Pre-USM EF 100 macro question

Hello guys, I'm selling a lens that was gifted to me a few months ago. It is seemingly a pre-USM 100 f/2.8 macro lens. I truly know nothing about macro and there has been a question I need help with. Would this lens be considered 1:1? Also for what it's worth, what does that even mean?

Here's my thread...

https://photography-on-the.net …showthread.php?​p=18066227

For the record I am not trying to promote my for sale ad, I just figured maybe it would be helpful to see the lens and also if someone has information they could post directly in the thread. If this is not cool I will delete this post. TIA

For future reference, this is a 1:1 lens.

Zehnn wrote in post #18068911
For future reference, this is a 1:1 lens.

Yes, and also for future reference, you can get the basic specs for any EF lens ever made (for any market worldwide) on Canon's site, including magnification factor. Here is the page for this lens:

http://global.canon …museum/product/​ef289.html

People have copied most of the model data to wikipedia as well, but not for the most obscure lenses like, say, the EF 100-200mm f/4.5 A (the infamous no-manual-focus-ring lens)

I think for reference this might be an overall linear extension focussing lens, ie it gets longer as you focus in.

Lester Wareham wrote in post #18077230
I think for reference this might be an overall linear extension focussing lens, ie it gets longer as you focus in.

If I understand what you're saying, yes that is correct. When I put the focus into manual and dialed it in and out you could see the innards moving forward and back. Sorry for the completely non technical description there.

Thanks for the help guys!