You might get an answer that help if you provided an idea of what you want to photograph and how small the subject is.

generally garden phenomena -- flowers and insects. but i meant the question to be academic.

{btw, i see no way to configure this forum so as to be notified by email of a response. is it possible?}

Flowers are one of my favorite subjects, partly because I live in a valley that is known for growing flowers for seed. I use a 100mm f/28 Canon macro lens for that kind of photography and it works ideally.

There used to be an e-mail notification function, but it has not worked for me for years.

The basic answer is that each device you're asking about has no glass. They are just tubes of different lengths and allow you to focus closer than the closest focusing of the lens you are using. Past a certain point, it becomes unnecessary because you end up with the front of the lens too close to allow any light to hit the subject. Two other factors enter the equation. One, the greater the distance from the rear of the lens to the camera, the less light reaches the sensor. The second is that you have no autofocus when using close up devices like these.