Did you set lens to infinity first? Did you take photos of other subjects besides a white wall, and see this dark ring? How long did the lens take to focus? 1-2 seconds? 2-3 seconds? Just trying to understand why Steve Huff had better experience. Thanks.
Actually, Infinity focus is not required if you've read through the manufacturers information however I've done both infinity and in between. I had contacted Techart and they have yet to reply. I wrote on their Facebook page today about this problem and we'll see if I get a reply.
To add to the issue, they note there is a firmware update available, 2.0, if after April 15th, ?, not sure if this is the manufactured date or what. Where would find a date? I asked them on their FB page how do you know what firmware version you have in order to update what you've got. (just for your information, my serial number is 000623).
Secondly, their instructions how to install the update tells you to set your aperture to F90, not F9, release the shutter and then off the camera. THEN, be sure your smartphone bluetooth is on and download the firmware. Sorry, but there is no bluetooth signal coming from the adapter if the smartphone is turned off. I've tried every possible way and I've yet to get a connection on my phone with their app and the adapter. Can't figure where the problem lies.
Not to completely heave this adapter into the next stratosphere, it does work on occasion, though not on a consistent basis. It will hunt at times and just never lock on. As noted by others, it is a unique step forward to take a MF lens and allow it to AF however, this one needs an update to 3.0 or someone else needs to perfect their design. This is $350 wasted IMO.