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On this page we'll try to collect tables of general information that don't refer specifically to Contax G cameras, but that may come in handy for using them. More tables coming as we acquire them!
Contents:
For quick estimates of the depth of field available with Contax G lenses from 21mm to 90mm at various aperture and distance settings, try this calculator dial. The dial is a downloadable Adobe Acrobat file in PDF format; print it out, assemble it, and it's ready to use. Although the calibrations are a bit coarse, it should help with approximate depth-of-field calculations. Click here to download the PDF file.
This table shows the "hyperfocal distance" at each aperture for each lens in the Contax G system (except the 15mm f/8 Hologon, which has its own built-in scales.) Hyperfocal distance is an especially useful concept for wide-angle lens users. When you set a lens to its hyperfocal distance, everything will be approximately in focus from infinity to HALF the hyperfocal distance. For example, if you're shooting a distant landscape with the 45mm lens at f/8 and want as much of the foreground in focus as possible, set the lens to its hyperfocal distance (10.1 meters, according to the table.) Then, everything from about 5 meters to infinity should be reasonably sharp.
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Focal length |
2 |
2.8 |
4 |
5.6 |
8 |
11 |
16 |
22 |
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21 |
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28 |
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35 |
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45 |
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90 |
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WARNING: The numbers in this table were calculated using a "shortcut" method suggested in one of Dr. Rudolf Kingslake's books on camera optics, so they may differ somewhat from hyperfocal distances calculated by other methods. Also, hyperfocal distance (like depth of field) depends on the value you select for "circle of confusion" (which refers to the smallest perceptible detail in the image.) This table was based on the value of 0.025mm for the circle of confusion, which should be adequate for fairly close viewing of ordinary prints. If you're a critical worker or make larger prints, you can make the table more stringent by multiplying the numbers -- if you want to use twice as stringent a value for the circle of confusion, multiply each number by two. In our example above, this would give a hyperfocal distance for the 45mm lens at f/8 of 20.2 meters, and a sharpness range of 10.1 meters to infinity. On the other hand, if you plan to make only 4 x 6 prints for casual viewing, you can probably get away with using half as stringent a value for the circle of confusion, and dividing the numbers in the table by 2.
The "custom function" feature of the G1 and G2 lets you change the way some of the cameras' features operate, to suit your own preferences. Information about setting and changing the custom functions can be found in the camera instruction manual -- but we've summarized it here for the convenience of prospective buyers (who might wonder what options are available) and used-camera buyers (who might not have received an instruction manual and want to know how to set the custom functions.)
You change a custom function by activating the camera's function-setting mode (how you do this depends on whether you have a G1 or a G2.) When the camera is in this mode, the top panel LCD indicates each custom function and shows how it is set. Each custom function is designated by a number. Another number shows whether the custom function is set for normal default option (0) or the "customized" option (1.) So, for example, if custom function 1 is set to the normal option, the top-panel display will read 1 - 0.
Here are the specifics for each camera model:
G1 Custom Functions
Turn on the main switch. To put the camera into function-setting mode, hold down both the Drive and ISO buttons for about 3 seconds. Release the buttons when the top panel LCD changes to the custom function mode. In this mode, the panel will show blinking numbers indicating custom functions and their settings.
Press the ISO button repeatedly to scroll through the numbers of the custom functions, until you reach the one you want to change.
Press the Drive button to select either the default (0) or customized (1) setting.
Turn off the main switch to lock in your setting choice. Using the Drive button to change custom settings may have changed your drive mode -- so be sure to check this the next time you turn on the camera.
The settings you can make are:
Function #
What It Affects
"0" (normal) setting
"1" (custom) setting
Useful for:
1 AE Lock operation
Autoexposure is locked when the main switch is moved to the "AEL" position
Autoexposure is locked when you depress the shutter release halfway (except when using dedicated flash.) If the main switch is moved to "AEL," it takes priority over the release switch.
The custom setting locks exposure at the same time you lock focus (by pressing the shutter release halfway.) Useful for tricky, fast-changing lighting conditions where you don't want to bother setting the AEL yourself.
2 Order of exposures when auto-bracketing is used
Normal, over, under
Over, normal, under
The order depends on your personal preference
3 Film leader after rewinding
Leader is wound all the way back into the cassette
Leader is left protruding from cassette
Winding the leader back all the way is safer, but leaving it out gives you the option of removing a partly-exposed roll and replacing it later
G2 Custom Functions
Turn on the main switch. To put the camera into function-setting mode, hold down both the ISO button and the focus lock button for about 1.2 seconds. Release the buttons when the top panel LCD changes to the custom function mode. In this mode, the panel will show blinking numbers indicating custom functions and their settings.
Turn the manual focus dial to scroll through the custom function numbers, until you see the one you want to change. (A "CLE" setting follows the function numbers; this allows you to reset all custom functions to their factory defaults.)
Press the focus lock button to select either the default (0) or customized (1) setting.
Turn off the main switch to lock in your setting choice.
The settings you can make are:
Function #
What It Affects
"0" (normal) setting
"1" (custom) setting
Useful for:
1 AE Lock operation
Autoexposure is locked when the main switch is moved to the "AEL" position
Autoexposure is locked when you depress the shutter release halfway (except when using dedicated flash.) If the main switch is moved to "AEL," it takes priority over the release switch.
The custom setting locks exposure at the same time you lock focus (by pressing the shutter release halfway.) Useful for tricky, fast-changing lighting conditions where you don't want to bother setting the AEL yourself.
2 Order of exposures when auto-bracketing is used
Normal, over, under
Over, normal, under
The order depends on your personal preference
3 Film leader after rewinding
Leader is wound all the way back into the cassette
Leader is left protruding from cassette
Winding the leader back all the way is safer, but leaving it out gives you the option of removing a partly-exposed roll and replacing it later
4 Manual focus adjustment method
To focus manually, turn focus wheel
To focus manually, turn focus wheel while holding in focus lock button
If you sometimes accidentally change manual focus distances by brushing the focus wheel, the custom setting can help.
5 Multiple exposure settings
Multi-exposure mode is cleared after each exposure
Multi-exposure mode remains set until you change it
The normal setting is good if you only want to make two exposures on a frame; it protects you against forgetting to reset the control. If you plan to make many exposures on each frame, the custom setting saves you the bother of resetting the control each time.