Contax G1 silver label conversion to green label

Upgrade your Contax G1 to support the 21mm and 35mm lenses

Posted by Davide Caniatti on Tuesday, October 19, 2021

TOC

Contax G1 cameras come in two versions: silver label (also called sometimes “white labels”) and green label. The white label version s the original one, while the green one was introduced a couple of years later to support the new lenses: the 21mm and the 35mm.

For a while, it was possible to send the first version to the factory or a repairer to get the camera updated. Now, it seems no one offers this service anymore. The good news is that it is not so difficult to do the process by yourself, especially following these instructions. Thank to the Contax G2 repair manual, some blog posts on the forum, my friend Andrea, and the help of a benefactor called Nate, I was able to come up with this procedure. I want to emphasize here that the procedure is not mine, but that I report it here because it is too precious to be lost in the maze of the web It can sound complicated at first, but it’s not, so let’s see it together! And remember: nothing is saved in the camera memory until you explicitly tell the camera to save your changes. If you are not sure about a passage, turn the camera off and start again!

Although the whole operation may be bit time consuming, it is the last way left to upgrade this camera and can save a lot of money!

1. Set the camera to any drive mode other than Multiple Exposure mode.

2. With the camera back open, press and hold the film rewind button for 2 seconds.

3. While still holding the rewind button, press the shutter button.

If you did it right the shutter will not fire and the camera will now be in “Manual Adjustment Mode.” You can do all sorts of things in the manual adjustment mode menus, like checking the shutter count, tweaking shutter speed timing, and calibrating the metering and autofocus.

Once you’re in Manual Adjustment Mode there are three separate “Adjusting Mode” menus, which are selected using the A.B.C. (Exposure bracketing) lever under the shutter speed dial. The lens data is entered in Adjusting Mode 2 which is activated by setting the ABC switch to +/-.5.

In Manual Adjusting Mode 2 you’ll see the lens data bank number in the frame count window. These banks are numbered 1-11 but not all of them are used. Bank 3 is for the 21mm and bank 6 is for the 35mm.

1. Use the Drive/ISO buttons to cycle through and select the lens data bank you want to edit.

2. Once the correct bank number is showing in the frame counter window, flip the power switch to AEL and then immediately back to ON. This enters the sub-items menu for the lens bank that you selected. The current lens bank will still show in the frame counter window and the sub-item number will be blinking in the top iso/drive/distance LCD top display.

3. Use the Drive/ISO buttons to select the sub-item number you need to edit.

4. Flip the power switch to AEL to enable the adjustment of the item’s value. The 2 digit value to the right of the sub-item number will now be blinking. Adjust the blinking value (which will be “00” [edit: or “FF”] on a non-updated silver label camera) to the new lens data value.

5. Move the power switch from AEL back to ON and use the drive/iso buttons again to select the next sub-item to edit. Again, switch to AEL to edit the value. Repeat for all the new sub-item data values. (If it seems confusing remember that ON=menu navigation and AEL=data adjustment). The correct values are shown below the last point.

6. After you’ve changed all the values, make sure the power switch is set to ON and navigate to subitem number 00. Press the shutter button to write all the adjusted values to memory.

7. Turn off the camera or close the back to exit manual adjustment mode.

8. Repeat for each lens data bank you are adding data to.

Here are the sub-item numbers and data values you need to add to point 5.

Here are the values for the 21mm lens, to be entered in bank 3. Any item numbers not listed stay at “00”

01-FC
02-FA
03-54
05-50
06-03
07-60
08-03
09-54
10-03
11-40
12-03
14-13
19-5b
20-3E
21-CA
23-30
24-18
25-02
26-47
27-19
28-11
50-01

Here are the values for the 35mm lens, to be entered in bank 6. Any item numbers not listed stay at “00”

01-FC
02-FE
03-8C
05-E0
06-05
07-dd
08-05
09-bb
10-05
11-b0
12-05
14-3b
19-24
20-FA
21-CA
23-30
24-10
26-7d
27-22
28-11
50-01

Have fun and feel proud in carrying out an operation now forgotten by the producers themselves!