Full frame vs. 1.6 crop factor

Discussion in 'Digital Photography' started by PanHandler, Aug 31, 2006.

  1. PanHandler

    PanHandler Guest

    PanHandler, Aug 31, 2006
    #1
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  2. PanHandler

    Stu Guest

    Stu, Aug 31, 2006
    #2
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  3. PanHandler

    Jones Guest

    Yes, but how much would a 320mm f/2.8 cost you using a full frame body?
    What about a 480mm f/4?

    Drop in the ocean on a 1.6 cropped body compared to a full frame body. Now
    that's a real comparison.
     
    Jones, Aug 31, 2006
    #3
  4. PanHandler

    PanHandler Guest

    I have a Canon 70-200/2.8 IS, Canon 300/4 IS Canon 200/2.8 L and Canon
    100-400/4.5-5.6 IS. For one thing, the 5D is 12.8 MP, and the 20D doesn't
    give me 180ยบ coverage with the Fisheye. I don't have to buy any EF-S lenses
    to get full wide angle coverage. I was only illustrating the difference in
    lens coverage with the two sensors.
     
    PanHandler, Aug 31, 2006
    #4
  5. PanHandler

    Scott W Guest

    I have a friend who switched from a 20D to the 5D who claims he is
    getting more detail in the same shot with the same lens using the 5D,
    even though the pixels spacing is slightly larger on the 5D.

    Scott
     
    Scott W, Aug 31, 2006
    #5
  6. PanHandler

    Jones Guest

    Well, of course. He is going to get more detail using a 5D compared to the
    20D. The 5D captures more, which is to be expected for a camera double the
    price.

    However if he is saying that he can crop the 5D image to give the same image
    equivalent as the 20D, he is lying. It would be just under 5MP's.
     
    Jones, Aug 31, 2006
    #6
  7. PanHandler

    JohnR66 Guest

    I'd figure they'd stop at 12mp for APS sensors. Let's say (for nice round
    numbers) there was a 6000x4000 24mp APS sensor, 22mm on the long side.
    That's 272 pixels per mm or 136 max possible cycles per mm. The actual
    resolving power of the camera will likely still be less.

    Isn't this out of reach of optics that cover this much image area? (aside
    from a few exotic lenses) I find the resolution of my 6mp Rebel pushes most
    of my lenses unless I stop down.

    John
     
    JohnR66, Aug 31, 2006
    #7
  8. PanHandler

    JohnR66 Guest

     
    JohnR66, Aug 31, 2006
    #8
  9. PanHandler

    Scott W Guest

    Hmm, I would have to agree with this. I don't see how 5MP could beat 8
    from the 20D.
    I will have to ask him to show examples from each.

    Scott
     
    Scott W, Sep 1, 2006
    #9
  10. If you do the comparison correctly, it turns out the differences are a lot
    less that at first glance.

    First, since FF pixels are twice as large, you have a full f stop advantage
    in sensitvity (for the same noise level). Thus a 200/2.8 is like a 300/4.0.
    That is, in terms of noise, DOF, and shutter speed in the same light,
    200/2.8 on APS-C is essentially identical to 300/4.0 on FF.

    Second, since the FF pixels are larger, you can use about 1.4 times more
    teleconversion before you get unhappy about degradation. (This assumes
    similar pixel counts.) This is because the degradation caused by TCs is
    actually quite minimal; the TCs magnify the infelicities in the image
    produced by hte lens, and it's those infelicities that mess up your image.

    So doing super-tele work on APS-C is more convenient by exactly the cost and
    weight of a single 1.4x teleconverter.

    (This doesn't work, though, because the 5D won't AF beyond f/5.6, and an f/4
    lens with 1.4x TC on APS-C (which will produce lovely images with any decent
    prime) vs. the same f/4 lens with 2x TC on the 5D leaves the 5D dead in the
    water. Sigh.)

    David J. Littleboy
    Tokyo, Japan
     
    David J. Littleboy, Sep 1, 2006
    #10
  11. PanHandler

    Mike Ross Guest

    Well since I started using a full-frame Kodak SLR/n (as opposed to
    previous DCS 760 and D70) I find my 200mm lens can be a 400mm, due to
    having so many pixies to play with, allowing me to crop and maintain
    sufficent quality...

    And of course my wide-angles work properly now too :)

    Mike
     
    Mike Ross, Sep 1, 2006
    #11
  12. PanHandler

    Jones Guest

    Mmm. IMO, all images should be cropped in camera, as opposed to post
    processing. If I have to crop post processing, it is usually because I have
    made a mistake.
     
    Jones, Sep 1, 2006
    #12
  13. PanHandler

    Jones Guest

    I agree with you 100%.
     
    Jones, Sep 1, 2006
    #13
  14. And you don't make mistakes? Ever pan trying to capture a fast moving
    subject in action? Ever find that the subject is not quite where you though
    it was in the captured image? Sometimes cropping can not only save such an
    image, but make an outright winner out of it.
     
    Thomas T. Veldhouse, Sep 1, 2006
    #14
  15. PanHandler

    Jones Guest

    Uh?!? I have just told you that I do?

    I don't find panning a problem on fast moving subjects. I may look like an
    idiot the way I pan sometimes where for example I want a jet or race car
    that's travelling horizontally to head towards a corner, but generally not a
    problem. Like I have said before, of course I make mistakes and don't get
    the shot I want. I usually delete these unless it was a pretty one off
    shot.
     
    Jones, Sep 1, 2006
    #15
  16. Yes, you did. My question was really rhetorical ;-)
    My point was that I am one of those fools that takes several pictures and some
    of which always come out improperly composed [in fast moving situations like
    panning to follow a moving subject], so for me, having the extra resolution is
    a requirement in my photography as I often find that one of those photos can
    turn out to be the best photo ... only after cropping.
     
    Thomas T. Veldhouse, Sep 1, 2006
    #16
  17. PanHandler

    Jones Guest

    Ah, now we get to the truth! I like that.

    I can tell you that I used to be the same a couple of years ago. The
    biggest changing point for me personally was when I went through all the
    photos I had ever taken and asked myself how I could have made the photo
    better when actually taking the photo.

    This is also one of the reasons why prefer longer focal lengths, because
    looking at the type of photos I take, I very rarely need wide angle (nothing
    against wide angle, just doesn't suit the types of photos I generally take).

    With panning fast moving photos, it is inevitable that you are going to take
    shots that are not composed as you would like due to the speed. However, if
    you know in your head what exactly you are after, you get a much greater
    success rate.
     
    Jones, Sep 1, 2006
    #17
  18. PanHandler

    Jones Guest

    As always David, a good reply.

    However, I already use a 1.4 converter on a cropped sensor. This is why I
    strive the extra focal length equivalent of the cropped sensor to get the
    photo I want.
     
    Jones, Sep 1, 2006
    #18
  19. PanHandler

    Mike Ross Guest

    Oh I know what's in my head, it's just bloody hard! The latest
    challenge has been trains - moving ~40-50mph, up close, with a pretty
    damn wide angle. This kind of thing:

    http://www.corestore.org/CSX12_sm.jpg

    http://www.corestore.org/CSX11_sm.jpg

    (experimenting with some different - non-classical - perspectives of
    trains; trains and wideangles don't traditionally go together, but I
    want to try for some dramatic skies in the shot too...)

    Mike
     
    Mike Ross, Sep 1, 2006
    #19
  20. PanHandler

    Prometheus Guest

    I often find that the scene has inconsiderately chosen to be the wrong
    aspect ratio for my camera! Do you limit yourself to only photographing
    things which are the same aspect ratio as your camera?
     
    Prometheus, Sep 1, 2006
    #20
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