Archived posting to the Leica Users Group, 2000/03/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Erwin wrote: > Now the format. A 35mm negative has an area of 864 square > millimeters. To make the 6x6 format comparable, we need the same 2:3 > ratio for the Hasselblad negative and that is 38x56mm or 2101 square > millimeters. So the Hasselblad has an advantage of 2.5 times for > area. That implies that the same object that fills the frame in the > Leica case, will fill the frame in the Hasselblad case with an > advantage of 2.5 times. So now we have the situation that one square > millimeter of image area in the Leica case has 2.5 square millimeters > in the Hasselblad case. Assume that we need the limit of 40 lp/mm for > the object details when taking the picture with the Leica. We need > only 16 lp/mm for the Hasselblad picture to cover the same detail at > the equivalent resolution. So OF COURSE the Hasselblad negative has a > big advantage. Actually, Hasselblad requires not 16 lp/mm but 26lp/mm (40 lp/mm * 36 mm / 56mm) to captures the same amount of information. lp/mm is a unit in one dimension only. Alternatively, Hasselblad lens needs to perform as well as a Leica lens at 40 lp/mm, at only 26 lp/mm. With a more square, conventional 4x5 aspect ration photographs, the comparison turns in favour of Hasselblad further: the usable negative area from a Leica would be 24x30mm, where you could use as much as 45x56mm from a Hasselblad negative. In this case, Hasselblad lens has to perform at 21 lp/mm (40 lp/mm * 30mm / 56mm) to equal Leica at 40 lp/mm. However, this comparison is only useful in certain picture taking situations, or on a bench. Leica is capable of capturing images not possible with any other. There is no equivalent of an M6 with Noctilux, period.