Sekonic Dualmaster L-558 Exposure Meter review

Why a dedicated exposure meter?

Nowadays pretty much all digital SLR cameras boast sophisticated built-in meters which usually operate in spot, center-weighted and matrix modes; apart from this, any more or less decent DSLR has the histogram display function which allows you to further examine precision of exposure and avoid loosing shadow detail or blowing highlights (and, when tonal range of a scene is wider than the imaging censor's exposure latitude you can choose between loosing shadow detail or blowing highlights or a combination of the two). This set of metering tools fully suffices to precisely determine and control exposure (the only situation when these might not be entirely convenient is when you shoot from a tripod), so if you own one of the modern DSLR wonders then there probably is no need to buy a dedicated light meter. However, if you still use manual cameras with film or need to analyze and manipulate flash output as well as use some other advanced features, a dedicated light meter still remains an irreplaceable tool.

It has been suggested on some Web sites that if you own a decent DSLR then it can be used as a light meter for a (manual) film camera. Whereas this, generally, is possible and might provide passable results, I find that using a dedicated light meter is simply a lot easier in the field - using a digital camera as a light meter for film is not as flexible; most importantly, though, one is bound to rather sooner than later run into the following issues:

Exposure latitude of a given film and that of a digital sensor are not necessarily the same. For example, my experience indicates that exposure latitude of the D70s' CCD sensor is somewhat broader than that of Fuji Velvia 100F slide film (roughly six stops vs. about five stops). This means that determining if you will loose shadow detail or blow highlights on film by looking at your DSLR's histogram is very unreliable.
Previewing a shot on a DSLR's LCD screen in an attempt to see whether a given exposure is adequate is a very erratic method as, first, what you see on the LCD will largely depend on ambient light (this is especially difficult in bright sunlight) and viewing angle. Second, what you see on a LCD display and what will be recorded on film is not going to be the same because of the exposure latitude difference described above.
Analyzing where tonal values fall on film using a DSLR's histogram function or spot meter is not very straightforward and rather difficult.

On the one hand, a histogram cannot tell you where exactly you are placing tonal values on film. Suppose you have chosen an exposure for a given shot so that all tonal values on the histogram fall nicely into, say, 80-180 range. Does this actually tell you what tonality your main subject is going to have on film? Would you want to change exposure so that tonal values on the histogram move a little to the right? Or a little to the left? And if you actually do change exposure, how much and how are you going to know what precise effect this is going to have on film?

On the other hand, using a DSLR's spot meter to determine where tonal values would fall on film is not entirely straightforward as DSLRs usually do not show exposure value (EV) difference - they simply show exposure for different parts of a scene as you meter them. Also, DSLRs' spot meters are usually wider than 1 degree.
Using your DSLR as a light meter is a much more expensive option - do you really want to waste your expensive camera's shutter cycles?
A dedicated meter's batteries normally last for months and if you still want to be on the safe side carrying only one small spare battery will have you fully covered.

Whereas it probably is possible to establish through tests a correlation between what a camera's histogram function shows and where tonal values fall on film of your choice in relation to it, I doubt that the relationship can be expressed in simple and easy-to-use terms. Lagging around a DSLR to only (inconveniently) use its spot meter is a bit of an overkill, too. Indeed, things can be done in a lot easier way - and this is exactly where a dedicated exposure meter such as the Sekonic L-558 comes in.

Sekonic L-558

The Sekonic L-558 replaces and significantly improves on the venerable Sekonic L-508 model and is an all-in-one meter - it offers flash and ambient exposure metering in both reflected spot and incident modes.

Though made of plastic, the meter feels quite solidly built. It is about average size for a meter of its class and comfortable to hold; operation of all buttons and dials is solid and substantial. The LCD display is large and easy to read. The 558 uses one 3.0v CR123A lithium battery, which normally is readily available and runs for ages.

The meter utilizes rubber seals throughout the housing and controls and is water and moisture resistant. It, however, is not waterproof and the manual says that "although the meter can be used in rainy or wet conditions, it should not be used underwater". Seeing that pro-level Nikon or Canon digital SLRs are "weather proof" to a similar degree as well as that they never seem to fail in very diverse shooting conditions, I reckon that the Sekonic L-558 can be fully dependent upon in the harshest weather conditions possible.

The meter's LCD panel background light turns on automatically in low light surroundings. This is an absolutely brilliant feature - it is much more useful than you probably suspect and I appreciate it to the extent that I would not consider a meter that does not have this feature.

The following is the list of some of the key features that the Sekonic L-558 boasts - they should give you a pretty good idea as to what the device is capable of (with my comments on the functions I use most):

Sensitivity: EV -9.9 to 46.6;
1 degree reflected spot metering: the perfect angle and I have never wished I had zoom capability;
In incident light operation the diffuser can be used for both 3D (when lumisphere is extended) and flat objects (when lumisphere is retracted);
Viewfinder display: I find it especially useful when using the brightness difference function as in this mode EV difference between a reference exposure reading and exposure measurements of other parts of a scene is shown as you scan the view with the meter; it also allows to take multiple readings or estimate lighting conditions in a fluid manner;
Aperture-priority, shutter-priority and EV (Exposure Value) modes when measuring ambient light (both incident and reflected spot) and shutter priority mode when measuring flash light (apart from the EV mode all in 1/3, ? or full stops selectable via Custom settings);
Flash output can be measured in the following modes: corded single or multiple (cumulative) flash and cordless single or multiple (cumulative) flash; wireless multiple flash triggering function is available, too;
Both analog and numerical readings are displayed on the LCD: quite interestingly, in shutter-priority and aperture priority modes numerical readings of aperture are shown precisely to 1/10 of a stop whereas in shutter-priority mode analog readings of aperture are shown in 1/2 stops; this might appear a bit confusing at first but actually is well thought out and useful;
Two ISO buttons are available so that the meter can be simultaneously used with films of different speeds; alternatively, ISO 2 button can be programmed via custom settings to directly show exposure compensated for filter factor (within a range of +/-5 EV in 1/10 increments);
Exposure compensation function (in a range of +/- 9.9 EV in 1/10 increments) - read my complaints about it below, though;
Memory function can store up to nine measured values for incident and reflected light independently;
Averaging function displays the average of up to nine values stored in memory: an equivalent of center-weighed meter but I personally never use this as I prefer to place tonal values exactly where I want them to be;
Brightness difference function: shows exposure value difference between two exposure readings ; this function makes life a lot easier as it allows you to simply take three readings (of a 18% grey, the brightest and the darkest parts of a scene) and immediately know whether you blow highlights (if exposure value difference between 18% grey and the brightest spot is more than +2.5 EV (film) or +3 EV (digital)) or loose shadow detail (if exposure value difference between 18% grey and the darkest spot is more than -2.5 EV (film) or -3 EV (digital)); it also allows you to quickly and conveniently analyze where tonal value of any part of a scene falls in relation to your main subject thus enabling you to pre-visualize subsequent tonal distribution on film; I use this function all the time!
Calibration compensation function;
Flash analyzing function.

All in all, the meter offers a very wide range of features and functions which should suffice for the most demanding photographers of all walks of life. I in fact think that most photographers will find it hard to utilize every single feature that the Sekonic L-558 boasts. I, for one, rarely use flash-related functions but having them at hand certainly does not hurt.

Any gripes?

The Sekonic L-558, generally, answers my needs very well yet the following (especially point no.1) has caused some inconvenience:

Exposure compensation indication entirely defies logic. Suppose you want your main subject to appear very light on slide film, in which case you would normally spot-meter the subject and dial in an exposure compensation of +2. After all, making a plus compensation means increasing exposure - at least, this is what logic dictates and how most meters work. So you meter the subject in, say, shutter priority mode at, for instance, 1 second and the Sekonic shows an aperture of f/8 (I am actually doing this as I write). You then dial in compensation so that "+2" is displayed on the LCD screen and expect the aperture on the screen to change to f/4. But guess what? The meter shows f/16! Quite amusingly, this actually is consistent with the manual which says that "making a plus compensation will result in underexposing when taking a photograph". I am not sure how Sekonic engineers interpret exposure compensation - they probably mean that making a plus compensation means increasing F number. Anyway, this, to me, is absolutely bizarre and confusing. I could probably get used to this but I do not want to because this is not how the rest of the world works.
The meter was designed to be held in the palm of your right hand. I am not sure whether it is only me but I felt like holding it my left hand right from the moment I took the meter out of the box. Maybe this has to do with the fact that I currently use Hasselblad equipment and need my right hand to be free to operate the lens. I am sure one can get used to this, though.
Having to replace lens cap every time is quite a nuisance; that said, though, I would not want to leave the lens unprotected.

Conclusions

The Sekonic L-558 is a superb exposure meter and I would give five points out of five if not for the exposure compensation inconvenience mentioned above. It boasts a comprehensive set of features and functions that caters for a very wide range of photographic needs and comes in relatively compact, robust and comfortable to use body. It might take some time to use the meter fluently and learn all it has in store but once mastered I reckon it would be hard to find a more powerful tool.