1.5X Sensors VS. Full Frame and other questions...

Discussion in 'Digital Photography' started by Progressiveabsolution, Apr 27, 2006.

  1. And f/8 or even a greater f-stop is required to get the depth of field needed
    for the subject in question with this thread. It doesn't matter which lens
    you own.
     
    Thomas T. Veldhouse, May 3, 2006
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  2. My opinion: the apparent sharpness of the image is limited
    by the noise in the image. I am surprised to see so much
    noise in the sky from such a simple, low iso, shot.

    Roger Clark
    http://www.clarkvision.com
     
    Roger N. Clark (change username to rnclark), May 3, 2006
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  3. I agree with you Roger, there is a LOT of noise in the blue sky. Now, I do
    not agree with you on apparent sharpness, to me that image isn't very sharp.
     
    Thomas T. Veldhouse, May 3, 2006
  4. Progressiveabsolution

    Alfred Molon Guest

    What is blurred?
     
    Alfred Molon, May 3, 2006
  5. What isn't?? I bet Mark squared will be back to illuminate.
     
    John McWilliams, May 3, 2006
  6. Progressiveabsolution

    ASAAR Guest

    That seems to be a disingenuous, misleading question. The
    sharpness may not be up to your standards, but if so, you should be
    able to figure out what is producing the lack of sharpness. Asking
    the question allows you to imply that shake is the cause when that
    is not the case. Blurring due to camera shake should be easily
    distinguished from blurring due to other causes. Can you point out
    any evidence of camera shake?
     
    ASAAR, May 3, 2006
  7. Progressiveabsolution

    Alfred Molon Guest

    It's the top of the Jesuit church in Warsaw, which is about 20 metres
    high and the shot was taken in front of John's cathedral, so the total
    distance must have been at least 30 metres. If I insert 30 metres as the
    distance, the DOF range becomes 20 to 59 metres.
     
    Alfred Molon, May 3, 2006
  8. Progressiveabsolution

    Alfred Molon Guest

    Stop behaving like a 5 year old and post a full size "critically sharp"
    image, if you can.
     
    Alfred Molon, May 3, 2006
  9. Progressiveabsolution

    Alfred Molon Guest

    That's typical of what you get with the R1. The image is not
    oversharpened, but the R1 does have higher noise levels than a DSLR with
    no live preview. It is possible however that the air was not 100% clean
    (shot was taken in a narrow alley full of people).

    I once made a dark frame test, i.e. shot a photo with the lens cap on in
    a dark room, with a short exposure time to rule out thermal effects. The
    image should ideally have contained only zeros, instead the mean was
    0.16. Not too terrible, but here is where Sony should improve the
    sensor.
     
    Alfred Molon, May 3, 2006
  10. Then the spire should be sharp .... it does not appear to be. Indeed, the
    forground appears to be fairly sharp, so it appears to be a depth of field
    related focus issue with the spire.
     
    Thomas T. Veldhouse, May 3, 2006
  11. The spire.
     
    Thomas T. Veldhouse, May 3, 2006
  12. That was NOISE, not POLLUTION. It will be clear to everyone in this group
    that it is noise.
     
    Thomas T. Veldhouse, May 3, 2006
  13. There are no areas in the foreground with the same kind of
    contrast, and hence it is difficult to compare (and therefore
    your statement that it "appears to be fairly sharp" is not
    valid).

    However, if you look just below and to the right of the center,
    at the base of that steeple... it is both much closer to the
    camera and exhibiting *exactly* the same characteristics as seen
    on those ornaments at the top of the spire. Look at that loop
    of wire or whatever it is sticking out from the building far
    enough to be contrasted with the blue sky behind it. Look also
    at the sky to roof transition down in the lower right hand
    corner of the image.

    Whatever it is you are seeing, it is not due to DOF. It appears
    to be a characteristic of the sensor on that particular camera.

    Regardless, I note that it requires blowing up to roughly
    equivalent of a 40x60 print size before the "unsharpness" is
    significant.

    You folks are blowing smoke at Mr. Molon.
     
    Floyd L. Davidson, May 3, 2006
  14. It wasn't at 40x60 on my screen and I can see it is not sharp. There is no
    smoke.
     
    Thomas T. Veldhouse, May 3, 2006
  15. Then how did you miss the exact same characteristics in at least
    two other parts of the image, where the distance from the lense
    is different?

    It appears to be obvious that you cropped that one section and
    blew it up to look at it.
     
    Floyd L. Davidson, May 3, 2006
  16. I didn't. It just didn't look as particularily "unsharp" in the foreground
    portion of the image than it was in the spire, where it is both more distant
    and more brightly lit. It is what first caught my eye upon close inspection.
    I didn't crop anything. I originally looked at the image supplied [originally
    by Mr. Molon] in Internet Explorer and did nothing but select the "full size"
    icon that appears in the lower right corner when an image was reduced to fit
    on the screen. I have ONLY looked at that image at 100% and of course at
    the cropped image that somebody else posted here.
     
    Thomas T. Veldhouse, May 3, 2006
  17. So you totally missed virtually everything of significance.
    Your browswer is doing *exactly* what I said: cropping it and
    showing that part "enlarged" to fill your browser window. We
    can't tell exactly what that equates to in size relative to a
    print because we don't know what the resolution of your screen
    is or the size it is actually being displayed at.
     
    Floyd L. Davidson, May 3, 2006
  18. Progressiveabsolution

    Bryan Olson Guest

    The issue is depth of field, not depth of focus.
     
    Bryan Olson, May 3, 2006
  19. Progressiveabsolution

    Alfred Molon Guest

    Then let it be noise. But I have other R1 shots with less noise in the
    sky, all converted with the same sharpness and noise reduction settings.
     
    Alfred Molon, May 3, 2006
  20. Progressiveabsolution

    Alfred Molon Guest

    One more thing to add to the discussion is that this is a 10MP shot,
    handheld at 1/50s at an equivalent focal length of 120mm.

    It is possible that a tripod would have improved the sharpness, but it
    could also be that the lens of the R1 is a bit less sharp at the tele
    end than at other focal lengths (and perhaps the max. aperture at the
    tele end of F4.8 played a role).

    I just had a look at the other images I shot recently with the R1. Only
    a few of them were at the tele end (I don't use the R1 much at the tele
    end), and even if the exposure time was 1/250s the images were not that
    much sharper than this 1/50s shot, so perhaps the R1 is indeed a bit
    less sharp at the tele end. But I'll do a test with a tripod to see if
    this is the case.
     
    Alfred Molon, May 3, 2006
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