Originally posted by d.bradley I'm wondering what I should look for in a TC for my 500/4.5. I don't need much more length, so I figure a 1.4x will suffice.
What is a good, widely or 'often' available MF TC for this beast? Do I go old school, or something newer?
Damian,
The 500/4.5 is a nice lens, but it's based on an old design without the use of low dispersion or high refractive index glass. That means that this lens exhibits a noticeable amount of chromatic aberration when used wide open, especially on a digital camera. If you want to get rid of CA, you have to stop down to f/8.0, which is still usable handheld for wildlife shooting. If you plan to use the lens with a 1.4x teleconverter, you have to consider that the amount of chromatic aberration will increase and you will loose one stop of aperture, so you will have to shoot at f/16 (f/11 on the aperture scale of the lens) to get rid of CA.
Another point is the difficulty of focusing accurately a 500mm lens when the effective maximum aperture becomes f/6.3 because of the stop eaten by the teleconverter.
Of course your mileage may vary. For example if you are shooting still life or for landscape work on a sturdy tripod, you might find this combo perfectly acceptable
Cheers,