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.