Panasonic FZ300 Optics

Zoom
A fast, 24x zoom, with good overall performance.

The Panasonic FZ300 is equipped with a 4.5-108mm lens, offering an optical zoom ratio of 24x, translating to a 35mm-equivalent focal range of about 25-600mm. The lens is quite fast (bright) for its type, with a maximum aperture of f/2.8 across the zoom range.

Far-field performance is good at both full wide angle and telephoto at f/4 as shown above, with good sharpness and contrast across most of the frame, with well-controlled chromatic aberration (like most cameras, the FZ300 suppresses it). Some minor flare can be seen from very bright highlights at full wide angle, though.

Note that these shots are use mainly to illustrate optical zoom range. See below for lab results on macro performance, geometric distortion, corner softness, etc.

Macro
A smaller than average minimum coverage area with very good detail, but minimum focusing distance is so close that it's difficult to illuminate the target with either ambient light or the built-in flash.

The Panasonic FZ300 captured a smaller than average sized minimum area in macro mode, measuring 1.65 x 1.23 inches (42 x 31 millimeters) at maximum wide angle. Sharpness over much of the frame is good with less corner softening than expected at f/8 (most lenses show some softening in the corners at macro distances). Exposure was very uneven though, because the lens focuses so closely (down to 1cm), blocking most of the flash and even a lot of the ambient light.

Geometric Distortion
Very low distortion in camera JPEGs.

Thanks to in-camera distortion correction, there's low geometric distortion in the FZ300's JPEG files. At full wide angle, we measured between 0.2 and 0.3 % barrel distortion depending on the edge, which is pretty low and not very noticeable. At full telephoto, distortion was very low, at about 0.1% pincushion distortion. This is the tendency for the lens to bend straight lines outward (like a barrel -- usually at wide-angle) or inward (like a pincushion -- usually at telephoto).

Chromatic Aberration and Corner Sharpness
Moderate to very low chromatic aberration in JPEGs. The lens produces some soft corners wide-open at telephoto though corner sharpness improves stopped-down.

Chromatic Aberration. Thanks to in-camera chromatic aberration suppression, there's moderately low CA in the corners at wide angle in JPEGs, though CA is higher at full telephoto. As expected, though, uncorrected RAW files (see below) show much more CA than seen in the JPEG crops above.

Corner Softness. Wide-open at full wide angle, the FZ300's lens shows remarkable performance in the corners with just a bit of softness despite the strong distortion correction, and the center is quite sharp (though with noticeable sharpening halos). However at full telephoto, corners are fairly soft wide open though softness doesn't extended very far into the frame. The center appears not to be quite as sharp as at full wide angle, but be aware that our telephoto target for long zooms is a scaled version of our standard target used at shorter focal lengths, which makes absolute resolution difficult to compare. (It's meant mostly to compare sharpness across the same frame.)

Vignetting. There's hardly any vignetting (corner shading) in JPEGs at wide angle, and fairly minor corner shading at full telephoto.

Stopped Down: Stopping down three clicks to f/4 didn't improve sharpness in the corners at wide angle, and actually made the center slightly softer due to diffraction, though sharpness was still quite good and contrast improved slightly. It's a similar story at full telephoto, with improved contrast but no appreciable improvement in sharpness, and stopping down any further will likely have a detrimental effect due to stronger diffraction with such a small sensor. CA did however improve slightly at both ends, and corner shading was eliminated at full telephoto.

Digital Lens Corrections

Like most digital cameras these days, the Panasonic FZ300 applies plenty of "digital optical corrections" to its images. See below for uncorrected images at wide angle and telephoto.

Geometric Distortion

To see how much correction is taking place in the camera, we converted RAW files from the above shots with dcraw, which does not correct for distortion. As you can see at maximum wide angle, barrel distortion is very high, at about 3%, while full telephoto exhibits about 0.5% of barrel distortion instead of the slight pincushion seen in JPEGs.

This is not unusual, though. We expect to see significant distortion in uncorrected RAW files in fast, compact lenses allowing lens designers greater flexibility in optimizing center sharpness and other aberrations, as well as in reducing cost, size, and weight. The downside is that the distortion correction contributes additional blurring to the corners of the frame where pixels are "stretched" during correction. And in the case of the FZ300, the image circle does not even cover the entire sensor at wide angle, which means there's quite a bit of interpolation going on, not just in the extreme corners. Note that most RAW converters are capable of applying distortion correction automatically, as specified by the manufacturer in an embedded lens profile.

Chromatic Aberration Correction

As you can see in the crops from uncorrected RAW images on the right (again, taken from RW2 files converted with dcraw), the FZ300's lens produces moderately high and bright lateral chromatic aberration at both maximum wide angle and full telephoto. But the FZ300's processor does a great job suppressing CA in camera JPEGs (crops on the left). Note that most RAW converters should also automatically suppress CA when converting the FZ300's RW2 files.

Vignetting

Mouse over the aperture links to compare corner shading in uncorrected RAW files. We calculate there is about 0.5 EV of corner shading at wide angle and at telephoto when wide open in uncorrected RW2 files. (Keep in mind the corners in the final image at wide angle aren't nearly as close to the edge of the image circle as at telephoto because of the lower sensor coverage.) When stopped down to f/4, corner shading at wide angle was reduced to less than 1/4 EV (at the corners of the final image), and at full telephoto shading dropped to negligible.

Overall, pretty good performance from the FZ300's lens when considering its zoom ratio and how fast (bright) it is.

Coverage
Very good accuracy from the LCD monitor and electronic viewfinder.

The Panasonic FZ300's LCD monitor and EVF both provide about 100% coverage at wide angle, and close to 101% coverage at full telephoto (a bit tight). This is very good performance, especially considering the amount of geometric distortion correction taking place at wide angle.