I've been working with mine:
>>3185452 (f/6.3 not f/6.8) a bit to see what it can and can't do.
A solid mounting system is a must when using anything to extend the lens off the body. The mirror needs to be in the up position when taking a photo with a timer/remote otherwise its movement will shake the camera too much. With the e.tubes and teleconverter it wanted to bow and hang down because of the cheap plastic e.tubes. The 10s timer on the D3400 isn't long enough for the camera to stop shaking after not touching it. Thus, I can't seem to get a clear photo using this more extreme setup in lower light levels.
