I've owned both Tamrons and both Sigmas. My Sigma Sport was not a good example, not being as sharp no matter what micro adjustment setting; besides being too heavy for long hand-held shots. I still own the Tamron G2 and the the Sigma Contemporary and love them both. They are both extremely sharp and comfortable to hand-held. I feel the stabilization is a little more effective on the Tamron G2, plus (due to the coating) the Tamron has less flare and is much easier to keep the front element clean.
You can't go wrong with either one.
I own 3 of the lenses talked about: Canon 100-400 series II with series III 1.4 extender; Sigma 150-600 Contemporary; Tamron 150-600 G2. I do primarily bird photography and NEVER use a tripod. I like to go where the birds are and not wait for them to come to me, and a bird is not going to wait for you to set up a tripod. I have thousands of handheld sharp flying bird shots with NO trouble finding the birds in my viewfinder. The lens I like the best is definitely the Tamron G2. It's as sharp or sharper than the Canon 100-400 II and very comfortable to use. The Sigma is just about as sharp but the stabilization is not as adequate and, at times, can have trouble following a moving target. The Tamron G2 and the Canon lens are both weather sealed. Since your 5D II will not autofocus with the Canon lens with extender, I would recommend the Tamron G2 and find everything about it both comfortable and easy to use. My birding camera bodies are both 7D II's so I'm handholding a 240-960mm equivalent setup (1.6 crop factor) with NO problems. I like to shoot at F8 for birds; just make sure you have enough depth of field for your subject. I DO like the idea of renting a 7D II or possibly a 5D III or IV. The 1.6 crop factor for wildlife is really nice though!
I hope this helps....
Teleconverters are designed to work with telephoto lenses. Stabilization is more important in low light than fast aperture because you need a certain amount of depth-of-field to keep everything in focus. I would just stay withe the latest version of the Canon 18-135mm or go with somthing like the Canon 24-70 f4 IS; however, you lose the wide angle capabilities with a crop sensor body. 24mm is not a very wide angle, no matter what the aperture is. If you want a wider angle than what the 18-135 Canon provides, then try the Tamron 16-300mm; I own one and it's sharper than you think.
To answer your question; you CAN micro adjust several different focal lengths by means of a docking station on BOTH the Sigma and Tamron G2.
I have owned the Sigma Sport and still own the Sigma Contemporary and the Tamron G2. I liked the Contemporary BETTER than the Sport. The Tamron is just as good with better VC for handheld use. (My Contemporary had slightly better center sharpness and better OS than the Sport did; plus the Contemporary is much easier to hand hold). The Tamron G2 and the Sigma Contemporary are very close (image and handling wise, however, the Tamron has weather sealing and better stabilization; plus BOTH had a docking station for upgrades and fine tuning adjustments) I hope this helps. Lynn
I have BOTH the Canon 100-400 II w/1.4 extender and the Sigma 150-600 Contemporary and the Sigma is a bit sharper with a bit more reach and f6.3 which means I can use ALL of the auto focus options. The Canon is f8 w/the 1.4 extender and you can only use the first three auto focus options. The only thing where the Canon is better is the IS; where it will hold the viewfinder a little more steady than the Sigma. With the latest updates, the Sigma will follow the subject just as well as the Canon. The added light gathering of the Sigma is a BIG deal when doing bird photography by adding a faster shutter speed or lower ISO depending upon the setting of your camera. I have 2 7D mark II's and use the Sigma much more....The Canon is great without the extender and is my choice if I don't need more magnification.
I have both the Canon 100-400 II with the 1.4x III extender and the Tamron 150-600 G2 and I can tell you that the Tamron is balanced comfortably and is just as easy and comfortable as the Canon with the converter. The weight of both is very close when you consider the extender. The image quality of both are very close with the Tamron being just a bit sharper at 600mm than the Canon at 560mm. The Tamron has the advantage of using ALL of the different focus area options on my 7D mark II and the Canon lens can only use first three options due to the F8 aperture focus setting when using the 1.4x III extender. Both are great options.
I have the lens with my Canon 7D mark II with no problems. Make sure you micro adjust the focus with the docking station first, so that the focus will lock on with the sharpest setting. I have my OS set for the highest setting that is noticeable in the viewfinder. It's a wonderfully very sharp lens, but the micro-focus must be accurate first.
Arthur Morris uses ISO 400 all the time, or so he says. So, far I've been using auto ISO and getting by just fine, but you are right, conditions need to be fairly bright for best results.
The IS on this lens does a super job...In AV mode I've been able to move right with the bird and get by with a slower shutter speed. You'll find that if the exposure is right on, noise no longer is a big issue. I've stopped action at 1/800 shutter speed if I'm moving right with the bird.
That's a pretty good shot (aside from being too dark). I have found the best success with use auto focus Case #2 in it's default mode (-1,0,0) or all the sliders all the way to the left, and use that same setting for perched birds as well. If you take the extender off, then use the appropriate Case number that suits you best for the focus pattern you choose and the environmental conditions.
You're getting good detail with the extender and the IQ is close to the lens alone IQ. I can see you probably need to micro adjust your focus. It's adjusted pretty close though; the big thing is to pick a time when there is no atmosphere turbulence. I can see a little waviness in your shots (not your fault). Good job!
You're right; I wish I had one....just don't have the bread to do it.....I've had pretty good luck with the expanded spot setting. However I can use all the focus options with my Sigma 150-600 C at f6.3.
You are right. The center auto focus points are: Single-point Spot AF, Single-point AF, and AF point expansion. ALL of these are available with the 1.4 III attached or any combination with the end result being F8. I was simply stating what the big hitters like to use; obviously they have to use less than F8 to use AF point expansion selection, surrounding points, and Zone AF. This is using the Canon 7D Mark II which is the body we are and have been talking about.