Leica X Vario: Exif Data - Inspecting Focus

Introduction | Examples | Conclusions | Links to ExifTool and More

On this page, I discuss how you can use the manufacturer-specific Exif data that I describe on page Leica X Vario: Manufacturer-Specific Exif Data to gain some insights in your photos, particularly if you did not document your settings meticulously when you took the photos... I will limit my discussion to focus data, that is, to distance and focus mode, plus shutter speed to decide about potential camera shake.

 

Introduction

My primary reason for looking into the Exif focus data is to find out what the camera's autofocus did, provided it was activated. If not, the distance had been set manually, that is, by me. In either case, I need to know

In the case of multi-autofocus, it would also be nice to know which autofocus fields were activated. But up to now, I regrettably do not know which Exif field(s) provide this information. And finally, if a photo looks like suffering from camera shake, knowing the shutter speed can also be helpful.

The question whether an autofocus mode or manual focus was used can be answered by inspecting the focus mode field 0x0404. This field consists of four bytes, with the first one listing the focus mode:

The Leica X Vario offers several autofocus modes: 1-point AF, 11-point AF, spot AF, and face recognition AF (which acts like 11-point AF if there aren't any faces). Knowing which AF type was used can give you some hints on the reliability of the different autofocus modes. They are assigned the values 1, 4, 5, and 6 in Exif field 0x0404.

Distance is coded in the first double byte in field 0x040a. This value is, however, not easy to decipher. Here are the preliminary results of my experimentations:

The graph below shows the S-shaped curve that I found in my experiments:

The graph may be useful for course distance estimations.

Finally, shutter speed (and many other data) are directly listed by many Exif data readers.

As already mentioned, on page Leica X Vario: Manufacturer-Specific Exif Data, I provide detailed information on how you can retrieve the manufacturer-specific fields for focus mode and distance. In the following, I will illustrate the use of the fields with some examples and interpretations.

 

Examples

I often take test photos to compare different settings or different cameras, but since I never document the camera settings, I usually have a hard time afterwards in interpreting the results. Being able to retrieve the settings from the Exif data is, of course, of great help, albeit typically cumbersome.

For example, if you find out that a fuzzy photo was focused manually you know that it was your fault and you need no longer brood about what the autofocus did wrong. If a photo taken with autofocus is fuzzy and you find out that the distance value is way off, you know that the autofocus missed its target - for whatever reason. You may also find that in a series of similar photos some are sharper than others. You can then look at the distance values to find out what the camera decided to set (knowing which AF fields were used would be of great help here...). There are many more questions that the Exif data can answer.

In the following, I present two sets of test photos (taken in close succession) where I wanted to test the autofocus behavior and also included some shots with manual focus (hoping that they would have correct focus...). I do not present the original photos here to save server space, but offer typical sections at 100% (original size), instead.

To gain more insight, I also included the hyperfocal distance (listed in the Exif data for the Leica X Vario) and calculated the depth of field using DOFMaster (sometimes using approximate values). Do not take these values too strictly, they just provide an indication of how far the camera missed the object with respect to the depth of field determined by the camera settings.

For illustration, I also included samples with camera shake to give you an indication of how this might look like.

Motif 1

Overview

Section

L1003550.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/320, aperture: f/5.6
0x404: 4 = 11-point AF
0x040a: 57878 25800 0 0 0 = Distance: 10 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 5.98 m (2.99 m to infinity); DOF: 3.71 m to inf (DOFMaster)

Comment: I expected the foliage a little bit sharper, but the focus is correct and shutter speed is high

L1003551.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/320, aperture: f/5.6
0x404: 4 = 11-point AF
0x040a: 57878 25800 0 0 0 = Distance: 10 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 5.98 m (2.99 m to infinity); DOF: 3.71 m to inf (DOFMaster)

Comment: Data and result identical to the previous shot

L1003552.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/320, aperture: f/5.0
0x404: 4 = 11-point AF
0x040a: 51600 25800 0 0 0 = Distance: ca. 9 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 6.70 m (3.35 m to infinity); DOF: 3.82 m to inf (DOFMaster)

Comment: Less sun, aperture more open, sharpness similar...

L1003553.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/320, aperture: f/5.0
0x404: 4 = 11-point AF
0x040a: 51600 25800 0 0 0 = Distance: ca. 9 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 6.70 m (3.35 m to infinity); DOF: 3.82 m to inf (DOFMaster)

Comment: Data and result identical to the previous shot

L1003554.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/200, aperture: f/5.0
0x404: 5 = Spot AF
0x040a: 65535 25800 0 0 0 = Distance: infinity, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 6.70 m (3.35 m to infinity); DOF: 6.2 m to inf (DOFMaster, inf=100m)

Comment: Longer shutter speed, distance set to infinity by AF; since DOF reaches to about 6 m at the far limit, the section is sharp

L1003555.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/250, aperture: f/5.0
0x404: 5 = Spot AF
0x040a: 26212 25800 0 0 0 = Distance: ca. 3.5 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 6.70 m (3.35 m to infinity); DOF: 2.3 m to 7.4 m (DOFMaster)

Comment: Slightly faster shutter speed, distance too close (but not far off regarding DOF), section slightly fuzzier

L1003556.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/400, aperture: f/5.0
0x404: 1 = 1-point AF
0x040a: 47323 25800 0 0 0 = Distance: ca. 7 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 6.70 m (3.35 m to infinity); DOF: 3.4 m to inf (DOFMaster)

Comment: Shorter shutter speed, distance OK

L1003557.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/400, aperture: f/5.0
0x404: 1 = 1-point AF
0x040a: 47323 25800 0 0 0 = Distance: ca. 7 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 6.70 m (3.35 m to infinity); DOF: 3.4 m to inf (DOFMaster)

Comment: Data and result identical to the previous shot

L1003558.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/320, aperture: f/5.6
0x404: 0 = MF (manual focus)
0x040a: 47371 25800 0 0 0 = Distance: ca. 7 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 5.98 m (2.99 m to infinity); DOF: 3.2 m to inf (DOFMaster)

Comment: Manual focus, distance nearly identical to previous shot with 1-point AF

L1003559.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/250, aperture: f/4.6
0x404: 0 = MF (manual focus)
0x040a: 46243 25800 0 0 0 = Distance: ca. 7 m, focal length: 25.8mm (39 mm)
Hyperfocal Distance: 7.28 m (3.64 m to infinity); DOF: 3.61 m to 118.3 m (DOFMaster, f/4.5)

Comment: Manual focus, aperture more open, distance about "hyperfocal", image overexposed

L1003560.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/160, aperture: f/5.1
0x404: 0 = MF (manual focus)
0x040a: 28196 32400 0 0 0 = Distance: ca. 4 m, focal length: 32.4mm (49 mm)
Hyperfocal Distance: 10.36 m (5.18 m to infinity); DOF: 2.93 m to 6.32 m (DOFMaster, f/5, 33m)

Comment: Change in focal length, distance too short (manual), object probably out of DOF range, section too fuzzy

L1003561.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/160, aperture: f/5.1
0x404: 0 = MF (manual focus)
0x040a: 29042 32400 0 0 0 = Distance: ca. 4 m, focal length: 32.4mm (49 mm)
Hyperfocal Distance: 10.36 m (5.18 m to infinity); DOF: 2.93 m to 6.32 m (DOFMaster, f/5, 33m)

Comment: Result similar to the previous shot, distance nearly identical, section too fuzzy

L1003562.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/160, aperture: f/5.1
0x404: 1 = 1-point AF
0x040a: 39646 32400 0 0 0 = Distance: 6 m, focal length: 32.4mm (49 mm)
Hyperfocal Distance: 10.36 m (5.18 m to infinity); DOF: 3.87 m to 13.4 m (DOFMaster, f/5, 33 mm)

Comment:Change to 1-point AF, distance a little bit too close, section sharper

L1003563.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/160, aperture: f/5.1
0x404: 1 = 1-point AF
0x040a: 56919 32400 0 0 0 = Distance: 12 m, focal length: 32.4 mm (49 mm)
Hyperfocal Distance: 10.36 m (5.18 m to infinity); DOF: 6.3 m to inf (DOFMaster, f/5, 33 mm)

Comment: 1-point AF, distance a little bit too far, section similar to previous one

L1003564.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/125, aperture: f/6.4
0x404: 1 = 1-point AF
0x040a: 54862 46000 0 0 0 = Distance: 9 m, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 5.85 m to 19.5 m (DOFMaster)

Comment: Photo fuzzy due to camera shake (1/125 at long end)

L1003565.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/100, aperture: f/6.4
0x404: 1 = 1-point AF
0x040a: 65535 46000 0 0 0 = Distance: inf, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 5.85 m to 19.5 m (DOFMaster)

Comment: Section sharp, camera held more steady, distance at infinity (AF)

L1003566.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/80, aperture: f/6.4
0x404: 1 = 1-point AF
0x040a: 65535 46000 0 0 0 = Distance: inf, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 5.85 m to 19.5 m (DOFMaster)

Comment: Section sharp, camera held more steady (at 1/80!), distance at infinity (AF)

L1003567.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/80, aperture: f/6.4
0x404: 0 = MF (manual focus)
0x040a: 65535 46000 0 0 0 = Distance: 9 m, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 5.85 m to 19.5 m (DOFMaster)

Comment: Photo fuzzy due to camera shake (1/80 at long end), manual focus at inf cannot be compared with AF at inf

Motif 2

Overview

Section

L1003568.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/125, aperture: f/6.4
0x404: 0 = MF (manual focus)
0x040a: 42577 46000 0 0 0 = Distance: ca. 7 m, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 4.94 m to 12 m (DOFMaster)

Comment: Manual focus at about 7 m, section OK

L1003569.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/125, aperture: f/6.4
0x404: 0 = MF (manual focus)
0x040a: 65535 46000 0 0 0 = Distance: inf, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 14.3 m to inf (DOFMaster, 100 m)

Comment: Manual focus at infinity, section blurred because object is outside DOF range

L1003570.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/125, aperture: f/6.4
0x404: 0 = MF (manual focus)
0x040a: 65535 46000 0 0 0 = Distance: inf, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 14.3 m to inf (DOFMaster, 100 m)

Comment: Identical data to previous shot, section slightly sharper but blurred because object is outside DOF range

L1003571.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/100, aperture: f/6.4
0x404: 1 = 1-Spot AF
0x040a: 50339 46000 0 0 0 = Distance: ca. 8 m, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 5.42 m to 14.3 m (DOFMaster)

Comment: Change to 1-Spot AF, section much sharper than previous shots (apart from the first one)

L1003572.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/125, aperture: f/6.4
0x404: 1 = 1-Spot AF
0x040a: 50339 46000 0 0 0 = Distance: ca. 8 m, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 5.42 m to 14.3 m (DOFMaster)

Comment: Nearly identical data like previous shot, shutter speed slightly highly, section visibly sharper than previous one (maybe even better than the first shot), probably due to less camera shake

L1003573.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/125, aperture: f/6.4
0x404: 4 = 11-Spot AF
0x040a: 36767 46000 0 0 0 = Distance: ca. 5 m, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 3.85 m to 7.12 m (DOFMaster)

Comment: Change to 11-Point AF, distance slightly too short, section fuzzy due to camera shake

L1003574.jpg
0x40d: 1 = Exposure mode: Aperture priority
Shutter speed: 1/125, aperture: f/6.4
0x404: 4 = 11-Spot AF
0x040a: 41291 46000 0 0 0 = Distance: ca. 7 m, focal length: 46.0 mm (70 mm)
Hyperfocal Distance: 16.75 m (8.38 m to infinity); DOF: 4.94 m to 12 m (DOFMaster)

Comment: 11-Point AF, distance more correct, section OK (one of the best results...)

 

Conclusions

Just a few notes on the examples:

  1. There are quite a few shots showing camera shake. Since the Leica X Vario does not offer any "real" anti-shake mechanism (due to the APS-C sensor - my Ricohs have the same shortcoming), one must hold the camera carefully and steady. In some cases, however, even slow shutter speeds lead to sharp results.
  2. Manual focus is often "off" the mark - I have to do better with this.
  3. Other than I expected and than I have observed in some situations, the camera does repeat settings under identical conditions. In some other tests I found a large variation in distance values.
  4. The DOF range helps understand why a photo is fuzzy because you can relate it to the set distance and the (assumed) object distance.
  5. The examples serve for illustrating the approach. They do not suffice to tell anything about the reliability of the various focus modes.

 

Links to ExifTool and More

ExifTool

DOFMaster

 

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14.02.2016