The use of the Depth of Focus Gauge

posted Sep 17, 2013, 7:28 AM by Yung Amos   [ updated Sep 17, 2013, 8:19 AM ]

I have long been away from manually operated camera since 1998. My last manually operated camera was a Minolta X700 which was great for photography at that time.  It is still in my sealed cabinet as a "collectible" as the cost to take photography with film is not accountable when compared to a digital camera. Since then, I used a few DSLR cameras (Fujifilm S1, Kodak DSC Pro/C, Canon 10D, Canon 5D Mk2) and many digital compacts. 

Even I had a long history with DSLR and digital compact, I still miss the flexibility and the feeling of complete control that the manually operated camera will provide. 

A manually operated camera does not helping to get the compliments, "Wow", "Cool" in modern day because people already set up their expectation of the speed of a photographer should be fast and accurate ( as the AF and AE speed of any digital compacts are faster than a manually operated camera in every senses).  However, if you did understand how to operate a manually operated camera, you can take better photo at a faster speed than your buddies whom were using a digital compact or a DSLR.

The key to operate your manually operated camera faster is to utilise the "Depth of Field Gauge (DOF Gauge)" on your manual focus lens.

The "Depth of Field Gauge" is a set of markers to indicate the depth of field of that camera lens under the marked aperture size. Let's take below photo of my Voigtlander 21mm f/4.0 lens as an example:

Counting from the top to bottom: 

  • The top ring marks with 4, 5.6, 8, 11, 16, 22 is the Aperture ring
  • The middle ring marks in red (ft.) and white (m.) is the focus distance ring 
  • The bottom ring which as a white dot in the middle and on both sides showing the Aperture size 4, 8,11,16, 22 is the Depth of Focus Gauge
The function of a DOF Gauge is to indicate the DOF of a lens under the indicated Aperture size.

In the above photo, the white dot is pointing to the approximate distance of the focus is 2 meter away from the CMOS Sensor (or film, in a manually operated camera). If you set the Aperture size to f/4, the DOF that this lens can provide is within 5 meters to approximate 1.3 meters. If the aperture size is set to f/8, the DOF will be within Infinity to approximate 1.0 meter -- or in other words, objects within the distance of 1 meter to infinity distance should be "in-focus" on the picture.

This DOF Gauge gives photographers maximum control of their cameras. There is no more mis-focus or out-of-focus as you can estimate the distance to the object, select the suitable aperture for the event you are participating, preset the focusing distance with the help of the DOF Gauge and let the camera choose the correct ISO speed and the shutter speed. Once you have preset your equipment and then you can focus on framing your photos.

The use of DOF Gauge will give you speed in photo taking. It can also eliminate the time for auto-focus, and allows the camera to shoot once you press the shutter.


- 17 Sept. 2013 -