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Thread: Confused about crop factor

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    Confused about crop factor

    In general terms, if I fit a 200mm focal length lens from a 35mm film camera to my Canon 600D does the crop factor mean just a smaller field of view or is the subject actually brought closer (larger if you like) than it would be on a film camera.

    I am sure this is a dumb question. I have read the other posts I can find on this but like I say, I'm confused.

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    Arch-Σigmoid Ausphotography Regular ameerat42's Avatar
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    Was. You are right the first go. You get a smaller field of view (FOV).

    Think: f=200mm lens gives x size image, no matter what, full-frame, crop frame. It is still the same size image.
    When it lands on a smaller sensor (crop sensor), it gives a reduced FOV. The edges are missing.

    OK, so some people say, "OOOOHH! It's like having a longer focal length." You can say, "Well, not quite."

    On the "dumb question" topic, well, unfortunately you're wrong there
    Last edited by ameerat42; 19-06-2014 at 11:08pm.
    CC, Image editing OK.

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    Thanks for that.

    I do wish people wouldn't advertise a lens as 200mm equivalent to 400mm on a digital camera. I am sure lots of people get caught out with that one!

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    Arch-Σigmoid Ausphotography Regular ameerat42's Avatar
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    Who knows why? I suppose those of us who have used 35mm gear would find it a useful comparison
    (like "miles-per-gallon"), but it may well just show a "Bigger (numbers) is better!!!" motivation.

    (Actually, I'm quite used to "litres-per-100km" now I won't ever get used to the skyrocket prices, though!)
    Last edited by ameerat42; 20-06-2014 at 5:09pm.

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    Still in the Circle of Confusion Cage's Avatar
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    Quote Originally Posted by ameerat42 View Post
    ........(Actually, I'm quite used to "litres-per-100km" now
    Am, it's only been 48 years.

    PS: A brief explanation and illustration of the crop factor from KR (Yes, I know he's not everyone's 'guru' )

    http://www.kenrockwell.com/tech/crop-factor.htm
    Last edited by Cage; 20-06-2014 at 5:26pm.
    Cheers
    Kev

    D600 : D7200 and too much stuff to list

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    Moderately Underexposed I @ M's Avatar
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    The library here on AP has a couple of illustrative examples of crop factor.

    Here

    &

    Here



    Quote Originally Posted by Cage View Post
    PS: A brief explanation and illustration of the crop factor from KR (Yes, I know he's not everyone's 'guru' )
    Kev, now be a good lad and toddle off and wash your mouth out. At least the excellent examples on this site were compiled by a member who has actually used a camera unlike that other person you refer to.
    Andrew
    Nikon, Fuji, Nikkor, Sigma, Tamron, Tokina and too many other bits and pieces to list.



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    Arch-Σigmoid Ausphotography Regular ameerat42's Avatar
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    Yep. That's a good illustration, Kev.

    And only 45 years! Why, it seems like just yesterday...

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    It's all about the Light!
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    regards, Kym Gallery Honest & Direct Constructive Critique Appreciated! ©
    Digital & film, Bits of glass covering 10mm to 500mm, and other stuff



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    It's all about the Light!
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    All Ken Rockwell refs should be removed as they are notoriously unreliable!

    Refer http://www.kenrockwell.com/about.htm quote:
    This website is my way of giving back to our community. It is a work of fiction, entirely the product of my own imagination. This website is my personal opinion. To use words of Ansel Adams on page 193 of his autobiography, this site is my "aggressive personal opinion," and not a "logical presentation of fact."
    Further he is downright dangerous as the KR mis-information does cause harm to beginners and even some more experienced people.
    Eg. in effect stunting photographic 'growth' or causing people to waste money

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    from KR (Yes, I know he's not everyone's 'guru' )

    http://www.kenrockwell.com/tech/crop-factor.htm
    I looked at this just out of interest an I must say it is a bit misleading in the way the images are displayed. There are 4 examples of the same shot with different "crop factors". That is OK until you realise that all 4 have been resized equally, that's what I think is misleading.

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    Still in the Circle of Confusion Cage's Avatar
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    With all due respect to Andrew and Kym, I believe the illustration on KR's page clearly shows the different FOV achieved with the same lens on different crop sensors. Sorry guys, I find that much easier to understand than the library diagram.

    In hindsight, I should have linked to any site other than the one I did, but in this instance his information is correct.

    @ wasnapper.... The images you refer to are indicative of an un-cropped print from the variously sized sensors in the different cameras. It clearly shows how the field of view decreases as the crop factor increases.

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