S45 -> getting underwater mode

[DragonJade]

Hi,

I've heard that on some of the later S models and have seen on my girlfriends ixy that there is an "underwater mode" in the white balance menu.

I've got an S45. Does anyone know of any hack or firmware around so that I can get this on my camera?

Thanks.

[ByteTheBullet]

I simply did some post processing with PS with my S50 and it worked out just fine. My S70 has the setting you are talking about but I have yet to take any underwater shots. And I gotta get the housing too.


ByteTheBullet (-:

[DragonJade]

Surely pre adjustment is better than post adjustment as you'd loose detail with colour correction after taking the picture.

I've used PS to adjust pics, but I'd rather be able to adjust the colours whilst I'm under the water so I have more "real" colours when I take shots, and just fine tune later in PS.

[Paul Engen]

Hi!

I saw in the dpreview.com that you have two manual presets to the white balance. If you are able to use the needed controls in "diving-mode", just take with you some purely white material and set the white balance at the depth where you are photographing. (I would guess that the light turns more blue for each meter you dive down.) If this is possible, I would guess this is better than a pre-difined color-temperature in the camera.

If the abowe is not possible, you might experiment with with blue-filters and make perhaps two pre-defined white balance presets in your two manual presets. I guess you would find what blue-filters to use, talking with divers using cameras with ordinary film (daylight film). (They would of course use a yellow filter. You must use a blue filter on the opposite side of the scale.) Then use the blue filters and set the white balance onto a purely white surface.

Paul Engen

[Jon]

If, like the later S-series cameras, you can shoot in RAW mode, post-processing won't lose anything over pre-processing as both will be working with the signals recorded by each individual pixel on the sensor. Otherwise, set a custom white balance as Paul describes, or use some warming filters at a daylight setting since the light tends to get bluer with depth. Canon has an underwater photo guide here (http://web.canon.jp/Imaging/uwphoto/index-e.html) with a section on white-balancing. Just remember, the light gets progressively bluer with depth, so using any kind of white balancing will mean adjustment as you descend. And on-camera flash will give you backscatter from suspended materila in the water unless it's extremely clear.

[DragonJade]

With the camera in the housing it's not possible to set the white balance or switch between any presets if I set some up. The only way is to have the adjustment made on the surface before I put the camera into the housing and use the same setting no matter what depth.

Using RAW is a possibility, but then I'm still left with pics where I don't know what the true colours are for comparison in the adjustment. At least if there was some kind of white balance to begin with it would put me in the general area of what the real colours were.

I usually either stick with auto white or daylight balance when I’m taking pics at the moment.

[Paul Engen]

Well, my yellow theory did not hold water. It is the reds that loosens its strength below the surface... Otherwise my theory would be good; putting your camera in user-set-white-balance-mode measuring pure white on the surface through a inversed filter of that used at the bottom of the ocean. Then your camera would be acting like a daylight-film camera with a diving-filter (red) in front of the lense. (Well, at least when measuring the white object on some sunny day. That means with daylight color-temperature - some 6000 Kelvin, isn't it?)

Anyhow why not buy a red diving-filter and mount it in front of the lense? If it is no room for it, I bet you could get a glazier to grind the filter small enough to make it fit inside the housing. You can buy such a filter here (and use it together with your daylight white balance preset):

http://www.urprofilters.com/

[DragonJade]

Paul.thanks for checking it all out.
Don't suppose you know what'll happen if you just use a standard orange filter, like a YA2 or a YA3?

I know they probably won't be as good as they'll cover different wavelengths, but are they a viable cheap alternative?

I'd have to get the filter cut down to size as there's no thread on the camera or on the housing.

[Paul Engen]

I'm sorry to say that I don't. I just love to figure out solutions to problems (even though I'm not a diver :-). You should send the question to the company in the link i sent you. Maybe they have the answer. Ask them also if it exists a card to measure white balance on, so you don't have to buy the filters (a card with the right green-blue color to it. It would be no problem to produse, but maybe there isn't enough money in it...)

BUT, LISTEN! Here is another proposal to solve your problem: Dive down to the depth you usually take pictures and do the following: Take a purely white card down with you. (The sun should be in zenit - I saw in a article that the angle of the sun affects the light greatly). Take a picture of this white card (with the day-light white-balance preset) and make a paper copy of this picture - without any color-correction and exposure-correction what so ever. I guess that would be possible in most photo-stores. Then make a white balance preset using this photo. If everything goes right, you would then have a camera taking redish pictures on land, and nice pictures underwater :-) (I don't think that the under-exposure would affect the result. If it does, then you'd have to use a laminated photographic grey card.) Maybe you also can measure how the water affects the light in a proper picture editing tool using this picture? Anyhow, if you try to make a "divers-white/grey-card", please tell me how it went :-)

[Paul Engen]

ONE MORE THING (THE ABOWE SUGGESTION MIGHT BE AN AWKWARD ONE TO DO):
Using the photoshop would not be a bad idea at all. If you keep in mind that if you find the right white-balance, then the camera (or the camera filter) would do the the same thing as the software in your computer would. The only (possible) damage done to the picture would be made by saving a compressed format twice (but that would not be wise, just save it together with the layer mentioned down under). Anyhow, I continue some "divers-white-card" thoughts in Adobe Photoshop (and this will allow you to know the exact canges you make):

Take one of your photos taken, most preferably one taken on high noon (sun in zenit). Load it in Adobe Photoshop. Go to "Layers - New Adjustment Layer - Channel Mixer..." Then you can adjust your colors so you get the correct color balance (white balance), and you will know exactly how the colors are affected (increases in the reds, yellows or what ever). (I'm no expert using the Color-mixer in Photoshop, but I believe you must change between the "Output channels" and using the "Constant"-slider.) I guess it will help you to have some purely white or grey in the picture for control - and to have a properly calibrated monitor. If you later want to see what corrections you did to the red - blue - green - channels, just go to the "Layer - Layer Content Options...".

This action you can automate using the action-tool in photo-shop, doing it on all your photos (using batch-conversion), just like a fixed white-balance preset (or a colored lense filter) would have done to your pictures. But that would not make any sense, because the light would change both because of water depth and due to the variating distance to the subject. But if the action saves the picture with the adjustment layer, then you can of course just do some minor adjustments to the pictures needing it. (Well, isn't digital a great thing? ;-)

SO TO THE "DIVERS-WHITE-CARD" to set the white-balance for "diving-mode": If you really want to have a fixed preset in your camera, then you'll just have to apply the color-correction made on the above picture to a white RGB-layer in Photoshop. Then you will have a plane redish surface on this "picture". When you invert this picture, you will get the green "picture" to make a white-balance-preset from (mentioned in the above post). (I believe the color would be more pure than it would be in my former suggestion. Print it out without color/exposure correction in the printing process and make the user-white-balance-set in the sun on high noon.) I didn't find out how to do that (apply the correction made to a picture onto a white RGB layer in Photoshop), but I guess someone more clever with Photoshop can tell you how to. If you manage, you will have a "white-balance-preset" where you know the exact increase in reds (and what other colors that might come to it).

As I already said - this subject was a nice one cathing my interest... ;-) I hope that this will help, and save you the money for a diving-filter.

P.S.
Using color correction in Photoshop like this (using a layer), I question if you loose any details in your pictures. I believe it just acts like a digital filter adding colors and cancelling out inverse colors. But again, I can't say it for sure, because I'm not a pro in this field.

[Jon]

Did you check the link I posted to Canon's underwater photography guide? It will answer a lot of your questions.

Rather than struggle with setting a CWB, I'd suggest just staying with AWB. It'll be "good enough"; If you find it's unsatisfactory, photograph a known white or neutral grey card right after anything crritical, so you get a standard for colour correction in post-processing.

[DragonJade]

Hi guys, sorry for the long absence - been really busy.

Paul -> thanks for doing the ground work and stuff.

Jon -> I read the guide, thanks. It recommends using the cloudy setting. Any comments on that? They give an example pic for daylight setting, but how would it turn out if it were on cloudy?

[Jon]

Cloudy conditions tend to be bluer than sunny daylight, so that'd be a good starting point.

[Poco]

Too bad about not being able to set custom white balance while the camera is in its housing. Is this a Canon housing? I have a s400 with underwater housing and I can use all the buttons on the camera so, while I have not, I could use custom white balance under water. Now that I think about - why didn't I? I suppose then I wouldn't have had the satisfaction of fixing them in PS.

If you can't adjust the mode does this mean that you can't adjust for the flash? So you can't take pictures with and without a flash in the same dive? That sucks, because the flash is key if you want to do something like this...

http://photos1.blogger.com/img/81/3086/320/IMG_9008_1.jpg (http://photos1.blogger.com/img/81/3086/1024/IMG_9008_1.jpg)

[DragonJade]

It's a Canon housing I've got. With the housing, you can't go up or down on the rocker control, only left and right.

I've managed to figure out a work around to the white balance, and that is to set the camera with the menu already up so that it's selected over the white balance mode, put in the case, and the set it when you're under water. The only problem is that once you've set one mode and turned off the menu, you won't be able to get back to the white balance menu as it resets to the top option, and you'd need up or down on the rocker control to get back to the white balance option. As would previewing your pictures. Also, if you're like me and like to have the power down option on for the long dives, it'll reset as well.

Same thing goes for the flash. You're screwed unless you always have that option selected before you put the camera into the housing.