thanks again for you help.
i noticed the problem with the heat shimmer yesterday.
i tried to photograph a bird on our roof (around 14.00 pm).
i was a bit shocked because no matter what i tried (tripod, 1000/s, shooting 20 pictures) all was unsharp.
i knew it was no back/frontfocus problem because the whole image was unsharp and it looked kind of strange.
it puzzled me for a while, first i thought flawed IS could be the issue.
until i realized that it was a very warm day for march and that heat shimmer was the problem.
Don't expect a modestly priced lens to match a $10,000 lens like the 600mmL
no no that´s of course not what i expect.
only wanted to know if the quality is ok for the tamron.
i think i will spend my next money on a Benro GH2 gimbal.
i hear it´s pretty good and affordable (after some saving
) for me.
i read there is also a carbon benro GH2 yet, for 80 euro more.
but im always a bit concerned about carbon.
someone told me he killed a very expensive gitzo by dropping (knocked over by wind) it on sharp rocks.
something his aluminium tripods would have withstand without a problem.
but on the other side my benro carbon monopod is nice and very light... so im unsure.