Panasonic FZ1000 vs GH4 with 14-140mm f/3.5-5.6 (5): winners and losers

Panasonic GH4 covers most of my needs but on top of that offers plenty of features I will never use, so effectively there is about 60-70% overlap. FZ1000 specifications sugested that this overlap could be increased (simply speaking I would have better use of what it offers), making it more sensible choice, provided it meets baseline in departments that need to be tested in field: image quality beight the most important factor. On top of that there is financial aspect: at about half of the price of compared body+lens combination, with plenty of GH4 value being wasted (not to mention its bigger depreciation), the hybrid had a great potential for exceptional value for money.

I compared the most important (for me) aspects of both sets: handling, controls, image quality and video capabilities. Since both cameras share many ideas (and I believe also many components), that made the contest easier to jusge and more fair as well. Because of my personal approach, this cannot be treated as independent review, but I include as much data obtained as possible to be analysed independently.

Quick recap before summary:

Handling
Heavy lens of FZ1000 forced Panasonic designers to adapt body shape and the result is excellent. I wish that could be used for future G/GH series cameras. Number and location of controls is good good on both cameras. Not very good, as there are little niggles, but not something that is a show stopper though.

Controls
GH4 wins with more direct buttons (especially focus point position), and touch screen. Menus are virtually identical and perfect for advance user, but in my opinion lacking a bit for professional (in case of GH4)

Image quality
Combination of lens and sensor of FZ1000 won in all the tests. The difference ususally wasn't huge, but definitely noticable. FZ1000 is more flexible due to 16x zoom range, both are poor in close-ups, with slight edge of hybrid again.

Video
GH4 rules, but only in proper setup. Handheld, with 14-140mm lens, apart from more potential for better output (settings), it doesn't rise above FZ1000. The latter on the other hand suffers from heavy cropping in 4K mode, but HD is great thanks to full sensor readout.

WINNERS

Panasonic FZ1000
Quite surprisingly it exceeded my expectations (=you get what you pay for) in all tests, for my use being better all-around camera than GH4 with 14-140 mm lens. Keeper!

Panasonic GH4
Since FZ1000 confirmed 90% of value for 50% of price, the opposite must be true: 10% of extra for twice the price. And indeed that is the reality: in chase of perfection, returns on investments are diminishing. This camera body offers many features that can be deal-breaker (lens mount, with large family of native and adapted lenses), dust&splash resistance (with proper lens), video (settings and external outputs) as well as many other, that combined show where the money goes: display (with touch control and colour calibration), EVF (very good optics, colour calibration), better battery life etc.

Panasonic 14-140mm f/3.5-5.6
That is a small, light and flexible lens, very good for stills, makes very good all-round combo with Panasonic MFT bodies.

LOSERS

GH4 with 14-140 mm lens
The lens is not bad, but got beaten by Leica branded optics of FZ1000, dragging GH4 behind. Especially for videos it offers all the opposites to what one would expect: average stabilisation, poor zoom control, terrible autofocus when zooming. I wonder why that is the only GH4 kit option in the UK. Also current GH4 body price means that next season value for money of this setup is going to be much better.

Panasonic FZ1000 vs GH4 with 14-140mm f/3.5-5.6 (4): movies

Disclaimer - I'm not a videographer, so far I mostly used movies for documentaries with tripod, fixed focus and relatively slowly moving subject. Tests I performed reflect mostly that approach.

Image quality 
The matter is simplified by the fact FZ1000 has got pretty much only two modes: 4Kp25@100Mpbs and 1080p50@28Mbps. GH4 matches at 4K, but 28Mbps is where it starts off with bitrates for HD.

In 4K (3840x2160) mode both cameras use crop of their sensors: in case of GH4 it results in extra 1.2 factor magnification (horizontal, 1.15 diagonal), but for FZ1000 it ends up in initial focal length becoming very moderate 37mm, not wide angle 25mm! To some extend it is compensated by proportional gain at longer end, but it is not the setting for most of the scenes...


Since sensor resolution is capped at the same level, it is only down to the lens and here again FZ1000 shows slight edge, additionally helped by the fact of using mostly the central part of the lens.

In HD mode the story is different: both cameras offer full sensor readout with binning/downsampling to achieve final frame size. But result is the same: sharper lens and more pixels to start with, FZ1000 comes slightly ahead of GH4 in acuity department. In both cases downsampled 4K shows slight advantage, so even this full sensor readout method is a bit lossy - still way above traditional line skipping though. Mind that I compare static scene - when dealing with movement, available higher bitrates of GH4 will benefit that camera. But what really makes it a winner, not only against FZ1000, is the amount of in-camera pre-grading controls. Remember, the output is 8-bit only, so any shifts outside of that range will end up as clipping - additional dynamic range together with master pedestal adjustment will help to squeeze as much of useful image information as possible. In skilled hands of course - if red button is enough to make footage, that won't matter much...

Google gallery limits long end to 2048px so 4K frames were squashed, click below to download files:
FZ1000 4k25p 100Mbps
FZ1000 HD50p 28Mbps
GH4 4K25p 100Mbps
GH4 HD50p 100Mbps
GH4 HD50p 200Mbps
GH4 HD50p 28Mbps
GH4 HD50p 50Mbps

Focus
There are reports that GH4 struggles with autofocus at 4K (due to lower sensor readout rate) more than in 50p HD and I would expect the same to apply to FZ1000. When slowly panning, that wasn't very noticeable though - again, more dynamic tests would be needed. Regardless racking speed, it seemed gradual in both cases and only when pressing shutter button, (I use that for start/stop of movie capture) AF kicked in and showed hunting.

 GH4 4K

 FZ1000 4K

GH4 HD

 FZ1000 HD normal zoom speed

 FZ1000 HD slow zoom speed

Zooming
FZ1000 is equipped with power zoom lens. It is very noisy, and although it seems to be suppressed when recording, still is audible. The zooming action happens at exactly the same speed as for stills: 2.4s to cover the whole 25-600 range at fast speed, 6 s at slow speed, which results in very rapid image angle change, with AF not catching up. Disappointment. Also the slower speed makes for more audible (lower frequency) noise being recorded
14-140 mm lens zooming is jerky, but even when going through a smoother range, focus changes in big jumps. It is a bit strange, as when manually focusing the effect seem to be fluid (even if the mechanism is based on stepper motors, the steps aren't noticeable). Useless.
Nobody would expect those lenses to be parfocal, but they could definitely behave better.

Stabilisation
Like for stills, so this time Power O.I.S on FZ1000 produces better result than its equivalent on 14-140mm lens, but I wouldn't say the outcome was completely shake free. FZ1000 offers additional digital stabilisation and levelling, but only in HD mode and that additionally crops the output.

Read next: Panasonic FZ1000 vs GH4 with 14-140mm f/3.5-5.6 (5): winners and losers

Panasonic FZ1000 vs GH4 with 14-140mm f/3.5-5.6 (3): image quality compared

Based on specs I deduced that FZ1000 can have slight edge over GH4 paired with 14-140 mm f/3.5-5.6 lens thanks to BSI sensor, downsampling effect and faster lens. What really matters though was of course whether the Leica glass could be comparable to Panasonic's own 14-140mm lens.

Here are charts comparing lenses' light gathering ability and achievable depth of field (equivalent of full frame aperture setting) as a function of focal length.

In light gathering ability at all focal lenghth FZ1000's lens is constantly nearly 1 stop brighter. At the same time depth of field produced by those lenses wide open is going to be also nearly identical. Mind that FZ1000 lens stops down to f/8 only.

Test procedure
Camera on tripod, IS off, 10s self-timer, base ISO (125 on FZ1000, 200 on GH4), mechanical shutter, aperture priority, the same horizontal angle of view, the same focus point (AF single, spot focus), raw image developed in LR 5.6 with default settings (all sliders at 0, sharpening 25), exported to Jpeg at 90% quality, sharpening to screen - normal, resized to 4608px on long edge (to downsample FZ1000). Crops for side-by-side comparison edited in IrfanView and saved as Jpeg at 90% (different percents than LR) quality. I have no intention nor tools to produce absolute numbers, just naked eye to subjectively judge which of a pair of images looks sharper.

First of all, due to already mentioned different aspect ratios, at given focal length 3:2 frame gives larger horizontal angle of view. In all the tests I tried to frame with the same left-to-right range and the difference of focal length is about 10% (eg 28mm (in 35mm equivalent) on GH4 required 31mm on FZ1000). That way FZ1000 also gains the most, so it is worth to bear in mind.

FZ1000 starts very wide, at 25mm, offering more than 14-140mm lens achieves. It struggles a bit at that setting, with increased chromatic aberrations and slight drop of sharpness (likely result of under-the-bonnet compensation for distortion)


Sharpness

In all side-by-side comparisons GH4 with 14-140mm is on the left, FZ1000 on the right 

Centre - far focus

Left - close focus

Right - medium focus

For wide angle I checked left hand side at about 10m distance, right hand side at about 20m and centre at about 50m (focus points marked on scene images). The reason was my typical (landscape like) use of camera. Note that FZ1000 at this setting is already at f/3, only 1/3 stop from 14-140mm initial f/3.5. At all aperture settings Leica glass is sharper, with 14-140 showing visible purple fringing wide open - exactly what affected FZ1000 at its widest. Also when comparing results at 1 stop difference, MFT combo loses.

Next test was in the middle of 14-140 range, at its (native) 50mm setting. Curiously Exif reports 92mm equivalent, but FZ1000 reporting 110mm equivalent shows to the same scene borders (I was worried unfair gain due to magnification, but later aperture vs focal length test showed GH4 reports 'bands' rather than actual values). I also set aperture accidentally at f6.3 rather than f5.6 in one case, but here differences between the lenses are even more obvious, so that did not give any advantage.

End of range of 14-140 mm lens is definitely its weakest. Here however FZ1000 at f/4 shows also big loss from its result when stopped down to f/5.6.

FZ1000 can stretch further, to 400mm equivalent focal length, but I downsampled the result and compared with crop from image taken at 300mm, and although I could see the difference, it was very tiny. So this lens also at tele end offers more on paper than there is of actual gain.

All the images are available for pixel peeping: developed from raw with default settings (WB as shot, Sherpening amount 25/ raduis 1.0) in LR5.6, exported to jpeg 90% quality, sharpened for screen standard and resized to 4608px horizontal (do downsample FZ1000 results) 

Stabilisation
I compared by shooting burst series handheld. FZ1000 seems to have produced more sharp results. I'm actually impressed that at 300mm 1/25s handheld I could pick a couple of identically sharp photos from a burst series.

Noise
I shot the same scene with FZ1000 at ISO400 and GH4 at ISO800, to test the idea that 1 stop extra of aperture can compensate (or even still keep ahead) FZ1000 shortcoming. I like FZ1000 result more, it seems of lower amplitude and proves gain from downsampling resulting in finer grain. To be honest even with both at ISO800 I could still call a draw, because increased noise amplitude of 1" sensor is partially covered by its finer structure. Note: the images were underexposed and pulled up 2 stops, so the absolute noise amount is closer to ISO1600 and ISO3200 respectively - those cameras aren't that noisy at moderate settings!

Although shot for noise, picture of FZ1000 is noticeably soft (spot focus on the vase in both cases), so I started suspect its lens may be optimised for far distance and struggle with closeups. I did a quick check in room conditions and results at wide again indicate 14-140 to be the loser, but this time it also lost at flower test. I think shiny vase is not great focusing target then...

From the left: FZ1000@ 25mm (equiv), FZ1000@ 45mm , 14-140 mm @ 280mm (E)

All crops from landscape.

Macro
FZ1000 is equipped in 'Macro AF' mode. However the way it works allows one to focus as close as 2cm from the lens front at wide angle, but with increasing focal the minimal focusing distance increases even more! That behaviour makes photographing the very close subject pretty much impossible, as there is risk of shadowing as well as scaring (live) subject away, distortion introduced by wide perspective aside. 14-140mm lens is no macro lens neither and produces the biggest magnification at its long end. Here perspective can also get distorted, on top of that lack of sharpness, small aperture and sensitivity to vibration play their roles. In such contest FZ1000 wins at its 45mm setting, where it produces the bigger magnification as frame fill factor and in absolute terms (2950 px height of the model used)

Focusing
With sunlight and in a room at daylight both cameras focused identically - instantly. Unfortunately I did not have chance to carry out any sensible test of continuous AF or tracking capabilities.
In manual focusing mode both cameras offer helpful focus peaking and image magnification, and here one of little differences show again: FZ1000 magnifies up to 6x, GH4 up to 10x.

Read next:  Panasonic FZ1000 vs GH4 with 14-140mm f/3.5-5.6 (4): movies

Panasonic FZ1000 vs GH4 with 14-140mm f/3.5-5.6 (2): ergonomics

 The box arrived, time to put FZ1000 to the test against GH4 with 14-140 mm lens.

Body and handling

With matte surface finish, sharper edges of the top plate and massive lens barrel FZ1000 looks like the boss of the pack. Inclusion of the large lens has some consequences. Firstly, the camera is more unbalanced to the front and to the left. Cleverly, hand grip was sculptured accordingly: it is deeper (64mm vs 60mm on GH4), but with narrower ridge to increase space between fingers and the lens barrel. That makes the hand to claw slightly more, and the security of the grip is further improved by slightly bigger protrusion of the step at the fingertips. Secondly, tripod socket is offset from the axis. That is of course inconvenient for panoramas, but very bad for access to battery and card compartment – with most tripod plates it will be impossible without removing a plate first.

The rear part of the grip is in my opinion improvement over GH4: more pronounced ridge is further away from all the controls – I can see no chance of accidental pressing right D-pad button (moves focus point on GH4), and at the same time ‘Disp’ button is much easier to operate (required to reset focus point on GH4, to add to annoyance).

The dial is gorgeous. It is wider, with deep, square profiled knurling - it actually beats those of GH4. With its push-action toggling between main exposure parameter and exposure compensation, that makes it absolutely equal alternative to dual dial setup. The only improvement I can see is to reduce angle between clicks to allow for more adjustment during one move, or add some intelligence and when fast movement detected, to change full stops rather than thirds.

The 4-way control on FZ1000 is not obstructed by the grip, but the biggest improvement against GH4 are the buttons: they are bigger, with better tactile feedback, image review button of different shape (concave top) to easily differentiate from the other two. My only wish would be to swap (or allow to redefine) review and Fn3 (Quick Menu by default, used more extensively on FZ1000 due to fewer direct controls) buttons, so Q.Menu operations, engaging 4 way controller, could be quicker by cutting the travel from the button.

My biggest worry - focus point selection - is gone: I programmed Fn4 button (delete/return by default, kudos to Panasonic for using this button at all in the record mode) to invoke that option and it is actually even better idea than using one of the positions on the pad itself (like on some other cameras): no confusion whether pressing pad activates function or already moves the position, especially on ‘mushy’ buttons. If necessary, 4-way controller can be used for direct focus point selection.

Dial mode on GH4 is taller, more metal and has got lock, but for me neither of those make a difference. ‘C3’ position present on GH4 becomes ‘Scene’ mode on FZ1000: another hint of who are the two models intended for, and clever way of differentiating product lines and still sharing guts.

Strap eyelet on the FZ1000 is a letdown, being very close to the index finger – on GH4 it is moved further back, which is better position.

Display

Both cameras have display of practically the same size (FZ1000 62x41mm LCD 921K dots, GH4 63x42mm OLED 1036K dots - this one feels bigger, being flush with the frame), but it actually makes a difference: on FZ1000 it matches sensor ratio so the full area is used, on GH4 there are vertical bars at native 4:3 aspect for stills.

Touch control is a nice addition on GH4 with Panasonic excellent touch-control friendly approach. Apart from useful ability to select focus point/trigger the shutter, it includes 5 extra Fn buttons. In its creative movie mode it adds even more controls and also lets to touch-focus even in manual focus mode. For button-challenged there is tapping, swiping and pinching (where applicable) provided.

The display of FZ1000 is more accessible, with large recess to open it, and feels more robust as it’s got bottom edge covered by the body and display surrounded by a bezel.

EVF

Both use the same OLED 2.359 K dots panel, but optics on GH4 is much better: I can see the whole area sharp, whereas on FZ1000 there is smearing in the corners with eye centered in the finder, and when off-axis, this affects the actual preview. Also on GH4 the eyecup can be replaced

Flash

On GH4 there is a flush fiddly button, FZ1000 is equipped with much more pronounced lever. In both cases hood shadow is present until about 55mm (equivalent), there is no shadowing with hood removed at any focal length.

Lens operation

There are 2 switches on the side of FZ1000 barrel: Power O.I.S on/off and zoom/focus action of the ring. I prefer zooming with the lever, especially that it provides 2 speeds, whereas the ring seems to operate only proportionally to the rotation angle (about 160 degrees for full range) and it keeps being activated every time it is accidentally touched by the hand holding the lens (and the best support is right on the ring). The ring rotates smoothly with soft stops at the end of range. In the focus position the focusing itself will work when manual focusing (MF or AF+MF) is enabled. The lens retracts with quite audible whirr, internal mechanism* is also louder than on 14-140 lens (* initially I thought it was stabilisation, but it is audible with IS off. Then I switched AF off but it did not make the lens quiet neither. Both lenses exhibit that, just on FZ it is noticeable). Movie tests will show how it affects recording. 14-140mm lens have only Power O.I.S switch, but 2 rings: wider for zooming, with 90 degrees rotation to cover the whole range, and narrow focus-by-wire ring at the front. Focus ring moves smoothly with soft end stops, lens extension is a bit jerky (steep helicoid I suspect) – it doesn’t matter when framing for stills, but it is terrible if attempted to use during movie.

Battery

BLC12E of FZ1000 rated at 1200mAh (8.7Wh), BLF19E of GH4 at 1860mAh (14Wh). Apart from obvious difference in capacity, FZ1000 consumes more by driving the lens. I started a test, but I quickly got bored of turning on/off, zooming and pressing shutter button, so no results. Guesstimate gives FZ1000 half to 2/3rd life of GH4 on a battery. BLC12E full charging takes 2 hours, BLF19E - 3 hours, so it looks like they are charged with the same current.

Burst

It is one of more important features for me, because my subjects include 5 year old boy (‘action’ photography, spray-and-pray proves to be the best option) as well as trains, which often happen to be obstructed by trees and other objects and the best location in the frame depends on perfect timing or high sampling rate. Modern cameras seem to get better in that respect, however marketing is happy to quote just one number (rounded up, with compulsory ‘up to’ prefix), whereas the reality is a bit more complex. This summary should be self-explanatory though:

GH4 + 14-140mm wide open 7fps (M) AFS	41/6.9s = 5.9 fps, then every 1.1s
GH4 + 14-140mm stopped to f/8 7fps (M)  AFS	42/7.9s = 5.3 fps, then every 0.95s
GH4 + 14-140mm wide open 12fps (H) AFS	35/3.6s = 9.7 fps, then every 0.7s, then 0.9s
GH4 + 14-140mm stopped to f/8 12fps (H) AFS	41/6.3s = 6.5 fps, then every 0.9s
FZ1000 wide open 7fps (M) AFS	6/0.8s (7.5 fps), 0.4 pause, 7/1.2s (5.8 fps), then every 1.8s
FZ1000 stopped to f/8 7fps (M)  AFS	13/2.5s (5.2 fps) then every 1.8s
FZ1000 wide open 12fps (H) AFS	12/1s (12 fps) then every 1.4s
FZ1000 stopped to f/8 12fps (H) AFS	12/1.4s (8.5 fps) then every 1.3s

(click on the link in the table to hear the burst series)

For the test I set my standard JPEG+RAW mode, if you save only one of those file types, expect some improvement. In both cases single autofocus, IS off, base ISO, super-duper fast card. In such conditions the results are about the best one can expect. GH4 is of course the king of the buffer, with about 40 deep bucket of photos. Speed-wise at M setting it is nearly there. At H it is just shy of 10fps, but when stopped down, lens aperture adjustment is the limiting factor. It is a bit curious, as focus and exposure are locked, so the aperture could stay constant, but clearly that is not the case. So if speed is what you need, open wide (that makes sense too) and you have a machine gun. Otherwise, settling at M doesn’t cap the speed much, and you gain live preview (frozen on first frame in H mode).

FZ1000 behaves a bit strangely: leaf shutter, acting as aperture at the same time, should not affect at all – but there is significant repetition rate reduction coinciding with aperture value. Then there is a gap (that is repetitive behaviour) at M wide open. Also card writes get faster at H, I’d expect the same write time from the moment the buffer is full. The buffer holds advertised 12 images, which at H wide open lasts for exactly 1s. I think realistically that is enough for a burst shooting – 4 times that, offered by GH4, is more important when there are consecutive series needed, so the top speed is maintained without need to wait for write to the card. FZ1000’s 12fps is very respectable figure, and even after stopping down it beats GH4. All that at bigger files size!

Read next: Panasonic FZ1000 vs GH4 with 14-140mm f/3.5-5.6 (3): image quality compared

Panasonic FZ1000 vs GH4 with 14-140mm f/3.5-5.6 (1): 90% of value for 50% of price?

Panasonic GH4 is a fantastic camera: on one hand it is based on long refined concept (4^th generation after all), with operation pretty much unchanged from its predecessor. On the other, it stirred the industry by introducing two breakthrough technologies: DfD (Depth-from-Defocus) AF system and 4K video internally recorded with very good codec. All this at a price point matching prosumer cameras of other manufacturers. In my case it got paired with the new 14-140mm lens, making very flexible and comfortable all-around combo.

However, recently another bomb dropped: FZ1000. With even larger range of focal length of its brighter built-in lens, the same DfD focusing, the same 4K capabilities, similar body shape and only half the asking price it felt as reasonable contender.

Why the contest? Since I’m an amateur photographer, I base my choices on value-for-money, provided image quality is at  acceptable level and there are no disqualifying handling and control issues. All that is obviously subjective, but I’ll be explaining my weighting factors. Anyway, based on paper specs, it looked like FZ1000 can provide 90% of GH4 capabilities at 50% price. I already learnt hard though, that many things can only be verified hands-on. A bit surprisingly, apart from excellent series by Andrew Smallman , I could not find any decent comparison of those two setups. Fate brought a well priced second hand FZ1000 in front of my eyes, and I pulled the plunge…

So there we go, waiting for the postman I start with spec-to-spec comparison, in part two I will verify how those assumptions meet reality.

1.     Body and handling

Both cameras are similarly shaped, with sensible ergonomics based on large hand grip and electronic viewfinder hump.

	FZ1000	GH4
Weight (with battery, card and lens hood)	856 g	844 g
Depth (transport:hood reversed, lens retracted, cap on)	134 mm	136 mm
Depth (hood on – wide angle)	193 mm	173 mm
Depth (hood on – telephoto)	232 mm	218 mm
width	135 mm	130 mm (135 with eyelets)
height	98 mm (103 with hood)	90 mm (93 with hood)

Menu system is based on the same scheme. Adapted for touch control it is very legible, but laborious to scroll through. Customisation capability (especially valid for GH4, competing for the top spot with Olympus E-M1) of the cameras is moderate.

Control layout is very similar too, although there are clear differences in absolute number of buttons (accessibility of main control parameters, direct vs indirect focus point control) based on price point and intended user group. Both cameras feature swivel display of the same proportion and size, but only GH4 offers touch control.

About the only feature FZ1000 gains that GH4 does not have is a zoom lever around shutter button. There is number of nearly equivalent solutions, however differing in implementation (due to construction):

• Dual dial setup of GH4 is replaced with push-dial known from G series. I like the idea, but execution of the latter was always poor, so look forward to see if there was improvement in that department
• Zoom/focus switch on the lens. If implemented properly (variable adjustment speed depending on the mode), it can be more valuable than focus-by-wire of 14-140 and most other MFT lenses
• Leaf shutter: fixed lens and smaller image circle allowed for the quieter and faster solution. Especially the latter is very important when taking photos in bright conditions with fill flash.
• Buffer depth reduced from 40 frames to 10

The most important loss of FZ1000 is lack of buttons to directly adjust major parameters: ISO, exposure compensation, and white balance, present on the top plate of GH4. That forces to use 4-way controller to take over these functions, losing direct focus point selection as a result. Of course that slows down speed of camera operations (that’s one of the reasons for the premium price of GH4), but on the other hand this can make the camera less intimidating for users that only occasionally drift out of Auto mode. The pad itself offers buttons action only, but dial capability of GH4 are pretty much limited to the same due to shape of the rear part of the hand grip. GH4 also offers 1 more position of custom settings on the mode dial.
Crucially though, FZ1000 keeps both focus mode lever with AE/AF lock button as well as drive mode dial.

The difference is the lack of touch control of the swivel screen of FZ1000: even though I am not a big fan of smearing the display, features like soft Fn buttons or other predefined controls, as well as ability to select focus point (especially when button selection is restricted) or to trigger the shutter by pointing the subject in some situations may be valuable. Again, that was the choice Panasonic accountants made to undercut Sony RX10, and something potential buyers need to judge based on their use preferences.

GH4 body is sealed to make it ‘dust and splashproof’, there is no rating for FZ1000.

Functionality for the stills is identical, including focus peaking, zebras, highlight/shadow curve etc.

Functionality for the movies on the other hand differs: the headline UHD 4K is the same (but no Cinema 4K), and all the high bitrate HD modes are axed. Also CinelikeD and CinelikeV curves are present, but gone are all the features that make GH4 so valuable for advanced videography: master pedestal, syncro scan, variable frame rate etc. Oh, and the headphone socket for sound control is gone too. That pretty much defines the audience for the hybrid camera, although lack of lens mount will be the fact putting off many movie makers in the first place. For occasional footage and try out of 4K (or recently added 4K-photo modes) options given should be plenty enough.

2.      Image quality

The main reason for the contest is theoretical very similar image quality. I’ll show some numbers to explain why it makes both setups to be in the same league.
The comparison is based on the assumption (valid for my usual subjects) of identical shutter speed - in that case exposure is defined by combination of aperture and ISO numbers. So GH4 would work with more moderate aperture of 14-140 mm lens, but bigger sensor lets it get away with higher ISO. FZ1000 would loose on quality because of noise produced by its smaller sensor, but makes up by offering brighter lens.

Panasonic GH4 is equipped with 17.3 x 13 mm 4632x3472 (4/3” 16Mpix) sensor, FZ1000 with 13.2 x 8.8 mm 5488 x 3644 (1” 20Mpix).

Comparing colour depth and dynamic range is simple and GH4 wins by about 1 stop each.

Noise quality of the image is a bit more complicated matter though. The obvious conclusion is GH4's twice bigger sensor area have twice bigger light gathering capability, however FZ1000 chip is based on BSI (back side illumination) structure. As a result its low light noise level is reached not at twice the gain (ISO value), but at around ISO800 for GH4 and around ISO500 for FZ1000 (the numbers were averaged with other cameras using the same sensors  - E-M1 if the first case, RX100III and RX10 in the second and rounded  - which is OK for approximation purpose). Assuming linear noise characteristics (valid in pretty wide band of exposure), that can be translated into proportional amount of noise at identical ISO setting. So the first coefficient would be 800/500=1.6

TZ1000 sensel count is bigger: 20Mpix vs 16Mpix, which would yield downsampling advantage of 25% (coefficient of 0.8 when based on GH4). Before I stick to this value, there is one important factor to take into account: sensor format. GH4 aspect ratio is 4:3, TZ1000 is 3:2. Both have pros and cons in general and I’ll come back to them, but at this stage it needs to be addressed, that for fair comparison crops of identical aspect ratios should be analysed, not the total count. So, 4:3 crop of 20Mpix reduces effective number to 17.6 Mpix (only 10% more or 0.9 ratio), but 3:2 crop of 16Mpix drops the number to 14.3Mpix and pulls the ratio down to 0.72. Picking the right value (or average based weighting factors derived from proportion of images taken at specific ratios) seems to be a bit fuzzy, so I will stick to the initial result as simple, round, and being average of the other cases.

At that stage GH4 lead reduced to only 30%, and we have still the last factor to compare: lens brightness. FZ1000 is equipped with lens of aperture ranging from f/2.8 at wide angle to f/4 at narrow. The test setup for GH4 contains lens of aperture ranging from f/3.5 to f/5.6. That means, at wide angle, the sensor of the former will receive proportionally from 56% (2/3 stops, translates to coefficient of 0.64) to 100% (1 stop = 0.5 ratio ) more light. Keeping exposure parameters the same and reducing image brightness proportionally at processing will suppress the noise of TZ1000 (ETTR approach) or it will let reduce gain (and noise) proportionally at the moment of exposure. Thus, especially at the long end, it is now the hybrid leading by up to 30%! That result is more likely to be true in the centre of the image, further away vignetting will play its role. What’s more, achievable depth of field at full aperture will be comparable.

Anyway, combination of excellent sensor together with bright lens might push GH4 with 14-140mm lens out of it leader spot.

There is no simple way to judge image sharpness (resolution and contrast) nor other factors (distortion, aberrations) other than take pictures. Looking forward to the real battle!

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