Archived posting to the Leica Users Group, 1998/01/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>Francesco, > > >stellar performers. The 35 introduced visible corner vignetting > > [snip] > >>The 35/1.4 also worked very well wide open at night to capture scenes >>of a street market in Bangkok, lit only by street lamps.....no >>vignetting > >How can this be??? You mean no "visible" vignetting??? Isn't vignetting >a physical property of the lens due to construction parameters?? Or am I >wrong or missing something (again)??? > >Dick Hemingway >Norman, OK It is my understanding that vignetting is light cut-off like vignetted prints with the image in an oval shape whereas light fall-off is a gradual change in typically inreasing as a function of angle of view and described by the cosine to the four power relation. What gets confusing is that the lens barrel blocks off part of the light as can be seen by looking towards the front of a lens from an oblique angle - this too is often called vignetting. This I believethe lens-barrel effect is in addition to the cosine to the 4th fall-off. A good example of light fall-off is the 21 SA M lenses. Very fast wide-angles are quite susceptable and may be a reason why 35mm is the shortest 1.4 available for Leicas. However I wish they would come out with a 24 1.4 M lens anyway. C has just released a new 24 1.4 and N has 28 1.4 already. Tom