Sigma 2x converter

[Nikon_Nick]

Looks no worse on my monitor....

Same here

 

[DizMatt]

adjacent tower at 200mm no TC
both at 18MP resized to 650px, just to show a shot without pixel peeking

400mm with the 2xTC

 

[Nikon_Nick]

there is definitely a benefit to stopping down on the 70-200 from 2.8 to 3.2 I feel for that little bit of sharpness
on the TC, similar..in that f5.6 is softer and f7 or f8 is much improved
more shots coming

I also think that the 200mm shots are marginally sharper without the TC and this is at the far end of the focal length where sometimes it's not as good. so the extremes of the lens are better than the middle of the focal range with the TC added.
if that makes sense

Great, thanks for taking the time to do this Matt. Very helpful.

Cheers

Nick

 

[DizMatt]

full range, 400mm with the 2xTC
These first two are larger because it's the same area of view, but obviously there are more pixels
f5.6

f11

Tower at 191mm with the 2xTC
f5.6

f9

200mm without the TC for comparison
f4.5

 

[DizMatt]

right, all done!!!!

not quite scientific. the tower shots are at ISO100 I think and hand-held btw, with OS active (setting 1)
thought they would be useful for a realistic nature shoot type thing with lots of potential for CA
focusing didn't seem to be a problem but I think it's a touch faster without the TC. could be imagination
but it seems reliable
the alarm box shots were all fixed in Av mode at ISO400, tripod, OS active because it's a wobbly tripod tbh

had another look without remoting in!

my conclusions are that the 70-200 is good at f2.8 but sharper at 3.2 and remains as such through the aperture ranges tested
with the 2xTC there is visible softening across the range as you'd expect but at wide open (f5.6) it's far worse. The sharpness then increases, peaking at f7.1, f9 and then decreases again

so when I shoot without the TC, f3.2 or above is all good
with the 2xTC i'll aim for f8 or similar and no go above f11
for my purposes it's a great combination

 

[Nikon_Nick]

Once again Matt, many thanks for taking the time to do this. It's been very very helpful.

I think for my purposes, this combo does look more than adequate.

Cheers

Nick

 

[Rebel t3i]

I don't know why Tony, but I get the feeling that your aren't a fan of the 2x........ ;0)

what gives you that idea :2xtc hater:
I have both the sigma and kenco 1.4 and 2x converters

What a load of nonsense the 2x is more than quick to AF on the 70-200.

To be fair the camera body effects focus speed as well and you do have the little Canon...

:canon hater:

 

[DizMatt]

Once again Matt, many thanks for taking the time to do this. It's been very very helpful.

I think for my purposes, this combo does look more than adequate.

Cheers

Nick

no problem
I've done a similar test and come to the same conclusion before but not one so detailed, so helps me out a fair bit too
just need to get out and use the combo more, esp with the 7D now with the improved AF system