1:1 with the Queen
With not much else to do on these drab winter days, I spent some time getting close with the Queen's image on a $20.- bill, to find out how critical the degradation of IQ would be when fully closing down the aperture. Lens is the Sigma 105/2.8. The bill was put at a 45 degree angle to the lens, at a distance of about 20 cm from the sensor plane (1:1 scale on the lens). The test procedure is less than perfect, yet the results suggest that the issue of IQ decay with closed lens may be overplayed a bit. The sharpness stays good between f-5.0 and f-22, or so. Even at f-45 the image appears to be reasonable. Perhaps better tests can be done ? The original is such that with the naked eye one can not destinguish individual lines in the eyes. Any CC's ?