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Scubakraut
10-02-2007, 13:55
Has anyone looked at some photos in certain "darker" conditions especially near corals that when you use the flash to bring out all the nice colors you see lots of particles like "dust spots" in your picture. If you don't use the flash they aren't there.
Anybody has a solution for this? Thanks

ScubaToys Larry
10-02-2007, 14:06
The secret is trying to get your strobe positioned so that the light from it hits the subject, and not the water column between the lens and the subject. The big spots you normally see are only an inch or so in front of the lens, and a tiny particle out of focus looks like a big bloob - like this:

http://www.scubatoys.com/store/cameras/pics/lessons/badeel.jpg


If you get the strobe out to the side or up high where the light is not highlighting the water column in front of the lens, it becomes more like this:

http://www.scubatoys.com/store/cameras/pics/lessons/goodeel.jpg

Same eel.. same day... at Stingray city - the difference, where the strobe was.

Scubakraut
10-02-2007, 14:36
Ahhh I see. That is good advise. Thank you Larry! So my next Accessory will be a external strobe. So I no longer have to use the flash of my camera and diffuser.

Vercingetorix
10-02-2007, 14:39
Larry, I was debating whether to buy the YS-15 or just rely on my camera's (Canon A620) flash with diffuser.

Thanks to your post you just sold a YS-15. (you sneaky...) I'll use this post to sell the wife...on the idea of the expensive flash. Not "sell the wife". Just the idea. To the wife.

You know what I mean

Flatliner
10-02-2007, 15:15
Larry, I was debating whether to buy the YS-15 or just rely on my camera's (Canon A620) flash with diffuser.

Thanks to your post you just sold a YS-15. (you sneaky...) I'll use this post to sell the wife...on the idea of the expensive flash. Not "sell the wife". Just the idea. To the wife.

You know what I mean

How much did you say you wanted for the wife?

ScubaToys Larry
10-02-2007, 15:28
How much did you say you wanted for the wife?

And what kind of warranty does she come with?? The warranty on mine was very short.

Vercingetorix
10-02-2007, 16:55
FlatLiner, Larry,

She's a fiery red-head with temper to match. Trust me. You'd rather be 60 feet down and OOA instead of facing this girl when she's p*ss*d. Regarding warranty, I've tried returning her. Her parents maintain a ScubaToys-like policy: once it's used, it's yours.

I'll do you both a favor and keep her. Besides, she's kinda grown on me.

//end of thread-jack

I sent the link to her so she can see the difference

I also looked at the SL960D while I was at the store. I prefer the YS-15.More expensive, but the articulated arm provides the kind of positioning that Larry mentions above.

BobArnold8265
10-04-2007, 22:13
Backscatter (the reflection of your flash off the particles in the water) can be a pain. The rule of thumb is that the further away from the object you are, the further your strobe needs to be from your camera lens. That's why when you are shooting close-up you don't see the particles (even with you attached strobe). Get more than a foot or two away while using your built in strobe and you start seeing the particles.

PrichDave
10-05-2007, 10:14
If you go diving and haven't bought your external strobe(s) yet, try taking underwater photos in shallow areas with a bright sun overhead and turn off the internal camera flash. The sun's light will give you plenty of color and the camera flash won't light up the particles in front of the camera. Shallow would be about 15 feet and closer to the surface. Also, clear water sure helps.

diversteve
10-05-2007, 11:32
If you have Photoshop there's a Backscatter action that can be used to minimize it. It works best on photos with more of a solid color background.
Get it here: http://www.justinunderwater.com/photoshopactions.htm

Scubakraut
10-10-2007, 13:02
If you have Photoshop there's a Backscatter action that can be used to minimize it. It works best on photos with more of a solid color background.
Get it here: http://www.justinunderwater.com/photoshopactions.htm

wish I had Photoshop, I currently use Paintshop.

diversteve
10-10-2007, 14:00
If so, it's more work but what you can do is pick a brush with an irregular pattern and clone out the backscatter if it's in the background, water or really varied terrain.

This works best when you keep re-selecting the area to be cloned from. Otherwise subtle variations in tone will be obvious. I generally clone 1-1, for each area to be corrected, I re-select from the closest original point near it.

Here's the before/after on a shot using a brush thickness of about 13. The brush I chose has a slight fuzziness on both edges.

http://forum.scubatoys.com/gallery/files/9/2/cloneb4.jpg

http://forum.scubatoys.com/gallery/files/9/2/clone.jpg

Scubakraut
10-10-2007, 14:53
great work!

Scubakraut
10-10-2007, 15:03
so with an external strobe attached and being triggered by the optical cable attached to the diffuser is it best to block the light from the local camera flash then?

WestTnDiver
10-10-2007, 20:27
You have to block the light from the on board flash or it will still cause back scatter. You might also, depending on the camera, be able to back down the camera flash thus increasing battery life. I have mine down to the lowest value and it still provides enough light to trigger the strobe.

fire diver
10-10-2007, 20:57
Larry, I was debating whether to buy the YS-15 or just rely on my camera's (Canon A620) flash with diffuser.

Thanks to your post you just sold a YS-15. (you sneaky...) I'll use this post to sell the wife...on the idea of the expensive flash. Not "sell the wife". Just the idea. To the wife.

You know what I mean

Got some more bad news for ya...

Now that you have that external strobe, you'll want to get a wide angle lens.

A WA lens lets you get WAY closer to an object and still get everything in the shot. This lets you get close enough to paint the whole scene with the flash. Your flash will only be good to maybe 15 feet. After that, it's all ambient lighting.

Look at the cockpit pic in my gallery here. That was taken at a depth of about 40 feet, with the sun high over head. Everything outside looks like night. I had the camera inside the windowfram of the plane, holding the strobe high and in front of the camera. I took another one (not uploaded) with the external strobe mounted. VERY back-scattery. Using the inboard flash would have been even worse. Without the WA lens, I would have had about half of that in the shot.

I'm still working on image composition issues from the WA lens though.

FD

Big Mike
10-30-2007, 11:58
Did you say I could sell my wife here??????:smilie39:


Larry, I was debating whether to buy the YS-15 or just rely on my camera's (Canon A620) flash with diffuser.

Thanks to your post you just sold a YS-15. (you sneaky...) I'll use this post to sell the wife...on the idea of the expensive flash. Not "sell the wife". Just the idea. To the wife.

You know what I mean

Silverlode
10-30-2007, 12:18
Do you take husbands too?

RonFrank
10-30-2007, 12:41
so with an external strobe attached and being triggered by the optical cable attached to the diffuser is it best to block the light from the local camera flash then?

Most optical (all?) fired strobes affix the optical cable over the camera's internal flash with a solid covering so that the cable will trigger when the internal flash is fired, but the flash is blocked.

WestTnDiver
10-30-2007, 20:42
The Ikelite strobes that fire optically have a sensor that's attached to the strobe arm. You have to block the diffuser on the housing. I used to use one made by Ike, but it got lost a while ago. Now I just use duct tape.

When there's a ton of particulate matter in the water, like after spawning, I'll remove the tape and use the manual white balance option on the camera. When set correctly, you'd be amazed at the color you can get. I have shots of divers 20-30 feet away where you can see their pink fins and red octo holder. No flash can do that. And no backscatter! My profile pic was shot using manual white balance.

bversteegh
10-31-2007, 00:35
point your strobe(s) straight out or even slightly away from the subject - the object is to light the subject with just the edge of the beam. That way your strobe won't illuminate the crud right in front of the camera. With one strobe usually mount on your left side, 45 degs or so above the subject (that way the shadows will look more natural).

diversteve
10-31-2007, 01:13
Another option for blocking light from your on-camera flash:

Inon sells a kit ($20) that blocks the visible light but lets the infrared through to fire the flash. It mounts on the camera and is reusable. They sell them for most popular cameras. This one is for an Olympus camera. A buddy uses it - it works.

INON America - Product Catalog (http://inonamerica.com/products.php?pagenum=3&prodcat=6&subcat=1)


http://inonamerica.com/content/products/pr_0316/pr_01312_md.jpg

kyfriedchipper
10-31-2007, 02:00
awesome photo - even better photoshop skills