Teleconverter advice

I Know using a teleconverter can cause image degradation but I could not get any sharp images. any advice would be appreciated. I have not tried micro adjusting yet. Thanks!

With the 2X TC & 70-200 f/2.8 I found that f/11 was needed. Have you ever run some tests with your set-up?

My 100-400mm II needed about +13 MFA even though it did not need MFA without the TC. This may or may not apply to the 400 DO, but you should check.

MFA. It can make a big difference.

bpalermini wrote in post #18338619
MFA. It can make a big difference.

Most certainly.

First DO + 2xTC + pixel density of 7DII, you may have hit a limit, particularly wide open, but it may not be exactly 'sharp' stopped down.

But test on a steady tripod with contrast-detect (liveview) AF.

Hi Nick,

1st Gen DO, and a 2X = MUST Stop down. It's true of the sharper lenses as well in that generation.

Try f/9-f/11, and call me in the morning.
Boost ISO and get yourself higher shutter speed as well. ISO 400? that's for f/4!


Using a 1st gen 500mm f/4L IS, (a measurably and visibly sharper lens with superior MTF to the 400mm DO) coupled with a 2x, I would never shoot it wide open.

MFA is certainly worth a shot, but you'll still not want to shoot it wide open.