D90 Ikelite Housing prob: what's going on?

[UW_again]

Just went digital u/w, previous had Nikonos I, II and V, but am newbie to u/w digital. Nikon D90 w/ 18-55 mm zoom in an Ikelite housing w/6" dome port and DS51 strobe. Camera & strobe worked fine on strobe and zoom test shots out of water. First 2 dives to ~60' I shot in manual mode, strobe and housing in TTL. Didn't realize camera was set for -5 EV! I had set ISO at 100 thinking to do more c/u work than I did since viz was ~20' and water was full of backscatter bits. All shots came out dark, some darker than others. Fish seemed to photograph lighter than the wetsuited divers. Salvaged some photos by futzing with them in the software. So maybe someone can learn from those mistakes. Yes I could've set ISO and had I known the camera better, I'd of reset the EV also - but still learning this DSLR (only second one I've owned). On the 3rd dive with the housing over 2 weeks later - here's the mystery - I had set the EV to 0 and used an ISO of 400 - I got down to about 85', viz was 30'-40' and I COULD NOT get the shutter to trip! It wasn't until near the end of the dive on my way back up that the shutter started working and I had turned the strobe off, so had to turn it back on again. After the SIT and on the 4th dive with the housing, sometimes the shutter wouldn't trip, other times no problems - almost as if the camera wouldn't focus (altho I did get one shot where everything was out of focus!). Seemed like I'd flip the housing shutter release up and then press it down and the shutter would fire... strange. SO, could there be some control on the housing which is getting depressed which deactivates the shutter release? I have a UV filter on the camera, is that preventing the camera from focusing? Has anybody had a problem like this? Don't know where to start to replicate the problem. I viewed the Nikon Niche for a couple of hours this morning and didn't see any mention of such a problem - but you all have some awesome photos taken with the D90, so I know what's possible! If no one has any answers, maybe Ikelite can shed some light on the problem?

 

[AussieByron]

I would check all the knobs on the housing to make sure they all line up correctly. I have experienced something simliar with my Ikelite and it was due to the camera not screw all the way in on its housing tray. It needs to be only out by a fraction of an inch to get the signs which you discribed.

Give that a go and see what happens.

Regards Mark

 

[marcaumarc]

2nd-ing checking the housing hardware. One time I accidentally had the shutter lever kind of flipped around so the spring wasn't pushing it back up and it totally messed with me. As soon as I figured it out I was able to fix it, I think without even opening the housing, but it was really confusing. There are also so many different buttons on the D90, occasionally I'll inadvertently move a lever that presses one and, if it's one I'm not too familiar with, I sometimes have to look all over the housing to see which one it is and unpress it. At least the housing is clear!

If you can, get up early enough to set up your gear and test it out before heading out for the day. If you do have an issue, it is easier to find and fix quickly.

 

[MarineResearch]

Check all of your camera focus settings. The problem seems to be associated with low light conditions and the camera may be having difficulty sensing and focusing on an object. I had a similar problem with a D300 and changed my focus settings (I'll have to check the camera to see what I ended up doing, but it involved more than one setting). Also, the UV filter can be contributing to the problem. I followed the Ikelite recommendation on the 12-24 lens to include a diopter, at which point the camera would not focus above water (I never tried underwater).

 

[flstingray]

Check and make sure that no outher buttons are being pressed when pressing the shutter.

 

[UW_again]

Thanks to everyone who responded to my post. I checked all the knobs and made sure they weren't pushing on something they shouldn't (thanks Mark); Yep, did the flipped around levers too (thanks marcaumarc). I also adjusted the focus point from wide to single spot as you suggested Marineresearch. So I am zeroing in on the operation. I am finding that in shallow water - 40' and up, with lots of sun, the camera is tending to overexpose on auto mode. This camera system is a LOT different than my Nikonos'! Thanks again everyone!

 

[jcclink]

The 12-24 zoom requires a +3 or +4 diopter. It will focus topside, only very close. The diopter clears up soft focus in corners.

 

[AussieByron]

Thanks to everyone who responded to my post. I checked all the knobs and made sure they weren't pushing on something they shouldn't (thanks Mark); Yep, did the flipped around levers too (thanks marcaumarc). I also adjusted the focus point from wide to single spot as you suggested Marineresearch. So I am zeroing in on the operation. I am finding that in shallow water - 40' and up, with lots of sun, the camera is tending to overexpose on auto mode. This camera system is a LOT different than my Nikonos'! Thanks again everyone!

Keep away from auto mode underwater. Its great onland but not so great underwater. With lots of sun I usually up the shutter speed (turn FP onto auto and go higher than 1/200th) and shoot manual mode.

Regards Mark

 

[bill22]

I concur with that.... I never use auto mode underwater. I normally using either aperture priority or manual.

Cheers,

 

[sabbath999]

For those of you using manual, how do you meter?