White/silver flares using digi camera.

**Freef** · 10th July 2007, 18:55

Anyone know how to stop the white and silver flares when using a digi camera?

The pic below was taken using a Canon Powershot A40 in a Canon housing and a Sea and Sea 16mm w/a lens. The shell is actually a metallic grey, but even in 6-8m the camera recorded it as dazzling white. No strobe was used. The wrist slate is also bright, as is the stage tank in other photos.

Johnny Christensen · 10th July 2007, 19:34

Hi Freef

It's the whole picture that's overexposed.
Autofunctions are relatively helpful on land, but underwater they suck.
See if you can do a manual exposure or do a compensation of the autoexposure program. Try out in the range of -1 to -2EV. That will bring the pictures closer to what it should look like.
There is a limit to the dynamic range of digital cameras, so when you are in shallow water the highlights may fall outside of that range, that's where you get the ugly flare. The dazzling white is where you lost all colour information.

The difference between the watercolur (background) and the diver wearing lots of black equipment is a hard task for the camera image chip to read. So now it's trying to obtain an average exposure. But lightmeters are basicly calibrated to see the whole world as a grey. So the amount of black on the diver, that is also dominating the centre of the picture, is being interpreted as being too dark. It want's it to be grey. Camera lets in too much light and your other colours get overexposed as well.

Crazyduck · 10th July 2007, 19:51

This kind of change is covered in Photoshop.
I am in the process of learning Photoshop and the options are wild!

This site Underwater lounge has a great DVD and they have a few lessons.
On of the lesson is masking and darkening.
Link- The Underwater Lounge

Plus, there are a few books out there on Photoshop.
If you have a local dive show they might cover it in lecture (using Photoshop.)

This is a cool website for digi stuff- Articles

Hope this helps.
Andrew

Crazyduck · 10th July 2007, 19:56

Wow-

Johnny
That was an awesome explanation!
Andrew

Quote: (Originally Posted by Johnny Christensen)

Hi Freef
It's the whole picture that's overexposed.

Marvintpa · 10th July 2007, 20:50

That was an excellent description of the problem.
To avoid it you can intentionally under expose, or better yet, bracket where possible. Ideally you would be able to shoot in some kind of RAW mode, but I am not certain that particular camera supports that format.

There are plenty of things you can do in PhotoShop, but if the information is gone, it's pretty much gone. Getting the exposure correct is the best thing you can do. Learning to shoot in manual mode will really help you out in situations like this. Unfortunately you've stumbled upon the worst failing of digital, the exposure range is still somewhat limited, but rapidly improving on higher end cameras which will eventually filter down.

**Freef** · 11th July 2007, 14:16

Thanks for the explanations, I will take the camera in again on Friday and play with the exposures. It has a setting I can access with a +/- on it so I will try that.

The water really is that green though!

10th July 2007, 18:55	#1 (permalink)
Freef Custom Title Disallowed! Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jan 2006 Location: Land of the Freef, UK. Posts: 1,353	White/silver flares using digi camera. Anyone know how to stop the white and silver flares when using a digi camera? The pic below was taken using a Canon Powershot A40 in a Canon housing and a Sea and Sea 16mm w/a lens. The shell is actually a metallic grey, but even in 6-8m the camera recorded it as dazzling white. No strobe was used. The wrist slate is also bright, as is the stage tank in other photos. __________________ David. Currently owner of two differently sized ankles.
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10th July 2007, 19:34	#2 (permalink)
Johnny Christensen Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Apr 2006 Location: Denmark Posts: 304	Re: White/silver flares using digi camera. Hi Freef It's the whole picture that's overexposed. Autofunctions are relatively helpful on land, but underwater they suck. See if you can do a manual exposure or do a compensation of the autoexposure program. Try out in the range of -1 to -2EV. That will bring the pictures closer to what it should look like. There is a limit to the dynamic range of digital cameras, so when you are in shallow water the highlights may fall outside of that range, that's where you get the ugly flare. The dazzling white is where you lost all colour information. The difference between the watercolur (background) and the diver wearing lots of black equipment is a hard task for the camera image chip to read. So now it's trying to obtain an average exposure. But lightmeters are basicly calibrated to see the whole world as a grey. So the amount of black on the diver, that is also dominating the centre of the picture, is being interpreted as being too dark. It want's it to be grey. Camera lets in too much light and your other colours get overexposed as well. __________________ www.johnnychristensen.com Wreckphotography from the cold north
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10th July 2007, 19:51	#3 (permalink)
Crazyduck Underwater Mechanic Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Mar 2005 Location: TEXAS, Dallas/ Ft.Worth Posts: 711	Re: White/silver flares using digi camera. This kind of change is covered in Photoshop. I am in the process of learning Photoshop and the options are wild! This site Underwater lounge has a great DVD and they have a few lessons. On of the lesson is masking and darkening. Link- The Underwater Lounge Plus, there are a few books out there on Photoshop. If you have a local dive show they might cover it in lecture (using Photoshop.) This is a cool website for digi stuff- Articles Hope this helps. Andrew __________________ Howdy Senor- What’s Happening! Rob Davie April 2005- Presently in a state of transition from Open Circuit to Closed Circuit. "You will not be punished for your anger; you will be punished by it." - Buddha. Last edited by Crazyduck : 10th July 2007 at 19:54.
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10th July 2007, 19:56	#4 (permalink)
Crazyduck Underwater Mechanic Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Mar 2005 Location: TEXAS, Dallas/ Ft.Worth Posts: 711	Re: White/silver flares using digi camera. Wow- Johnny That was an awesome explanation! Andrew Quote: (Originally Posted by Johnny Christensen) Hi Freef It's the whole picture that's overexposed. __________________ Howdy Senor- What’s Happening! Rob Davie April 2005- Presently in a state of transition from Open Circuit to Closed Circuit. "You will not be punished for your anger; you will be punished by it." - Buddha.
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10th July 2007, 20:50	#5 (permalink)
Marvintpa Bad knees, matching brain Current Rebreather/s: Classic Kiss Other Rebreather/s: Join Date: Mar 2005 Location: Ontario, Canada Posts: 265	Re: White/silver flares using digi camera. That was an excellent description of the problem. To avoid it you can intentionally under expose, or better yet, bracket where possible. Ideally you would be able to shoot in some kind of RAW mode, but I am not certain that particular camera supports that format. There are plenty of things you can do in PhotoShop, but if the information is gone, it's pretty much gone. Getting the exposure correct is the best thing you can do. Learning to shoot in manual mode will really help you out in situations like this. Unfortunately you've stumbled upon the worst failing of digital, the exposure range is still somewhat limited, but rapidly improving on higher end cameras which will eventually filter down.
(Offline)

11th July 2007, 14:16	#6 (permalink)
Freef Custom Title Disallowed! Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Jan 2006 Location: Land of the Freef, UK. Posts: 1,353	Re: White/silver flares using digi camera. Thanks for the explanations, I will take the camera in again on Friday and play with the exposures. It has a setting I can access with a +/- on it so I will try that. The water really is that green though! __________________ David. Currently owner of two differently sized ankles.
(Offline)

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