D70 on Wide

Well, if you saw my last post re- missing a deco stop, you will have noticed that my wide shots were crap (excuse my french) . Many reasons, main one really was for some reason the auto focus did not work under water, i could not press the shutter and get the shot. Had to click it into manual, and manually adjust ( and since i cold not see the focus through that small view finder.....everything was blurry ). Back on land, it worked like a dream again

Any idea why? I did not have this issue ona previous trial in Phi Phi.

D70, Nexus housing, 16mm fisheye lens, small glass port.

could be AF-S or Af-C related, C takes the shot even when not in focus

AF-S fires only when the camera is locked in focus. This gives consistent focus results but can be troublesome if in low light or low contrast. Sometimes its necessary to move the focus area to the edge of the subject (fish coral etc) to get enough definition to lock focus. This is particularly bad when shooting objects that are at the edge of visibility. I once (in the first 5 minutes of my first dive with the D70 I must confess) chased an eagle ray for 100 yards without being able to fire a shot with the 60mm. The subject was just too far and the shots would have been useless anyway. I for one need to resist the temptation to chase fish and shoot too far away.

Anyway you will notice the same problem with the D70 topside in low light and low contrast situations. Try and focus on a smooth white wall indoors with the lights on. If it isn't a well textured wall it hunts and hunts. Focus on the edge of a picture frame for example and it locks up instantly.

Once I learned this I lock focus without any trouble.

I once tried AF-C (which fires wether you are locked in focus or not) and had poor results. I had fun shooting machine gun style but then ended up with a lot of out of focus shots. This works ok on land where your camera to subject distance is stable but not with moving fish in Cozumel currents.

Good Luck

You may need a diopter to make it focus thru a port....I'm not familiar with your setup, but I've had the same problems when I forgot to put on the +4 diopter with the 18-70mm and Ikelite port

Karl