Underwater photograpy..newbie to it

Lars has a lot of good info. Here's a bit more.

thicks13 wrote:

Going to Hawaii in sept. Going to snorkel and snuba.

I've snorkeled and scuba'd (349 dives) but never Snuba. I don't know if there is anything particular about Snuba that recommends for or against any particular type of equipment.

1. Looking for thoughts on a good camera for it. Have researched for hours on the internet..found the olympus tg6, sony 100, gopro, and a couple others mentioned. The one i have settled on is the canon g7x mk iii with housing. Any thoughts on this selection..pros, cons? Thoughts on a different one? Havent bought one yet.

First question I would ask is if you primarily want video or stills from your dives, or a good combo of both. If leaning toward mostly video, I'd say a GoPro may be a good choice. But if you are leaning toward mostly stills, I'd avoid a GoPro as they typicaly have not been very good for stills. (I don't know about the latest model.)

In the past there were more inexpensive choices for a camera + housing, especially from Canon. An s95 or s120 with housing could be had new for $500, both camera and housing. I'm not sure what's available in that price range now.

My personal experience was a series of Canon point-n-shoots in matching Canon housings (sd630, sd870is, s95, s120) followed by a Sony RX100 II in a Nauticam housing followed by DSLRs in housings.

I like the Sony for its slightly better IQ than the s120, but I like the Canon menu system FAR more than the Sony. And I think disdain/dismay/disappointment with Sony's menu system is widespread. It's difficult to see all the small print underwater and find your desired menu entry.

I have no recommendations (except maybe against the GoPro) of the cameras you listed, but I want to point out another option. You can get a universal housing for a smartphone from Kraken for about $300. Connects to phones via bluetooth so doesn't have to have a dedicated housing for a particular model.

2. Regardless of which camera, does shooting thru a housing add stops as shooting thru a filter? Assuming it might, was one reason i selected the canon..fast lens.

No, it does not. It does add a layer of glass between the lens and the water, and there is a lot to know about that air/water interface. WIth a flat port, you get about a 20% magnification. End your corners will look awful. With a dome port you get better corners, but no magnification.

A fast lens doesn't do you too much good underwater as you typically have to stop down a lot more than you are used to above water. My typical starting settings (with strobes) are 1/160th shutter speed and F8 for wide angle, F16 for macro.

3. Using a housing, how difficult is it to see and change settings..i would probably use P mode, not auto, because ,i want to shoot RAW as well.

Lars made it clear why Auto or P is typically a bad idea. You have to control the shutter speed to a minimum AND you need to keep the lens stopped down (for the corners). This situation screams out for a floating ISO, or strobes to add light when needed.

4. I read something about using color filters depending on blue water or green water..is this just for video or does it apply to photography as well? ..if so, then that is one more piece of glass...hmm

There are some specialized situations where a red or yellow filter comes into play, but typically with JPG instead of RAW output.

I do so little video I don't have a clue for the answer there.

5. Any other thoughts..i am sure I will have more questions as i go..thanks..tim

Two thoughts:

1. White balance

2. Post processing

White balance is tricky to set underwater, because it changes so much so quickly. For shooting stills, I don't pay a lot of attention to it and shoot in RAW, Neutral. I adjust white balance in post processing 100% of the time.

It's a critically important step, and it needs to be the first step. Every other adjustment tends to be impacted by white balance, so do it first. (May first have to boost exposure enough to see white balance changes of course).

You can carry some sort of white balance card, or know how to do it off your hand or some bit of gear, and that may be critically important for shooting video, but it's not important shooting stills in RAW.

Don't expect good underwater shots to just 'come out of the camera'. A lot more good shots 'come out of post-processing', though it certainly helps to get things right in-camera first.

Here's the thing about post-processing typical underwater images. And I'm talking about the ones that are mostly below snorkel depth. At snorkel depth you may have excellent sunlight and good lighting down 10 feet or more. You may be able to shoot great JPGs with an underwater option on your camera, especially a Canon. But if the sun goes away, or you get a little deeper, you're going to get a lot of blue- and green-dominated images. It helps to know how to set white balance in post.

Setting white balance (using Lightroom). You'll use an eyedropper tool to get in the ballpark, and experience after that. The eyedropper tool needs to select some neutral object, but what is that? Lots of wide shots have a diver in them, and divers typically have neutral black surfaces. A gray scuba tank or other metal piece is often a good choice. If shooting a macro, you very often have some spec of bright white coral bit you can use if not overexposed. If shooting near a sandy bottom, a whitish grain of sand works. In Fiji i saw a videographer using a dedicated video camera adjusting white balance at different depths by metering off a white balance card he'd zip-tied to a fin.

Once you get a white balance that looks decent, you can tweak it with color temp and tint. I do it on a calibrated monitor by eye until 'it looks good'.

After that you typically run into two situations:

a. you have a very contrasty subject and need to tame the contrast. (Typically a close up image, especially with flash). Your histogram has blown highlights and blocked shadows.

b. you have a very flat image with little contrast. Your histogram looks like a little blip in the middle with long flat sides. Typically shot with subject too far away and the water between has robbed contrast.

In shot A, you're going to be pulling down highlights and boosting shadows, with whatever slider options work best for you. In these situations you want a camera with extremely good dynamic range, as the highlights may not actually be blown, and there may be some visible detail in the shadows.

In shot B, you'll be trying to add contrast in different ways. You'll perhaps center the histogram as needed by adjusting exposure, then dial in ridiculous amounts of contrast. You may now have a subject that is viewable, but often the whole scene is 'cloudy'. A trick here is to carefully pull down the black slider, pulling the left side of the histogram toward the left edge and darkening things. You are adding contrast, but only on the dark half of the histogram. Do it carefully and the water haze sort of disappears.

I have some examples of before and after processing results at this link:

http://www.cjcphoto.net/beforeafter/index.html

Here are a couple of examples from that link:

Too much light?   Pull down the highlights.  (Note that I am shooting with a DSLR, not a point-n-shoot, and the cameras I use here have huge dynamic range.)

Thumbnails only:

After post processing

White balance example: