How often do I need a focus distance scale and a depth of field scale?

It so happened historically that lenses that have on their body a scale with a focusing distance and a depth of field scale are considered more advanced than lenses that do not have such scales. How much are digital scales with fast auto focus in demand such scales?

Nikon ED AF Nikkor 80-200mm 1: 2.8D (MKII) Focus Distance Scale

Lens focus distance scale Nikon ED AF Nikkor 80-200mm 1: 2.8D (MKII)... Please note that there is no depth of field scale, as well as the fact that the number of marks in meters and feet is very meager and it is almost impossible to manually focus on them. The '80' mark is for infrared focusing.

From my personal experience with digital cameras, I can tell you that I have never used the distance scale and the depth-of-field scale for manual focusing for its intended purpose. This means that despite my fascination with manual optics, I have never measured the distance to the object being shot and did not focus using the distance scale indicated on the lens. Moreover, I did not calculate and did not particularly take into account the depth of field. It so happened that I do not like depth of field calculators and do not use them. Fortunately, the genres in which I have to shoot are not very demanding on accurate calculations and calculations. In my practice, I prefer to use a simple and concise rule - not to complicate your life. For focusing, I am completely satisfied with the optical or electronic viewfinder and the Live View mode. To control the depth of field, I am completely satisfied with viewing the footage on the camera display or on a computer monitor. You can almost always take a test shot and check the depth of field (see if the model's ears fall out of the field of focus). Over time, the feeling of the focusing distance and the obtained depth of field at a certain focal length and F number reaches automatism and do not require any special calculations.

But still, in some cases, having a lens with a focus distance scale and a depth of field scale helps me out:

  1. On the scale of the focusing distance, you can determine which way you want to rotate the focus ring in order to quickly focus on infinity, or MDF. With a quick focus on infinity, there are some peculiarities that I’ll try to write about somehow. When shooting with different cameras and lenses, I am faced with the fact that every manufacturer likes to create lenses with different directions of rotation of the focus ring. If the auto focus does not know what to do, but you can’t figure it out in the viewfinder, just look at the distance scale once and manually start focusing in the right direction.
  2. Sometimes, taking a tripod with the remote control, you can determine whether refocusing has occurred by moving the focus distance scale.
  3. The presence of the focus distance scale and the depth of field scale gives at least some indirect confirmation that the lens is made in good faith. This is a basic attribute for good optics. If you recall, the whale and other cheap lenses lack the depth of field and focus distance.
  4. Using the focus distance scale, you can quickly find out the minimum focus distance and, without delving into the instructions for the lens, make certain conclusions.
  5. Using the focus distance scale, you can visually compare the speed of the focus motors for different lenses.
  6. A scale of depth of field and focus distance for beginners can help to understand some of the relationships between depth of field, F number and distance to the subject.
  7. Using the focus distance scale, you can quickly find out the approximate distance to the subject.

I would like to add that even on expensive lenses, the depth-of-field scale may be completely absent, or be greatly reduced. Don't believe me? Then check out the Nikon N AF-S Nikkor 70-200mm 1: 2.8GII ED VR or Canon Zoom Lens EF 24-70mm 1: 2.8 L USM. Even with macro lenses, the depth-of-field scale is severely truncated, and usually only has marks for the extreme aperture values ​​such as F / 22 or F / 32. The focusing distance scale on modern lenses is also greatly reduced - there are very few marks with distances on it. Such a truncated scale has no practical application. In addition, the focusing ring travel of many modern lenses is very small. The long travel of the focus ring is often sacrificed for fast autofocus.

My little conclusion: in our time, digital photography, the scale of the distance of focus and depth of field have almost completely lost their original role.

Write your thoughts about the practical applications of the distance scale and the depth of field scale in the comments.

Thank you for attention. Arkady Shapoval.

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Comments: 61, on the topic: How often do I need a focus distance scale and a depth of field scale?

  • Dmitry (e_dimas)

    And I use this scale for aiming at infinity when I shoot night landscapes (autofocus in such conditions greatly misses). Sometimes I use it during the day when there are a lot of objects in the frame at different distances and autofocus clings to them, and I need infinity.

    Still sometimes on a distance scale I control whether auto focus or not. For example, if the object is about 3 meters away, and on the scale it shows 7, then you need to focus again (more precisely).

  • Elena

    Thanks so much for the article. Now I have a clear idea of ​​what it is for!

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