GH5 FHD and 4K downsampled from 6K sensor? Slo Mo too?

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filmguy123

Veteran
The EVA-1 is a 5.7k S35 sensor, downsampled to 4K.

The GH5 is a 6K m43 sensor, downsampled to 4K... correct?

Is it also downsampled from 6K to FHD?

Does the sensor maintain this downsampling even when shooting in slow motion in all modes? 60p? 120p? 180p?
 
filmguy123 said:
The EVA-1 is a 5.7k S35 sensor, downsampled to 4K.

The GH5 is a 6K m43 sensor, downsampled to 4K... correct?

Is it also downsampled from 6K to FHD?

Does the sensor maintain this downsampling even when shooting in slow motion in all modes? 60p? 120p? 180p?
Click to expand...

GH5 is more like a 5.2k sensor. The 6k is just a marketing thing and more to do with a theoretical total resolution from a 4x3 sensor.

Yes as far as I know FHD also uses the full sensor. You can tell because there is no extra crop. If there is no extra crop then the full sensor is used. What differs is the method used to down convert and from what I can tell the FHD is vastly better than the pixel binning on the GH4 when shooting FHD. If it is as good as shooting 4k and down converting in post to HD is something you can tell for yourself by trying it. Keep in mind every software program under the sun scales differently and some programs like Fusion even allow you to select the scaling math used to down convert. Thats why I say test it out for yourself in whatever program you use to see how it compares.

60p should use the exact same processing but everything above that does cut some corners. What method is exactly used to cut corners I can't really say. I believe it just uses less sampling for each pixel. The high quality video on the GH5 users 9 pixels surrounding each pixel to create an average new super pixel. Kind of like bi-cubic scaling in software programs. It is possible due to processing speed that the higher frame rates can't use the full 9 sampling and just take each pixel as is or go back to a form of pixel binning like the GH4 used for FHD. This is why you get more aliasing and moire when shooting slow motion on the GH5. It isn't just a lower resolution but a lower form of scaling each pixel and the sampling from the full sensor is not as good.
 
Thomas Smet said:
It isn't just a lower resolution but a lower form of scaling each pixel and the sampling from the full sensor is not as good.
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Thomas, what is your opinion about externally recording the higher frame rates? Would it help the higher frame rates or do the shortcuts get baked-in upstream?
 
So the GH6 is always full sensor downscaled for slow motion, not windowed, up to 180fps. I know there is more to the final image quality than this, but why then might the EVA-1 be windowed before 180fps? Sure, the sensor is larger, but it's all about the amount of pixels being pushed, not the size of the photosites. If the GH5 actually is 5.2k downsampled to 4k/2k and can do up to 180fps full sensor, the EVA-1 for 4x the price really couldn't handle the extra .5k of resolution to be downsampled?

I know we don't have official specs yet, but the Varicam guys said this and Mitch affirmed it by saying "not all 2K will be windowed". So we don't know where the cut off is.

Just trying to understand why the EVA-1 might not be able to do the same thing the GH5 can?
 
filmguy123 said:
So the GH6 is always full sensor downscaled for slow motion, not windowed, up to 180fps. I know there is more to the final image quality than this, but why then might the EVA-1 be windowed before 180fps? Sure, the sensor is larger, but it's all about the amount of pixels being pushed, not the size of the photosites. If the GH5 actually is 5.2k downsampled to 4k/2k and can do up to 180fps full sensor, the EVA-1 for 4x the price really couldn't handle the extra .5k of resolution to be downsampled?

I know we don't have official specs yet, but the Varicam guys said this and Mitch affirmed it by saying "not all 2K will be windowed". So we don't know where the cut off is.

Just trying to understand why the EVA-1 might not be able to do the same thing the GH5 can?
Click to expand...

It does what it can and nobody here is going to know the answer to that question. Perhaps it was so the quality would be better than the GH5 which uses a lower quality form of scaling. The GH5 sacrifices a lot of quality to pull off slow motion. If you knew you had a tradeoff between pixel perfect but cropped slow motion vs full sensor with extra artifacts which would you rather have?
 
filmguy123 said:
So the GH5 is always full sensor downscaled for slow motion, not windowed, up to 180fps.
Click to expand...

Image quality is sacrificed when shooting high-speed with the GH5 because there isn't enough camera processing power to properly handle the 5.2K image when downscaling it to 1080p. So image detail and moire will creep into the image once you are shooting faster than the "normal" camera frame rates.

The EVA1 is also restricted by it's internal processing power, so Panasonic made the smart choice to crop the sensor down to produce a better looking image when shooting highspeed footage. Yes it's not using the full sensor size, but who cares as long as the final image is better ?
 
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