This is a similar lens to the Irix Firefly 15mm, but has a bit better build quality so it is heavier. It also has fluorescent markings so these will glow under UV light. The weather sealing is also quite good on this lens. [url=https://www.astrobin.com/27171q/][img]https://cdn.astrobin.com/thumbs/0JtrAJF9bv0a_130x130_Pzq8wK0O.png[/img] Sunflowers Don't Sleep [/url]