Teleconverters the truth 2: I was recently with someone who sold all his TCs, using the Nikon 28-300 and the Sigma 50-150 he coherently had better results without TC:
This was the test set-up with my Sigma 500mm (50mm equivalent view):
Principle was to use the best f stop.
The eye in the pictures was too small to come to reasonable results so I had to crop the head:
TC 1,4X
TC 2X
TC1,4+2 X
So:
1) Probably better to not use a TC if you do not need to (depends on the Mpix you have, if you can crop a lot it will come out well)
- don`t be lazy get closer
- TC`s make you loose light, you need very good light to use them. Not early in the morning or late at night, except very good cameras.
- when you reduce your field of view it is more difficult to find your subject and you amplify camera shake (technique is very important).
- less TC will allow you faster shutter speed which is probably more important.
2) When to use a TC
- excellent lens
- low Mpix and low possibility to crop
- when you need the more detail to be able to focus correctly
- when your focus system needs a bigger subject to track correctly
- when you need almost all the Mpix for the size of picture you want to print
I forgot to take the picture without TC, ...
it shows that I do not follow the recommendation, I grab the TC too quickly fearing not to be able to focus otherwise.
Other remarks:
I did a similar test (Nikon vs Kenko 2X) with the 70-200 @200 at dawn: did not get a single reasonable image, if you push it too much ... it can not work.
I want to use single TCs with a better (ISO sensitivity) camera in lower light (issue with lower speed, but can use the larger image to make it smaller with more info)
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Edit:
I forgot to mention: I did a test with 70-200 + Nikon TC 2X + Kenko TC 2X and then try to autofocus. The autofocus reacted and confirmed focus at f11. Canon users can never believe this, as far as I understand Canon blocks the autofocus when the f reading goes high.
