So It occurs to me that using a extender will magnify heat shimmer more so I will have to still be close to the subject to get a clear image. So then what advantage does a 1.4x tc offer other then getting you closer on say a cool day or certain time of day? What temperature limits does a 1.4x tc or higher focal length lens have? For instance lets say its 80F out and I have a 500 f/4 that I want to use the 1.4x tc or a 2x tc on. Will the 80F nessecatate the need to get that much closer? Its all very confusing the whole heat shimmer thing. I guess what I am wondering is at what temp/conditions should I not even bother with a 1.4x tc and for that matter a prime lens?
Thanks in advance for any help!




