I am going to be shooting a short film for a bunch of friends and I was hoping to shoot it in 16:9 if possible.

My TRV38 can shoot in true 16:9 but the other camera (TRV-18) can't.
What would be the best way to combine the footage of the two cameras in post? Would it be best to shoot the TRV-18 footage in 4:3 and then just crop it in post? Or use the fake 16:9 effect on the TRV18? I am affraid of shooting with the effect as it might lessen the resolution overall.

Any suggestions?

If you use both cameras, the footage will look very different. I would just stick with using the TRV38.

Why don't you just shoot some test clips with both cameras and bring them onto the timeline to see what looks best?

Using the in-camera 16:9 or cropping 4:3 in post will both reduce resolution by 25%. Another question is whether the TRV18 records 16:9 anamorphically or letterboxed?

Why are you using two cameras? Just curious.

The reason for two cameras was because we are trying to get the whole thing shot in one day. We only have access to this location on the one day. So I was trying to streamline the production.