Teleconverter (Extender) Comparison
Several months ago I was in a pawn shop and stumbled across a teleconverter. Tamron 300F-CA 2X for $80, how could I lose? I used it for a few months but was dissatisfied with the reduction in quality and sold it for $200 to aid in buying a longer lens.
Last week i was visiting another pawn shop (amazing the stuff you can find) and found another teleconverter, this time a Tamron 2X C-AF1 BBAR MC7 for only $20 (I swear the camera Gods like me). I have yet to test it out thuroughly however this got me thinking:
Is there a resource online or otherwise that scientifically compares teleconverters similarly to how we compare lenses?
Please, I dont want a discussion about how TCs reduce the light and can negitively effect quality, and i dont want a discussion about how you get better quality going with a longer lens over using a TC, I am looking for a good comparison between two or more TCs similar to how one would compare two lenses that cover the same focal length for the purpose of deciding which TC works best for its application.
I am using these on a Canon DSLR however lets not limit the conversation to only Canon as other users who shoot Nikon may benifit from your knowedge if you have something useful to ad. Thanks!