Lens adaptors/step up rings for camcorders, same for all brands?

I want to get a step up ring for my Sony CX105E Handycam, is the thread the same for all brands? Could I use an adaptor for a Nikon or Canon?

Not exactly. The camcorder first needs to have the threads… In the case of the Sony HDR-CX105E, the lens filter diameter is 30mm. Most camcorders in the same range as the CX105 do not have threads. As the camcorders increae in price, the lens filter diameter increases to 40, 47, 50… And larger.

To use a Depth of Field adapter, it needs to match up with the lens filter diameter on the camcorder - in your case 30mm… If it does not, then that is what the step-up rings deal with.