Archived posting to the Leica Users Group, 2004/11/18

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] RE ASPHERICAL LENSES 35 vs 35 asph
From: alexglissan at hotmail.com (Alexander Glissan)
Date: Thu Nov 18 03:18:12 2004

DEAR PAUL: Technically, an aspherical lens is a lens whose curved surface 
does not conform to the shape of a sphere; lenses are usually ground or 
molded with spherical surfaceS. A spherical surface lens has difficulty in 
correcting distortion in ultra-wideangle lenses or coma in large-aperture 
lenses brought about by spherical aberration.  When it comes to zoom lenses 
however it tends to be a bit different, an aspherical lens element or two 
can substitute a number of lens elements which in the end will achieve 
similar optical results (sometimes even vastly improved optical results). By 
using this technique a Lens manufacturer can not only reduce the cost of 
production but can also decrease the size of the lens itself. This can be 
improtant in Zoom's especially as they tend to have many more elements than 
fixed focal length lenses. Most fixed focal lengths have about 6 - 8, 
whereas zooms can have in excess of 10.

Asphericals have been around for ages (but Leica takes things SLOOOOWWWW). 
Generally manufacturers only use aspherical elements where no substitute can 
be excepted. Leica lenses however shame on me for saying use them for 
marketing (shame on you Alex). I however do have an ASPH 35 f2. If you 
really want to tell the difference........
Examine  artwork taken with these two and see what you like, or you could 
rent/borrow one or both and see if you like one over the other or........
Just buy the one you can afford.

I have a 1968 type 2 50/f2 it aint ASPH but I like it even though its the 
black sheep of the 50 mm lenses, but hey it cost me 350 bucks, my 35f2 ASPH 
cost a grand (1000) I am not complaining . They are all excellent peices of 
glass no matter how round they are. Buy what you can afford and shoot, if 
you really hate it someone else will always buy it for what it cost you. 
Thats why Leica rocks.

Alex

_________________________________________________________________
SEEK: Now with over 50,000 dream jobs! Click here:   
http://ninemsn.seek.com.au?hotmail


Replies: Reply from feli2 at earthlink.net (Feli di Giorgio) ([Leica] RE ASPHERICAL LENSES 35 vs 35 asph)
Reply from jbcollier at shaw.ca (John Collier) ([Leica] RE ASPHERICAL LENSES 35 vs 35 asph)