A useful wide-angle lens for the Sony a7 IV must cover both the photographs you make and the video modes you actually record. Our overall choice is Sony FE 16-35mm F2.8 GM II; Sigma 16-28mm F2.8 DG DN Contemporary for Sony E is the value-oriented alternative, while Sony FE 16-25mm F2.8 G suits a lighter hybrid kit.
The FX30 is a Super35 cinema body at about 646 g with IBIS. Wildlife video wants native reach and OSS. The Sony E 70-350mm F4.5-6.3 G OSS is about 105–525mm equivalent at 625 g.
The a9 III is a 24.6MP global-shutter body at about 702 g with 120 fps. Field wildlife on that body is the Sony FE 200-600mm F5.6-6.3 G OSS, an internal zoom you can leave on a monopod.
The a7CR puts about 61MP in a 515 g body. The wildlife zoom that does not erase that compact shell is the Tamron 50-400mm F4.5-6.3 Di III VC VXD at 1,155 g.
The a7R V is a 61MP full-frame body at about 723 g. Wildlife on that file is the Sony FE 100-400mm F4.5-5.6 GM OSS, because a crop still holds a frame a 24MP body would miss.
The a1 II is a 50.1MP stacked body at about 743 g with 30 fps. Distant birds on that file want the Sony FE 400-800mm F6.3-8 G OSS, not a 100-400mm you then crop.
The a6700 is a 26MP APS-C body at about 493 g with IBIS. Far-field wildlife on that crop is the Sigma 150-600mm F5-6.3 DG DN OS Sports, about 225–900mm equivalent.
The a7C II is a 33MP full-frame body at about 514 g. The wide zoom that keeps that compact kit useful is the Sony FE PZ 16-35mm F4 G at 353 g.
The a6700 is a 26MP APS-C hybrid at about 493 g with IBIS. The native wide zoom is the Tamron 11-20mm F2.8 Di III-A RXD, about 16.5–30mm equivalent.