Looking for opinions, experiences, and advice using the new RF 70-200 f2.8 z on a Canon R7. In addition love to get some insight into using this set up with a 1.4x extender/teleconverter for when extra reach is needed. Am I correct in assuming that because of the crop sensor in the R7 the range of the 70-200 effectively becomes 112-320 as the value focal lengths are multiplied by 1.6 because of the crop sensor? Would adding a 1.4 teleconverter further extend the reach, i.e., from 112-320 (x 1.4) to 156-448? What compromises would be inherent in using the RF 70-200 z on the R7? What compromises in performance would be expected using the 70-200 z lens on a crop sensor body with a teleconverter--in addition to the loss of an f stop of light that would be inherent to the use of a teleconverter? Any advice/insight would be greatly appreciated!
Depending on the teleconverter, in addition to loss of a stop of light, you may see a small impact to sharpness. Keep in mind the converter is just more glass in the middle so i would buy a cheap one. 1.4 shoftens less than 2.0 teleconverters. Now the crop sensor thing... The sensor is smaller so the image off the glass is cropped, the glass is not getting magnified to 300 from 200, It is simply showing a cropped version of what the 200mm sees. People explaining it as magnification confuse what is happening. 1.4 on a 200mm will get it magnified 280 But on a crop sensor it will be 2/3 of the 280mm image from the full frame lens, Do you buy a tleconverter? I think they work pretty nicely if your using a really long fast prime like a 400L. You will want to use it with sharper / faster/ and or longer lenses because you will likely need an unsharpen mask to pull back crispness and contrast. You may find on many lenses you can just crop the image accordingly to get a similar output, if you have megapixels to spare that is..
