ISO 100 and ISO 12800 cannot be set　(EOS REBEL T5/EOS 1200D)
04-Feb-2014
8202022600
Solution
If you set [C.Fn II -6: Highlight tone priority] to [1: Enable] on your camera, the settable ISO range will be limited to ISO 200-6400, so "ISO 100" or "H"( equivalent to ISO 12800) cannot be selected.
The [D+] icon will be displayed on the LCD panel and in the viewfinder when highlight tone priority is enabled.
To make the "ISO 100" or "H"(equivalent to ISO 12800) setting (ISO expansion), change the setting as follows.
1. Set the camera’s power switch to <ON>.
2. Press the <MENU> button to display the menu.
3. Press the <
> keys to select the [ 
] tab. Press the <
> keys to select [Custom Functions (C.Fn)], then press <SET>.
> keys to select the [ ] tab. Press the <
> keys to select [Custom Functions (C.Fn)], then press <SET>.
4. Press the <
> keys to select Custom Function [6:Highlight tone priority], then press <SET>.
> keys to select Custom Function [6:Highlight tone priority], then press <SET>.
5. Select [0: Disable], and then press <SET>.
6. Press the shutter button halfway, and the camera will be ready for shooting.
Confirm that [D+], which indicates Highlight tone priority, is not displayed on the LCD monitor and in the viewfinder.
NOTE
About Highlight tone priority
- With setting [1: Enable], improves the highlight detail. The dynamic range is expanded from the standard 18% gray to bright highlights. The gradation between the grays and highlights becomes smoother.
- With setting [1: Enable], noise (grainy image, banding, etc.) may become slightly more pronounced than with setting [0: Disable].
- With setting [1: Enable], the Auto Lighting Optimizer is automatically set to [Disable] and the setting cannot be changed.
1. Press the <MENU> button to display the menu screen.
2. Press the <
> keys to select the [ ] tab. Press the <
> keys to select [Custom Functions(C.Fn)], then press <SET>.
> keys to select the [ ] tab. Press the <
> keys to select [Custom Functions(C.Fn)], then press <SET>.3. Press the <> keys to select Custom Function [2: ISO expansion], then press <SET>.
> keys to select Custom Function [2: ISO expansion], then press <SET>.
4. Select [1: On], and then press <SET>.
5. Press the shutter button halfway, and the camera will be ready for shooting.
When you set the ISO speed, you will be able to set "H" (equivalent to ISO 12800).
NOTE
Note that if [C.Fn-6: Highlight tone priority] is set to [1: Enable], "H" cannot be set.
If [C.Fn-10: Flash button function] is set to [1: ISO speed], you can set the ISO speed with the < 
> button.
> button.