RF 35mm F1.8's "AF with full-time manual" spec doesn't apply in 4K video mode

[kevinjohnsonbos]

The RF 35mm F1.8 Macro IS STM's spec says, "AF with full-time manual." While on the EOS RP the lens's MF ring works in HD video mode with 1-point AF on, it has no effect in 4K (cropped) video mode (Movie Servo AF disabled, Lens electronic MF on).

The focus rings of these two lenses work in 4K video mode on the RP with 1-point AF on: EF 50mm f/1.4 USM, and Tamron's SP 24-70mm F/2.8 Di VC USD (with "Full time manual focus").

I purchased the 35mm, refurbished, on usa.canon.com, but only discovered this misspecification after their 14-day return window.

Canon won't accept a late return even though the lens doesn't meet its "full-time manual" spec, and they're apparently not willing or able to correct this in firmware as I'd hoped. I'm considering attempting a belated credit card chargeback.

I shoot rock concerts where the AF often needs to be corrected, so I'd apparently be better off with an EF or Tamron lens.

[John_Q]

Hello kevinjohnsonbos,

It appears that the RF 35mm F/1.4L VCM lens is actually the version that would meet all of your needs.

[kevinjohnsonbos]

Why can't the firmware in the RF 35mm F1.8 Macro IS STM be updated so that the focus ring works with AF in 4K video mode, as it does in HD video mode? If it can't, the spec and manual should be corrected.