Leica X Vario: Functional Issues - Autofocus (Introduction, Older Version)

Archive

Note: This is an older version of the page; it is provided for reference purposes only. See the current version of the page.

While I like my Leica X Vario, it also has a number of functional issues or, in my opinion, deficits that need improvement. I will list and discuss these on this and on related pages. Hopefully, most of the issues can be resolved in the future (a few are with firmware update version 1.1)...

This page introduces the issue of autofocus (AF) errors, which are discussed controversially in the Leica camera forums. On another page, I examine autofocus (AF) issues in real world photos, namely my 2013 photos. One a third page, I discuss photos that I took to produce AF errors in order to identify potential conditions and causes for these errors. Other functional issues are dealt with on page Functional Issues.

Note: The AF issues discussed here refer to the case that the camera signaled a correct focus (green rectangle(s)). The case that the camera cannot find focus and indicates this with a red rectangle is another matter. This may occur, for example, because there are no contours in the focus field. Some remarks on this can be found on page Autofocus Characteristics.

Update: Some users who installed the firmware update version 1.1 posted that they found an improvement in autofocus speed and accuracy whereas others denied this (including me). Since Leica did not mention autofocus in the instructions for the update, I simply assume that nothing has happened in this area. This is supported by the fact, I still encounter AF issues from time to time after having installed the update (but the photographer is still the same - and he may be the reason for the AF issues, as some X Vario users who never had the issues insist on...).

Introduction to Autofocus Issues

There are still heated debates about the autofocus (AF) behavior of the Leica X Vario, but the final word has not yet been spoken in this issue. The fact is that there are users who experience AF issues, and there are others who do not, but the reasons for these different experiences are still unknown. It is also important to note that these issues refer to cases in which the camera confirmed focus (using green rectancle(s)) - otherwise one would try again...

The initial testers always praised the X Vario's AF accuracy (not so much its speed - although Leica does so), except for - not surprisingly for a contract detect AF - low light conditions. But maybe they just repeated what everybody would expect.

My Experiences in Short...

Since I own the Leica X Vario, a few of my photos, usually taken with 11-point AF and sometimes also with 1-point AF, are - for unknown reasons - completely out of focus. The focus errors seem to occur unpredictably. I am a hobby photographer and do not protocol the settings and/or my behavior. So I have primarily the - sometimes very fuzzy - photos to guess from what went wrong and ask, "Was it my fault or the camera's?"

The focus mode is one indicator that can help in this decision. If focus was set manually, a fuzzy photo is obviously my fault, if one of the AF modes was set, both me and the camera can have their share in the issue. Since I discovered the Leica-specific Exif focus mode tag (independently of ExifTool that also lists it), I have some support in making this decision: I can sort out those photos where the error clearly was on my side.

Now to the remaining photos, taken with one of the three AF modes: 11-point AF, 1-point-AF, and spot AF. A closer look at the photos often reveals that the focus is set to a near-by distance. There are also shots without any foreground, so that I cannot tell whether the distance was set too close. Luckily, since I discovered the Leica-specific Exif distance tag, I am able to check what distance the camera set automatically (or better, what distance it listed in the Exif data). Usually, I find that the camera set a distance of around one meter or even less, confirming the visual impression. There are also cases, in which the camera sets a too close distance, but it is beyond 1 m. Finally, I found that, in rare cases, the camera states in the Exif data that it set distance to infinity, but it did not: the image is rather fuzzy. And there many be similar photos in my set, where the camera lists the same distance - and these photos are sharp (as they should be).

Having scanned most of my 2013 "real world" photos (see here for details), I found that, except for the rare "infinity" cases, the X Vario unpredictably sets the distance too short, never too far (while sending a "green" focus confirmation). This is true for 11-point AF and 1-point AF and should, considering my tests (see here), also apply to spot AF.

Others' Experiences

barjohn

One of the Leica X Vario users who experienced and reported similar AF issues is barjohn. He documented them in several threads in the l-camera-forum. In 2014, I looked at his older samples that he had provided on Dropbox once again and also at the new ones that he published in January 2014. The old samples all use spot AF, the new ones, too, apart from the first one, which uses 1-point AF and which is the only one in focus. For all of his photos, he reports to have had a "green" focus confirmation. Moreover, barjohn published out-of-focus photos that were also taken with 1-point and spot AF. Regrettably, I cannot find out which photos used which type of AF...

Just User Error?

So I am not alone with encountering AF issues (see also the thread originally started by VETTRAN in the l-camera-forum that includes some recent postings), although many Leica X Vario users report that they don't have any. Some of the latter attributed the issues to the users, not the camera. That's definitely a "killer argument" and, in my opinion, unfair and most probably wrong. But I am not willing to quarrel with these X Vario owners.

There is one argument that, in my opinion, contradicts the "user error" hypothesis: I often get fuzzy images within a series of photos of the same scene (there are, of course minor differences in the section and sometimes in the "technical" data). Thus, under nearly the same conditions, I get photos that are in focus, as well as photos that are fuzzy. In the case of a "pure" user error, all the photos in a series should be fuzzy.

Potential Explanations for AF Issues

At the moment, I speculate that the discrepancy in the explanations for the X Vario AF issues is caused by (1) the AF focus modes that the different photographers use and (2) also by their shooting habits. But there may also be technical reasons (or problems) for the differences.

The following issues/explanations for AF issues have been proposed in forums:

AF makes more errors with spot AF or 1-point AF than with 11-point AF
Possible explanation: The area to evaluate the focus is smaller und thus, it is more difficult for the camera to find the correct focus.
Initially, I could not confirm this finding. When I had problems with 1-point AF due to low contrast, the camera showed a red rectangle. But in the meantime, I have found cases in which the camera sent a green confirmation, but the focus was completely off (see my investigations).
Focus goes beyond infinity
I was able to decipher undocumented Exif fields for focus mode and distance. From investigating the distance Exif data, I cannot confirm this finding. I found that typically the focus is too close (about 1 m or even less...)
Since focusing is performed using a step motor, focus may be slightly off, because the steps are too large.
Hopefully the steps are small enough and do not cause any focusing problems, particularly considering the not so fast lens. Nevertheless, when inspecting Exif distance data, it is evident that only certain values appear, which might be an indication of the steps. But the focus errors that I usually find are so big that this argument does not apply.
Finally, the following argument was put forward in the l-camera-forum: Other cameras, including expensive studio DSLRs also exhibit focus errors from time to time. Thus, the X Vario's focus errors are quite "normal."
My simple answer to this that I am willing to believe that any camera makes focus errors. But I have encountered more errors with my Leica X Vario than I was used to from my previous (much less expensive) cameras.

Further Investigations by Me

Since I cannot see any indication that Leica will ever solve the X Vario's AF issues, and being frustrated by the spurious inexplicable AF errors of my camera, I started some investigations into this matter. I do not believe that I will find the technical causes for the errors, but I may find conditions under which they occur, and, more importantly, may be able to produce such errors to prove that they do exist (even though I may have to take tens or hundreds of photos - or just AF measurements). I do not think that my camera (and perhaps barjohns's...) is the only one that makes such errors (there have indeed been several such reports). Actually, I still believe that other cameras have this bug, too, because for me it seems to be a firmware bug. But it may very much depend on the users' shooting behavior whether the errors will surface...

Final Words...

People like barjohn, whom I know for his impatience, will probably move over to other cameras soon... Perhaps, I will follow him one day when I do not see any reaction from Leica (as was the case with my two attempts to contact them via e-mail). At the moment, however, this is not my intention and I am still patient and optimistic.

What Ricoh Has to Say...

In the Ricoh GR manual I found the following statement (p. 33; mode dial set to "auto shooting" mode):

"The camera cannot focus or a subject may not be in focus even if focus frames are displayed in green in the following cases.

Objects that lack contrast (the sky, a white wall, the hood of a car, etc.)
Flat objects with only horizontal lines
Fast-moving objects
Objects that are poorly lit
Objects with bright reflections or backlighting
Flickering objects, such as fluorescent lights
Point light sources (light bulbs, spotlights, or LEDs)

If the camera is unable to focus, lock focus on another object at the same distance from the camera as your subject, then recompose the photograph and take the picture."

There is no mentioning of this issue in the sections for advanced photographing, where the focus modes are discussed in detail. Most probably, the above-mentioned statements apply there as well...

Transferring this information to the Leica X Vario, it may well be that there are inherent technical restrictions to autofocus that caused wrong "green" focus confirmations under certain conditions.

Preliminary Conclusions - Summary

Preliminary Conclusions for Real World Photos

Overall, my "collection" of photos with AF issues (and similar ones that are OK) does not point to a fundamental difference between 11-point and 1-point AF with respect to AF errors. In some cases, 11-point AF may have been distracted by foreground objects, but I tried to exclude such examples from my collection (I included a few samples where foreground objects were at the periphery and therefore, should not be considered by 11-point AF). I also found examples, where 1-point AF may have been distracted by peripheral foreground objects, although this shouldn't have been the case, either.

All in all, except for the very few "infinity errors," there seems to be one common pattern in the AF errors that I encountered: The camera erratically and unpredictably focuses too closely. The reasons for this behavior are, however, still unknown to me... There "inifinity" errors point to a different issue: Here the camera reports a correct focus in the Exif data, but focuses too closely (I discovered this issue just recently, that is, in March 2015, again).

Preliminary Conclusions for Spot and 1-Point AF

Taking together barjohn's and my results (both real world and tests), evidence enough has been collected to conclude that on certain occasions - and for unknown reasons - spot AF and 1-point AF signal to have found focus but completely miss the target (typically the camera sets a distance of about half a meter in such cases).

The picture may be somewhat different for different focal lengths and perhaps lighting conditions, but the fact of wrong focus confirmation coupled with a completely "off" distance setting exists at all focal lengths. In my opinion, both issues - incorrect focus confirmation and missed focus - go together: There seems to be a severe bug in the spot AF firmware. Leica should investigate this issue further and correct the X Vario firmware. But note Ricoh's statemant in the GR manual that wrong focus confirmations can happen under certain conditions.

Tripod tests show that AF errors happen when a tripod is used as well. But the camera's distance settings are much more consistent than when the camera is used hand-held.

I did not look more closely at "near misses" when using spot and 1-point AF, particularly because I mostly used 11-point AF in the past. But a retest suggests that such "milder" focus errors may occur in these focus modes as well - and in the same unpredictable manner. At least, spot AF may tend to make "slight" AF errors, setting the distance to about 2 m, although the object is farther away. This may be the case under better lighting conditions, but at the moment this is just a speculation.

Preliminary Conclusions for 11-Point AF

When 11-point AF fails (but indicates to have found correct focus), the camera typically sets a distance of about a meter. Thus, the photos do not look as blurry as in the case of focus errors for spot AF and 1-point AF. Here, the problem is that such errors are much harder to detect in the viewfinder (on the fly....). You only find them when you inspect your photos at home, but then it's usually too late...

11-point focus errors seem to occur more rarely than the drastic focus errors for spot and 1-point AF. Nevertheless, they occur - unpredictably - and may ruin valuable photos (which led me to take each photo at least twice...).

The Infinity Issue

There are also rare cases, in which the Exif data lists a distance of infinity (65535), but the photo is completely blurry as if the camera had selected a nearby focus (as is the case for most completely blurry photos). Here, we have the issue that the Exif data is not correct - and the focus neither... Probably, this is a separate firmware issue...

What Can I Do Now?

Perhaps, Leica will resolve the X Vario's AF issues one day in a firmware update - perhaps it will not... Particularly in the latter case, one might ask what one can do to reduce the number of AF errors.

During the first months of ownership, I encountered many more AF errors that I do now. I attribute this to a number of measures that I took - or changes in my shooting habits. One reason is that I now use the 11-point AF less often, another one is that I set automatic review to "Zoom" so that I can check sharpness more easily after I took a photo. In extreme cases, you can already see in the viewfinder or on the LCD screen that a photo will be fuzzy, but this requires that you take a little time for a closer look at the preview...

Suggestions

In the following, I would like to make a few suggestions based on my own experiences. They may also help other photographers to reduce the number of AF errors (if they should have any...):

Use 1-point AF (or spot AF if needed) instead of 11-point AF, particularly when there are objects in the foreground, whereas the target objects are further away.
Reason: 11-point AF seems to be easily distracted by objects in the foreground, even if they are in the periphery (even 1-point AF seems to exhibit such a tendency...).
Use face detection AF if you are taking photos of people instead of 11-point AF.
Reason: Face detection prevents foreground objects to interfere. If there are no faces, it's just 11-point AF...
Note: I did not yet test this proposal, it's just theory...
Use 11-point AF for uniformly colored objects, not 1-point AF or spot AF.
Reason: 11-point AF has a larger target area and therefore is more likely to find a suitable focus target.
Set the distance manually to infinity when there are a lot of objects in the foreground and you use a wider focal length (for longer focal lengths you have to be more careful with the distance setting...).
Reason: This prevents objects in the foreground to interfere (for details, see here).
Set the distance manually (either using the viewfinder/LCD screen or the lens' distance scale) when the scene might be confusing for the AF system.
Reason: This prevents other objects from catching the focus (for details, see here).
Use the the "Zoom" setting for automatic review.
Reason: The magnification allows you to evaluate "after a photo has been taken," whether the photo is sharp (for details, see here).
Caveats: (1) I often do not wait long for until the magnified section to appear, (2) the "central" object may not be at the center and therefore its sharpness cannot be judged.

Caveat

Often AF errors occur when there is little time to think, you take photos of people, or the location is unclear (like in a boat). In such a situation you would, of course, prefer just to take photos and not think of technical issues or check focus and exposure. I am well aware that, for such situations, my suggestions may not help a lot...

Afterword

With my previous digital cameras, I often took more than one shot of a motive, because I was unsure about the correct exposure, but never because of focusing issues (except for macro shots). With the Leica X Vario, I often take more than one shot not because of the exposure (sometimes, I do...), but because of the focusing. Whenever I take only one shot, often enough, the focus is off... Of course, there are also a lot of "operator's errors" involved, but I am learning and use manual focus to avoid some of the pitfalls (which may also introduce new errors because I forgot that I had set manual focus...). Nonetheless, there are, to my taste, far too many occasions left, where I have to blame the camera. In the l-camera-forum, some posters insisted that the users have to adapt to the camera's behavior. This reminds me of related discussions with developers in my profession as a usability engineer. There are also usability people who maintain that it is always the system that is to blame, not the users. I tend to a middle position...