Point and shoot fiddles

Hi

OK, slowly unravelling these mysteries.

I have been a point and shoot guy for years and have only just got into underwater photography. So when I started out I simply bought the best P+S camera I could find that came with a manufactorers dedicated housing - hence the Canon Ixus 950is

I dived with this happily, so thought I would add some lenses - and that is where the trouble begins. I am now somewhere in no-mans-land between Mr Snaphappy and Mr Fullyloadedfeatures.

I started out by trawling the web for tips and came across http://www.jimchurchphoto.com/index_podcast.html. Mike and Mike explained the real basics of U/W photography, and I found these podcasts enourmously helpful.

(Sorry to Gus_Smedstad - see thread http://wetpixel.com/forums/index.php?act=S...=29&t=24006 - I didn't realise you had 37years photo experience, you where snapping away when I was 3! Anyway - back to Mike and Mike....)

Their major tips were

1) Go Manual

2) The 5 tricks to good pictures are ISO / White balance / RAW / Metering patterns / Adobe RGB

3) Fix speed and flash, but change f-stop as you get closer

No the real dilemma. I am happy with my camera and do not want to upgrade (Yet B) ) so can I follow these tips with my Ixus?

ISO - no problem, I can control that

White Balance - I have an underwater setting and manual white balance - no problem there

Metering - this is OK too, I get the choice of spot or center weighted

RAW - not an option, only does JPG

Adobe or sRGB - no clue which the Ixus uses, and no way to change it anyway

F-stops - This seems a good idea. Without sTTL the flash output is fixed, so fix the shutter speed and control the F-stop with distance. However my camera has no manual control over the F-stop BUT I can control the ExposureCompensation from -2.0EV to + 2.0EV in 1/3EV steps. Is this essentially the same?

Any tricks or tips would be helpful

Cheers

Hal

Hey, no apology necessary - I appreciated the link, I just wished they'd been more helpful.

To be fair, when I say "37 years" that means I started photography when I was 6. Really. Though I guess I had more of a background in it than most kids, since my father had a darkroom and we did our own negative and print development.

Exposure compensation will actually give you undesirable results. The camera is deciding shutter speed and aperture for itself, based on ambient light and the built-in flash. Fiddling with +EV is only going to give you overexposed images, rather than properly exposed subject lit primarily with flash.

If you're shooting manual, you're still shooting correct exposure, for the subject lit by the strobe. What you're not doing is exposing for ambient light. It's very important that your strobe be the primary light source, rather than ambient light, because otherwise the subject looks very blue and washed out. The sun has filtered out most of the red from ambient light, and white balance ("underwater mode") cannot fully compensate for that.

Both images are from my first trip - from my first dive in program mode, and from a later dive in manual. Click for a larger version.

There are some situations where the flash will provide most of the light naturally. Basically, you need the subject to be so dark that the camera needs to provide a lot of flash to expose it. Setting low ISO will push you in that direction, and taking photos of subjects inside dark nooks will definitely do it. But you cannot count on it.

You may also get good results if you're very close, because the flash provides a lot of light at short distances. The camera should compensate by dialing down the exposure when you're very close.

But for many situations, there just isn't any substitute for manual exposure. Whether you're shooting manual flash or TTL, the end result is the same. You're underexposing based on ambient light, and making up the difference with flash to bring it back to the correct exposure.

- Gus

OK, I am following along so far...

I have noticed the "dark nook" phenomenon when I was using my Ixus as a simple point and push, relying on it's in built flash. I was hoping that now I am investing in a strobe I would get more photos like your second Moorish Idol.

What about target lights?

A target light on the subject make it easier for the camera to focus, but will it give enough light to alter the perceived ambient light on the subject and cause the camera to change it's settings?

Waht about ISO?

I can set ISO as Auto, 80, 100, 200, 400, 800, 1600.

Traditionally lots of light = low ISO (100) and dim = high ISO (400)

Am I right in saying that you are telling me to reverse this because I cant control the aperture, and set a low ISO so that the camera belies there is less light than there is, forcing it to change the aperture?

Cheers

Dave

Use a filter!

Balanced strobe is difficult without manual control, although TTL control can work reasonably well when the foreground isn't very dark or very bright compared to the background. Shooting with the sun over your shoulder can help, and works well with a filter in the first 30' or so (AutoMagic, URPro filters are pretty good: for an Ixus I guess that the AutoMagic might be best).

Be warned: the temptation to but a DSLR only grows with time!

Tim

B)

Hi Hal,

I just upgraded from the Canon SD 800 IS in the Canon housing which is the prior incarnation of your camera. You can take some great pics with it, just takes some practice. After much experimentation, talking to people , and gnashing of teeth, I found the best results were in underwater mode, macro setting, flash always on (an aside - when my camera timed out and went to sleep, it goes back to the default settings, so when you go to turn it on again, you'll have to redo these settings). With just the internal flash, you have to get close. Then get closer. The more water between you and the subject, the less light gets there and the more washed out the colors. Even getting as close as you can, there are still plenty of critters that you won't be able to approach close enough to fill the frame, so I say keep the lowest ISO and the highest resolution/files size - that way you can at least crop down. Also, I noticed with my housing, the lens portion actually blocks some of the flash, so you get a sort of shadow on the right side of the frame (this is becaues you're now really close to your subject ). Practice with this and you'll get the hang of putting your subject slightly off center to the left for better illumination. Here are some results:

http://gallery.mac.com/philsokol#100038

The next step after that would be an external strobe. I got an Inon D2000 based on a friend's recommendation and it worked really well. Easy to hook up and operate. Being the point and shoot guy, I found the best results were on the default settings and auto. You can get the whole shebang, strobe, arms, tray, etc. for about $900 or so from Reef, Backscatter, etc. (yes, I know that's more than twice what the camera cost - welcome to the world of u/w photography!). Like Gus says, it's all about the light and the external strobe makes a huge difference. Here are some results:

http://gallery.mac.com/philsokol#100023

I actually found the exposure compensation to be pretty helpful in certain circumstances, mainly with close-ups if the subject had alot of white or a white sand background. Turn it down 1/3 or 2/3 to prevent overexposure. I would never go the other way - you want your flash to provide the light.

After all this, you can add wet mount lenses as well. I found the Inon wide-angle to be a great addition. The reefscapes in the second gallery were done with this lens.

Mostly stay happy and snappy and have fun playing around with it!

Phil

A focusing light is a source of white ambient light. Since the subject is now brighter, the camera will use less flash, or go for a shorter exposure or smaller aperture, but it's not a huge drawback because the light source is white, not blue. It will only be an issue if the focusing light's beam is narrow compared to the subject. If it's bright enough, the area within the beam will be brighter and a different color than the rest of the subject.

On my Hawaii trip I had real problems with focus on night dives, so I think a focus light is a definite advantage. I bought one that shuts off when it detects flash, but I'm shooting manual. The focus light shutting off just as you take the exposure might give you different results in program mode. I can't say because I haven't experimented with it.

As long as we're talking about focusing lights, one alternative to flash is a strong, broad beam constant light source. One diver on my Hawaii trip had a light strapped to his arm that he used to illuminate his subjects for his point-and-shoot camera, and he got pretty good results. However, his light sucked power in a big way, and he had a high-power battery in his BC that fed power to the light via a cable.

You're correct, you want low ISO, as low as you can get. It's not so much because you want to force an aperture change so much as forcing the camera to demand more light than is naturally available, which in turn means it will use more flash. High ISO is good for ambient light photos under low light conditions. You're trying to avoid ambient light because it's the wrong color.

The main exception I can think of is that if there's essentially no ambient light, i.e. it's a night dive, high ISO will give you longer maximum range for your flash. Light falls off with the square of the distance, so multiplying your ISO by 4 will double your effective flash range, if there are no other light sources. Of course, you then have to deal with noise, which is much more of an issue with a P&S at high ISO than with a DSLR.

Canon's pretty good with noise, but it's an inherent physical drawback in a sensor 1/7th the area of the smallest DSLR sensor.

- Gus

I actually found the exposure compensation to be pretty helpful in certain circumstances, mainly with close-ups if the subject had alot of white or a white sand background. Turn it down 1/3 or 2/3 to prevent overexposure.

Just to clarify, this is why exposure compensation exists. Program mode looks at everything in the frame, and exposes to get the parts that are in the middle in terms of brightness correct. It has no idea which parts of the image you care about. If your subject is much brighter than everything else, on land or underwater, program mode is going to overexpose it, and you want to turn EC down. If there's something very bright you don't care about in the frame, like a sunlit window, you may want to turn EC up.

Underwater, you rarely have a hotspot you don't care about, so you usually don't turn EC up. You might if you're taking a photo of the interior of a lava tube, and there's a hole leading to the surface that's bright sunlight. The range of contrast in such a photo is very large, so you can either get a dark interior and a nicely exposed patch of surface water, or a glaring white spot from the water and a clear picture of the interior of the tube.

The camera will almost certainly expose for the sunlit water unless you intervene.

- Gus

I just upgraded from the Canon SD 800 IS in the Canon housing which is the prior incarnation of your camera. ...

I got an Inon D2000 based on a friend's recommendation and it worked really well. ...

After all this, you can add wet mount lenses as well. I found the Inon wide-angle to be a great addition. The reefscapes in the second gallery were done with this lens.

Phil

This is incredibly comforting, you were shooting with almost exactly the same rig that I have currently got. Thanks for your advice, there is hope for my photos yet.

Use a filter!

...

Be warned: the temptation to but a DSLR only grows with time!

Tim

Thanks for this, I was thinking of the AutoMagic filter, but was hoping that the strobe would offset the need. And you are right, Oh the DSLR temptation...

Thanks to you both

Hal