To be able to drive a car, one takes numerous lessons, does countless hours of supervised practice and then has to pass a rigorous test.  Driving a public vehicle, such as a bus, coach or taxi is tzorchei rabim and is thus permitted even though it is maaseh uman. If there would be a real financial loss if one did not drive, it would be permitted even though it is maaseh uman. However driving for pleasure, which could be classed as tzorech hamoed, is only permitted if it is maaseh hedyot and surely driving a vehicle cannot be so classed!

In the era when one photographed onto a photographic film, such photography was halachically writing. (The 39 Melachos by Rav Dovid Ribiat, volume 4, pages 952-53)  One sees numerous photographs of gedolei hador carrying their arbaas haminim and the fact that they did not prevent the photographers strongly indicates that it is permitted to take such photographs on Chol Hamoed.  Since the only time in the year that one can take such photographs is during Chol Hamoed Succos, it might be classed as davar haovud. Furthermore, since almost every child can use a home camera, it could be classed as maaseh hedyot. Possibly today’s digital cameras are even more permissible.