<p>Hello Dan,<br />Thanks for your information. yes i think its my bad which always buying those unusual lens without any knowledge haha. But i'll try to figure it out how to put this lens on SG 4x5, maybe it will took a long long time to do and success or maybe it cant be used for SG. I just doing a gamble for this lens but i wish it can be use.<br /><br />mistakes gives new experiences. <br /><br /></p>