I hope you found the tests useful and I guess the key question is:

Is the GH5S still worth it in 2022?

I have prepared a comparison table with the GH5 and GH5M2 using data available and for noise my subjective measurements supported by the video evidence.

As you can see from the table the GH5S still has some unique features:

• RAW support (ProRes RAW and BRAW)
• VLOG performance
• High ISO performance straight out of camera
• Slightly lighter and better battery life

So if any of the above are essential to you there is still a case for the GH5S.

However the GH5M2 with Neat Video will cost you $1,699+$129=$1,828, for sure you will have to work without Vlog and RAW but you will have many other benefits and you will not need a recorder to shoot 50/60 fps bringing the overall cost down significantly.

For part 3 of my test I ran the GH5S side by side with GH5M2 with the same settings used for daylight. The GH5S used VLOG which is the best photo style for it while the GH5M2 used CineD2, again the best photo style for it. Bear in mind if you had run this comparison with both cameras on VLOG the GH5S would have trashed the GH5M2 at high ISO because the implementation of VLOG in the GH5M2 is simply not performing.

The two cameras were set in multi metering with focus at hyperfocal distance. I tried to match the field of view using the 10-25mm on the GH5M2, make no mistake the PL 15/1.7 I used on the GH5S is an amazing and very sharp lens. Both cameras were set to auto white balance and I put the GH5M2 in auto ISO because it shows on screen the value it is using while the GH5S was set in complete manual. Whenever the GH5S was displaying a negative value on the meter I would increase ISO 1/3 Ev. The GH5M2 was left to deal with it in auto as I had previously confirmed the meters were aligned, or at least this is what I thought until this test.

I started all the way from ISO 200 and waited until night fall.

If you want to watch the video and form your own view here is the link. You will need a Tv with zoom function to be able to see the fine details.

My expectation was that the cameras would perform almost the same until ISO 1600 at that point the dual gain of the GH5S should produce better results. I will spare the analysis at lower ISO values as it does not really say much.

Analysis

As explained in the video you need to focus on three part of the image. The top part and any residual tone of the sky tells you if the camera is loosing DR. The tables at the bottom are a sign of loss of detail due to noise but also of possible temporal noise reduction. Temporal noise is a flickering resulting from noise scattered differently in the frames. When the image retains detail but has this flicker it is said to have temporal noise. If the clip looks stable but lacking a bit of edge details it is a sign of potential temporal noise reduction in camera.

Due to the lower pixel count temporal noise reduction in the GH5S would perform better than in a higher pixel count camera.

ISO 1250

Here the GH5S is in low gain and my expectation was performance to be very similar. At this ISO value the GH5S retained good detail however showed more noise in each part of the frame.

The noise levels appear identical in the static parts of the frame.

All in all at ISO 1250 the situation appears very similar the GH5S has a bit more noise but still have detail compared to the GH5M2.

ISO 2000

The light dropped suddenly so I did not manage to record the ISO 1600 step on both camera at the same time as I was distracted by external factors (had to order at the bar).

Although the noise appear similar I would say the GH5S retained more detail at ISO 2000, consider the observation is far away and on the edges of the frame so it is a difficult scenario.

Looking at the static part gives a different picture with the GH5M2 having an edge and the GH5S smudging details.

ISO 2500

I was expecting the GH5S to be a clear winner at its second native ISO.

The part of the frame with motion did not show a much better detail for the GH5S while the static part looked cleaner.

This behaviour makes me think that the GH5S has a stronger temporal noise reduction filter. When it does not detect motion it goes down hard resulting in a very clean image. When it does detect movement it becomes more cautious especially if the moving parts use only a small area. This would explain the mixed behaviour in the ISO 2500 situation.

Overall I was expecting much better performance and a clear difference between the two.

ISO 3200

My expectation was that as the ISO was going up the gap between the two cameras would have increased however at ISO 3200 I was surprised to see the GH5M2 made a recovery and the quality is almost identical.

In addition I can see the GH5S noise reduction starting to eliminate some details when it can’t quite work out what to do. Look at the table tops near the two walkers in the frame.

ISO 3200/4000

At this point I was presented an additional surprise the two camera started to have a gap in the metering so for a good few minutes the GH5M2 stayed on ISO 3200 while the GH5S was reaching out for more gain.

Ultimately this resulted in identical image quality in the parts with motion with the GH5S retaining some fine details better but the GH5M2 producing at the end a comparable result.

I won’t bore you with the static parts as they look identical.

ISO 4000/5000

The GH5M2 reached ISO 4000 however the GH5S had already moved to 5000. The consequence is that the image quality was the same.

Again the static parts were the same.

ISO 5000

Eventually both cameras were at ISO 5000 and here I could see a lead of the GH5S in the motion details but no benefit in the static details in terms of sharpness. However when you actually play the footage you can see the flickering of the temporal noise on the GH5M2.

The static details retain the same definition and resolution.

At this point is very clear to me that what is giving an edge up to now to the GH5S is the superior performance of noise reduction in camera as the actual dynamic range did not seem to be an element. If at all the sky becomes washed out sooner in the GH5S.

ISO 6400

From this point onwards the GH5S takes the lead however I would not say that the resulting image quality was very high. I would frankly avoid this ISO level but in desperate cases can certainly be used.

Perhaps more interestingly the GH5M2 although more noisy seems to preserver more details of the static part.

Noise Reduction

It became apparent during this test and you will see it clearly in the video that the GH5S has a very effective in camera noise reduction (even with NR=-5 this is still on) potentially because it does not have many pixels and can be quite aggressive with it. I tried using Neat Video with the GH5S however there was loss of detail, with the GH5M2 I could apply a temporal filter to the ISO 5000 you can see the results in the video and see what you think.

Light Levels

I was surprised to see the camera meter reading differently considering the matched set up. I also could see that the light level had to fall considerably so that the GH5S would have a benefit. In substance until both cameras were at ISO 5000 (I was using f/1.7 lenses) it did not look like the higher sensitivity of the GH5S was sufficient on its own to give a performance edge.

Higher ISO

I continued the test all the way to ISO 25600 for the GH5S the results were not exciting although you could say the camera does a decent job at showing some information. In general it seemed the camera was running out of dynamic range and also of image quality.

At this point (ISO 12800) I would say that the benefit of the GH5S was now a full stop. In addition it can go to 25600.

Low Light Sensitivity

I was expecting to see a material difference between the GH5S and the GH5M2 from ISO 1600 or at latest ISO 2500 with this gap growing at higher values. What I have seen instead is a bizarre progression where the GH5M2 would catch up and almost match the GH5S until ISO 4000 with a clear benefit only when the exposure was 5000 for both. It looks like in line with the aptina Dr Pix paper benefits only arrive near 0.01 lux*sec becoming higher later.

So we need 50% of ambient light * exposure time / aperture stop to be 0.01.

If we think about it f/2 1/60 this means aperture in stop is 2 which means a factor of 4. So working the inverse in order to get 0.01 lux*sec we would have 2*60*4*0.01=4.8 Lux.

If we consider an f/1/7 lens than this becomes 3.4 Lux and finally with an f/1.4 lens this would be 2.4 Lux.

In reality most f/1.4 or f/1.7 lenses really are just f/1.8 or f/2 so a value of 4 Lux for ambient light is reasonable. And this is the point where the benefit would start getting better as it goes darker. This is also consistent with my test the real performance difference started really to manifest a lot at ISO 5000 and became higher later.

We also have to consider thought that certain part of the image like the deep shadows will show a benefit sooner even if the ambient light is broadly sufficient. So it is not as clear cut as it would appear and the test confirmed such behaviours.

Conclusion

Perhaps the biggest surprise was how effective a traditional front illuminated sensor can be and how small was the gap with the GH5M2.

A key difference between my tests and others you can find on the net is that nobody actually runs tests with two cameras side by side and we have seen that at high ISO values the cameras did not meter exactly the same but what matters is the image quality at that point in time so the test still stands.

One thing has to be said though and this is that as of today if you want a micro four thirds camera style device (not a box or a cinema camera with no weather sealing) that works in low light with VLOG you are left with only one choice and that is the GH5S.

In the next part a wrap and some considerations about use cases and current competition for the GH5S.

The second part of the test consisted in running the GH5S in parallel to the GH5M2 using CineD2. If you wonder why I did not use VLOG on the GH5M2 is because as discussed in a previous article VLOG on the GH5/GH5M2 is just a picture profile and does not really do anything other than deteriorate the noise in the shadows. So I used CineD2 as I wanted the maximum performance out of the GH5M2. The GH5S instead performs better in VLOG for reasons explained in the VLOG article as well.

So with the two cameras on tripods I went out for a walk and took several shots with similar exposure settings. Instead of using ISO 400 I used 200 on the GH5M2 which means the lens was one stop brighter on the GH5M2.

The practical tests confirmed what I was expecting based on the light box tests:

1. The GH5S has a tendency to oversaturated reds and move blue to cyan so deep blues in the sky are almost never available. This was not so much of an issue during this test as the sky was overcast however you can see the clouds do not really have any blue tones.
2. Auto white balance during the day performed consistently to the GH5M2 generating most times the same reading or at most a 200K difference. On this basis I do not understand why users speak about a magenta cast in some shots.
3. The GH5S had better battery performance of the GH5M2 and I think this has to do with the LCD which is now much dimmer than the new camera as you can see in the picture.
4. I did not see any more dynamic range in the GH5S. I would say a tad less than the GH5M2 on CineD2 at base ISO. This is visible in the second scene where I spot metered on the subject. Both camera had almost no tones left in the sky although they did not clip with the GH5M2 having perhaps an edge there.

Looking at the waveform after ETTR with the cameras showing near clipping you can see that the highlights are practically the same however VLOG has lower midtones and less darks.

This is the full video on youtube so you can make your own calls. The footage has been stretched to maximise DR ad hoc in the first scene and hues have been corrected for daylight. No other grading has been performed. In the second scene both cameras were maxed out and no further stretching has been done as it was not improving the scene.

The potential benefit of the GH5S over other models

The following table extrapolates the GH5S dynamic range considering a shift of 3dB in gain (ISO 400 -> 200 shifted)

ISO Setting	GH5M2	GH5S	GH5	Delta GH5M2 Max	Delta GH5 Max
400	9.08	9.29	8.53	0.21	0.76
503	8.71	9.04	8.22	0.33	0.82
636	8.48	8.68	7.84	0.2	0.84
800	8.17	8.39	7.53	0.22	0.86
1006	8.02	8.08	7.25	0.06	0.83
1273	7.65	7.76	6.95	0.11	0.81
1600	7.33	7.87	6.61	0.54	1.26
2011	6.90	7.63	6.30	0.73	1.33
2546	6.66	7.27	5.96	0.61	1.31
3200	6.28	6.99	5.65	0.71	1.34
4022	5.98	6.69	5.32	0.71	1.37
5091	5.64	6.37	4.97	0.73	1.4
6400	5.30	6.06	4.60	0.76	1.46
8045	5.01	5.71	4.31	0.7	1.4
10183	4.68	5.40	3.94	0.72	1.46
12800	4.33	5.04	3.59	0.71	1.45
16090		4.76		GH5M2	GH5
20366		4.39	Avg	0.503125	1.16875
25600		4.07	Min	0.06	0.76
			Max	0.76	1.46

Please note this is an extrapolation I have not take measures however assuming VLOG impacts all cameras equally once gain is taken into account what you see there is that the GH5S has a potential benefit between 0.76 and 1.46 Ev over the original GH5 which is consistent with user experiences and website tests.

When you look at the GH5M2 the potential benefit drops to 0.5 and under 1600 is almost zero becoming 2/3 Ev when the GH5S is in high gain. This is also consistent to various tests on websites like dpreview and CineD.

The table does not consider however that CineD2 on the GH5M2 does accomplish more than VLOG in virtue of less noise and also does not consider the fact that some of the DR will be lost in the underexposure happening behind the scenes.

Part 2 Wrap Up

It is not difficult to see that the GH5S has good performance in daylight conditions however it does not really have any edge worth investing in it for this use case. So if you are not always at high ISO levels (>>1600) you may be getting better value from the GH5M2 that costs less takes photos and has IBIS. To be perfectly honest due to the way VLOG works I did not see major benefit even when I tested the S5 because the extra DR in the highlight was not really useful.

When we look at the GH5 instead the GH5S does remain superior but this is due to weakness of the GH5 itself. It really is quite clear that the software stack of the GH5 is really dated and the camera fairly noisy.

In the next article I will analyse two side by side shots of the GH5S and GH5M2 in low light.

Since its announcement exactly 4 years ago the GH5S has been an enigmatic and successful camera for Panasonic. Today 4 January 2022 it still retails at £1,899 and it has upheld price more than the original GH5.

You would wonder who would want to get a 10 megapixel camera without stabilisation and the answer is many people that are solely focussed on video. The camera has built a reputation for low light performance and dynamic range and has been praised for its ‘color science if there is such a thing.

So after using the GH5M2 for six months I decided to rent a unit from Wex Photo and run a side by side comparison for myself.

When I say side by side I do not mean just in theory I mean in practical with the cameras close to each other and shooting the same scene.

For my tests I used a light box and a set of grey, white and color checkers and the same identical lens Panasonic 30mm macro. And for the outdoor scenes I set the GH5s with a Panasonic Leica 15mm 1.7 and the GH5M2 with a 10-25mm. As the GH5S has a multi-aspect sensor I needed to zoom the lens to less than 14mm to get the same field of view.

Before getting into the actual tests it is time to debunk a few myths about the GH5s.

Less Pixels = Less Rolling Shutter not more Dynamic Range

Camera readout is limited mostly by the speed of the Analog to Digital conversion. So having less pixels helps readout and reduces rolling shutter. This is the reason why all camcorder and dedicated cinema cameras have the minimum amount of pixels required and nothing extra.

This is true for the GH5S, the reputable website CineD as well as dpreview show a benefit of a couple of milliseconds for the GH5S over other cameras with a 20 megapixels micro four third sensor. This may be important when doing panning shots or using the camera on a dashboard or gimbal.

On the bigger pixels helping dynamic range there are a number of sources that explain why this is not the case but more importantly the the GH5S sensor has actually a quad bayer structure with cells of 4.6 microns made of 4 pixels each. So in reality the GH5S sensor has 43.64 megapixels arranged in 10.91 million cells that give 10.91 megapixels in 4:3 aspect ratio 9.07 megapixels in the 17:9 wide format. So not only bigger pixels are no help to dynamic range but the GH5S sensor actually has more pixels.

The sensor in the GH5S does not have higher dynamic range than other MFT cameras

Photonstophotos managed by Bill Claff is the only site that has measures of almost all camera models. While engineering dynamic range is purely determined by the difference between saturation signal and lowest readable signal, photographic dynamic range is what we see and is generally determined from setting a defined SNR for the image scaled to 12″ size long or 8 megapixels. This is roughly the 4K video resolution so it is a good starting point.

From this graph we can see that the G9, although based on the same sensor of the original GH5, outperforms the latter and the GH5s when it comes to dynamic range.

I am always cautious with measures taken by others so I did a full test and asked Bill to check the difference.

While in some cases there was an improvement of 0.18 Ev this would not be sufficient to push this sensor above the G9.

So the Panasonic GH5S sensor does NOT have more dynamic range of other Panasonic cameras with more pixels on the same format although it does quite well and at high ISO outperforms the GH5 at RAW level.

The multi aspect sensor has a bigger size in video but this does not improve dynamic range significantly

Due to the multi aspect ratio it is true that the sensor does not loose from a crop when changing aspect however we need to understand more what the potential benefit is.

A higher megapixel sensor with pixel of 3.3 microns will use its whole width and a cropped part of the height. If we look at 5184×2916 pixels surface this measures (5184×3.3)x(2916×3.3)=164.62 square millimeters. The GH5S with a cell size of 4.6 microns will have a surface of (3840×4.6)x(2160×4.6)=175.5 square millimeters.

Considering that dynamic range is proportional to the square root of the surface the improvement would be SQRT(175.5/164.62)=1.032 which in Stops is 0.046. So the larger area does not really do anything in 16:9 aspect ration.

In 17:9 the situation is a bit different and this benefit is 0.14 Ev still nothing so large to have a very significant impact.

During my tests I found the change of horizontal field of view which is what really matters confusing so personally I like to have a standard sensor with crop considering the benefits of multi-aspect are really limited.

The sensor of the GH5S has higher sensitivity

One of the features that the GH5S has is the so called Dual Native ISO. This is a marketing term for the Aptina DR-PIX technology which has been implemented by Sony for some time.

A white paper is here as you can read the technology enables sensors to increase sensitivity at the expense of dynamic range. The potential improvement is up to 5 dB however this is only true for very low light levels. To give an idea at deep twilight there is around 1 lux so with an exposure time of 1/50 of a second we have 0.02 lux*s this is not in the core range for this technology so more is required.

Back illuminated sensor give the additional sensitivity required as explained on Sony semiconductors page.

Now the combination of dual gain and back illumination means that the GH5S can do better at low light levels but also can tolerate very high levels of ISO. So the GH5S has additional high ISO capability for around two stops which means you can almost shoot in the dark. The key question is when does this matter when you have a fast lens.

Looking at an exposure waterfall calculator we can see that with an f/1.4 lens at 1/60 and ISO 3200 we can still cover twilight which is when public illumination is switched on.

In general terms all being equal the GH5S would have around 2/3 stops benefits in low light or in deep shadows compared to other cameras with MFT sensor.

This is quite interesting to test and quite simple using a color checker and a noise reduction software like neat video.

Here the first two samples are grey and black patches in VLOG at ISO 1600 using the Low Gain setting.

We can see that while the noise level on the middle grey is contained the black patch jumps to 4.4.

If we take the same reading manually selecting the High Gain range we can see how the situation changes.

On the middle grey we are in a very similar situation. However when we look now at the black patch we can see that the level of noise has dropped significantly.

So we can see that switching the camera from low to high gain at the same ISO has a significant benefit on darks in terms of noise.

VLOG to the rescue

With what we have said so far there has not been enough to substantiate why the GH5S would have more video dynamic range than the GH5 but VLOG comes to the rescue.

When Panasonic introduced the Varicam 35 in 2014 they were presented with the issue of having too much dynamic range.

Panasonic already have their CineLike Gamma that was able to manage 12 stops of dynamic range however this was no longer sufficient.

So the Varicam35 was provided with RAW output and with AVC Intra recording on their expensive expressp2 cards. VLOG provided an opportunity to compress the camera dynamic range in a 10 bit container that could then be recorded on card.

Panasonic made a first attempt to deliver VLOG to their Lumix with the GH4 however at 8 bit depth it did not work well. The GH5 is the first camera to have a 10 bit implementation however due to the smaller sensor it was limited to a smaller range called VLOG L which covers 12 stops of dynamic range.

A report by EBU indicates that the GH5S has more dynamic range in both CinelikeD and HLG modes compared to VLOG. Those are not scientific but are a suggestion that perhaps for a sensor with a maximum dynamic range around 12 stops VLOG is not the most efficient option. HLG presents challenges due to the color space and gamut differences however CineLike D does not require anything specific to process. Users have complained about the color accuracy of CinelikeD and generally Panasonic has been sponsoring VLOG and so have many websites under the assumption that this was the best way to preserve the full dynamic range.

While this may be true for larger sensors it would appear that this is not definitely true for the smaller MFT format.

In addition the implementation of VLOG among different camera is not the same as I already wrote here.

So in summary it is true that if you want to use VLOG the GH5S is a better option with a benefit that can be around 1 stop at high ISO over the best performing MFT camera at time of writing the GH5M2.

If you want to see the behaviour of the GH5S using a color checker you can appreciate the low level of noise at high ISO.

Color Accuracy and White Balance

I used a vectorscope to evaluate how the GH5S reproduces hues in VLOG. All tests done with factory settings and official Panasonic VLOG

You can see that the skin tone marker is exactly on target however red is more saturated than other colors and cyan is desaturated

The blue use is also shifted towards cyan.

This means that the GH5S can potentially produce a red cast and not give deep blue skies.

The weather was rubbish during my tests however from this example you can see how the red is definitely overboard by looking at the hat of the runner that comes on the scene.

This is something to watch out and a hue correction in post is required in most cases to bring things to normal.

Note that this issue with VLOG and the oversaturated red is also present in the GH5M2 that has very much the same color science or lack of thereof and will produce reddish tones on your skin that need to be corrected.

Take into account that hue correction is not resolved by setting a custom white balance.

For the hardcore pixel peepers I have shot a whole sequence of xrite color checker at all ISO steps

Exposure Meter

On a positive note the GH5S in VLOG meters correctly unlike the other GH5 siblings that are 1 stop overexposed.

You can see on the waveform monitor that setting the target at zero gives middle grey exactly on 50% on multi metering. On spot it will go at 45% which is what is expected.

Part 1 Wrap Up

From a series of quite simple tests done in a light box my expectation is that the GH5S will do ok but not sensationally in bright scenes and will do better in low light low dynamic range scenes.

In the next article I will analyse two side by side shots of the GH5S and GH5M2 in daylight.