If it is a Canon EOS 5D mark II it will remember the 24p but, we work in 25 fps as we believe it gives a better "look" on pans and motion. As far as 1/50 sec goes you can set it manually but, if you have set the ISO rating at Auto it will change in low level light to get the exposure right, and it does.If it is a Canon HV20,30, 40 we can only set at 25P (Pal) which gives a near 24P look, but, it is not always ideal. the colour is fine but, there is some artifact movement in fast motion or panning ? Make sure the - above ON is selected and the wheel is engaged when you hold your trigger finger down .
Read Page 94 M Manual Exposure, which can fix the speed, aperture, exposure index if you have set it correctly, then return to ON, to set you must depress the shutter button, see page 16. The settings should remain unless changed.
If not phone Canon Technical Service.Note : The new Firmware Version 2.0.4 Functional Enhancements 2.Adds a function for manually adjusting the sound recording level (64) levels.
3. Adds shutter - prority AE mode TV( for shooting movies) and more.
Be warned " if you only use the mono microphone on the camera it will pick up the Image Stablizer working and you will need to use a Low Band filter when editing in Premiere Pro. You must push the Rode Video Mic for stereo or (similar mike) fully in to the body to remove body noise.