Yeah, my only STM lens is the EF 40mm f/2.8 STM pancake, and I have such a mixed relationship with it: on one hand, I love the compact nature for casual walk-around — but on the other the AF drive and manual interaction really irks me. I won't say I hate it, but I will say the only reason it remains in my kit is the compactness. If that's how STM lenses in general are being done I wouldn't vote for them with my cash. It's been such a turn off I haven't even made time to try the RF editions, but I suppose I should to see if they've improved.
STM is also noisy, at least from what I can remember when I tried it.
This is not to say that Canon completely reinvented them, but the latest iterations of STM motors are more enjoyable to use. It really depends on the lens, though.
The EF 40mm was the first or second STM lens ever, its autofocus is pretty slow and somewhat noisy. There's still a few lenses that I'd say are about as noisy as the 40, such as the RF 50mm f/1.8 and the RF 35mm f/1.8, but some others are different.
There's not a lot of lenses with the newest STM motors yet, as far as I know it's just the RF 7-14mm L, 10-20mm f/4 L (I think), 16-28mm f/2.8, 28-70mm f/2.8 and the 45mm f/1.2, but they are provide a significantly better user experience, being quiet and smooth. Some of them are pretty fast, and that includes the 28-70mm f/2.8, which seems to be about as fast as the EF 24-70mm f/2.8 II.
Additionally, it's important to distinguish the two types of STM motors. Lenses driven by gear type STM motors tend to be a little noisier and jerky (RF 16, 28, 35, 50,...), while lead-screw tends to be quieter and smoother (RF 24, 85, 10-20, 7-14, 16-28, 28-70,...).
The 45mm uses a new gear-type STM, being an exception, that feels to me like a slow but modern USM, it's pleasant, it's smooth and quiet.
Gear type STM are the smallest motors, being the only choice to equip the smallest lenses.
?
. And yes, I'm suppose to know that it's all about the regulation (aka non-protein codding DNA).
). I hope it is not the lens. Can you borrow (or rent) another EF 1.4 TC to verify that it is not the lens?
