Updated: We've finished our evaluation of the retail version of Panasonic's LX7, and have upgraded our former preview article (on 18th July) to a full fledged review. If you've know the basics of the LX7 camera, you can jump straight to our Image Performance review page and our Conclusion.
It's happy days for camera lovers. Everything that we've known as certain has been thrown topsy turvy in 2012; we have entry level full-frame DSLR cameras, compact APS-C mirrorless cameras and even full-frame compacts.
We also have a boon of compact cameras with fast lenses. It's a happy trend for photographers which could easily have not happened had the camera manufacturers kept fighting a senseless megapixel war. Instead, we have more compacts today with faster lenses than ever before.
The great problem for the camera companies is that what most people will secondly ask about fast lenses is "so what?", and the first question is likely "what's that?" while only photographers who understand obscure terms like "f/1.4 wide open and f/2.3 racked out" will be smiling. It's a great risk to bet your flagship product on a feature less understood than a megapixel number, but hey, that's why we're here.
The Big Deal about Fast Lenses
If you already understand fast lenses and wide apertures, feel free to skip this section. If not, then here's why fast lenses matter. Cameras are all about capturing light, and there are three elements which decide just how much light gets captured - these three elements are known as the exposure trinity.
First in the exposure trinity is shutter speed, which determines just how long the eye of your lens stays open - the longer the lens stays open, the more light will be captured. This is why you sometimes get shaky pictures in dim settings; the camera tries to stay open for a longer period of time than a human hand can hold steady.
The second element in the exposure trinity is ISO sensitivity, or how sensitive your image sensor is to light. The higher the ISO setting, the more sensitive your sensor will be to light, but also to noise. Which is why images taken in dim settings tend to look noisy and smudgy.
The third element is aperture, or how wide your lens can open up. The wider it can open, the more light can be captured. You can use any of the three elements to capture more light, which is really important when you're trying to shoot in dim situations. But having a wide aperture reduces your need to increase shutter speed or ISO, which also means reducing the risks of shaky or noisy images.
Lenses with wide apertures are also called bright lenses, because they allow more light in. They're also called fast lenses, because they let your shutter speed stay faster - the lens opens wider, so it has to stay open for a shorter amount of time compared to a lens with a narrower opening. This is why fast lenses are great; they let you capture more light at a time, and are especially useful for low-light shooting. They're also the essential factor (among others) to create background blur, also known as bokeh. The wider the lens can open, the more background blur there is.
Special Thanks to the LX Series
Now, one of the reasons why we're seeing more compact cameras with fast lenses is thanks to Panasonic's LX series. Bright lenses have been a staple feature in the series from way back when, starting with the Lumix LX1 in 2005. Of course, the lenses now pale in comparison to what we have today, especially with the brand new Lumix LX7 which has an aperture range of f/1.4 at the wide end to f/2.3 at its maximum zoom (despite the number, this is the fifth camera to bear the name).
|Canon S110||Fujifilm XF1||Olympus XZ-2||Panasonic LX7||Panasonic LX5||Samsung EX2F||Sony RX100|
|Focal Length (35mm equiv.)||24-120mm||25-100mm||28-112mm||24-90mm||24-90mm||24-80mm||28-100mm|
|Max. Video Resolution||1080/24fps with stereo||1080/30fps with stereo||1080/30fps with stereo||1080/60fps with stereo||720/60fps with mono||1080/30fps with stereo||1080/60fps with stereo|
|Battery Life (by CIPA)||200 images||300 images||340 images||330 images||400 images||Unlisted||330 images|
|Dimensions||99 x 59 x 27mm||108 x 62 x 33mm||113 x 65 x 48mm||111 x 67 x 47mm||110 x 66 x 43mm||112 x 62 x 29mm||102 x 58 x 36mm|
When compared against its competitors, the Panasonic LX7 is the fastest lens on the block. Not only is it fastest at the wide end of 24mm at f/1.4, it's also fastest when racked out to 90mm at f/2.3. The other camera that comes closest is the Samsung EX2F, which can open up to f/1.4 at the wide end but is slower at f/2.7 at its furthest.
When it comes to zoom, the LX7 has one of the shorter zooms in this category. It has a focal length of 24-90mm (35mm equivalent), which is comparable to the basic 18-55mm (27-82.5mm with an APS-C crop factor) lenses which come with most entry-level DSLR cameras. The Canon S110 has the longest 5x zoom at 24-120mm, but with a slower lens.
One unfortunate downgrade is the hit to battery life; the LX7 is rated good for 330 images compared to the LX5's 400 images. While 330 images is a comparable number, especially when squared against the Canon S100's paltry 200 images, it's too bad that the latest LX camera dropped from amazing stamina to just good.
Why No Large Sensor LX7?
While Panasonic has increased the lens' speed, it has chosen not to increase the LX camera's sensor size. In fact, the sensor size has been slightly reduced, the LX5's sensor measured 0.61-inch diagonal and the LX7's measures 0.59-inch diagonal (it’s worth pointing out that the LX7's image sensor is still larger than most consumer compact cameras'). Michiharu Uematsu, from Panasonic's Advanced Planning Group explained to us that when designing the LX7, Panasonic mapped out three possible directions for the camera:
- A fixed focal-length lens with large sensor.
- A small sensor camera with a fast, wide-aperture zoom lens.
- A large sensor camera with a slow, narrow-aperture zoom lens.
Panasonic decided to go with option two for the LX7, as producing the same performance lens with a large sensor would have required making a much larger lens and body.
As for keeping the megapixel-count the same, Uematsu said that based on printing needs, 8.64MP would be enough to print an A4-sized photo at 300ppi, while 7.68MP would be enough to print an A3-sized photo at 200dpi. Considering that most compact camera users aren't likely to print above A3, Panasonic reasoned that 10MP would be enough for most users. To print A3 at 300dpi however, you would need approx. 17.4MP, a resolution only the Sony RX100's 20.2MP can reach today.
So the question really is; does the LX7's faster lens provide a sufficient advantage over a competing camera with a larger sensor and slower lenses?