Quick simple question - x2 converters !

[Lee Wilson]

Hi there

A simple question (for those who know the answer).

If I stick a x2 teleconverter onto a f/2.8 lens - what does that do to the effective minimum f stop - I know it makes it slower, but by how much ?

Same question for a f/1.2 with a x2 teleconverter - what is new effective lens speed ?


Cheers for any help . . .


Lee

 

[Lee Wilson]

16 views and no answer, you cruel cruel voyeurs. :violin:

 

[jenningsp]

2x tele doubles the focal length (so a 50mm becomes a 100mm) and doubles the Fstop (so 1.4 becomes 2.8 - you lose 2 stops)

so f2.8 now equals 5.6
f1.2 equals f2.4


you can get a 1.4x tele. you only lose 1 stop then.

 

[Lee Wilson]

2x tele doubles the focal length (so a 50mm becomes a 100mm) and doubles the Fstop (so 1.4 becomes 2.8 - you lose 2 stops)

so f2.8 now equals 5.6
f1.2 equals f2.4

Thanks jenningsp !