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Andrew Reid

Panasonic GH5 - all is revealed!

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2 hours ago, Towd said:

I don't want to derail the discussion about the GH5, but I hate seeing bad information out in the world, and just have to correct this.

For all intents and purposes, as long as the focal plane of the camera is in an identical place in the world between shots with different focal lengths, the effect is mathematically identical to a crop from a larger FOV to a smaller one.  In other words you can animate a crop on an image to recreate the effect of a zoom with a lens.

The only things that could possibly be different would be characteristics of the different lenses, such as pin cushion or barrel distortion throughout the zoom.  Of course there are going to be varying resolving differences depending on the technique used.  For example a digital zoom is going to reduce pixel resolution,  but an optical zoom is going to be affected by any resolving differences of the lens at different focal lengths.   That said, if you took a theoretically "perfect pinhole lens" and performed a zoom it would be identical to to a crop on an image with infinite resolution.

I've run into so many photographers who don't get this, but I think it's an important bit of information to keep in the back of your head while out shooting--  you can crop in on an image and  it will have the same basic effect as putting a longer lens on your camera.  What's neat about the GH5 is that trick doesn't seem to have much effect on the detail in the image, so it really effectively gives you two lenses which is very cool.

Just as a side note, that Jaws effect is achieved by combining a move through the environment combined with a zoom or crop in to keep the subject in the same scale in the frame.  The key to the effect is that the camera is moving and not in the same spot from the beginning to the end of the shot, so you are getting the parallax of moving the camera.  In fact even before digital, they used to do the effect using optical printers in the same way in which we can crop a shot today.

To satisfy my curiosity (it has been a while since I used the variable zoom with my A7s in video), I just mounted an old crappy Canon 28-90 zoom on my A7s, mounted on a tripod and set it to 47mm then used Clearzoom (virtually lossless variable digital zoom to 2x) and zoomed in to 2x then back out, then I used the optical zoom to zoom to 90mm.

The Clearzoom actually looks better as the optical zoom is not parfocal  so is a bit out of focus at the end of the 90mm.    The optical zoom is also quite shaky (even on the tripod) while the digital zoom is smooth.

I am not going to post it as it is pretty lame and not a great lens but anyone with a Sony E mount camera with clearzoom and a zoom lens that covers 2x at least can test it.

For stills I would always prefer an optical zoom but for video in SOME circumstances, I would go with the digital zoom.

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EOSHD Pro Color for Sony cameras EOSHD Pro LOG for Sony CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs

The autofocus is a bit bizarre on this camera. It works pretty well for stills, but for video it's inconsistent. I went outside and shot at ISO 400 in V-Log. It seems to be having issues focusing when there are big objects close to the lens.

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13 minutes ago, zmarty said:

The autofocus is a bit bizarre on this camera. It works pretty well for stills, but for video it's inconsistent. I went outside and shot at ISO 400 in V-Log. It seems to be having issues focusing when there are big objects close to the lens.

What lens?

What about tap to focus? Have you tested it for video?

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28 minutes ago, Emanuel said:

What lens?

What about tap to focus? Have you tested it for video?

The new Leica 12-60 variable f/2.8. Shooting 4K 60fps 8 bit and 4K 30 fps 10 bit in V-Log.

I did tap on the screen and used the shutter button a few times to coax it into focusing. It was slow. The reason why I am saying it's bizarre is that I don't yet understand what circumstances makes it fail to focus. Sometimes it works fine, especially for wider shots and when the entire object is in the frame.

Am I correct in assuming the contrast based focusing is done before the image gets converted to flat V-Log?

P.S. When the image does get in focus the image quality is fantastic.

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1 hour ago, noone said:

To satisfy my curiosity (it has been a while since I used the variable zoom with my A7s in video), I just mounted an old crappy Canon 28-90 zoom on my A7s, mounted on a tripod and set it to 47mm then used Clearzoom (virtually lossless variable digital zoom to 2x) and zoomed in to 2x then back out, then I used the optical zoom to zoom to 90mm.

The Clearzoom actually looks better as the optical zoom is not parfocal  so is a bit out of focus at the end of the 90mm.    The optical zoom is also quite shaky (even on the tripod) while the digital zoom is smooth.

I am not going to post it as it is pretty lame and not a great lens but anyone with a Sony E mount camera with clearzoom and a zoom lens that covers 2x at least can test it.

For stills I would always prefer an optical zoom but for video in SOME circumstances, I would go with the digital zoom.

I used clearzoom few times and most of the time it sucks balls, result is too soft/pixelated when mix the footage with another one with proper zoom on another angle in multiple cam setup during event/theater setup, ETC mode while gives you really good result without degrading sharpness except the increase in noise at lower light environment, though both wont offer you the same bokeh as proper zoom.

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4K 60 fps 8-bit 150 Mbps footage shot in V-Log L yields green and magenta (compression?) artifacts when converted to Rec709 by DaVinci Resolve with their color management solution.

While the image below is a 2X magnification, it is also plainly visible in moving images at normal size. This is my dog's hair, btw :)

I wonder if the color processing for V-Log in Resolve is mostly geared towards Varicams.

I will also check 4K 30 fps 10 bit internal and external.

4k60vlog8bit.png

HOWEVER, if I color grade the same footage manually starting from the V-Log, without using automatic color management, then I can make it look better. The artifacts are still visible when pixel peeping, but not obvious during play:

4k60vlog8bit-2.png

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17 minutes ago, ntblowz said:

I used clearzoom few times and most of the time it sucks balls, result is too soft/pixelated when mix the footage with another one with proper zoom on another angle in multiple cam setup during event/theater setup, ETC mode while gives you really good result without degrading sharpness except the increase in noise at lower light environment, though both wont offer you the same bokeh as proper zoom.

What camera/s was that with?      My experience with Clearzoom with my A7s and previous A7 is that it really IS virtually lossless.

Above 2x (normal digital zoom), I start seeing degradation which is why I have clearzoom set rather than digital zoom.

ETC with the GX7 is ok too but not quite as good as the Sony clearzoom and again, it is not variable so nowhere near as useful.     

As for bokeh, I think I would prefer the bokeh of a fast prime used to zoom rather than that from most zooms (at least those I have seen or used).     This is very subjective though and very much individually lens dependent. 

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24 minutes ago, ntblowz said:

I just did a quick compare

 

 

 

a7szoomcompare.jpg

gx85zoomcompare.jpg

What lenses?

I would love to see you use the same zoom lens on each.

I might do that using a Canon APSC kit lens though will be the GX7 and A7s.

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4 minutes ago, zmarty said:

Do you remember the settings for the first video? What is your opinion of the pans in the first video? I think there are movement problems, I don't know why.

To me, it doesn't look great. The ghosting is causing a strobing effect with anything with contrast. Especially with some of the pans near the end of the first video. I couldn't use that for professional work but I guess it's fine for personal footage? Colors look great though. It is only $2000. I wonder what the larger files will bring in the summer.

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7 minutes ago, hyalinejim said:

Shutter speed is too fast, IBIS is not switched on, and camera movments are too fast.

I just assumed it was 1/50 (180 on this camera) because any respectable shooter would set it on that for 24fps, but looking at his notes he didn't write down the ss.

Can you share some contrasty shots with simple pans and tilts?

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58 minutes ago, ntblowz said:

I just did a quick compare

 

 

 

a7szoomcompare.jpg

gx85zoomcompare.jpg

Clearzoom VS ETC, same lens used on each camera. (which is an APSC lens used FF on the A7s).

This is off topic though, my original point was simply that I wish Panasonic would make ETC variable as Sony does, so that way, if someone likes the quality of ETC at 2x, why wouldn't they like it variable for less than 2x?

clearzoom VS ETC.jpg

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1 hour ago, hyalinejim said:

Shutter speed is too fast, IBIS is not switched on, and camera movments are too fast.

Bingo. You just can't go that with 24p. You can certainly do that with 60p. That would have looked like butter.

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13 hours ago, Ken Ross said:

Very odd. I got my GH5 yesterday, and as usually happens whenever I get a new camera, it rained. So all my testing was indoors, as I went through the house with lights off and on, testing AF with a 14-140 lens. When the lights were off, it was fairly dark given the weather we had been having. I experienced nothing like what he did with the AF.

I'm surprised he never tried a central zone for his AF mode as I did in my tests. Most often I was testing objects and not faces since my wife wasn't home, but I still would have used a center zone if I was only doing faces. I learned from my G85 that that's often more reliable than face tracking. 

I found the AF to be much improved over my G85 as well as my RX10iii and in the same ballpark as my now sold A6300.

On another unrelated note, I watched his entire video and was trying to figure out why his split screen tests with the tele extender mode (as it was labeled) was less zoomed than the side without it. Unless I'm misinterpreting what he did, it looked to be mislabeled. 

When I first saw this test (Max Yuryev's AF test), I thought it was pretty disappointing myself. After all, it would seem that for the simplest of scenarios - a subject moving slowly toward the camera, at a steady pace, with no erratic, unpredictable movement and no obstacles, that the camera's default settings in AF-C should be able to handle it without having to dive into the menu and spend hours customizing the settings. And I also believed this method of testing video AF-C was the best - it's the one most commonly used by photographers to test autofocus tracking, people walking directly toward the camera or riding a bicycle...  for the reason that tracking a person or vehicle moving horizontally shouldn't be that demanding. Then I started to ask myself how often I would have a subject move from the back of the room directly toward the camera if I were doing the kind of narrative work I intend to do. And the answer came back, 'never'. For vlogging, I see many YouTubers using AF-C when AF-S would work much better. For example, if I'm at home sitting in front of my computer and talking to the camera, there really isn't any need for me to set the camera to autofocus continuous. Yet many YouTubers do just that. The same goes for vlogging out on the street Casey Neistat syle - If I'm holding the gimbal in my outstretched arm three feet from my face, AF-S works fine. Of course, I realize that for event shooters, wedding photographers and sports photographers, it can be a deal breaker, but if I were vlogging or shooting a budget film, I don't think it would be that critical. Or am I missing something?

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1 hour ago, jonpais said:

When I first saw this test (Max Yuryev's AF test), I thought it was pretty disappointing myself. After all, it would seem that for the simplest of scenarios - a subject moving slowly toward the camera, at a steady pace, with no erratic, unpredictable movement and no obstacles, that the camera's default settings in AF-C should be able to handle it without having to dive into the menu and spend hours customizing the settings. And I also believed this method of testing video AF-C was the best - it's the one most commonly used by photographers to test autofocus tracking, people walking directly toward the camera or riding a bicycle...  for the reason that tracking a person or vehicle moving horizontally shouldn't be that demanding. Then I started to ask myself how often I would have a subject move from the back of the room directly toward the camera if I were doing the kind of narrative work I intend to do. And the answer came back, 'never'. For vlogging, I see many YouTubers using AF-C when AF-S would work much better. For example, if I'm at home sitting in front of my computer and talking to the camera, there really isn't any need for me to set the camera to autofocus continuous. Yet many YouTubers do just that. The same goes for vlogging out on the street Casey Neistat syle - If I'm holding the gimbal in my outstretched arm three feet from my face, AF-S works fine. Of course, I realize that for event shooters, wedding photographers and sports photographers, it can be a deal breaker, but if I were vlogging or shooting a budget film, I don't think it would be that critical. Or am I missing something?

My main concern would be using it on a gimbal with a fairly wide aperture.  But even doing something like vlogging.. if it is a moving shot with a narrow DOF, a reliable AF-C seems pretty important. 
For most other stuff, I'd be ok with going to manual focus. 

 

 

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1 hour ago, jonpais said:

When I first saw this test (Max Yuryev's AF test), I thought it was pretty disappointing myself. After all, it would seem that for the simplest of scenarios - a subject moving slowly toward the camera, at a steady pace, with no erratic, unpredictable movement and no obstacles, that the camera's default settings in AF-C should be able to handle it without having to dive into the menu and spend hours customizing the settings. And I also believed this method of testing video AF-C was the best - it's the one most commonly used by photographers to test autofocus tracking, people walking directly toward the camera or riding a bicycle...  for the reason that tracking a person or vehicle moving horizontally shouldn't be that demanding. Then I started to ask myself how often I would have a subject move from the back of the room directly toward the camera if I were doing the kind of narrative work I intend to do. And the answer came back, 'never'. For vlogging, I see many YouTubers using AF-C when AF-S would work much better. For example, if I'm at home sitting in front of my computer and talking to the camera, there really isn't any need for me to set the camera to autofocus continuous. Yet many YouTubers do just that. The same goes for vlogging out on the street Casey Neistat syle - If I'm holding the gimbal in my outstretched arm three feet from my face, AF-S works fine. Of course, I realize that for event shooters, wedding photographers and sports photographers, it can be a deal breaker, but if I were vlogging or shooting a budget film, I don't think it would be that critical. Or am I missing something?

I guess I should be the only one to write it here today for the umpteenth time but tap to focus is already present in my 5-years GF5 and works just fine!

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