Shooting macro with ultrawides/20-28 and rings?

Is it possible or will the working distance be behind (inside) the lens?

I was thinking sigma 10-20 and ~10mm worth of rings, or possible a 20/24/28 with rings.

You are correct, you'll wind up with no working distance very soon. Macro should be done with telephotos, in general.

Will it actually be inside the lens or like a working distance of a cm or 2 you´d say?

And if you dont know its ok, I guess its not really that important. I would just like to know if it was possible, I already knew it was a generally bad idea.

Yeah, doesn't work well. I was able to shoot with my Tokina 12-24 and a 12mm tube, but only at 24mm, and the working distance was (I kid you not), less than 2mm.

Now, my Olympus 28 f/3.5 works fine with a few tubes, since it's so small.

Rogert wrote in post #7427461
Will it actually be inside the lens or like a working distance of a cm or 2 you´d say?

And if you dont know its ok, I guess its not really that important. I would just like to know if it was possible, I already knew it was a generally bad idea.

With a single 12 mm tube, if you're lucky, it will be a WD at maximum magnification of 0 mm.

I do this with my TS-E 24 mm occasionally, and the objects touch the front lens, essentially .

Kind regards, Wim