The seventh iteration of Panasonic’s successful LUMIX GH line has arrived in the lab: the LUMIX GH7. For the first time, the model features internal 12-bit ProRes RAW recording at 5.7K. Are you curious to know how this new flagship model works? Then read on…
The LUMIX GH line has always been in my heart, as my journey with mirrorless cameras began in 2009 with the LUMIX GH1 camera. Now, I have the GH7 in my hands and I wonder if Panasonic has once again managed to create a new milestone in the camera world. This model is not only capable of recording internal 12-bit ProResRAW HQ video with its 25.2MP Micro Four Thirds CMOS BSI image sensor, but also 32-bit floating audio (with the new optional DMW-XLR2 unit). By the way, if you’re curious about how the GH6 predecessor and the first GH1 model perform in the lab, head here.
If you want to read the full specifications of the GH7 first you can read it here, and in case you missed it, don’t forget to tune in to our weekly episode of the Focus Check podcast where Johnnie and Nino talk about the LUMIX GH7 (and don’t worry, the Johnnie’s LUMIX GH7 hands-on review is in progress).
Before we begin, a big “thank you” again to my dear colleague Florian, who helped me perform this test and analyze the results.
Rolling Shutter de la LUMIX GH7
Rolling shutter is measured as usual using our 300Hz strobe, and here’s the result for 5.7K and 4K DCI (17:9): 13.2ms (less is better). This is a very similar result to its predecessor, the LUMIX GH6, as well as the LUMIX G9 II.
Rolling shutter for the LUMIX GH7 in DCI 4K mode. Image credit: CineD
Full scan of the 4:3 sensor (open gate) takes 20.8ms (5760×4320 resolution). Visit the CineD Databases for more information.
LUMIX GH7 dynamic range at ISO500
If you don’t know how we test dynamic range, go here to read the full description.
Unfortunately, DaVinci Resolve 19 doesn’t support ProResRAW yet (I wonder if it ever will), so we had to resort to the Windows RAW Convertor app to convert the files to 12-bit CDNG and then import them into DaVinci Resolve. In Resolve, we use the following development settings for Cinema DNG files to bring them into Panasonic’s V-Gamut/Log space:
DaVinci Resolve 19 Cinema DNG development settings. Image credit: CineD
From ProResRAW HQ 5.7K with the new lower base ISO of 500 (the LUMIX GH6 used ISO2000 to activate the dynamic range increase, which is now the default for the GH7), we got the following waveform graph:
LUMIX GH7 waveform graph with ProRes RAW 5.7K at ISO500. Image credit: CineD
We were able to identify 11 stops above the noise level, with an additional 12th and a weak 13th within the noise level. Now let’s look at the IMATEST for the same mode:
IMATEST result for the LUMIX GH7, ProRes RAW 5.7K. Image credit: CineD
We obtained 9.85 stops with a signal-to-noise ratio (SNR) of 2 and 11.6 stops with an SNR = 1. What can be seen in the middle graph above the blue “11.6” curve are additional stops identified in the noise level. With 12-bit ProResRAW HQ, it should be possible to “dig out” those extra stops in post-production using noise reduction.
I would also like to talk about the lower right graph “Noise Spectrum”, which shows the latter with respect to frequency or resolution. The LUMIX GH7 maintains very high amplitudes up to very high resolutions (towards the right side of the graph). This is: a) a clear sign of very little or no in-camera noise reduction and b) it means that high frequency details are still visible (and not blurred). This is the power of RAW format, very good!
For comparison, here is the IMATEST waveform and result if we switch to the 5.7K 10-bit ProRes HQ recording (using V-Log):
Lumix GH7 V-Log ProRes HQ waveform. Image credit: Cined5.7K ProRes HQ Imatest results from GH7. Image credit: Cined
We got 11.3 stops with a signal-to-noise ratio of 2 and 12.6 stops with a signal-to-noise ratio of 2. Therefore, there is noise reduction in the camera which can also be seen in the bottom right graph “Noise Spectrum” : If you look at the amplitudes at higher frequencies, they drop very quickly to levels below 0.4 and then to around 0.1; Noise reduction blurs higher resolution details. With ProRes RAW, this doesn’t happen, as the amplitudes never drop below 0.5 even at the highest frequencies. This means that the noise should be very finely distributed, which is great! Again, we can see the power of the RAW format here.
The CineD Database will be updated soon with more results.
LUMIX GH7 exposure latitude
As written in previous lab reports, latitude describes a camera’s ability to retain colors and details when overexposed or underexposed and normalized back to a zero reference exposure level in post-production.
In our case, we have a standard studio scene where the base exposure is (arbitrarily) set to a luminance value of 60% on the forehead waveform of our artist, my dear colleague Johnnie.
DaVinci Resolve 19 development settings. Image credit: CineD
Camera settings were 5.7K ProRes RAW HQ at ISO500, we again converted the files with RAW Convertor to 12-bit CDNG files and then imported them into DaVinci Resolve 19, with the same V-Log development settings as above in the Camera RAW tab. Exposure is adjusted using the exposure slider, but it only works from +4 to -4 stops. Therefore, we further use a 3-node arrangement. In the first node there is a color space transformation from Panasonic V-Log to DaVinci Wide Gamut, then we have the middle node where additional adjustments are made and then a last node with a color space transformation to carry the DaVinci files Wide Gamut to Rec709. Any noise reduction is always done at the first input node.
So, here is our base exposure:
The LUMIX GH7 in base display. Image credit: CineD
Quick note: The moiré on Johnnie’s shirt is an artifact of downscaling the images to the 1920×1080 web resolution, it is not present in the original image.
At this point we exposed our artist’s forehead until the red channel reached the apex of the crop, which is 3 stops overexposure, then brought it back to the base exposure. We used the ZEISS 35mm T1.5 Compact Prime for testing, which is unfortunately quite soft at T1.5:
The LUMIX GH7 at 3 stops above, returned to the base exposure. Image credit: CineD
Now, we close the iris of the lens in increments of 1 stop, and at T8 we double the shutter value until we reach 4 stops of underexposure, returning to the base exposure:
The LUMIX GH7 at 4 stops below, returned to the base exposure. Image credit: CineD
With 4 stops below we have already reached the maximum exposure latitude of the predecessor model, the LUMIX GH6. Surprisingly, the LUMIX GH7 still offers a good look with the same underexposure, the noise is very well distributed. Noise reduction would easily fix that, but let’s move on.
This is already a very good result for a Micro Four Thirds image sensor; even some consumer full-frame sensors are reaching their limits at this point (e.g. the Sony a7S III).
Let’s see what happens when we reach the 5 stops below, returning to the base exposure:
LUMIX GH7 5.7K ProRes RAW – DNG 5 stops down, back to base. Credit: CineD
The noise is much more pronounced, but is still very well distributed, and a greenish tone appears. Let’s see if we can fix it with noise reduction in DaVinci Resolve 19:
The LUMIX GH7 5 stops lower, returned to the base and with noise reduction. Image credit: CineD
We’re 8 stops underexposed, back to base exposure, and the image still looks pretty good. However, we must keep in mind that there is still a more intense color tone towards green and faint vertical bands appear. My criteria for judging is always the shadow side of our artist’s face, and the skin here still looks pretty good.
Let’s see if we can get to 6 stops of underexposure:
The LUMIX GH7 at 6 stops below, returned to the base exposure. Image credit: CineD
There is a loud noise that is corrupting the image and vertical lines are visible. Noise reduction won’t be able to mitigate this, but let’s take a look:
The LUMIX GH7 at 6 stops lower, returned to the base exposure and using noise reduction. Image credit: CineD
As we can see, this is it, “game over”: the greenish tone becomes stronger and there are pronounced vertical lines that cannot be eliminated with noise reduction. However, the image still looks surprisingly good considering we are at 9 stops latitude; Also, the shadow side of Johnnie’s face is relatively intact, let’s not forget that we are talking about a Micro Four Thirds sensor! With 8 stops of exposure latitude, most recent consumer full-frame cameras are reaching their limits.
Obviously, we have the RAPTOR NETWORK [X]which can handle 9 stops of exposure latitude, or the ARRI Mini LF that reaches 10 stops. And let’s not forget the ARRI ALEXA 35, which can handle 12 stops of exposure latitude and is our current benchmark.
Summary
Panasonic did it again: the LUMIX GH7 is one of a kind considering the size of the Micro Four Thirds sensor. Not only does it show good rolling shutter values, but also the dynamic range results do not disappoint. They are quite similar to those of the Sony A9 III or the Canon EOS R5 C that we recently tested, for example. As mentioned, it plays in the league of recent consumer full-frame cameras with those results (although it is a bit behind).
Exposure latitude tests again reveal the power of 12-bit RAW images: we can take this little camera to 8 stops of latitude, with some leeway towards 9! This is at least one stop better than the predecessor LUMIX GH6, which only offered 10-bit ProRes HQ internally, and also one stop better than the full-frame Canon R5 C or the Sony a7S III, for example, which boasted 7 stops of latitude. of exposure.
I can’t help but imagine what would happen if Panasonic managed to bring “dynamic range enhancement” technology and internal ProRes RAW recording to their full-frame cameras in the form of an S1/S1H Mark II. Well, I’ll keep dreaming…
Have you already used the Panasonic LUMIX GH7? Do you like working with Micro Four Thirds sensors? Tell us in the comments below!
