How to turn green water blue

[justleesa]

Hi

I noticed that some of my pictures have greenish water. What causes this and how do you avoid it (without photoediting)? It happens sometimes with or without the flash but not in all of my pics.

I'm using an oly 5060 in PT-020 with only an internal flash and no lense attachments. When not using the flash I adjust the white balance manually with my slate

Here are some of my green pics without photoediting

What am I doing wrong?

CLA

Question...what technique did you use on which picture? With or without flash?
My guess is...
With WB: Everytime your depth changes (a noticeable change) on your dive you would have have a different condition that would require you to recalibrate your white balance.

Pictures with Flash: The flash only goes so far. If the object you are taking the picture of is out of that range, your pictures will be more green as they will not benifit from the flash

As for the question on the shadow, I am guessing that it is the shadow of the port

 

[CLA]

Re what techniqueI used...

I don't remember the exact settings for the posted pics but in general, this is what I do;

for reef pics/ wide-angle or when not using flash, camera is set to program mode with manual white balance(ex. puffer)

for close-up or when using flash(ex. all the other pics), I use manual mode, f4-8 and shutter 1/60 to 1/200.

I select aperture and speed just by trial and error but most of the time I use f4-5 and shutter 1/100 to 1/200. In the last 2 pics with dark background (nudi on squirt and scorpionfish), I think I tried f7 or 8 with shutter 1/200.

I use spot metering for all underwater photos. What metering mode is best?

Thanks for all the useful suggestions. Just want to confirm if I understood them correctly. To get better background color and exposure I should:

adjust white balance more often with changes in depth
use manual mode and adjust shutter speed according to background
point camera upwards rather than to the ground
if water is green, try out filters or photoshop​

I hope I got it right and can apply your suggestions properly on my next dive.

For Bobf -- I hope you could start that thread on controlling background and foreground exposure. It will be very useful for newbies like me.

For kirsten - there's a discussion on the dark shadow in this thread - "how to change diffuser for oly pt-020" (also in this subforum).

Thanks again to everyone. You've been very helpful.

 

[TheNitroxinator]

I don't remember the exact settings

If you're using windows, right click on your photos and look at the properties/summary dialog. Olympus is pretty good about storing the EXIF data in the pictures, which should tell you the shutter speed and aperture settings you used.


Once you know the settings, you're still marginally hosed. I find that I change the shutter speed, aperture, and strobe power on just about every picture I take depending on the depth, available light, distance from my subject, lens being used, ... Its more of an art than a science. Fortunately, you can see what you just took with a digital. If you get a subject like a nudibranch that doesn't tend to move, you might want to take the time to do "saturation bombing". Take a series of pictures at different settings to see how it changes things - you don't even have to remember the exact settings, the EXIF data is stored in the original. Heck, you could do that with a piece of seaweed, it won't move on you. Its not like you're paying to develop the photos, and it doesn't take long to do a series of shots if you've gotten good at using the controls. Just don't overdo it - if you have a great subject, other divers will get pissed off with you if you're sitting there for 10 minutes using every setting on your camera while they're waiting to get a shot (wasn't me, it was my buddy doing that).

 

[MarkH]

What's wrong with green?

 

[CLA]

If you're using windows, right click on your photos and look at the properties/summary ....

Wow. You learn something new everyday. hope i wasn't the only one on this board who didn't know how to retrieve EXIF data

puffer: F/3.2 ,1/40sec (no flash)
nudi, stonefish hermitcrab: F/4, 1/100sec (w/flash)
nudi and scorpionfish with black bckgrnd: F/8, 1/250sec (w/flash)
scorpionfish with green bckgrnd: F/5.6, 1/00sec (w/flash)
clownfish: F/7.1, 1/125 (w/flash)

Thanks nitroxinator. You spared me a lot of trouble and guesswork.

what's wrong with green

Good question. I really should stop worrying aout this. The victoriadiving pics look great.

 

[SmokeAire]

If you go to this link you might learn how to turn a white boy green:http://www.scubaboard.com/showpost.php?p=590621&postcount=79:D

 

[bobf]

Wow. You learn something new everyday.............
nudi and scorpionfish with black bckgrnd: F/8, 1/250sec (w/flash)

getting back to your black background.....

My definition of the "background" of an image is any part of the composition that is not influenced by strobe light. The part that is influenced by strobe light I refer to as the "foreground".

The background exposure as I mentioned previously is controlled by the aperture and the shutter speed. The aperture refers to the size of the iris opening leading to the sensor. The shutter speed controls how much time light will be allowed to pass through the iris and subsequently be captured by the sensor.

Although 1/250 sec may not be considered an extremely fast shutter speed, when combined with a relatively small aperture such as f/8, very little ambient light is able to be reflected back into the lens on it's way to the sensor. The resulting background color as you confirmed with your images will most likely become black.

by the way, the aperture and shutter speed combinations of :

f/8 at 1/250 sec
f/5.6 at 1/500 sec
f/4 at 1/1000 sec

will all allow a similar amount of light to pass through the lens and shutter and through to the sensor.

When I chose f/5.6 in the above example, I doubled the size of the lens opening with relationship to f/8. But I also halved the amount of time the shutter remained opened by increasing the speed from 1/250 to 1/500. Larger opening, shorter time the shutter allowed to expose the sensor to light= similar result. The term for this is reciprocity.

Why is reciprocity important to understand? Some day your goal may be to control depth of field. Another day you may wish to control motion blur. On another dive trip you may wish to choose an aperture that maximizes image sharpness (not talking DOF). And some day you may wish to control the background exposure of your composition. By understanding the relationship between shutter and aperture, you will be able to predict what combination of the two will yield the preferred result you desire.

btw,
two stops from wide open will probably result in the "sharpest" image
the smaller the aperture, an increase in DOF
the smaller the aperture, the darker the background
the larger the aperture, the lighter the background
the faster the shutter speed, the less likelyhood of capturing motion blur
the faster the shutter speed, the darker the background
the slower the shutter speed, the lighter the background

btw,
increases in depth of field are not always the most desirable goal. At times choosing a wider aperture to limit DOF is a technique used for increasing the viewers interest to a particular part of the composition that remains in focus when everything else is OOF.

hth,
b

 

[CLA]

Thanks for taking the time to explain this bobf. Had to read your post several times just to understand it but I think the concepts of shutter speed and aperture are clearer to me now. Hope I can remember the principles and apply them while I'm down below. Just have to remember to stop and think before fumbling with the controls and shooting away.

CLA

 

[parrotfisch]

Your computer will have some sort of program that will show you the settings that were used. It usually is in a dialog box when you preview the photo. I do not continually adjust white balance. I use a Coolpix 5000 in a Tertra5000 housing and a color correction filter from URPRO. I set my white balance on "cloudy day", set the saturation to highest and keep the camera on shutter proirty. The green is easliy cleaned up in a photo imaging program like Photoshop Elements. You need to add in red to counter balance green.The internal flash will usually produce backscatter and won't be good past 4 feet. I suggest an exterior strobe attachment if you do want to have a light source other than the sun..

 

[SCUBA-Do!]

Thanks for the info. I successfully used the white balance feature yesterday on the Ruby E. Although conditions barely permitted me to change it, and normal viz was less than 10 feet, the video on my Oly 8080 came out exceptionally good (given rapid movement due to surge and low viz). I didn't get a chance at any photos so I can't speak for how well it works with the DS-50 strobes. But the video has exception colors, red, green, yellow, and variations. I have a color correcting mask and the video is by far superior to what I could see. It was as if the low viz was eliminated. As a matter of fact, the video has a viz range of 10 -15, but I could barely see 10.

I was unable to set the 4 customer WB values. When conditions are more favorable, I plan on trying C1 -> 40 fsw; C2 -> 60 fsw; etc. And then only need to set it on the fly when I am not near those ranges.