    Thanks.
     
  6. robbieduncan Moderator emeritus

    robbieduncan

    Joined:
    Jul 24, 2002
    Location:
    London
    #6
    Whilst it's your decision I've got both a 50mm f/1.4 USM and a 35mm f/1.4 L USM and I find that I rarely use the 50mm lens as it's too long on a crop body indoors for parties/pub etc where the speed is useful...
     
  7. Scarlet Fever macrumors 68040

    Scarlet Fever

    Joined:
    Jul 22, 2005
    Location:
    Bookshop!
    #7
    Regardless of what the review says, get the 50mm f/1.8. It is easily my most used lens. It has taught me a lot about photography.
     
  8. ChrisA macrumors G4

    Joined:
    Jan 5, 2006
    Location:
    Redondo Beach, California
    #8
    On the web anyone, even your dog can review a product. You just have to figure that the advice you get on these forums is worth what you paid for it.

    Print media at least has some minimal level of editorial review but on the web that function falls on the reader.
     
  9. ftaok thread starter macrumors 601

    ftaok

    Joined:
    Jan 23, 2002
    Location:
    East Coast
    #9
    I was deciding between the 50 and the 35 by setting my 18-55 to approximately those focal lengths. I found that I preferred shooting at 50 rather than 35. My little girls like to grab at the camera lens and I found that with the 50mm setting, I could stand farther away and get more candid shots. With a 35mm lens, I got a lot of shots of my daughter reaching for the lens.

    ft
     
  10. Westside guy macrumors 601

    Westside guy

    Joined:
    Oct 15, 2003
    Location:
    The soggy side of the Pacific NW
    #10
    I don't think there's any confusion with the review's wording. Unfortunately, what it says is flat-out wrong. :D

    Someone should ask the reviewer about the Canon EF-S 10-22. If there's some "multiplier built-in"... that's one seriously wide-angle piece of glass. :rolleyes:
     
  11. taylorwilsdon macrumors 68000

    taylorwilsdon

    Joined:
    Nov 16, 2006
    Location:
    Bay Area
    #11
    Who gave this idiot a 50d? That was one of the worst reviews I've ever read. I'd demand my camera back and ask for the writeup to be killed if I was Canon.
     

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