Can you simulate UW light conditions

[Larry C]

As a newbie at UW photography, I've had some really good luck so far. My camera (Oly SP-350/PT-030) is fairly easy to use in the std. settings, and I've gotten some really nice shots, especially in Macro. My real problems start when I get into manual settings and try to duplicate those results with RAW images. I've tried the small aperture for depth of field approach and end up with black pictures. I've moved the f-stops down and the time up in small increments, but I can't seem to hit that "ideal" setting for my usual conditions (green water, 40-60ft.) It doesn't help that I don't have a strobe yet, although that will probably complicate things further. I also don't want my dive buddy (wife) having to hang out for five minutes while my far-sighted 52 year old eyes struggle with resetting the camera under water. Is there a way to simulate UW conditions so that I can predict and preset some of my shots. The camera has a very nice "my" feature that will allow me to keep up to four settings and scroll up and down the aperture and time as well. I'm tired of depending on pure luck to stumble onto a setting that works, and missing a great picture when it didn't.

 

[Warren_L]

Larry, I presume you had been using some automatic settings then? What you might want to do is have a look at the settings that were used under the automatic settings that worked well and use that as a baseline to adjust your shots in manual mode. If you change too many things at once, it becomes difficult to fully understand the effect of changing any particular setting. Unless you shoot in the exact same conditions every dive, you'd be hard pressed to have a specific set of settings that will work all the time. After a bit of practice and experience, you get to know roughly what sort of settings work for you under certain conditions. And the great thing about digital is that you can adjust on the fly.

Remember also that with RAW files, you need to do some post-processing and may not look all that great off the camera, so you really can't compare to shooting jpg.

 

[Larry C]

I know that there is a lot of experimentation involved, and every dive has different conditions. I've done post editing in RAW with quite a bit of success. My JPEGs have been in the UW Macro and UW Wide presets. I'm fairly sure that they automatically alter aperture and exposure time. I don't believe the exif on the presets says anything but "Underwater Macro" or "Underwater Wide 2", etc. What I'm trying to avoid is the all black shot or the wash-out. Should I just start at f2.8x175 or something like that and work my way up one scale and down the other until I get a good shot? Thanks for the help.

 

[tkring]

Larry,

My UW photographer teacher told me to practice shooting fruit at the kitchen table. I'm not sure if this will simiulate the UW conditions but he said that it will get you used to your menus and settings.

 

[Monkey Knife-fight]

You can definitely get a feel for manual settings above water without simulating underwater. Just take pictures of little flowers and anything else. Force yourself to use full manual and you'll get the hang of the settings.

 

[alcina]

Larry - if you right click on your image in Explorer you should see Properties -> Advanced Go in there and you might see the "real" settings?

 

[alcina]

And for dark water and internal flash for subjects within the flash range, I'd say start around f4.5 - 5.6 and shutter 1/125. Work from there.

For ambient light, I'd do a test shot from those settings when you first get down - then adjust. If it's way too dark move to f4. Still too dark, drop the shutter to 1/100 or 1/80.

Shoot, review, adjust, shoot, review, adjust If you do a test series on decent and right when you get to the bottom your wife won't have to wait so much, she'll likely be getting settled and be happily watching the first creatures on your dive!

 

[gert7to3]

Try using your camera in the U/W housing. This way you will become accustomed to managing your camera controls through the housing levers. If you wear gloves, then wear them too.

Also try it in low light conditions. Don't just use it in some comfortable stable environment, like on your table. Crawl around in the yard with it.

To work out depth of field try shooting a ruler.

Crumpled aluminum foil is a good, but difficult target, quite similar to fish.

Finally, if you have access to a fitness center with a pool, try it in there, if they'll let you.

 

[Larry C]

Larry - if you right click on your image in Explorer you should see Properties -> Advanced Go in there and you might see the "real" settings?

Thanks Alcina, I didn't go far enough in Properties. The exif info was in the "Summary" section. It turned out that the preset macro pictures were mostly adjusted by f stop using a base setting of 1/60 at ISO 100. For wide shots, especially in darker water, the aperture was adjusted to f2.8 and the ISO upped to as much as 400 at 1/125, but generally 200-250. My natural light shots with a filter in 60 feet of green water brought the setting down to 1/30 at f2.8, which would explain the blurring in surgy conditions that I had attributed to the lack of stop effect from the flash. This gives me a pretty good idea of the way the camera is set up to do auto adjust in the UW modes which produced pretty good pictures. Still looking forward to the ability to up the f-stop settings with a strobe on board, but that should give me a pretty good place to start, e.g. fixed exposure time with adjustment of f-stop and ISO according to water conditions.

 

[RonFrank]

I'm not familiar with your camera, but there are really only three things that control exposure, and those are aperture, shutter, and ISO. Shutter speed needs to be enough to stop action, and prevent camera shake. Aperture controls DOF and UW IMO the smaller the better, but not at the expense of inadequate shutter speeds. ISO is a film based term that has little to do with digital photography, but the lower the ISO the lower the noise, and most PnS camera's produce unacceptable results beyond ISO 200.

So set your camera to a shutter priority mode, choose a speed that is reasonable, set the ISO to 200 at most, and let the camera determine the aperture. Selecting shutter is is based on the lens used, and in general the reciprocal of the 35mm EQ of the lens is the minumum shutter. IOW's if shooting at 60mm (35mm EQ) use a minimum of 1/60 shutter speed.

If you don't understand how this all works, I'd suggest a basic photo book. The bottom line is that if you are not prepared to shoot topside, then expect nothing good UW as it's going to task load you, and make for a situation where you are taking up too much time messing with things UW. I suggest to get comfortable with your camera topside, and then shoot UW.