Canon RF 24-105/4.0 L IS USM

The RF 24-105 f/4 L IS USM is a more robust and professional-grade lens compared to the RF 24-105 f/4-7.1 IS STM. It features a constant aperture of f/4, while the STM model has a variable aperture that narrows to f/7.1 at the telephoto end, which affects low-light performance and depth of field control. The L series lens offers dust and moisture resistance, a larger filter size, and includes a lens hood, making it more suited for demanding shooting conditions. Additionally, the L model uses an ultrasound autofocus motor, providing faster and quieter focusing compared to the step motor in the STM. However, the STM lens is significantly lighter and more compact, which might appeal to users prioritizing portability and a lower weight.