12-35 is more practical. If it is 14- 140, then the focal plane in front of it is heavier than 12-35. If you need telephoto effect. A very good parametric lens can be obtained by switching other lenses with the adapter ring. For example, I also have a suitable horse's 50 1.4 plus the adapter ring, which is 100 1.4. Even the small spittoon 50 1.8 can become 100 1.8.