Question about macro lenses and tubs

Hi Guys!

I posted a question in the "Talk about Photography" section but as it is a lens questions I thought I'd post the link to the post to invite some feed back from everyone in this section. Please take a look and let me know your advice. It would help much for my furture lens purchases.

Thanks!

https://photography-on-the.net/forum/showthre​ad.php?t=571466

Tubes or tubs, they push the lens further away form the camera and thus enlarge the spread of the image the lens is making. The camera then only sees a small part of the image. Thus things seem bigger. You lose light but since there are no glass elements, the quality can be very good. A nice, cheap way to get started into macro - get some tubes and use them on the lenses you already own. Even if you do get a true macro lens, you'll still use them once in a while for more "power."

Here is some good stuff about extension tube math (see post 5):

https://photography-on-the.net/forum/showthre​ad.php?t=19350

i originally really wanted to buy a 100mm macro - so i got some inexpensive kenko EF tubes to use in the meantime. now i no longer want the 100mm - if someone gave me one i'd just sell it. for the type of macro work i do (wedding details, jewellery, flowers etc) the tubes are more than adequate - i never even usually combine them to get the highest magnification, 12-24mm is often enough. i just use them with my 50mm f/1.8