I like to have a bit more macro with my 75 1.8! Any experiance with extension and 75 1.8??

No, but if you want to send me your 75, I would be MORE than happy to try it out for you. :smile:

Seriously though, they aren't very expensive; you should buy a cheaper set and try them out. You want tubes that will pass the electronic contacts.

These are the Fotga's at a cheaper price; they look exactly like the Fotasy tubes I bought for significantly more...

http://www.amazon.com/Neewer®-Automatic-Extension-Olympus-Panasonic/dp/B00E38CTVI/ref=pd_cp_p_1

 

I don't use ext tubes, but I do have a Raynox 250 close-up diopter. It delivers surprisingly good IQ and at around $50 it's good value. It works well on the 75 - certainly well enough for casual macro work.

 

As there is no glass in these extension tubes, there should be no IQ degradation. Lots of generic brand extension tubes out there at different price levels. Can't tell you which ones are good, as I have not used any, but you can get more info here:

http://www.dpreview.com/forums/thread/3595669

https://www.youtube.com/watch?v=VKZdtQwCp9M

Kenko Auto Extension Tube Set:

http://www.bhphotovideo.com/c/product/859014-REG/Kenko_AEXTUBEDGM43_DG_Extension_Tube_Set.html

Vello Auto Extension Tube Set:

http://www.bhphotovideo.com/c/product/971885-REG/vello_ext_mftd_auto_focus_extension_tube.html

Fotga Auto Extension Tube Set:

http://www.amazon.com/FOTGA-automatic-extension-Olympus-panasonic/dp/B00CANGBIK

Meike Auto Extension Tube Set:

http://www.amazon.com/Meike-Automatic-Extension-Olumpus-Panasonic/dp/B00BY0F0P0

eBay options:

http://www.ebay.com/bhp/macro-extension-tube-micro-4-3