Panasonic FZ1000 Lens Evaluation

FZ1000 at E400mm, hand held. 1/1000 sec f5, ISO 125.  I included this photo to show that even at it's "worst" focal length the FZ1000 lens still does a very good job. The boats in the foreground are about 500 meters from the camera, the trees in the background about 1000 meters. I have printed this photo at 600x400mm size, 360 dpi on an Epson 4880. It presents very well in print with no apparent grain and very good definition of fine details.

 

This post is part of my ongoing evaluation of the FZ1000. In due course I hope to discover whether the FZ1000 can replace my interchangeable lens camera (currently a Panasonic GH4) and a bag of  lenses.

In the previouspost I looked at ISO range picture quality. Now it is time to investigate lens quality.

Method   I went about this in two ways. The first was to go forth into the world and make hundreds of photos at all focal lengths and apertures using many different types of subject material. Most of these pictures were hand held. 

The second was to photograph my standard test chart on tripod with timer delay, focus confirmation with MF and peaking. This chart is a repeating set of classified newspaper adverts affixed to a board. It does not give any kind of absolute reading but is very useful for comparisons. In this case I used a Panasonic GH4 with 12-35mm, 35-100mm and 100-300mm zoom lenses for comparison. These are three of the best zooms in Panasonic's lineup. I have used them extensively and know they deliver high quality pictures.

To assess resolution/sharpness, I  compared  pairs of frames matched for E-Focal Length and Aperture on screen at 100% in Photoshop. 

Focal length range  I will use "Full Frame Equivalent" (E)  focal lengths throughout this post. The FZ1000 refers to it's own lens focal lengths in this way by inscription on the lens barrel and by display  in the EVF or monitor.

The FZ1000 has a focal length range of E25-400mm.  This covers most of the combined range of the comparison lenses which is E24-600mm.

Pricing and dimensions  The Australian retail cost of the  GH4 + 3 lens kit is around $4600. At the time of writing the FZ1000 is selling for about $1150.

The FZ1000 weighs 865 grams and fits easily into a Lowe Pro Apex 110 AW bag with space for two spare batteries, SD cards and microfiber cloth.

The three lens kit weighs 1965 grams and requires a much larger bag such as a Lowe Pro Nova 180 AW.

Expectations  I think it reasonable that one would expect the high grade three lens kit to easily best the FZ1000 at all focal lengths. My findings indicate a more complex comparison with a  closer result than I had originally expected.

Results

Sharpness/resolution   Best lens indicated.  Test aperture indicated. Approximate optimum aperture for the FZ1000  indicated in brackets.

Wide angle, E25mm  f2.8.  [f4]
            Center: FZ1000

Edges: Equal

Corners: 12-35mm

Comment: Any lens which can match the 12-35mm over most of the frame is doing very well. A very good result.  

Short Mid range, E70  f3.5   [f4]

Center: FZ1000

Edges: 12-35mm

Corners:12-35mm

Comment:  Another good result from the FZ1000. The 12-35mm is really excellent at this focal length and the FZ1000 is close.

Mid Mid Range, E 170mm  f4   [f4]

Center: FZ1000

Edges: FZ1000

Corners: FZ1000

Comment: The comparison lens at this focal length was the 35-100mm which is a very fine performer. Both lenses delivered an outstanding result at this focal length but the FZ1000 was just slightly ahead.  Remarkable for a superzoom.

Long Mid Range, E230mm  f4  [f4]

Comment: The comparison lens was the 100-300mm which I know from experience delivers very fine results at this focal length. Both the FZ1000 and the 100-300mm gave an outstanding result and both were equal across the frame.

Maximum focal length for the FZ1000, E 400mm  f5.0   [f5]

Center: Equal

Edges: 100-300mm

Corners: 100-300mm

Comment: The FZ1000 lens is suffering a bit from loss of contrast right across the frame at this focal length. There is also some loss of resolution towards the edges. The overall result is still good however as shown by the photograph at the top of this post. Careful technique and a bit of help from Adobe Photoshop Camera Raw can produce very satisfactory prints.

Super tele, E600mm  f5.6  [f5.6]

For this I used the 100-300mm at it's longest optical focal length and the FZ1000 on iZoom (JPG) at E600.

Comment: As expected, the 100-300 was clearly and substantially superior, center, edges and corners. Unlike all the other focal lengths where there was a surprisingly even contest between the two kits, this focal length saw a no contest with the 100-300 well ahead. Bird photographers note.

Corner shading  Was not much of an issue with either kit, I assume it is corrected in the camera software.

Chromatic aberration and Purple fringing   was quite noticeable from the FZ100 especially in the corners at the wide end.  Both are correctable in Photoshop Camera Raw or Lightroom.

Distortion  is being corrected in camera software in both cases, with the FZ1000 applying almost complete correction.

Flare, sun  All lenses can exhibit various streaks, spots and veiling when exposed to the sun in frame or just out of frame. All four lenses in this test were so affected. However I made many photos with the FZ1000 pointed directly at the sun with no ill effects. Flare is very well controlled in the FZ1000.

Flare, local  The FZ1000 showed a sometimes obvious tendency to flare out a halo around very bright subject elements such as white boats in direct sun. The 12-35mm can also do this.

Contrast/microcontrast  You would expect the GH4 lenses to have higher local contrast than the more complex lens on the FZ1000, and they do. The FZ1000 loses contrast toward the long end.  This can make AF more difficult with low contrast subjects and requires extra  sharpening in Photoshop Camera Raw, plus often a bit of Clarity increase.

Bokeh  Out of focus rendition from the FZ1000 is very smooth in the great majority of photos which I have made. There is an occasional minor tendency to nisen (double line) bokeh with branches, twigs and the like but this is not common.

Mechanical Function 

Zoom type  One would expect a lens like this to be varifocal which means it has to be refocussed after zooming.  A parfocal lens stays in focus while zooming.  Using manual focus I found that if I focus on a subject at the wide end then zoom in the image goes out of focus. But if I focus at the long end then zoom out the image appears to stay in focus. Hmm...  It's a varifocal.

Image Stabiliser  The stabiliser in the FZ1000 is much more effective than that in any of the Panasonic M43 lenses which I have used.  I will report on this separately.  Fair warning though, OIS does nothing to counter subject movement.

Zoom   For those of us accustomed to manual zooming, the FZ1000 power zoom comes as a bit of a surprise. However it works well in practice, with practice. The trick is to understand that the zoom ring is just an actuator for the zoom motor. Gentle but constant turning pressure on the ring allows full zoom from wide to long in about 3 seconds. Twisting the ring faster/harder is counterproductive.

Manual focus  This uses the same ring as zoom after setting the control lever to "Focus". Focus is motorised. With practice MF works well and is accurate, assisted by peaking which is well implemented in this camera. However like zooming, Manual focussing requires practice and familiarity with the behaviour of the actuator ring. This can be a bit disconcerting at first as the position of the ring is not directly related to the focus movement of the lens elements.

Decentering  I cannot remember buying a zoom lens in recent times without some small or larger degree of decentering. This occurs when the lens elements are not located in the optical pathway in exactly the correct position to very fine tolerances.  My copy of the FZ1000 is a bit soft on the right side at mid zoom and a bit soft on the left side at full zoom. Closing the aperture one stop minimises the problem.

Summary  The FZ1000 lens has performed well above my initial expectations.  It  is capable of making highly detailed photos across the focal length range.

For all focal lengths except E400mm and E600mm it performs at a level comparable to the three comparison M43 zooms, especially in a large central area of the frame where most critical subject information is located.

I am investigating strategies for optimising sharpness/resolution at E400 and E600 and will report on these in an upcoming post.