If You have photolens then You have to choose right mount for that, have a look under our mount section. There You can find appropriate mount for Your camcorder:52mm CamMount should be right choice for Your JVC GY-HD100. Rest is simple. You need just between those mounts Indie35/HC.
In case You don\\\\\\\'t have any photolens right now then You may want to choose simple bundle Indie35 H@