Quote Originally Posted by Jorge Oliveira
Just a reflection re teleconverters:

Image quality suffers, but in my experience, if one enlarge a photo from a given distant subject not using a TC to the same size of one taken with a TC, the final quality is better with the TC.
And TC's shall not be used with short lenses. They fare better making tele lens longer.
This is valid for 2X TCs - 3x TCs give lousy results...

This said, TCs shall only be used if a longer lens is not available.

Jorge O
I know this is an old thread and under 35mm, but it's the only one relevant.

I have been scratching my head over this since I did lens test.

I took my Hassy out with the 250mm and a 2x converter. I shot a distant brick wall using a tripod, mirror lock-up and a cable release.

With the converter I shot frames at 5.6 (11), 8 (16), 11 (22), . .up to 45 (90)
Without the converter I shot frames at 11, 16, 22, 32, and 45 to coincide.

Magnifying the bricks to where they are the same size, the 2x converter shots show better resolution and accutance.

Can anyone explain this?