I'll try to help with these
Grajan:
The reason I tend to shy away from manual is that photography is a secondary purpose when I dive and I have to be considerate of my buddy so I don't want to spend too long "messing about". I'm probably willing too make more image compromises than you would consider reasonable for speed.
See my suggestion below, get some baseline settings and work from there. I'd be surprised if you are having to mess about too much. The only time you are really going to have to change settings dramatically is when you totally change your shot:
macro of a shrimp then a wide reef scene into the sun...and even then you'd be surprised.
Manual gives you the control...it doesn't dictate that you change settings for every shot. But if you need to, it's usually ONE (shutter or aperture) that is easy to change quickly...especially with practice!
Grajan:
The camera has ISO 50 but I think that might be a little tough on the small lens. The ISO 100 looks fine in the image so I will lock that in.
Go with what works for you. But I would experiment. And try to blow things up/crop down when you experiment...you may find that there is some "hidden" noise in using 100. Might not be a factor for you, but might be something you want to look at later on.
Grajan:
Can't I just stay in P and stop it down a little?
As far as I am aware, P mode doesn't allow you to "stop down" or up or anything. The camera sets the aperture, not the user.
Grajan:
If I am in manual is the flash is not TTL controlled which adds more uncertainty to the process...
...That works in P mode but I will have to manually set flash in M (three levels)
Nope. TTL is a wonderful thing, I guess. But my strobes don't even have it and if we took a vote I'd say the non-ttl users would be more numerous. Don't even worry about ttl when we are talking internal flash. Your flash is controlled by its output level - which you've already said you dial down one notch and I've said I've had to do on all my Canon A series cameras.
You shouldn't have to set your flash any more in M mode than in P. You will still use the dialled down setting, it doesn't change. And you will still select the icon to make the flash fire (forcing it). Viola, you're good to go.
It's digital, experiment.
Grajan:
How much validity is on land experimentation. I was thinking of going out at dusk and photographing plants in low light. Am I going to learn anything or confuse myself?
The more you use your camera and the settings the better off you are going to be underwater. Don't worry too much about the actual shutter speed and aperture, some will translate to underwater but some won't. This practice will help you identify what changing settings will do and make it all smooth so you don't lose shooting time to fiddling time. More so concentrate on:
- minimum focus distance at all focal lengths. This is the number one problem I see: too close for the camera to focus crisply as divers have been told over and over "Get Closer!" It's true we need to be as close as possible but we also have to work with the limitations of our camera system.
- see where your flash goes. Especially important when you are doing close up work...some flashes produce a shadow in the housing.
- get a base line setting for aperture and shutter. Then practice changing one or the other by feel so you don't have to look. Also tilt the camera up and down to change the amount of ambient light hitting your subject. See what happens to the exposure and shadows.
- see how far out your macro setting will quickly focus. Mine does it far enough out that I don't take it off underwater. If it's too far for the macro, it's too far for the internal flash AND too far for anything other than a pot shot (worth doing if it's a once in a lifetime opportunity, otherwise it's just frustration waiting to happen)..
Grajan:
OK - here are the problems: 1) I am assuming that, as the histogram is looking at ambient light and I am going to use the flash anyway, it is not telling me anything useful and 2) I have no idea what decisions I would make or what I would change based on that information. I do use the post-shot histogram to check the shot but I'm still a little unsure what I am learning
OK, the magical histogram in brief:
I use the histrogram when I review the image I have just shot. This will show me if I am in the right ballpark. If I have hard spikes on the far right or left - and I wasn't going for dramatic shadows or highlights - then I know I fuffed the exposure and can adjust my shutter or aperture. This is especially useful for the highlights as sometimes you can't see that the blues are totally washed out until you get it on a monitor - with the histrogram, if you've got big spikes to the right side, you know that you've got blown highlights and can adjust to let a bit less light in.
Pre shot, if your histogram is showing you that you have huge highlight spikes in ambient light, you know that adding flash isn't going to help things so you need to close your aperture and/or increase your shutter. If it's showing that your image is likely to be very underexposed then you can either say "Yup, that's great. I want a darker background and my flash will light my subject" or "Nope, I need more light so I am going to go from f5.6 to f4.5 (or 1/200 to 1/160 etc)." It's all about choices.
Grajan:
Right - having displayed the true depth of my P&S ignorance, can you recommend any good books before I drive you crazy?.....
LOL...it's a short drive some days, believe me!
I like the Scott Kelby books. They are on Photoshop, but if you have a look at them you will also start to understand more how light is so important to photography (hence hearing "it's painting with light" all the time!) and how your camera resolves those issues. The histogram sections alone are worth the book.
For uw photography itself a MUST have is Jim Church's
Essential Guide to Composition. It was written for the Nikonos systems mainly, but everything still applies to newer cameras. And he gives apertures and shutters and strobe information which helps one visualise how all the elements come together to create the photo. It's pretty easy to read and it's a book you will come back to over and over again.
Beyond that, go to the library and get any book with underwater photos you can lay your hands on. See what you like, see what doesn't turn you on. Think of how you would get that shot. Also look at non-uw photo books. The more images you surround yourself with the better foundation you get in developing your own style - you can see what's out there, get ideas for things you would like to try, use the images to start figuring out what you need to do BEFORE you get underwater and are faced with the shot you really want.
And most importantly, I believe, practice practice! Shoot, review, adjust, shoot, review, adjust. I just did a dive yesterday where I didn't get anything I'd want to share but I learned a lot about a new lens and some lighting things. Practice, it's all about practice.
HTH
On land is extremely valuable!
