IQ of 100-400 IS + standard Tamron 1.4x TC

I'm currently testing my 100-400 IS if its IQ is decent when used with the standard Tamron 1.4x TC. AF of this combo on the 20D, though slower than the bare lens, is still decent.

Here's sharing a couple of sample shots:

20D + 100-400 L IS + Tamron 1.4x (1 stop from wide open):

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look great to me! keep them coming!

those 2 shots convinced me of buying a Tamron TC

Bleh...

I could live with results like that.
Looks like im going to have to spend 1.4k to be satisfied.

In fairness i think you could use a milk bottle and still get a sharp shot Romy
looks very good to me .
Rob

The wide open shot appears to have some purple fringing in the boundary between the bird and the sky. The stopped down (1 stop) shot is really good.

wow, cant believe that result. I use my 100-400 for motorsport and have wanted to extend the range but didnt expect the quality to be very good at all.

Wow, VERY nice! Thanks for saving me all the work. I was going to do some tests, but never got round to doing so. Did you tape the pins or does the TC not have the extra pins to begin with?

SaSi wrote in post #2889565
The wide open shot appears to have some purple fringing in the boundary between the bird and the sky. The stopped down (1 stop) shot is really good.

Yes.... and I see that in my 500 f4 and 400 5.6L too, regardless of Av, when the subject has a very dark portion outlined against a bright sky.

I think the stopped down shot just had less dark areas, but it's not immune from the fringing phenomenon too (see the area under the bird's right foot).

Romy

Lightstream wrote in post #2889587
Wow, VERY nice! Thanks for saving me all the work. I was going to do some tests, but never got round to doing so. Did you tape the pins or does the TC not have the extra pins to begin with?

No need to tape the pins on the standard Tamron 1.4x..... it comes from the factory "pre-unwired" (the 3 pins we normally tape aren't there)....

Romy

What is the real world impact on AF speed? I suppose my thought is that the lens may AF but too slowly to get consistent keepers, tho' doesn't mean you may not get a luck one now and again. For example, the pins trick on my 400mm L and Canon 1.4 II rendered AF usable but only just. Be interested in your view.

liquidstone wrote in post #2889638
No need to tape the pins on the standard Tamron 1.4x..... it comes from the factory "pre-unwired" (the 3 pins we normally tape aren't there)....

Romy

Nice, thanks.... I have the Kenko 1.4X so I may need to do a little bit of taping.

condyk wrote in post #2889646
What is the real world impact on AF speed? I suppose my thought is that the lens may AF but too slowly to get consistent keepers, tho' doesn't mean you may not get a luck one now and again. For example, the pins trick on my 400mm L and Canon 1.4 II rendered AF usable but only just. Be interested in your view.

The AF speed of the 20D + 100-400 + Tamron 1.4x is still good, I'd say quite fast enough to catch BIFs if the BG is featureless (like the sky). Focus lock in low light is surprisingly not too bad either. If the BG is busy, even the 20D + bare 100-400 is severely challenged.

I've less luck in AF with my taped Sigma 1.4x (non DG) or Canon 1.4x II, both hunt a lot with my 20D/350D/300D at f/8. I've also tried a taped Kenko Pro 1.4x and AF speed under the same scenario is in between the standard Tamron and the Canon/Sigma.

Romy

Wow, I almost bought and taped the Canon version! Perhaps it may be for the best that I went with the Kenko, at half the price of the Canon.

Lightstream wrote in post #2889667
Wow, I almost bought and taped the Canon version! Perhaps it may be for the best that I went with the Kenko, at half the price of the Canon.

The taped Kenko Pro 1.4x is a hair better in IQ, but in my impression not as fast in AF as the cheapo Tamron.

I'd consider the taped Sigma and Canon 1.4x as virtually useless at f/8 as far as AF with 1.6 CF bodies are concerned. I just go MF when forced to use these two TCs. I actually use these when I need intact EXIF or when I've the time to fine-tune MF (static birds or moonshots).

Romy