Fig 1. Photo from Olympus page
Fig 1. Photo from Olympus page
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 3456 pixels 4.63 mm = 746 px/mm 
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| Wide | Tele | |
|---|---|---|
| Focal length | 4.5 mm | 18 mm |
| ƒ/stop | ƒ/2 - ƒ/8 | ƒ/4.9 - ƒ/18 |
| Diffraction-limited * | Yes (ƒ/4.3) | Yes (ƒ/4.3) |
| Arc-seconds/px | 61.4 | 15.3 |
* At smaller apertures, resolution is limited by diffraction, not the sensor
Remote capture: Yes, via smartPhone app
Remote focus control: Yes
Lens compatible with eyepieces: Not sure
Raw mode: Yes
Filter mount: Yes, with adapter
The TG-4 can be controlled using an Olympus smartphone app via battery-charge-consuming wifi, with live view (a view on the smartphone of what the camera sees). However, the camera cannot be controlled via USB from a computer.
The entrance pupil of this camera is similar to the human eye, so it's suitable for taking photos through optical instruments such as a microscope or binoculars, using an afocal adapter.
The camera was set 173cm from a perpendicular tape measure (measured from the back of the camera). Photos were taken at various focal lengths, and then the angle of view was calculated. It's possible the angle of view is affected by the focus distance.
| Focal length (mm) | Angle of view (degrees) |
| 4.5 | 67.8° |
| 5.1 | 61.9° |
| 5.9 | 53.0° |
| 6.4 | 51.4° |
| 6.9 | 48.5° |
| 7.3 | 45.6° |
| 9.9 | 37.5° |
| 11.8 | 28.8° |
| 14.4 | 23.6° |
| 18.9 | 19.2° |
In 'Microscope' mode, the camera can focus right up to the lens. That close, the field of view is about the same regardless of focal length:
| Focal length (mm) | Field of view (mm) |
| 4.5 | 6.3 |
| 18.0 | 5.0 |
With about 1.5cm between the lens and a ruler, the field of view was measured as:
| Focal length (mm) | Field of view (mm) |
| 4.5 | 37 |
| 18.0 | 10 |
In 'Microscope focus bracketing' mode, the camera will rapidly take a user-specified number of photos, stepping through a range of user-specified focus steps, and then stack them to make one image with higher depth of field. This can be quite good, even hand-held.
