Canon EF 24-70mm F2.8L USM

ef24-70.jpg

4 Responses to Canon EF 24-70mm F2.8L USM

  1. John Nevill says:
    February 14, 2007 at 6:12 pm

    Incredibly sharp lens with a minor drop off at f2.8.

    CA gets better as you stop down, but its quite significant wide open, although easily removed in post processing.

    Its quite a heavy beast, build quality is excellent and it offers good dust and water resistance.

    Couple this with a EF 70-200 f2.8 IS and you don’t need much else.

    The f2.8 aperture easily outweighs the lack of IS and it’s a favourite amongst wedding and landscape photographers.

    Used on a 1.3x or FF sensor you get excellent coverage. I love it!

  2. Ian Lockwood says:
    February 25, 2008 at 12:07 pm

    Dear Sir
    I find the graphs of sharpness and chromatic abberation very interesting. I have reservations concerning my recent purchase of a Canon 40D with a 24-70mm f2.8L
    lens. The lateral CA between focal length of 24mm and around 38mm seems
    excessive with red fringing at high contrast boundaries at the left or right hand parts
    of the image. Could you indicate what the vertical scales represent on your graphs
    to help me assess my Lens/Body performance and better discuss the matter with
    Canon.
    Yours faithfully
    Ian Lockwood

  3. John Nevill says:
    February 25, 2008 at 1:22 pm

    Hi Ian,

    The CA graph depicts one or two bars per aperture. Each bar represents a region of interest (ROI) taken from the target frame e.g. Edge and Extreme Edge. The value unit is area width in pixels i.e. the lower the value the less area width of pixels visible, hence lower chromatic aberration.
    In general, values >2 pixels are poor.

    The EF24-70 Quality Assurance varies significantly!

    I know some people have bought / exchanged multiple copies to get a good one.

    To be honest if you are getting high levels of CA on a APS-C sized sensor then I would suggest returning it.

    My copy is both sharp and relatively CA free even on a 5D, although worse wide open at f/2.8.

  4. Ian Lockwood says:
    February 26, 2008 at 5:07 pm

    Hi John
    Thanks for your info. Canon suggest I send Camera and lens for calibration.
    I guess I’ve got to follow the system.

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