Night Photos

[CustomTech]

I have a Canon A40 camera and a sealife 960 flash. On my last night dive I found that I had to light my objects with my dive light and use the flash to get any picture at all. How are others doing it? Am I missing something? I am new to all this and any help would be greatly appreciated.

 

[gert7to3]

Are you sure you have the right synchronization setting for the camera/strobe combination? SeaLife says they have 5 preflash settings. It's possible that you are only getting a partial exposure because the camera shutter was open for only part of the flash duration.

The way Sea&Sea (I have a YS 25) works this out is to take a picture with the strobe visible in the picture. Try this at each pre-flash cancelation setting to make sure the strobe is triggering while your shutter is open. Do this with all of the settings.

I assume you use your dive light to find your subjects in the dark. If you have the ISO set kind of high, this might be enough light so the camera doesn't fire the flash. You also need some light on the subject for your digital camera to focus. Many u/w housings, especially with a wide angle lens adapter, can block focusing illuminators positioned on your camera body.

Spot vs multi-spot metering could also influence flash triggering and exposure. Multi-spot metering could result in overexposures of small bright subjects against a dark background. Spot metering on a small bright area might not give you enough light for surrounding darker (but not totally dark) areas.

And these are just the problems I have encountered so far.........

 

[Dr. Doug Ebersole]

Often digital cameras have a difficult time focusing withou illuminating your subject. However, dive lights often give a "hot" spot on your photos. I use a focus light for night dives. That way you can light your subject with a wide soft light without the hot spot from dive light. Backscatter (www.backscatter.com) carries a wide variety of them.

 

[fdog]

<snip> On my last night dive I found that I had to light my objects with my dive light and use the flash to get any picture at all...<snip>

Yep, that's about it.

Although it's nicer to have strobes with built-in modeling lights, you can make do with a dive light. Just use a weak one to avoid hot spots as debersole mentions.

Years and years ago I tried shooting in bright moonlight with recording film (ASA 3200+ and grain like boulders). Ha! Wasn't worth the effort.

All the best, James

 

[bobf]

To avoid hot spots caused by focus lights, increase shutter speed to reduce the effects of ambient light. With my particular system, I don't shoot slower than 1/125 sec at night.

There are systems that will automatically shut off the focus light at time of image capture.

The focus light at night does not have to be white. I use a small, 4AA light which emits a red beam to aid in focus lock. I place a thin piece of Roscolux red gel #027 on the interior of a UK mini Q 40, between the lens and the reflector. Roscolux films of various shades can be purchased online or at a local theatrical supply store.

I still rely on the modeling light of my Ikelite DS 125 for navigation and search of interesting subjects. But many of the critters that come out at night are very light sensitive, therefore the red focus light. Once a subject is identified, the modeling light is turned off. The red beam then allows me to approach crustaceans and capture them with their eyes still open as opposed to squinted or shut as a result of a relatively blinding white light in their eyes.

I would test in a pool first to insure that your particular camera can achieve focus lock with a red beam. I do know that the Oly c4040 and c5050 can.