NOT TOO MANY ARTICLES AND OR BOOKS REGARDING DIGITAL SLR SETTINGS WHEN USING A FLAT PORT AND A 50MM LENS FOR SHOTS.FEELINGS ABOUT WHETHER YOU SHOULD SET YOUR SHUTTER SPEED AND ADJUST THE APERTURE ACCORDING TO YOUR DISTANCE FROM SUBJECT OR VICE VERSA.ALSO, IF ANYONE IS FAMILIAR WITH WHAT SHUTTER SPEED IS PREFERRD 1/60 OR HIGHER.I PERSONALLY USE 1/125 WITH GOOD RESULTS.THANKS

Good Point Steve, But try not to YELL...{All Capital letters is considered yelling in the cyber world..} Let's see some more of those pictures and if you have the aperature settings/shutter speed to go along with them all the better..

Steven, it's really an apples and oranges decision. It your looking for DOF (depth of field), larger aperture, if you have a lot of motion then go for faster shutter speed. It's really shot dependant, every shot may de different. The skill to practice is to be able to preview the last shot and zoom in to check focus in the LCD.

I have lost way to many shots to motion blur underwater so I'm more apt to go for the faster shutter speed. Then I have a much smaller lens and get pretty good DOF even wide open.

If I had a choice I would set the aperture and let the camera select the shutter speed and the adjust from there. Don't forget the other adjustment is the flash power.

The other advice is shoot many shots of the same subject with different settings. Digital allows for the shotgun approach, you don't have to put away the camera after 36 pictures.

Thank you, I am in the process of resizing some of my pictures to post them here.

everything i've read seems to recommend aperature priority over shutter priority...and if your shutter spped is ending up 1/30 or faster you are not gonna have that much problem with holding still for the shot...in fact the only reason you might even care at all what the shutter speed is just for that reason - too slow and you need a tripod...

so anyway, i ordered a 105mm macro for my f100 - i gonna get that thing wet one of these days

Steve,

You're leaving out a large part of the equation, the strobe.

Also consider looking at the questions of shutter and aperture settings from a different perspective, the overall composition.

Try breaking the composition into two exposure categories, the foreground and the background. The foreground exposure in your composition will be controlled by aperture and strobe intensity. The background exposure relies solely upon ambient light for illumination and therefore is controlled only by aperture and shutter speed.

The strobe, any strobe, will not be influential much beyond 5'-6'.

To determine the correct aperture, consider the guide number of your strobe and follow a simple equation: A=Gn/D
or Aperture equals Guide Number divided by distance. (BTW, since this is an equation, it may be written several ways, such as Gn=A*D. Choose to write it whichever way best fits the situation)

Say that your strobe's underwater Gn is 22 at full power, (ISO=100), and the distance between the strobe and subject ( target ) is four feet. Then by choosing an aperture of f/5.6, you should be very close to an acceptably exposed foreground:

(Gn)22 divided by (D)4 equals (approximately!)(f/)5.6.

Make sense?

I recommend a shutter speed of 1/125 sec to start. By choosing a shutter speed faster, you will darken your background exposure (quite acceptable!!!!). If you use a speed slower than 1/125, you will make the water appear a lighter blue in color. Suit to taste! The only considerations are too slow a shutter may cause motion blur (slower than 1/60 imho) and too fast may cause sync clipping, where the full influence of the light emitted by the strobe is cut off due to poor synchronization with the camera's shutter (lens) opening. Sync issues vary from camera to camera.

btw, imho you should be shooting in full manual. As Cecil pointed out, the digital age mantra of : Shoot, review, adjust, shoot again, is a worthy technique, especially considering pixels are so cheap.

hth,
kadushi bob

hey guys.thanks for the thoughts. i agree with all opinions.my question arose because when i bought the canon digital slr rebel my primary objective was fish photography.i spoke with cathy church from the sunset house in caymans and she favored a shutter priority(1/125,and or higher)and use f-8for 3 feet,f-11 for two feet and f22 for one foot.nice shots resulted however i also read recently that aperture priority also performed better.thanks again.