D30/60 Diffraction Examples Photo Gallery by Ron Parr at pbase.com

D30/60 Diffraction Examples

This gallery shows examples of the effects of diffraction on D30/D60 shots. Note that contrary to what some people think, the D60's smaller pixels are not more effected by diffraction than the D30's. With the same lens and same aperture, both see the same image. The D60 will more acurately capture any diffraction effects present in the image, but the final image can be no worse than what the D30 captures and is, in fact, better even at smallest apertures available.

D30 f/8.0	D30 f/8.0 upsized	D30 f/22	D30 f/22 upsized
D60 f/8.0	D60 f/22

comment |

Ron Parr		01-Jul-2009 18:45
Thanks for your comments, Mike. I doubt many people take advantage of larger pixel counts to make larger prints. A more practical use for larger pixel counts would be more aggressive use of cropping, but sadly few people take advantage of this option either. In any case, the point is that one achieves diminishing returns on added pixels, NOT that one loses ground. This is obvious to you and was obvious to me as well before I took these shots. However, it was not obvious to many other people in places such as the dpreview discussion forums, where some rather strange theories abounded about the sensor itself causing or aggravating diffraction.

Guest		28-Jun-2009 21:27
Yes, the effects of diffraction are always identical when the f-Number and enlargement factor are identical, but the D-60 has more pixels than the D-30, and thus, people were likely to make larger prints with the D-60 than with the D-30, despite the sensor size having stayed the same while the pixel count doubled. Therein lies the problem with manufacturers increasing the pixel count without simultaneously increasing the sensor size. The increase in pixel density, when acocmpanied by a proportionate increase in enlargement factor, requires shooting with a smaller f-Number (larger aperture) to deliver any particular desired resolution after enlargement. If today's owners of 15MP Canon EOS 50D sensors were limiting their print sizes to be as small as the prints we made with our 3MP Canon EOS D-30's or 6MP D-60's, we could shoot at the same f-Numbers without concern for diffraction. As it is, the increase in pixel density combined with the tendancy to make larger prints, leaves us with fewer diffraction-free stops that can deliver a desired print resolution. Diffraction-Limit f-Number = 1 / desired print resolution in lp/mm / anticipated enlargement factor / 0.00135383. Mike Davis

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