"Underwater Mode" for Digital

Seth T. · Post by **Seth T.** » Fri Oct 12, 2007 12:50 pm

I just bought a Canon point shoot digital camera that I plan on using on my dives.

(Unfortunately the housing isn't available until next month.

)

What's the story on the "underwater mode" that virtually all the compacts have now? Canon states that it reduces backscatter. How? It looks to me like nothing more than a set white balance and slightly different color settings.

What "mode" do you guys shoot with?

Tommy? Cardiver?

Tom Nic · Post by **Tom Nic** » Fri Oct 12, 2007 1:00 pm

Hmmm... not really sure. My guess is that the underwater mode is primarily geared toward blue water divers. I tried it at the Red Sea in lieu of manual white balancing... sometimes it did OK and sometimes not. My guess is that it is not geared toward our dark green water diving.

Good thing is that it is digital!!! Shoot like crazy, just make sure you're keeping track of what you're shooting when and how so that you can make intelligent comparisons!

Tom Nic · Post by **Tom Nic** » Fri Oct 12, 2007 1:02 pm

And the backscatter thing??!?

Sounds fishy to me... not sure how a camera setting could legitimately reduce backscatter (a function of flash reflection coming back from particles in the water)... maybe by reducing the strength of the flash? Doesn't make sense to me, but perhaps some one else knows more than I do out there!

(not too hard, I know...) ](*,)

Seth T. · Post by **Seth T.** » Fri Oct 12, 2007 1:11 pm

Tom Nic wrote:And the backscatter thing??!?
Sounds fishy to me...

Yeah, sounds like marketing to me.

Nwbrewer · Post by **Nwbrewer** » Fri Oct 12, 2007 1:12 pm

I use a Canon SD550. If I'm diving some place like EUP on a bright sunny day with good vis, the UW setting works pretty well. Other than that, if I can get good ambient light, (no flash) I use manual white balance on a slate (or a white anemone if one is handy.) Usually with the ISO set to 400 and the exposure set between 0 and -1. In days when it's really dark, I use the "cloudy" white balance setting and the flash.

I'm sure that some of the better photographers will jump in with better suggestions.

Jake

Tom Nic · Post by **Tom Nic** » Fri Oct 12, 2007 1:16 pm

Quite honestly, the majority of my shots are just with the auto setting.

Car-Diver leaves his on macro most of the time (I believe... Ron?)

When shooting the white nudi's and the lemons I have been experimenting with dialing down the intensity of the flash a bit. I think that has helped on some of the very close shots (which 90% of mine are). The flash would tend to wash out the center of the subject (the nudibranch), leaving the background just fine, but the what you were trying to shoot not in it's best light.

With my new northern diver wet gloves it is much easier to change the settings underwater than with my thicker and clumsier high tide gloves.

PRACTICE changing the settings above water until you are VERY familiar with whatever it is that you might do below water. Guaranteed, what you aren't doing above you won't do below! :-)

Seth T. · Post by **Seth T.** » Fri Oct 12, 2007 1:22 pm

Thanks Jake and Tommy. Some excellent advice. :occasion5:

Zen Diver · Post by **Zen Diver** » Fri Oct 12, 2007 1:31 pm

I tend to use the underwater macro setting on mine (Olympus SP-350) for the majority of my shots, and very occasionally the UW wide angle settings (only on those very good viz days, like we've seen lately). Keeps the colors bright and more realistic it seems.

-Valerie

Nwbrewer · Post by **Nwbrewer** » Fri Oct 12, 2007 1:36 pm

Oh yeah, Macro mode. Almost all of my shots are macro mode. I think the best tip I've gotten is, get close. When you think you're close enough, get a little closer. Using your flash in PNW waters at any type of distance is just inviting a massive amount of backscatter.

Close -

Not close -

Jake

Tom Nic · Post by **Tom Nic** » Fri Oct 12, 2007 1:43 pm

I don't think the Casio has as good a macro setting as the Cannon. Not 100% sure about that, and not a deal killer with the Casio, but from what LawGoddess said her Cannon was rated for closer than the Casio.

I think I will just put my Casio on the Macro setting and leave it there for an entire dive when I hit Sund tomorrow (I rarely shoot further away than a foot or two anyway) and see what happens.

I LOVE DIGITAL!! $\:D/$

Seth T. · Post by **Seth T.** » Fri Oct 12, 2007 1:49 pm

Tom Nic wrote: I don't think the Casio has as good a macro setting as the Cannon.

Ah, Tommy? It's "Canon".

Cannons go BOOOOM. Canons go *click*

Tom Nic · Post by **Tom Nic** » Fri Oct 12, 2007 1:51 pm

Boom. Boom Boom. Boom Boom.

You mean we weren't talking about guns?

Seth T. · Post by **Seth T.** » Fri Oct 12, 2007 1:53 pm

Tom Nic wrote:
You mean we weren't talking about guns?

Whoa! I was talking about how creamy and smooth Guinness is compared to any other beer. What were YOU talking about?!

spatman · Post by **spatman** » Fri Oct 12, 2007 3:07 pm

Seth T. wrote:What's the story on the "underwater mode" that virtually all the compacts have now? Canon states that it reduces backscatter. How? It looks to me like nothing more than a set white balance and slightly different color settings.

What "mode" do you guys shoot with?

hey seth

from what i understand, the canon underwater setting just adds a little bit of magenta to the color balance, in an attempt to compensate for blue water natural light photography. with my canon, i don't notice a difference in UW vs automatic modes here in our green waters.

as for backscatter: makes NO difference whatsoever, as far as i can tell.

what model canon did you get?

Seth T. · Post by **Seth T.** » Fri Oct 12, 2007 3:46 pm

spatman wrote: what model canon did you get?

Canon Powershot SD870 IS : Link

The 3 inch screen is going to be wicked underwater!

Celeus · Post by **Celeus** » Fri Oct 12, 2007 4:02 pm

Here is what I was taught, and seemed to work for me:

wrt white balance, you shouldn't set it if you use a flash, or should set it to auto in that case. Things came out a bit odd when I manually wb'd before flash. In natural light, wb is key if you are below 15-20 feet.

You can fix wb in raw mode, and can even adjust it with photoshop on jpeg- just not without loss.

There are lots of disagreements on whether to use TTL for your flash, and whether a ttl cord is worth it. For me, I went with the new Canon G9 as the replacement for my Casio 1050 in order to get RAW, ttl, better glass and Aperature/Full manual modes.

From what I've been told, especially if you are switching from close up work to further away work (hey look, shark!), TTL just makes it easier. Yes it is harder to bracket your flash output with TTL- even if you push the EV up or down, how are you sure it is metering the same spot? But for a newcomer to flash UW photography, I think I'll be using TTL for most shots.

If your camera doesn't natively support RAW mode, you might look to see if it is one of the Canons that has been hacked to support it- http://scratchpad.wikia.com/wiki/CHDK/FAQ

Post by **H20doctor** » Sat Oct 13, 2007 12:39 pm

I have the cannon power shot A540, and use the Housing WP-DC2.. Mine also has the underwater setting, But I never use it. I have tried it a couple of times but it makes the pictures look funny. I shoot almost all my pics on the Manual mode.. That way I can set ISO, and flash, and Macro setting on the fly...

nwscubamom · Post by **nwscubamom** » Sat Oct 13, 2007 1:21 pm

My understanding of the UW setting on Canons is this:
It is supposed to add color back in that you lose below about 15 feet. It's really geared towards blue water diving, not our lovely green water diving. In essence it's sort of a preset white balance.

It 'reduces' backscatter, because you're not supposed to use a flash when on that setting. Using the camera's onboard flash for a subject more than a few feet away creates quite a bit of backscatter. When I need to shoot subjects (like divers) a bit away, I always turn OFF the flash.

You can WB manually while underwater using a white slate or a plumose anemone (as Nwbrewer already mentioned) if you want to shoot WITHOUT your flash. The problem I find though is that it's usually too dark and if you or the subject moves, you wind up with a blurry photo.

The rule of thumb is your shooting distance should be 1/4 the Vis distance, OR LESS. So, for a typical 10-15ft vis day here in the NW, your shooting distance should be about 3 feet or less. I have much better luck shooting in the 1-2 foot range (or even less for macros!)

Hope that helps. I'm still playing with digital - not horribly satisfied with the results at this point - and pretty much still shoot film when I want GOOD results with rich color and clarity.

- Janna

Tom Nic · Post by **Tom Nic** » Sat Oct 13, 2007 4:29 pm

Very helpful, and makes sense.

Thanks Janna!

Gives some food for thought for some buddy shots in these 40' viz days at Redondo!

Seth T. · Post by **Seth T.** » Sun Oct 14, 2007 7:09 pm

Wow, that's excellent information, Janna. Thanks!