White Balance with Flash

I’ve have an Olympus C-8080 with a PT-023 housing and Ikelite tray. Just back from its first use and still experimenting with the myriad of white balance options which I’m finding a bit clumsy underwater.

I think a CY filter would be useful but there’s no room on the front of the camera lens and the housing thread is quoted at 138mm – rather large, probably expensive and as far as I can see, pretty difficult to find – unless someone in here knows different

Even if I do find one, what about the flash. I’d like the option of a flip up complimentary (blue) flash filter so that having set a good average WB, any flash macro work doesn’t come out red. So what’s your experience guys – am I expecting too much - do I just put up with the inconvenience of selecting different WB modes underwater, let photoshop do its thing, or is there some guru out there with a better solution.

Does your camera have a manual WB like a DSLR? If it does then not to worry. You can set the WB with the filter on and strobes. If you aim at your subject and turn your strobes on before WBing, then hit the WB function (if like my D70 it sets off the strobes..) then you are all set to go and your photo won't come out red as long as you remain on that subject. Then redo the WB thing again before heading to your next subject

Thanks Mike.

Yup, I've just discovered how to enable the one touch WB button. Previously nested deep in the menus. Doh' - Lesson 1 - take the manual with you on holiday for new cameras.

Does your camera have a manual WB like a DSLR?  If it does then not to worry.  You can set the WB with the filter on and strobes.  If you aim at your subject and turn your strobes on before WBing, then hit the WB function (if like my D70 it sets off the strobes..) then you are all set to go and your photo won't come out red as long as you remain on that subject.  Then redo the WB thing again before heading to your next subject

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Sorry for intruding this thread but I'm also interested in WB. ;-)

I was under the impression that I had to use a white surface when setting the WB. I.e. not point at the subject but instead point at the white board (I was thinking about using my white uw plastic drawing board). I also thought it had to fill up the frame.

Am I wrong!?

I've just converted to digital and only read about WB, so I'm eager to learn from experienced uw photographer.

/Peter

Hi Peter, if you go to the main wetpixel home page, you can find an article i wrote about the Magic Filter that explains a few things about that.

WBing on your subject does work quite well actually, and is very good for most subjects. But if you are out in blue water or something then yes a white slate works great. Tis best to use something more cream coloured or preferably with a slightly greenish or grey tinge than pure white. WBing on pure white (like most slates) tends to make the colour too cold and therefore too blue. You want to cover about 2/3ds of the lens to get best results

M

Is RAW an option with this camera?

yes it is but......

It is incredibly slow to write to the card and is more annoying than anything. I would stick to Hi rez jpegs

Is RAW an option with this camera?

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Not sure if you asked me or Balrog, but yes RAW is an option on both the 7070 and 8080. Actually, both cameras has more or less every feature a SLR has. It may not perform as well as an SLR in all areas though.

I don't use RAW as the 7070 doesn't have a raw buffer as many SLR have. So, it takes x seconds to write the raw file, seconds that you have to wait for after each shot. Perhaps I should reconsider?

I presume what you are coming to is that it's possible to adjust the WB afterwards in Photoshop if you use RAW. Or!? ;-)

But can't you do that even if you use jpg?

I must admit that I don't fully understand this (even though I know the technical difference between the file formats).

Is it perhaps so that it's easier to do it if I use RAW but still possible with jpg?

/Peter

I owned a oly 5060 before I converted to dslr.

I started with shoting hi res jps underwater but everytime i got a good shot i couldent stop woundering how it would have been if had been shooting raw.

So i started shooting raw instead and I never looked back, it took a few seconds for the picture to be saved on the CF but when i got used to it easent that enoying. I unsed this time to plan the next shot and if nessecary reposition myself.

Another adavantage was that I didnt have to worry about the wb underwater, If it was nessecary I changed this when coverting the raw.

I owned a oly 5060 before I converted to dslr.

 

I started with shoting hi res jps underwater but everytime i got a good shot i couldent stop woundering how it would have been if had been shooting raw.

 

So i started shooting raw instead and I never looked back,  it took a few seconds for the picture to be saved on the CF but when i got used to it easent that enoying. I unsed this time to plan the next shot and if nessecary reposition myself.

 

Another adavantage was that I didnt have to worry about the wb underwater, If it was nessecary I changed this when coverting the raw.

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Interesting, and I do agree that underwarter, things takes time. I mean often there are currents that moves you away from the macro subject after taking one shot so you will have to swim around to get back for the second shot. At after that time I'm sure that the RAW picture is saved on my CF extreme III. ;-).

I've also added an xf card that I use for video mode so storage is not an issue either...

But please tell me this:

Why do I have to shoot in RAW to be able to alter the WB afterwards in e.g. PhotoShop? I mean, sure the jpg compression adds some unwantend artifacts (even though in hi res / lowest compression they are mostly very hard to see). But, lets say I can live with those. What extra information is saved in the RAW file and is lacking in the jpg, that makes it impossible to alter the WB afterwards in a jpg?

Or is it simply so that it's _easier_ to do it with a RAW, but it's still possible to do it with a jpg??

RAW is not just a JPG without compression, RAW and JPG are completely different types of data.

It has to do with the way the sensor is designed. There are 3 types of pixels on the sensor: red, blue and green.

A raw file has a bunch of values for red green and blue pixels.

A jpg is a bunch of full colour pixels.

When you shot jpg, the camera combines the red, green and blue pixels to make pixels that are one of 16million colours.

The WB setting determins how thouse RGB pixles will combine to make full colour pixels.

So you see the it is not a matter of compression, but a fundimental differance in they type of data. Once you apply a WB setting to a JPG it is set. You cannot change it because you no longer have the RGB data so you can not re-interpret it.

At after that time I'm sure that the RAW picture is saved on my CF extreme III. ;-).

Unfortunately it is not the card that limits the time it takes to save a picture, it is the camera. But an Extreme III will probably shorten the download time to your computer.

Why do I have to shoot in RAW to be able to alter the WB afterwards in e.g. PhotoShop?

To simplyfy things, lets call raw a digital negative, it has to be developed in the computer. It means a little more work in front of the computer, but the fact that you have one thing less to think about while underwater makes it a sacrifice well worth.

Or is it simply so that it's _easier_ to do it with a RAW, but it's still possible to do it with a jpg??

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No, it is impossible to do if the picture is saved as a jpg.