Grey Ghost

If you are pleased with the result then it probably makes no difference!

fetzler Loc: North West PA

Extension tubes and adapters are two different things and serve different purposes.

1. An lens mount adapter allows one to mount a lens for Camera manufacturer A onto a camera body made by manufacturer B. This is easy to do for mounting DSLR lenses onto mirrorless camera bodies as the mount to sensor distance is greater for a DSLR camera. Generally adapters allow the DSLR lens to be used manually but there are a few exceptions. An adapter for Nikon DSLR to Nikon mirrorless usually retains all lens functions. Most often the adapted lens will focus at infinity.

2. Extension tubes extend the lens further from the sensor in order to increase image magnification for macro work. Extension tubes have the same type of mount on both ends. Extension tubes can be manual or automatic.
The latter allow for the retention of all lens functions. It will not be possible to focus at infinity with extension tubes attached.

3. Extension tubes reduce the effective aperture. Adapters do not change the effective effective aperture. If you have a speed booster in the adapter then the Image circle diameter is reduced and the effective aperture is increased.

olemikey Loc: 6 mile creek, Spacecoast Florida

I use both.... I've found extension tubes paired with large/long lens to be excellent when shooting from relatively close (from a blind) for small birds, and for macro of course... I use adapters to mate a number of different lenses (brands/types) to Sony/Nikon/Canon bodies. Some are better than others....I want AF, VR and aperture control in any I use, which is limiting... full manual adapters are ok in a pinch.

Dennis833 Loc: Australia

I have two cheap Commlite adapters and an EF extension tube. Both work well with EF lenses on my Sony A7R111.
AF is very quick but sometimes I have to pre manual focus my 400mm a bit first. One thing to mention is that EF lenses remain fully open until the exposure. I actually find this useful when shooting two images that are going to be stitched together. I can AF on two different focus points very quickly.

Architect1776 Loc: In my mind

No change at all as the lenses are designed to be a certain distance from the sensor.
Once you exceed the designed distance then there is falloff.