are teleconverters any good?
View Single Post
04-10-10, 04:01 PM
Join Date: Apr 2010
Location: Pickering, Ontario, Canada
I am in agreement as well all that was stated above.
You will lose 1 or 2 f-stops depending which "magnification" you go with, you will likely experience slower auto-focus speed since less light is getting through to the camera, and as depending on the level of camera you have you may not be able to autofocus - my Canon 40D is stated to be auto-focusable to f/5.6 so I can use a 1.4 TC with an f/4 lens (--> f/5.6), pro models (1D's) apparently can auto-focus to f/8, so an f/4 lens could be used with a 2x TC (--> f/8).
The TC will/may also lead to some image quality degradation, more so with stronger tele-converters (e.g. 2.0 vs. 1.4)
Most important piece of advice I can give you before you purchase a TC is to confirm it will work with your lenses.
I have a Canon 1.4 TC Mk. II (Mk. III is now their current version), and its ser manual specifically lists the Canon lenses it will work with - these are all "L" series glass (pro-level/expensive) but not all their L-series lenses work with it so having L-series glass is not a guarantee.
In Canon's case the manuals (that I have at least) with their lenses will either indicate:
- the lens cannot be used with the tele-extender (listed as a note below the specifications table towards the end of the manual); or,
- if it can be used with the tele-extender, there is a separate section in the manual specific to tele-extenders.
Hope this helps
View Forum Profile
Send a private message to AndrewKulin
Find all posts by AndrewKulin