The idea of wide converters is cool but as a user of GXR system I would like to compare GR with 21 converter against GXR A12 module with VC 15/4.5, both quality and sizelike.
From what I read on Ming Thein blog the converter is O:K at F 2.8 and very good at F 5,6. Well, my VC15/4.5 is very good at 5.6 too and takes filters ( the old version which is miniscule, you just jam reversed leica 39mm in the built-in shade, immobilizing it with bit of tape. There`s one thing more. The moustache distortion, I didn`t know it that prominent. Would be disturbing in architecture shots.
The fotos look somewhat familiar. Let me guess before going to your site.. Tulum on Yucatan, perhaps?
If right then I`ve been there once some 30 plus years ago on the way back from South America vagabonding. Memories, memories.
Riccadonna, you are right. I doubt this converter will stand up to a 21mm prime lens. However, for general landscape and architectural panoramas, this will serve just as well.
And yes this is Tulum. Glad your memory serves you well. Fond memories no doubt.