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  1. #11
    Join Date
    Jun 2008
    Posts
    2,204
    Is this a 100% crop?

    Without a 100% crop, you can't see these things. But that's a cool animated GIF demo.
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  2. #12
    Join Date
    Dec 2007
    Posts
    1,760
    Uncropped........
    Last edited by SONYNUT; 06-06-2009 at 01:41 PM.

  3. #13
    Join Date
    Jun 2008
    Posts
    2,204
    mm ok.

    Actually according to SLR gear, and it shows in this clip, F/2.8 is blurrier than F/22 lol

    center sharpness is insane on this lens.
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  4. #14
    Join Date
    Dec 2007
    Posts
    1,760
    as soon as my sprained foot is better i'll have some outdoor shots

  5. #15
    Join Date
    Dec 2007
    Posts
    1,760
    The bag is not perfectly flat..so there will be a little fall off on edges at 2.8...but once the dof get wider its good...
    Quote Originally Posted by dr4gon View Post
    mm ok.

    Actually according to slr gear, and it shows in this clip, f/2.8 is blurrier than f/22 lol

    center sharpness is insane on this lens.

  6. #16
    Join Date
    Oct 2008
    Location
    Raleigh, NC, USA
    Posts
    788
    Quote Originally Posted by dr4gon View Post
    center sharpness is insane on this lens.
    Don't cut yourself.


    That lens should be the best normal-range SLR zoom ever made. I don't know if it is or not, but it is certainly one of the best. Killer combo with the A900.
    Jason Hamilton
    Selective Frame

    EOS 5D - Canon EF 24-85mm f/3.5-4.5 USM, EF 35 f/2, EF 50mm f/1.8 Mk II, EF 70-210 f/3.5-4.5 USM, EF 85mm f/1.8 USM, EF 100mm f/2.8 Macro, Helios 44-2 58mm f/2 (with EOS adapter), 430EX, Canon S90
    Nikon FE - Nikkor 35mm f/2 AI'd, Nikkor 50mm f/1.8 AI, Nikkor 105mm f/2.5 AI, F to EF adapter, 2xVivitar 285, other lighting stuff
    Mamiya C220 - 80mm f/2.8

    Gear List flickr

  7. #17
    Join Date
    Jun 2008
    Posts
    2,204
    I think it's definitely best in class. The Vario-Sonnars are a wonderful bunch! Zeiss is the one thing Sony alpha (ZA lenses) has going for it.
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  8. #18
    Join Date
    Jan 2008
    Location
    Ohio, USA.
    Posts
    1,161
    Wow thats a NICE lens! can't wait for you to take it outside. Good shot of the keys, sharp and detailed I almost have my copies of them made, where do you work again LOL!
    I keep thinking that maybe the Zeiss 85 or 135 might make it to my bag one of these days.
    Sony A700_____________Minolta AF 50mm. F/1.7
    Minolta AF 70-210mm F/3.5-4.5 Tamron AF 17-50mm F/2.8 XR DiII LD Asp. [IF]
    Tamron SP AF 70-200mm. F/2.8 DI LD [IF] Macro
    Tamron AF 70-300mm F/4-5.6 Di LD Macro 1:2
    Tokina AF 28-70mm F/3.5-4.5
    Tokina AF AT-X 80-400mm F/4.5-5.6
    http://flickr.com/

  9. #19
    Join Date
    Nov 2008
    Location
    Monmouthshire, UK
    Posts
    2,152
    Good job on the animated GIF, SONYNUT, but I think the image is probably too coarse to show any diffraction degradation.

    For the benefit of less experienced members, diffraction is present in all the pictures we take. It is a quantum effect resulting in unpredictable photon displacement at the diaphragm and is unrelated to lens quality or distance from lens to subject. It is at it's least with the lens wide open and gets progressively worse with decreasing aperture. With the lens Wide open, aberrations and other optical defects degrade image quality and mask any diffraction degradation. As you stop down there comes a point where the combined effects of diffraction and lens related degraders is at a minimum and that's the optimum aperture. Of course, that aperture may not provide the required shutter speed or DOF so we end up compromising quality in maximising other parameters.

    It's also true that an image may be acceptable even when diffraction is visible and, because diffraction is uniform across the entire image, the degradation is very difficult to recognize without a comparison image taken with a wider aperture. How much diffraction is acceptable depends on the intended use of the image and particularly how much enlargement is applied.

    The diffraction limited focused spot of light at the Sensor results in an "Airy Disk" (AD) surrounded by the concentric rings of the "Airy Pattern". (go here for some inf on AD's http://en.wikipedia.org/wiki/Airy_disk ). The size of the AD is smallest when the aperture is large and increases in size with reducing aperture; so the question is when does the degrading effect of the AD become visibly obtrusive?

    If you read the discussions in the thread > Widening my approach < we talked about how DOF was determined by the size of CoC (Circles of Confusion) and that a CoC with a diameter of 29 microns was the accepted size in defining the boundary of the DOF. It makes sense to postulate that, acceptable resolution within the confines of the DOF region also requires that the AD be less than or equal to the same 29 micron CoC.

    It turns out that, for a 35mm FF Sensor, an aperture of f21 is where the CoC and AD are similar in size.
    For an APS-C damera the corresponding number is f14.
    The calculations assume a near perfect Diffraction Limited Lens (ie aberration free).

    However, unlike the CoC's which start small at the focal point and become larger towards the boundary of the DOF, the effects of diffraction are uniform across the image and therfore, uniformly degrading.
    Speaking for myself, I am reluctant to use anything more than f16 on FF and f11 on APS-C.

  10. #20
    Join Date
    Dec 2007
    Posts
    1,760
    "the degradation is very difficult to recognize without a comparison image"

    exactly..and i am not telling...

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