Secacam 1 is more basic than on the Secacam 3. The Secacam 1 supports video capture and can send short clips at lower resolution (typically 480p for mobile transmission) while also storing Full HD video locally on the camera itself.
ZEISS Secacam 3 Trail Camera is the more advanced model with better video performance. It offers higher-quality video generally and faster, more capable processing and transmission, plus features like a front display for easy setup that the Secacam 1 doesn’t have.
So if video is important to you especially good quality clips and smoother transmission the Secacam 3 is the better choice. The Secacam 1 will still do video, but it’s more limited and focused on the basics.