GH4 Panasonic GH5 coming in 2017

Thomas Smet said:
4k on the GH4 always looked cleaner because there was no scaling of the sensor. A perfect 1:1 output. The GH5 is a bit different this time which is why some have a concern. The full sensor is being scaled to 4k. So far all the 4k material I have downloaded from the GH5 looks great without any of the issues I was concerned about. Its still too early to know for sure if the down conversion method the GH5 is using will not have any aliasing or moire at all but so far so good. VFR is a pretty big down conversion from the full sensor and we don't know what corners have to be cut in order to process 180 frames per second. Sometimes the GH4 uses different down conversion methods based on how much extra processing the camera has to do. Thats why 96fps 1080p looked worse than 1080p FHD at up to 60 fps. different scaling methods were used to cut down on processor load. 60p is a normal functionality of the camera so it should always look at good as 30p or 24p. It is beyond that where things tend to get a bit funky.

Honestly the 180 fps is more of a gravy feature for me anyways. Cool to have it when needed but if I'm concerned about quality which is why I use a 4k camera in the first place then I'm not likely to use very much. With that said not all the shots at 180fps looked all that bad and I think they look much better than how the 96fps looked on the GH4. On the GH5 it seems to be more of just a high frequency detail issue vs just a really bad down conversion. Overall outside of some potential aliasing of extreme fine detailed patterns I think it looks pretty clean.
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In addition to the scaling, the other big change is the removal of the OLPF. I haven't yet seen a moire-prone 4K sample, so not drawing any conclusions, but this is definitely something to watch-out for. Nothing is ever free...the bump in sharpness may have trade-offs.
 
joe12south said:
6k Photo or anamorphic. Not how most people need to shoot most of the time, but nice to have as an option to get out of jam.
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According to a 2 page data sheet of the GH5 there is still an ETC mode which apparently supports 4k which would be a crop. Not 100% sure if that will be a real feature or not or if it was a mistake in that document. So far that has been the only mention of it. If it is a feature then you could use 4k ETC for a little extra crop but a 1:1 sensor readout. I agree however that this isn't the norm for the camera.
 
Thomas Smet said:
According to a 2 page data sheet of the GH5 there is still an ETC mode which apparently supports 4k which would be a crop. Not 100% sure if that will be a real feature or not or if it was a mistake in that document. So far that has been the only mention of it. If it is a feature then you could use 4k ETC for a little extra crop but a 1:1 sensor readout. I agree however that this isn't the norm for the camera.
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I vaguely remember this as giving a 1.4x crop versus normal m43 lens coverage. Perphaps useful for extra reach on telephoto end of zooms.
 
joe12south said:
In addition to the scaling, the other big change is the removal of the OLPF. I haven't yet seen a moire-prone 4K sample, so not drawing any conclusions, but this is definitely something to watch-out for. Nothing is ever free...the bump in sharpness may have trade-offs.
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Yeah I kind of freaked out over the removal of the OLPF. Low pass filters were designed for a very good reason. It kind of looks like what the GH5 is doing for down scaling however is similar to a bi-cubic approach with how they use the 9 surrounding pixels to calculate the value of each pixel. Technically an image with no low pass filtering that uses a form of cubic scaling should work out fairly well. Should being the key word here because I don't know exactly how the GH5 is utilizing that 9 pixel concept to help with scaling.

It is very possible the GH5 uses a nice 9 pixel scaling method for 4k video and FHD video and has to reduce that to a normal pixel averaging or even nearest neighbor for the VFR stuff. Doubt it is nearest neighbor but maybe more of a pixel binning process typical of the HD modes on the GH1, GH2 and GH3.
 
philiplipetz said:
I vaguely remember this as giving a 1.4x crop versus normal m43 lens coverage. Perphaps useful for extra reach on telephoto end of zooms.
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should result in about a 2.8x crop factor (for UHD) compared to 35mm photo. In some ways kind of nice if you need a little extra reach. Gives you two 4k modes for each lens which could be kind of useful. Not a huge difference but a single 25mm lens could be like a 50mm or 70mm photo lens (give or take a few mm).
 
Thomas Smet said:
should result in about a 2.8x crop factor (for UHD) compared to 35mm photo. In some ways kind of nice if you need a little extra reach. Gives you two 4k modes for each lens which could be kind of useful. Not a huge difference but a single 25mm lens could be like a 50mm or 70mm photo lens (give or take a few mm).
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And help with 16mm and c-mount lenses.
 
Thomas Smet said:
Yeah I kind of freaked out over the removal of the OLPF.
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Me too. I clearly remember that being the day that I checked out of the whole BlackMagic thing, since they (at least at the time) didn't have OLPF's. I griped about it, then someone showed a resolution chart and it was a Canon 7D-caliber mess. As you said,
Low pass filters were designed for a very good reason
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In that document though, they do spell out that they've taken specific steps to address moire. Maybe digital processing is good enough that they felt that they could do without an OLPF at this point? We'll have to see the results, but yeah, I'm a bit cautious on that.
 
joe12south said:
In addition to the scaling, the other big change is the removal of the OLPF. I haven't yet seen a moire-prone 4K sample, so not drawing any conclusions, but this is definitely something to watch-out for. Nothing is ever free...the bump in sharpness may have trade-offs.
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Luke Neumann commented on the YouTube video to say that he's only seen moire in VFR, and noting that the same backpack is throughout the original promo video (4K) without issue.
 
Barry_Green said:
Me too. I clearly remember that being the day that I checked out of the whole BlackMagic thing, since they (at least at the time) didn't have OLPF's. I griped about it, then someone showed a resolution chart and it was a Canon 7D-caliber mess. As you said,

In that document though, they do spell out that they've taken specific steps to address moire. Maybe digital processing is good enough that they felt that they could do without an OLPF at this point? We'll have to see the results, but yeah, I'm a bit cautious on that.
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I may be a bit off with this but I think Panasonic's 9 pixel sampling acts like an anti-alias filter similar to how 3D rendered graphics uses anti-aliasing. The 9 sample is kind of similar to how cubic image processing works where it samples multiple surrounding pixels for a calculated value. It very well could be that the multi-dimensional 9 pixel sampling (or whatever they call it again) is a digital anti-aliasing alternative to an optical low pass filter. If that is the case I would also want to get rid of the OLPF to create as detailed of pixels as possible for that kind of calculation.

There are plenty of anti-aliasing methods out there but one method does use a similar approach of looking at a block of surrounding pixels to create interpolated anti-aliased edges. This puts the control over the details in the camera instead of throwing a dummy optical filter in front of the sensor to blur everything coming in. Smart way to go if a camera has the processing horsepower to do it.
 
Nikon got rid of the OLPF when their Nikon D5300 camera came out a few years ago, and it showed pretty much the same high quality moire performance at 1080p as their previous cameras that used OLPFs.

I think it comes down to the GH5 having enough image processing power to handle moire, which goes out the window when your are shooting at 180 fps.
 
DeadEyesSmiling said:
Am I reading correctly from that leaflet that the current 12-35mm and 35-100mm will NOT be getting firmware updates for the Dual IS?

-DES
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Both lenses (after a firmware update) already work with dual IS, however they will most likely not work with Dual IS 2 which is an updated version.
If I am not mistaken a mark II of both lenses compatible with Dual IS 2 is planned.
 
Cary Knoop said:
Both lenses (after a firmware update) already work with dual IS, however they will most likely not work with Dual IS 2 which is an updated version.
If I am not mistaken a mark II of both lenses compatible with Dual IS 2 is planned.
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Okay, that's what I was afraid of. Thanks for the clarification!

-DES
 
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