White balance help please! Nikon D90

Hi everybody,

I have recently upgraded to a dSLR system, I chose a Nikon D90 in a Aquatica housing and on the whole I think its a really nice bit of kit.

As yet I don't have any strobes so I use ambient light and white balance correction. (or rather I don't)

My idea was to take white balance measurements at different depths and store them in the white balance presets memory, which is possible on the D90. This is where I met the problem. Following the user manual, I did several dry runs with the camera out of the housing to make sure I was ok with the process. I then tried it with the camera in the housing, all seemed ok.

However when I tried this during the dive it would not enter the "preset" mode to take and store a measurement. I'm wondering if the little black covers on the inside of the housing buttons are moving to a point where they do not make contact with the camera function buttons?

Can anybody shed any light on this, or maybe offer a solution.

Cheers

Andy.

Hi Andy,

If it is OK at the surface but not at depth then it has to be related to pressure and the buttons.

Often if a button is pressed it does all sorts of strange things to the camera - was the camera working aside from this ?

If it was working then it sounds like the button just ain't making sufficient contact - check that the camera is mounted correctly - after that try extending the button in some lash up / temporary way or other.

Honestly suggest a couple of other things :-

1: Shoot RAW you will need the exposure attitude anyway - then WB happens in post (aka computer) and the WB at capture time is not relevant.

2: Beg borrow or steal a strobe - you won't get far in the UK or most anywhere else without one, the housing and camera you have there deserve it!

With ambient light you can do lots of stuff as long as there is a decent amount of sunlight without you will be having problems with exposure times.

Paul C

Sorry cant help that much, but only to say that you can use white balance correction in Lightroom on jpgs too, and I strongly support the "get a strobe" comment

Good luck Andy

white balance correction in Lightroom on jpgs too

Yea you can - but you do not get the exposure latitude that RAW will provide.

OTOH maybe you nail the exposures right on first shot - myself I don't :D.

Look for a used strobe - there are often some listed here on Wetpixel.

Paul C

Hi Paul,

Thanks for your advise.

It is working fine at the surface, I will try to "jig" the button. I do now shoot raw, but I'm new to the realms of photoshop etc. Though I am trying to gain speed with this.

I come from the darkroom age. I was a professional for 20 years. I was taught to shoot it right first time in the camera and its hard to "shake off". Of course your right, if you know how, just post process. There's no cost involved anymore in shooting loads of images, just time now.

I know I've gone a bit off topic here, but on that subject. When I look at the levels and in particular the reds. Theres very little, and what's there is in the blacks at the far end of the scale. I thought if it wasn't there you couldn't put it there. Forgive my ignorance but is this wrong. Hope so!!!!

Thank again,

Andy

Hi Andy,

I would suggest getting the trial version of Lightroom, rather than using photoshop. I find it's interface much more intuitive for photography than PS, and it is definately simpler to use. Try it and see!

It's WB ajustments are very simple, and as it's a metadata rather than pixel editor, you can press the reset button as many times as you like with no effect on the image quality (In PS, you can do this too via the Raw convertor as well to be fair)

Red is absorbed with depth and as you say, you cannot add what isn't there. This is why the red will be in the black end of the histogram and there won't be much much of it. The only way to add this back in is to stay very shallow in sunny places with good water clarity(!), use a filter (like a magic one), or add a strobe. You can use white balance in post production, but this is limited too what wa sthere to start with!

Adam

I come from the darkroom age. I was a professional for 20 years. I was taught to shoot it right first time in the camera and its hard to "shake off". Of course your right, if you know how, just post process. There's no cost involved anymore in shooting loads of images, just time now.

That is still a good aim - even with RAW there is a limit to how far you can go before you will see the result.

Expose for the highlights not the shadows - turn on highlight warning on the camera and jack the exposure until the specular highlights show - if you under expose with digital the price is worse than with film.

Some cameras output (CCD's) seem to hold up better than others - with RAW and Nikon I can push or pull about a a stop maybe a stop and a half - after that the blue channel noise comes in to party.

The reds attenuate disproportionately in the water column - they are the first to go. Tools like the magic filter aim to balance the spectrum again - but there is a downside ( about a stop and a half to two stops ).

Lightroom is good by the way and is the way to go. If you have not got it get the Martin Edge book - cannot recommend enough - order the new one.

Lightroom book - I would look at this

Paul C

There is an on-going WB thread here:

http://wetpixel.com/forums/index.php?showt...mp;#entry234825

See my Lightroom example in post #9

I agree with the others, you will need a strobe before long, even magic filters have a practical depth limit. Filters overshoot if you are very shallow like my example.

Thanks for all your help and advice guys.

Really glad I found wetpixel. Excellent!

Andy.

I'm gonna have a look at the white balance thread now........