I received my 24-105 f/2.8 yesterday. So far, I am very impressed.
Initial impression...this is a big lens. Very next step after mounting it to my R5, "this foot has got to go!"
That helps a little....but this is a big lens. About the same size as the EF 70-200 f/2.8 II and just a tick lighter. (5.7 oz).
But...the very next impression....this AF is FAST and SILENT. I'll do a test on the speed, but it being noticeably faster than my EF 24-70 II is a solid impression. I am wondering if this is my fastest focusing lens. The silence is not doubt.
Image quality...extremely good. Good enough I am not going to worry about it. It's bokeh is very nice. I was hoping for better than the EF 24-70 II...and maybe it is, but for now, for similar framing, I would call them more similar than different. But...70 mm on the RF 24-105 is longer than 70 mm on the EF 24-70 II. So, I need to work on the framing and check again.
Some pictures (no editing, RAW processed in LR to fit TDP requirements):
EF 24-70 II @ 70 mm f/2.8 (1/10 sec, ISO 400), aimed at a Christmas tree decoration on a table with our Christmas tree in background.
RF 24-105 f/2.8 @ 70 mm, same settings except I dropped to 1/15 sec...not sure why. So, this is darker, but there is a reason.
@ 105 mm (1/10 sec...same settings otherwise)
But..the next thing I wanted to test...Image Stabilization. So, with my R5 and EF 24-70 II, I can routinely hand hold 24 mm at 1/4 and even 0.5 secs and out of a burst of 3-4 images I usually get a keeper.
This is a 1/9 crop (center of image) of 0.5 sec @ 105 mm, f/2.8, ISO 400 :
This is a 1/9 crop (center of image) 2 sec..hand held...105 mm, f/2.8, ISO 100:
I took two images at 2 sec...one was definitely blurry....but the one above...that is usable...that is legit 8 stops of IS. I can't wait to test 24 mm. I doubt I'll get 8 stops...but if I can hand hold 2-3 seconds and consistently get good images, my travel tripod is coming with me far less often.
Overall, first impressions are very positive. The 24-105 range is very nice. The EF 24-70 II was already excellent, but AF is noticeably improved/faster, especially in low light. AF is silent, which will be great for videos (as desired), the extra range is good, and the Image Stabilization is as advertised for 105 mm.
I am not complaining.....