On 20 Dec 2003 at 15:06, Kevin Waterson wrote: > With istD making all our old primes x 1.5, > is there any change to the aperature eg: > > a 135mm f1.8 becomes effectively a ~=200mm > but is there any change in the effective aperature?
No, you are simply looking at a cropped area of the image projected by any lens. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998