Canon 5D Mark IV AI servo settings for fast cats (moving towards you, changing direction, speed etc)

hello, I still have some technical data, unfortunately you will have to explain here it is explained how slow af this lens is, besides the cats are very busy so in the mode you have chosen it will be difficult to have success. I use the BIF technique and it is much better because the cat can be as fast as a bird (after all, it hunts perfectly). The faster the shutter, the better. Even 1/2500. Remember that FF is not the same as APSC. I know you'll have better results. Regards
https://www.optyczne.p​l …cro_IS_USM_Auto​fokus.html

In my experience this lens can not focus fast enough to keep up with moving cats. For stationary cats it works very good. For indoor pictures I would try flash, available light is usually not enough(I'm in the same region light-wise) and now even outdoors there is not much light(up your iso, a 5DIV can take it). Further I mostly use only centre point or centre + 4 surrounding points. Practice to keep on target!
The 50 1.4 can also be used at f4 etc (and it's also not the fastest and certainly not the most consistently focussing lens I own).

The OP's biggest problem is that the 100mm L macro, while a very fine lens, does not have the AF speed to keep up with his/her subjects. The 5D4 AF system should easily handle this. And use ISO 6400, should be duck soup for the 5D4.

russbecker wrote in post #19006988
The OP's biggest problem is that the 100mm L macro, while a very fine lens, does not have the AF speed to keep up with his/her subjects. The 5D4 AF system should easily handle this. And use ISO 6400, should be duck soup for the 5D4.

Disagree. I use the EF 100mm f/2.8 Macro USM (not L, not IS) on an 80D. It has no problems with focus speed, pre-supposing I've set up my AI-Servo parameters to do the job at hand. I can't imagine the L/IS version is worse.

IS can negatively impact focus speed on some lenses. It is not needed at the expected shutter speeds. Turn it off if your 100L struggles in AI-Servo.