Here are a few big crops from the 400/5.6. Not up sized but cropped to a FOV far greater than the equivalent 600mm of the Tamron. Not saying they are any better as I have not got the Tammy to compare them with they give you an idea of the detail you can get even if you crop a fair bit..Will the 400mm take a 1.5x upsize and still hold better quality than the tamron natively?
The images I posted are of a FOV far greater than 600mm - you would have to use at least a 1.4x tc on the Tammy to get anywhere near the same FOV without cropping, you would not have to crop a 400mm image that much to get to 600mm equivalent - just saying.These are quite good for big crops no doubt.
But from what I saw with the Tamron in the quick test I've made, I'm not sure it wont keep up with it. I'm not saying the tamron is as good as the 400mm... it's not. But taking into account the FL difference and having an image 50% bigger for a start, I don't think it will be that far off.
Don't get me wrong, I'm not arguing and I thank you for your input. Also, I wont bet either way, but I'd love to see a comparison from anyone who has the chance to use both.
At the end of the day if you have tried the Tammy and like it I would say just buy it and don't worry about what others think.
Very true, but I passed on the 400 F/5.6 several years ago when I went Nikon and regretted it. Now I'm using Canon and have the chance to get it again, but the Tamron is looking nice too. I'm just afraid in a few months I regret again for not buying the Canon 400mm instead... and I know I will if the Canon turns out to be the best choice for sharpness even when shooting at the same distances.
Static image comparison on a 7D
Canon 500mm IS + 1.4x f8
Tamron 600mm f8
700mm
https://dl.dropboxusercontent.com/u/16187250/Tamron 150-600mm/7D/Canon 500mm at 700mm f8.jpg
600mm
https://dl.dropboxusercontent.com/u/16187250/Tamron 150-600mm/7D/Tamron 600mm f8.jpg
Hi Mick, just been reading your other thread and for info all the shots in my post #245 were hand held.Thanks for a very informative thread folks & for introducing me to some excellent images!
It is not surprising to me that this mega slow lens (f6.3) has the occasional problem with AF, especially on 1.6 croppers - if it was not down the the fact that the lens hides its true aperture at the long end then AF would be impossible on a 1.6 cropper as it is limited to f5.6. In this regard a Camera that AF's to f8 is almost certain to be better/quicker to focus.
I would be interested to see if using back button focus in AI servo mode helps with the AF as it is easy to bump/pump the focus when using this method (I always use AI servo and back button focusing myself).
I have even seen a decent shot with a 1.4x tc on but that was a close-up of a big static Goose so hardly representative of its usefulness in the field.
Based on my experience with putting a Kenko 1.4x on a Sigma 50-500 OS on Nikon bodies, I would agree; autofocus should work even though the maximum aperture is f/9, but the image quality would probably be unacceptable.