<p>Dave, I hope the lens/body communication issue gets solved. Heck of a way to start out, eh?</p>
<p>Anyhow, this Lexar is a great card and price. I have it and two 1000x KomputerBay 64 gb cards as well. These are supposedly cards that didn't pass Lexar's QC....but feedback from card owners say they work well. Both mine have. Here's the 1066x version:</p>
<p>http://www.amazon.com/Komputerbay-Professional-Compact-Flash-Extreme/dp/B00J9OS4V0/ref=sr_1_fkmr1_1?ie=UTF8&qid=1457069995&sr=8-1-fkmr1&keywords=KomputerBay+64+gb++CF+card+1000x<br>
http://www.amazon.com/Lexar-Professional-CompactFlash-Software-LCF64GCRBNA1066/dp/B00IAYFDIC/ref=sr_1_1?s=instant-video&ie=UTF8&qid=1457068755&sr=8-1&keywords=64+gb+Lexar+CF+card</p>
<p>As well, Samsung now makes some fast SD cards, and inexpensive. As others stated, CF cards are faster in the 5D MkIII than SD cards. </p>