NOTE: The terms Chronograph and Chronometer are often used indiscriminately, although they are two different types of watches. The term chronometer is more of a title a watch can "earn" after a series of severe tests. An official Swiss institute is in charge of these tests, which are strictly prescribed in protocols. In 1961, one of the rules was, that a mechanical watch was not allowed to gain more than 12 seconds or to loose more than 3 seconds in order to receive the title. Because the quality and accuracy of wrist watches improved, these rules needed adjustment through the years.
A chronograph can also aquire the Chronometer title, if it meets the set standards. If so, the dial will most likely have the inscription "officially Certified Chronometer".

Using Polaroid on your Speed requires at least a watch giving proper and constant time reading.
A chronograph lets you time the exposure much more precise when you're using the elder Polaroid holders.
The latest "Polaroid 545 Pro" does not need the extra hand. Time processing is built in.

What else can we do with a chronograph watch?

• Replace a compass. Nice to know where the Northern light is! If cloudy use the shadow of a pencil or the like.
• Determine how much time you have to find a shelter when a thunderstorm is coming up. Watch the light and hear the sound .
• Use as a Tachymètre.

It's possible to determine your orientation using an analog watch (i.e., one with hands) in place of a compass. The direction will be correct if the watch is set for true local time, without adjustments for daylight savings time. And the further you are from the equator, the more accurate this method will be. In the northern hemisphere, hold the watch horizontal and point the hour hand in the direction of the sun. Bisect the angle between the hour hand and the twelve o'clock mark to get the north-south line. North will be the direction farthest from the sun. In the southern hemisphere, hold the watch horizontal and point the twelve o'clock mark in the direction of the sun. Bisect the angle between the hour hand and the twelve o'clock mark to get the north-south line. North will be the direction closer to the sun.

1. Watch the sky for a flash of lightning.

2. Count the number of seconds until you hear thunder. If you have a watch with a second hand or a digital watch that has seconds, begin timing as soon as you see the lightning and stop as soon as you hear the thunder start. If you don’t have a watch, do your best to count the seconds accurately. Say "One one thousand, two one thousand etc." in your mind for each second.

3. Divide the number of seconds by 5 to calculate the distance in miles (or divide by 3 for kilometers). In other words if you counted 18 seconds from when you saw the lightning, the strike was 3.6 miles (6 kilometers) from your location. The delay between when you see lightning and when you hear thunder occurs because sound travels much, much more slowly than light. Sound travels through air at about 1100-1200 feet (330-350 meters) per second (depending on altitude, relative humidity, pressure, etc.), which is a little more than one mile per five seconds (one kilometer per three seconds). In comparison, the speed of light is 983,571,058 feet (299,792,458 meters) per second.

* For example, if lightning strikes a point 1 mile away, you will see the strike approximately .00000536 seconds after the strike while you will hear it approximately 4.72 seconds after the actual strike. If you calculate the difference between these two experiences, a person will hear a strike approximately 4.71999 seconds after the strike actually occurred. Therefore, 5 seconds per mile is a fairly robust approximation.

4. Seek shelter immediately if a storm is approaching.

A tachymeter (also tachymetre or tacheometer) is a kind of theodolite used for rapid measurements and determines, electronically or electro-optically, the distance to target, and is highly automated in its operations. Tachymeters are often used in surveying.

A tachymeter is also used as the name of the scale sometimes inscribed around the rim of an analog watch. It can be used to compute speed based on travel time. To use it for this purpose, start the chronograph at a mile marker. At the next mile marker, the point on the scale adjacent to the second hand indicates the speed (in miles per hour) of travel between the two. A standard tachymeter will only determine speeds greater than 60 miles per hour using this method; slower speeds can be measured by decreasing the unit of measurement (to half-miles or kilometers, for example). The speed of an object is defined by the equation The tachymeter scale computes the function . The spacings between the marks on the tachymeter dial are therefore proportional to 1/t where t is the elapsed time, but because of the somewhat similar pattern and because of people's familiarity with logarithmic graph paper, the tachymeter scale is sometimes also mistakenly described as logarithmic. The function performed by a tachymeter is independent of unit of distance (i.e. is not specific to miles or kilometers). A tachymeter can be used to measure speed in nautical miles per hour or meters per hour, or to measure an industrial production process in units per hour. A tachymeter is simply a means of converting elapsed time in seconds per X to X per hour. The scale is generally only accurate for elapsed times over approximately 7 seconds.

Seeing those watches from WWII and considering the tasks that were carried out, we must admit probably just a simple watch like this A-11 will do all jobs we need to do.
However, some features of today's time machines can be more convenient and faster.

"The greatest luxury in life is time, savour every second."

S U R V E Y
Interesting question: Speed Graphic/AE users and Large Format photographers in general seem to be very critical choosing their equipment. Do they use chronograph watches?
Feel free to tell us.

Tempus fugit - Two years passed since we published and launched this site and finally we came to the conclusion that all has been written...!
This is the last page added to "The MasterSite for the larger Camera". Minor corrections and new photographs may be published without further notice.