Looking for a fast lens, mainly for indoor(with low light) use. It will be used in family events, indoor parties at night and its usage will range from single to group portraits. Most of the time I will have external flash attached. Right now I take my 24-70 f2.8L in such events but I am looking for something lightweight and fast. It will be paired with a 5d3 and at times 60d. Oh, I use the 50mm 1.8 II at times and it often hunts for focus in dim lighting conditions where the 24-70 snaps on to the target almost instantly. I am on the verge of selling the 50mm 1.8 II.
Thanks in advance.
You can set the camera to continuously hunt for focus.... or just give up. My camera is set to give up if focus can not be found....
I am sitting in a poorly lit room with a 60D, a Sigma 30/1.4, a Canon 50/1.8, and a canon 100L2.8. I have tried this both with selecting the center focus point, and by selecting the far right focus point.
For the 50 F1.8.... focused in a second on about 50 percent of the items, both focus points.
For the 30 F1.4.... focused in about a half to 3/4 of a second on about 3/4 of the items, both focus points.
For the 100 F2.8.. focused on about 90 percent of the items in a quarter of a second with both focus points.
Since it is the same room, same lighting, same camera, same settings, same targets.... I think it is safe to say that the choice of lens does affect autofocus and just like the OP, I had a F2.8 lens outperform a F1.8 lens in low light.