Aperture priority again? (Page 3): I teach photography in a public high school, as part of the intro course I cover camera settings; Aperture, Shutter speed, ISO (the exposure...

MrMophoto Loc: Rhode Island "The biggest little"

I teach photography in a public high school, as part of the intro course I cover camera settings; Aperture, Shutter speed, ISO (the exposure triangle) If I may I'll cover this unit in short form; Each setting controls a different aspect of image capture.
Aperture controls depth of field which is a distance (of focus) thing, measuring from the camera, it's the beginning of what's in focus to the end of what's in focus. Generally, the wider the aperture the shallower the depth of field. however, the further away from the camera you focus the deeper the depth of field will be.
Shutter speed controls how the camera records movement. the faster the shutter speed that is used is, the faster a movement can be will be recorded as a "stop action" and not a blur. Also the further away from the camera the movement is, the slower a shutter speed has to be to stop action, i.e. at 50 ft a train traveling at 100 mph would take approx 1/2000 sec to stop action, but the same train shot at 1/8 mile would only take approx. 1/125 sec to stop action.
ISO controls how sensitive the recording device is to light. The more available light you have the less sensitive the camera needs to be, thus in low light situations you will need a higher ISO. A lower ISO results in more detailed sharper images. The problem is that generally the higher the ISO the grater amount of noise you will have especially in the shadow areas. I tell my students to shoot as low an ISO as possible.
The overall approach; Depending on what you are photographing will determine whether you use aperture priority, shutter priority, and ISO. If there is nothing moving (landscape), shutter speed is not a concern, your priority is the depth of field, Aperture Priority. If there is a lot of movement (sports) aperture is not your concern, your priority is stopping the action or creating a blur (some blurs can be a visual representation of movement), Shutter Priority. Never shoot with ISO on auto, as mentioned, you should always shoot with the ISO as low as possible to record as sharp an image as possible, unless you like the look of noise.
One more thing thing to consider, Exposure is a combination of shutter speed and aperture. As the aperture gets wider, the faster the shutter speed will be to get the same exposure. The old analogy of light as water through a spigot, the bigger the opening in the spigot the faster you will get a gallon of water and the smaller the opening the longer it will take to get the same gallon of water.
I hope this helps.

Weddingguy Loc: British Columbia - Canada

amfoto1 wrote:

Doesn't matter whether indoors or out...

When my concern is controlling depth of field... either with a larger aperture for shallow DoF and stronger background blur or a smaller aperture for greater DoF and sharpness from my toes to the horizon... and I need to use an auto exposure mode... I use Aperture Priority.

When my main concern is freezing movement with a fast shutter speed or deliberately blur parts of the image with a slow one... and I need to use an auto exposure mode... I use Shutter Priority.

When I have concerns about both DoF and motion blur.... and need to use an auto exposure mode.... I use Auto ISO with Manual mode.

When I don't need an auto exposure mode... I use Manual (no Auto ISO). It's always nice to be able to really lock down the exposure settings. But Manual mode isn't always possible. Auto exposure modes are necessary at times. It's just a matter of picking the one that best meets the current situation.

I never use Aperture Priority AND Auto ISO... both at the same time. That would be an "auto-auto" mode, would make for less predictable results... And, I tried, but can't think of any purpose it would serve. The same with Auto ISO combined with any of the other auto exposure modes. I only use Auto ISO with Manual.

You mention flash, and with the cameras I use there are some additional exposure considerations. I don't know how all systems work, but with Canon cameras, when you use ETTL flash with any of the auto exposure modes it will automatically act as FILL. Unless you override it, the camera makes the exposure based upon ambient light and flash output is dialed back by approx. -1.66 stops, enough to open up shadows and supplement existing light. But if you want FULL flash, it's as easy as switching to Manual mode. With full flash the shutter speed is largely irrelevant when using flash, too. When flash is the dominant or only light source, it acts like a fast shutter speed, freezing movement. ISO and the aperture are what control flash exposure and the distance flash can reach.

Doesn't matter whether indoors or out... br br Wh... (show quote)

Very well explained!!

ronpier Loc: Poland Ohio

HardwareGuy wrote:

Or, try the "Pro mode". Meaning, "Program". Most all enthusiast cameras allow you to manually choose to control the aperture and/or shutter speed via dials while in "Program" - and still get the correct exposure.

AKA “ISO Priority”, another name for Program Mode.

Piman-jimc

i have a physical condition called "Essential Tremors." It is age, not Parkinson related. It causes shaking of the fingers and hands. Therefore I almost entirely use Shutter preferred mode or flash when taking photos [auto ISO] to eliminate camera shake. I typically shoot at 1/320 or faster. The results are satisfactory.
JC

MrMophoto Loc: Rhode Island "The biggest little"

Program mode sets the aperture and shutter speed automatically and lets you choose the ISO. In both Priority modes, aperture and shutter, You can choose the ISO,

ronpier Loc: Poland Ohio

MrMophoto wrote:

Program mode sets the aperture and shutter speed automatically and lets you choose the ISO. In both Priority modes, aperture and shutter, You can choose the ISO,

You can also change the shutter or aperture by turning the dial while the ISO remains what you chose originally. The camera will then complete the 3rd leg (shutter or aperture) of the triangle. Exposure or white balance adjustments can be made also.

Weddingguy Loc: British Columbia - Canada

MrMophoto wrote:

I teach photography in a public high school, as part of the intro course I cover camera settings; Aperture, Shutter speed, ISO (the exposure triangle) If I may I'll cover this unit in short form; Each setting controls a different aspect of image capture.
Aperture controls depth of field which is a distance (of focus) thing, measuring from the camera, it's the beginning of what's in focus to the end of what's in focus. Generally, the wider the aperture the shallower the depth of field. however, the further away from the camera you focus the deeper the depth of field will be.
Shutter speed controls how the camera records movement. the faster the shutter speed that is used is, the faster a movement can be will be recorded as a "stop action" and not a blur. Also the further away from the camera the movement is, the slower a shutter speed has to be to stop action, i.e. at 50 ft a train traveling at 100 mph would take approx 1/2000 sec to stop action, but the same train shot at 1/8 mile would only take approx. 1/125 sec to stop action.
ISO controls how sensitive the recording device is to light. The more available light you have the less sensitive the camera needs to be, thus in low light situations you will need a higher ISO. A lower ISO results in more detailed sharper images. The problem is that generally the higher the ISO the grater amount of noise you will have especially in the shadow areas. I tell my students to shoot as low an ISO as possible.
The overall approach; Depending on what you are photographing will determine whether you use aperture priority, shutter priority, and ISO. If there is nothing moving (landscape), shutter speed is not a concern, your priority is the depth of field, Aperture Priority. If there is a lot of movement (sports) aperture is not your concern, your priority is stopping the action or creating a blur (some blurs can be a visual representation of movement), Shutter Priority. Never shoot with ISO on auto, as mentioned, you should always shoot with the ISO as low as possible to record as sharp an image as possible, unless you like the look of noise.
One more thing thing to consider, Exposure is a combination of shutter speed and aperture. As the aperture gets wider, the faster the shutter speed will be to get the same exposure. The old analogy of light as water through a spigot, the bigger the opening in the spigot the faster you will get a gallon of water and the smaller the opening the longer it will take to get the same gallon of water.
I hope this helps.

I teach photography in a public high school, as pa... (show quote)

Great way to explain the priorities. Only challenge is that ISO is NOT an adjustment of the sensitivity of the sensor, but an amplification of the signal received by the sensor. Like amplifying sound, the greater the amplification, the less clear the image or sound will be.

rdfarr Loc: Floridian living in AL

"f8 and be there". I think I got that from Scott Kelby.