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.