IanF
Moderator
The other replies have covered the points really.
The FZ7 has a lens that moves in and out when the zoom is powered up, so any filter needs to be mounted on a lens adpater - sometimes called lens armour. The lens armour has a thread on the end of it which is 55mm in the case of the Pemaraal adapter. The Tcon-17 has a 52mm thread so a step-down ring 55-52mm is needed to mount the Tcon-17.
There are other adapters available and other teleconverters which may have the same or different thread sizes. With Pemaraal you order by selecting the right one for your camera model - http://www.pemaraal.com/fz7ac.html
I opted for the metal version of the Pemaraal adapter as I find the plastic versions are seldom sufficiently durable. The body of the adapters is okay but the threads being fine are two easy to damage/cross-thread.
The FZ7 has a lens that moves in and out when the zoom is powered up, so any filter needs to be mounted on a lens adpater - sometimes called lens armour. The lens armour has a thread on the end of it which is 55mm in the case of the Pemaraal adapter. The Tcon-17 has a 52mm thread so a step-down ring 55-52mm is needed to mount the Tcon-17.
There are other adapters available and other teleconverters which may have the same or different thread sizes. With Pemaraal you order by selecting the right one for your camera model - http://www.pemaraal.com/fz7ac.html
I opted for the metal version of the Pemaraal adapter as I find the plastic versions are seldom sufficiently durable. The body of the adapters is okay but the threads being fine are two easy to damage/cross-thread.