Help with Teaching

Discussion in 'Exposure Discussion' started by bmac, Apr 27, 2003.

  1. bmac

    bmac Member

    Messages:
    2,156
    Joined:
    Sep 30, 2002
    Location:
    San Jose, CA
    lately, several people have asked me how to "use their new cameras" to take better photos. I have attempted to explain the relationship between shutter speed, F-Stop, and Film Speed to no avail. I have realized that I am a better photographer than teacher (which isn't saying much!). Do any of you Apuggers know of a site on the web, or have a handout that explains this all important relationship in plain english?
     
  2. Aggie

    Aggie Member

    Messages:
    4,925
    Joined:
    Jan 1, 2003
    Location:
    So. Utah
    Shooter:
    Multi Format
    ..
     
  3. SteveGangi

    SteveGangi Member

    Messages:
    485
    Joined:
    Nov 30, 2002
    Location:
    Southern Cal
    Shooter:
    Multi Format
    Use the sunburn thing for film speed too. Faster film burns fast, just like blue eyed, blond haired, fair skinned people. Slow film burns slower like dark haired, dark skinned people.
     
  4. bmac

    bmac Member

    Messages:
    2,156
    Joined:
    Sep 30, 2002
    Location:
    San Jose, CA
    I'm looking for more along the lines of caculating exposure. Such as F8 at 125 is the same exposure as F11 @ 1/60, etc.
     
  5. Aggie

    Aggie Member

    Messages:
    4,925
    Joined:
    Jan 1, 2003
    Location:
    So. Utah
    Shooter:
    Multi Format
    ..
     
  6. Donald Miller

    Donald Miller Member

    Messages:
    6,242
    Joined:
    Dec 21, 2002
    Shooter:
    Large Format
    Brian,
    The way that I relate exposure to people is to explain that a given film will require a given "quantity" of light to expose it. There are in photography two different "controls" to affect this quantity of light. The first is the size of the aperature or "opening" through which the light passes. The second is the length of time that the opening is open "Shutter speed".
    The important thing to remember is that the measurement of apertures and of shutter speed is a ratio of doubles and halves. Thus if one reduces the opening by one half the offsetting factor would be to allow the opening to be open twice as long. This effectively gives the same quantity of light. Conversely if one opens the opening by twice as large, then the offsetting factor would be to allow the opening to be open only one half as long.
    Once the quantity of light is determined by a light meter, either in camera or hand held, the user determination is one of "depth of field"or of shutter speed (ability to stop photographed subject movement). The more the opening is restricted the greater the depth of field (near to far plane of focus). The more the opening is increased the faster the required shutter speed to compensate. (Higher shutter speeds stop movement). I hope that this helps and gives you some idea of how to present this to your friends in your own words. Good luck.
     
  7. Nige

    Nige Subscriber

    Messages:
    2,126
    Joined:
    Sep 8, 2002
    Shooter:
    Multi Format
    you need a diagram! two scales, one for shutter speeds, one for apertures. Explain how the camera determines how much light is needed to expose the film (has a device to measure the quantity of light) , line up those settings and show how all the other combinations are equal in the quantity of light using Donald's explanation. Once they have a grasp of that, add in filmspeed and how that moves the reference point back and forth along the scales, then explain high/low shutters speeds, big/little aperture effects and how you need to stay with matching 'pairs' of shutter speed and aperture. For the moment, I'd let them believe their camera's meter! If they come back again, then you can try to explain that!!

    Reminds me of trying to explain the game of cricket or Aussie Rules football to a foreigner... Seems simple enough having been brought up on them, but really quite complicated to explain, where one thing implicates on another.. and another... etc!
     
  8. Flotsam

    Flotsam Member

    Messages:
    3,221
    Joined:
    Sep 30, 2002
    Location:
    S.E. New Yor
    I use a faucet and pail analogy with a full pail representing proper exposure.

    Say it takes one minute to fill a pail with water. If you open the faucet (Aperature) to double the flow and then you cut that time (shutter speed) in half to thirty seconds, You'll have exactly the proper amount water. You don't even have to look. Conversely, if you halve the flow it will take twice the time, two minutes to get the same amount.

    This analogy can be extended futher in either direction and the consequences of abandoning the rules of reciprocity are obvious, either not enough water (underexposure) or wet shoes (overexposure). [​IMG]

    The real pisser is trying to explain how to determine "proper" exposure.

    Neal
     
  9. fhovie

    fhovie Subscriber

    Messages:
    1,247
    Joined:
    Mar 20, 2003
    Location:
    Port Hueneme
    Shooter:
    Large Format
    When all else fails show them the program button and the auto focus setting - then help them understand:

    have a subject
    draw attention to the subject
    simplify the image

    Some people were made for auto cameras - they can still learn to see a good image and compose it well. That would be a big service to them. ---- of course if simplifieing the image means to through the backgound out with a long lens and a large aperature ,,,, well - I guess they may as well go digi - at lease that way they can erase the bad ones! - Frank
     
  10. Ed Sukach

    Ed Sukach Member

    Messages:
    4,518
    Joined:
    Nov 27, 2002
    Location:
    Ipswich, Mas
    Shooter:
    Medium Format
    I tried posting this yesterday, but somehow, the message must have gone to "bit heaven".

    Hasselblad (of all people) produced an excellent explanation of f/stops and shutter speeds by relating f/stops to pipe diameters and shutter speeds to time, with "exposure" being the amount of water that has flowed through. Excellent analogies, with the intensity of light related to water pressure. All in one slim "freebie" book.

    Contact Hasselblad USA - I'm sure they'll help.
     
  11. glbeas

    glbeas Member

    Messages:
    3,307
    Joined:
    Sep 25, 2002
    Location:
    Roswell, Ga.
    Shooter:
    Multi Format
    Thats pretty similar to the analogy I like to use, a faucet and a bucket. Rate of flow versus time turned on to fill the bucket. Very easy to understand and a very visual approach.
     
  12. FrankB

    FrankB Member

    Messages:
    2,147
    Joined:
    Apr 27, 2003
    Location:
    Northwest UK
    Shooter:
    Medium Format
    I'm glad I'm not the only one that keeps using water to explain this! :smile: I have the analogy slightly different:

    "Imagine a bath full of water. Beneath the plughole is a bucket. Your job is to exactly fill the bucket with water.

    You can control three things; the size of the plughole (aperture), the size of the bucket (film speed) and the amount of time that the plug is out of the hole (shutter speed)."

    I generally elaborate with Delta 3200 being a thimble, Velvia being a whacking great barrel and so on. Once they've grasped the "double the size of the plughole and then either a) double the size of the bucket or b) half the time the plug is out of the hole" and all the permutations you can explain about film grain, colour saturation, d-o-f and blurring in small easy stages.

    The problem with analogies is that it's easy to sound damn patronising when using them, so I usually start off with a warning that this is a noddy-level explanation and a pre-emptive apology!

    Regards,

    Frank
     
  13. Brien

    Brien Member

    Messages:
    1
    Joined:
    Mar 6, 2003
    I teach a basic beginners nature photography class at night. "Taking Better Pictures" is always the goal. I do teach f/stop, shutter speed etc.., but what works best is giving them examples of composition.

    My first class I always teach them to:
    1. Move in closer, 2. Watch Headroom 3. Rule of Thirds. I don't need to tell you about these three but you need to try and communicate it by examples.

    I want my students to feel better about just taking better pictures. As their composition improves so does their willingness/eagerness to take it to the next level. The tech stuff and their understanding of it comes later.
     
  14. Aggie

    Aggie Member

    Messages:
    4,925
    Joined:
    Jan 1, 2003
    Location:
    So. Utah
    Shooter:
    Multi Format
    ..
     
  15. tommorris

    tommorris Member

    Messages:
    24
    Joined:
    Apr 27, 2003
    Teaching exposure - deepest symphaties. It's bloody difficult to teach at the best of times.
     
  16. Nacio Jan Brown

    Nacio Jan Brown Member

    Messages:
    62
    Joined:
    Oct 1, 2003
    Location:
    Berkeley, CA
    A terrific tool in teaching exposure is a 4x5 camera, a Polaroid back, a bunch of Type 55 P/N film, and a light box. Students get an instant and engaging demonstration of what might otherwise be vaguely understood words. A favorite exercise of mine when I was teaching was to ask the students how the appearance of negatives made of the following subjects would differ: full frame shots, metered throught the lens, of black, white, and gray poster board. Knowing what a meter is up to goes hand-in-hand with understanding exposure.
    I just found this website, so excuse this long-belated reply. njb
     
  17. Aggie

    Aggie Member

    Messages:
    4,925
    Joined:
    Jan 1, 2003
    Location:
    So. Utah
    Shooter:
    Multi Format
    ..