I've read conflicting items regarding whether the LA-EA3 or LA-EA4 is the preferred adapter to use with the Tamron 150-600 A mount zoom on an A7ii. In the quest for knowledge, I picked up the LA-EA3 adapter so I could compare the results first hand (already have the LA-EA4). Thus far, I've concluded that better focus accuracy is possible using the LA-EA3 with manual focus, but I have much more experimenting and practice to do. No doubt autofocus will likely be better for moving objects, but it is possible to pull in a manual focus reasonably quickly with this lens. My test was simple. Camera/lens mounted on a tripod. Target focus was the bright yellow leaves in the middle of the first image shown below (shot at 50mm with the FE28-70 lens). The 50mm image shows the relative capability of the Tamron to zoom at maximum focal length. In resizing the images to post here, the LA-EA3 example lost a fair amount of detail; it was actually much sharper than what's posted below. This is the manual focus shot with focus peaking taken through the LA-EA3: Using the LA-EA4, with the lens set to autofocus, it seems clear that the camera focused slightly in front of the target yellow leaves: I'm really pleased with the Tamron lens and look forward to gaining full mastery of it.