About extension Tubes

There are three "levels" (maybe four?) of extension tubes.

The simplest (and cheapest?) are simply tubes with k-bayonette mounts at each ends. They haven't got the coupling lever and the lens then acts a a purely manual lens that stops down when you turn the aperture ring. If it doesn't, the photo will be taken with the aperture wide open even if you have stopped it down with the ring. The only lens I have that would work with this kind of extension tubes is my 28mm shift lens, a fun but complicated device that I'd never use for macro shots. I guess that old m42 screw mount lenses with a k-mount adapter would work.

Next level is marked as "automatic". This simply means that there is an aperture coupling lever, and the lens will stop down to the chosen aperture when you take your photo. But it still acts as a manual lens, you have to set the aperture with the aperture ring and use the green button or d o f control to set the correct exposure. And you have to choose the "use aperture ring" option in the menu.

Third level are tubes with both the lever and the electric contacts for aperture control from the camera body. With these tubes, lenses with an "A" setting on the aperture ring work just like they do without the tubes. Just set the ring to "A" and handle the rest from the camera body. After much search I actually found this type of extension tubes, used on ebay. They are only marked "made in Japan", no brand name or anything like that. But they do work well.

The possible fourth level would be tubes that also have the autofocus screw. I have never heard of or seen such tubes.

Kjell