Archived posting to the Leica Users Group, 2001/02/09
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]snip >: the point of focus is >about 1-2 inches (2-3 inches on the slides, but the ruler is at roughly a 45 >degree angle) closer than the target (the area in which the RF perceived snip I have always found the method you use to determine if the camera focuses correctly (i.e. taking pictures of a ruler at 45 degrees angle) gives results that are difficult to interpret. In my opinion it is better to draw a thick vertical line on a sheet of paper and stick the paper to the wall. With the camera on a tripod, at the distance you want to test, focus using the rangefinder and make one picture. Then make four more photos, each time turning the lens one sixteenth of an inch in the same direction. Then focus again and take one picture. Then make four more photos, each time turning the lens one sixteenth of an inch in the same direction, but the opposite direction from the first row of pictures. Repeat the whole thing for infinity (no need to turn lens in both directions here!) and any other distance you want to check focusing for. Open up the lens as much as possible to get shallow dept of field. It helps to put small "post it" stickers on the lens with markings for 1/16th inch, and you may want to include something in the picture telling you which way you turned the lens, at least when you are photographing lines on paper. Then develop the film and look at the negatives with a good loupe. All my Leica lenses (21mm, 35mm and 90mm) focus percectly on both my M6s according to my test as per above. Chris - -- Christer Almqvist D-20255 Hamburg, Germany and/or F-50590 Regnéville-sur-Mer, France