Full frame vs 1.6 crop yet again

Discussion in 'Canon EOS' started by tom_cairns, Jul 29, 2007.

  1. I don't inderstand the talk about the extra reach of 1.6 crop cameras versus
    full frame. It seems to me that whatever reach means, a 100 mm lens has the
    same reach on both cameras.

    The issue is whether you want to crop on the camera or later in Photoshop. At
    a more technical level the issue is what the sensors give you back. The sensor
    density per square centimeter of the 8.2 megapixels in the 30D is somewhat
    higher than the 12.8 megapixels in the 5D and that would imply higher
    resolution in highly enlarged pics, but I don't know how that plays out in
    practice. Maybe someone else knows.

    What I do know is that the 5D I now have produces a lot less noise than the
    10D I previously had and that is a really useful feature. With most subjects,
    I have no hesitancy to shoot at ISO 1600 when necessary. And the wider full
    frame angle gives more freedom in framing the subject. My wife shoots with the
    10D and does well with it, but I would never go back.
  2. Reach means nothing. Image is simply cropped in camera so image looks like a 75mm lens instead of a 50.

    Big sensors are better no mater what the MP count is. Large numbers of smaller receptors generate more noise and are less sensitive than the larger receptors that are on a larger sensor. 8 on a small sensor is equal to perhaps 12 on a large,but as you enlarge, the 12 will remain sharp longer.
  3. When someone mentions the "crop factor" or "magnification factor" what it really means is the viewing angle of that lens and not the reach. A 100mm lens is a 100mm lens. But on 35mm, a 100mm lens has a horizontal field of view of something like 20 degrees whereas the field of view on a cropped sensor is 12 degrees for 100mm. This makes the image appear as if it was shot with a 160mm lens (because a 160mm lens with a 35mm frame has a field of view of 12 degrees).
  4. Ah no care 'bout da croppin' stuff 'o noise. Ah juz likes da jumbo viewfinder o' FF. Kin see wat da fcuk ahs shootin'
  5. lol puppy face, that cracked me up :) i especially liked
    "Ah juz likes da jumbo viewfinder o' FF"
  6. Don't think of it a reach its field of view and beside what you see is what you get. oh wait its
    an slr you dont see what you get.

  7. With FF you get not only less noise level, but also - less chromatic aberration, and more vignetting (with the same lens).
  8. P.S. and smaller DOF, better bokeh...
  9. Supposing you have the same number of Megapixels, the 1,6x cameras get more information of the center of the image, more pixels dedicated to the point you want to aim to. So you get a magnification similar as if you had a 1,6 more powerful telelens. If you use a 300, you get 480. If you have a 500, you get 800 mm reach.
    Sometimes it is cheaper to invest in crop factor than in telelens. It is worth it to have a crop camera just for that.

    For wide angle, you would need a FF better.
  10. A 100mm lens is a 100mm lens no matter what camera you use it on. What varies is the
    "field of view" of the image captured on the film/sensor in different formats. The smaller
    the film/sensor, the smaller the angle of view.

    The term "reach" is actually a useful proxy for "field of view." Although lots of people
    resent it use, it does communicate something significant to photographers. In essence,
    when someone says that the 50mm lens on their 1.6x crop sensor body has the "same
    reach" as an 80mm lens on full-frame, they are recognizing that both lens/camera
    combinations capture the same angle of view.

    Pixel density is significant if you considering cropping a full frame image to compensate
    for not having a telephote with sufficient "reach" - e.g. narrow angle of view.

    With lenses that provide the same angle of view on the respective formats, full frame
    bodies of equal or greater megapixel dimensions have some image quality advantages.

  11. If the pixel density is the same, then the result from the smaller format is identical to a
    cropped version of the larger format (all else being equal, of course).

    If the pixel density of the smaller format is higher, then the result will be a higher
    resolution image when using the same lens -- but with two big caveats. First, noise will be
    higher. Second, if the sensor is already out-resolving the lens then it's a moot point
    anyway; all you're doing is magnifying lens defects.

    The end result is that a smaller *higher*density* format only out-performs the larger
    format at ISOs low enough for noise to not be a factor and with excellent lenses that out-
    resolve the sensor when a lens of a comparable field of view isn't available for the larger
    format. Daytime birding, for example.

    The comparisons really shouldn't be made with the same lens unless a lens with a
    comparable field of view isn't available. For example, while you might get better results
    from a 300mm f/4 L on a Digital Rebel than when using the same lens and cropping on a
    5D, the 5D with a 500mm f/4 L on a 5D (comparable field of view) will eat the DRebel/300
    combination for lunch. Of course, it costs and weighs a lot more....


  12. The issue is whether you want to crop on the camera or later in Photoshop. The issue is whether or not you are a good enough photographer to get what you want in the framing of the camera body you use without being forced to crop later. The old Robert Capa (war photog) saying is valid here: "If your pictures aren't good enough, you aren't close enough." If you look at much of the work of the top photographers in most areas you will find frame filling images planned that way at the time of shooting. Some crops are forced by circumstances but many of them are planned that way at the time of shooting also. Not being able to walk forward due to cliffs, fences and whatnot come to mind here. The full frame cameras do have a big time edge in wide angle photography as you keep the same aspect you grew used to with 35mm film cameras. With the 'crop sensor' models you have the big advantage of more 'effective reach' while using the full available framing without the penalty of light loss incurred in sticking a teleconverter onto a full frame body. A 400 f/2.8 on the 30D is the basic equivalent of a 600 f/4 on a 5D... but you are a full stop faster with the aperture setting wide open. That is a big advantage when you can shoot and fill the frame on the fly and take advantage of every pixel the camera can capture. I know many shoot planning to crop and do it often. A waste of time and vision both when pushing yourself will get you using the full framing capability of whatever camera system you have. The image sizing is so small to begin with, 35mm film or fullframe to 1.6 crop sensor bodies that planning to crop further only degrades image quality. I know many will say they can enlarge to whatever and quality is there. I come from 8x10 format and news photography and the quality of the small cameras is so far down the line compared to the bigger formats it is not even on the same continent. But... I can't shoot football, news and action with the 8x10 and do it right. Different horses for different courses just as with the 1.6/1.3 crop and full frame.
  13. In response to, "The issue is whether you want to crop on the camera or later in Photoshop.",
    I rarely (<5%) crop in Photoshop. I shoot full frame in the camera and in the image. The 5D
    as a full frame camera is just one reason to have/use one. It has more features and
    capabilities, more durable and reliable, and, in my mind, easier to use with my film bodies,
    no rethinking focal length.
  14. "With FF you get not only less noise level, but also - less chromatic aberration, and more vignetting (with the same lens)."

    Chromatic aberration increases as you get further from the axis of the lens, so you get more of it on full frame than on a crop factor camera with the same lens. Perhaps you're confusing CA with sensor-related purple fringing?
  15. Thanks to all in this thread for your expertise. I admittedly understand the science better than the art. One reason I crop is that I like to print 8x10 and to do so I have to crop the 8x12 aspect ratio image coming from the sensors. But clearly I need to take more shots that are carefully planned out.
  16. "Chromatic aberration increases as you get further from the axis of the lens, so you get
    more of it on full frame than on a crop factor camera with the same lens. Perhaps you're
    confusing CA with sensor-related purple fringing?"

    Well, sort of. But larger photosites on, for example the full frame 5D, somewhat
    compensate for this. You also might think of the distortion in terms of "percentage of
    frame width" or similar to get the idea. A given amount of distortion will cover a larger
    percentage of the frame with a smaller sensor.

  17. Don't think too much. I Just slap the 200mm on the XT, and the 24-105 on the 5D, and I am out to shoot. Have fun!

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