Nathan Gabriel

Right, you weren’t specifically referring to the GH5 as much as you were referring to any modern camera with modern conveniences but you have been known to defend the GH5 to no end... which is cool, I do it with my 5D3 as well.
It doesn’t much matter anyway, this thread has nowhere to go until some footage is released and some cameras are released into the wild.
With that being said, I really do appreciate John Brawley’s contributions to this site. The discussion I had with him the other week regarding his experience on the production of The Resident was insight rarely received from a pro to an aspiring director. And he seemed more than happy to offer it.
So maybe it’s a little unnecessary to pick apart the minutiae of every sentence and every word he ever posted on this forum to “win” an argument?

Agreed ;-)
You're saying you can tell the camera's apart that took the two pictures from Andrew's original post? Nah man.

We are living in a post-truth / alternative facts world now so while it may be factually provable by optical calculations and various laws of physics that the only thing that determines perspective is the subject to object distance it is also equally valid to say a 'wide angle' lens has a certain 'look' that is independent of the format and personal belief in this or any other similar notion is just as valid. Indeed there is evidence to be had that there is a vast conspiracy involving all the camera manufacturers and scientists in the world to promote the idea of 'perspective' to sell more cameras and lenses. For many years now we have all been ready to accept the scientists opinion that the world is round but thanks to a growing number of brave and pioneering individuals and groups around the world the truth is finally emerging that the world is infact flat. Only just recently was I able to satisfy myself that this was indeed the case when I took my old school ruler down to the sea and held it up to the horizon - no so-called expert can argue with that can they!

I'll put my hand up too and say I never use AF and only sometimes use IS.  IS is great on static shots, but problematic on moving / tracking shots.  Just like gimbals, with many "tells" for bad operating.
But I'm not everyone.
JB

As soon as the HDSLR Revolution hit in 2008 that was the start of the death bell ringing for any ultra low budget indie film to ever shoot on film. 
Then when the BMCC launched in 2012 that was the final strokes of the clock counting down until it was time over for even more "mid budget" indie level films. 

This is not even counting the impact RED and ARRI had, and honestly today an indie film can totally shoot on a RED or ARRI camera if they really really want to. I've worked on plenty of ultra low budget films using a RED or ARRI. 
Of course the other impact RED and ARRI had, is as the bulk of the high end productions switched over to them and away from film, that then dried up the source of work for the film processing labs. 

Once the last film processing lab is gone in your country (like is the case in New Zealand. Park Road Post closed its film post-production facilities in 2013, that is a looooong time ago!) then it becomes very very hard to produce a film film.  At least in the USA they're massive enough I think there is still a couple of commercial scale ones left. 

Another big impact upon indies this switch from film to digital at the high end is that in the past indie filmmakers would beg/borrow/steal/scrounge the ends of rolls of film, and thus at least have the raw beginning materials to make their film with (but have to work around the hassle of having incomplete rolls of film as they're short ends). Which would help bring down costs for them. Of course today there is much less opportunity to source these, as there simply are less of these film ends around. 
I looked up Jim's films: The Limits of Control (2009 released, so perhaps actually filmed a couple of years earlier in 2007? Maybe, could be more, could be less), then Only Lovers Left Alive (2013 release, but again the actual production would have been earlier).

First of those two was filmed with an ARRI film camera, the 2nd of those two with an ARRI digital camera. And those two dates aligned up with my earlier comments about the timing of the transition. 
Am sure of that.
 
An old RED ONE is practically free to rent. Heck even say a Scarlet MX (maybe even Dragon) you can get owner OPs throwing it in extra for nothing at all. 

Even at the highest end of RED cameras, they've always been cheaper than the high end latest ARRI digital cameras. 

Peak of image detailness and specific traits of rendering quality on Voigt m43 lenses is around f2-2.5 - see Shane Hurblut reports. Double with factor 1.5-2, that's even more shallow dof than mostly preferred value in today's cinematography (assuming super 35 as standard). Contrary, similar peak for most FF lenses is most often at about f4 or even at f8 with older generation lenses.
Another question is actual quality of these Voigts lenses and corresponding values - these are lenses quite in league with Zeisses (of course, the same Cosina manufacturer) which are mostly priced higher.
So, I think that comparing Voigts with cheaper FF lenses just because of simple dof mathematic is not quite correct - besides, there are also cheaper m43 solutions such as Mitakon or even SLR Magic with more players just in the game - Laowa or so.
Importance of shallow dof vs easier affordability of deeper dof in real narrative experience is so often and endlessly discussed, also here in different threads. With little bit of shame for repeating it, I'd just again note that, imo and im-practice, extreme shallow dof is simply secondary effect - because totally destroying environment discernibility most often is not in the favor of story. Photography has different preferences.
About light gatherings - the must calculated condition is to compare just sensors at least of the same generation, preferably of the same manufacturer. Than it will be clear that f stops provide approximately identical effects in m43, APSC or FF when sensor light reactivity is the same for all. Factors of bigger surface (FF) and lesser need for lightening power (m43) are mostly in compensating relationship.

You're like 90% of the way there.
 
See if this doesn't help:
The following examples would provide the exact same image, and therefore are "equivalent" assuming the camera is always in the same spot.
On a M34 sensor: A 25mm 1.4 lens  (and it doesn't matter if the lens was made for FF, APSC, or M43 - this is important) On a M43 sensor: A 50mm 2.8 lens, speedboosted (pretend it's a 0.5X speedbooster).  (This is because you're now actually putting a 25mm 1.4 lens on the M43 once you've added the speedbooster, just like #1) On a FF sensor: A 50mm 2.8 lens  - - - For #3 the ISO will have to be multiplied by the crop factor squared to get the same exposure. - - - 
 
 
 
I ran out of likes for today but this is very important for new filmmakers to know
I used to think this but focal length has nothing to do with perspective, only the location of the camera and the relation to the objects in frame. The easiest way to test this is to shoot a camera at a chosen focal length, say 50mm, and then shoot from the exact same place with a lens with 2X the focal length (a 100mm lens in this example). Go into an editor and compare the full shot at 100mm to a 2X crop of the shot at 50mm. They will be the exact same image. This is no different from shooting a FF camera at 100mm and a M43 camera at 50mm. This shows how the perspective never changes if you don't move the camera, no matter what lens you're using. Seriously, try it out.

My reference to $5M was actually about camera equipment, and was around the point that anyone using a >$5M camera setup would think of the entire DSLR revolution in the same way that this board seems to talk about vloggers..  basically as spoilt whiney teenagers 
You're right that the situations I describe don't have anything to do with budget.  You can shoot in a highly controlled environment with a phone, a couple of desk lamps and a wired lav mic if you wanted to.  On low budget films as soon as you don't pay people minimum wage you can get away with spending almost nothing (except lots of social capital!).  I co-produced films at $2K and $5K that were absolutely situation A with months of pre-production, >20 cast/crew, and one of them had >10,000 person-hours in it (I didn't estimate the other).
I understand that my post is a huge simplification, but I think the principle stands.
As someone who shoots at the C/D end of things its amusing/frustrating when I mention a challenge I have in shooting my home videos and the reply is to add crew (take extra people on my holiday), to multiply the weight of my rig by three (or more!), or to get my family to repeat parts of the holiday over and over until I get a shot with the right lighting!  
This topic is an attempt to get people to understand that there is a huge variety in film-making outside of the niches they seem to live in.
I was going to say this!  Film is too slow for most commercial shoots, and for indie it is too expensive!!!
I think I heard somewhere that it's cheaper to rent a RED than to shoot on film these days?

Absolutely
I mention $50K because I thought that was expensive enough to distance it from what we're talking about (mainly GH5 / GH5s / BMPCC4K / A7 series) which aren't anywhere near $50K.  Also, a production that large is outside my experience
I watched the ARRI Academy HDR Masterclass series and just about had to poke myself with pins to stay awake, the pace of the guy running it was so slow that I would consider him a fire risk - ie, if the place caught on fire I'm not sure he would be capable of leaving the premises fast enough to make it to safety!  During a real shoot he might move faster, but it's hard to drive a Ferrari at walking pace so...
I'm aware that one metric is 2 minutes of final footage a day for a feature film and that's not a case of going fast by rushing, it's a case of going fast by being thorough and doing things right the first time, so that pace is understandable and I'm not criticising it at all.  However, if you compare a big film set like that where a squillion people worked a 12+ hour day to capture 2 minutes of final footage with a production like event or documentary shooting where a single operator captures 2-10+ minutes of final footage in a day the ratio of speed is huge....  (maybe 50-100 times?) .....Let alone a vlogger like Casey Neistat who captured, edited and published videos 5-15 minutes long every day without a break (with no gaps for planning) for months at a stretch then the ratios may as well be in parallel universes because you have to include all of pre and post-production person-hours.
In terms of people thinking their situation in C or D but it's really situation A, yeah, that's inevitable.  Film-making is an industry so big that people can be involved in part of it but be completely unaware that other parts of it even exist.  One of the challenges I have with home video stuff is that because it's mostly kept private there's very little visibility of it.  Just like how many people use fancy DSLRs to take pics of their kids - it's hard to understand how many are doing it because people don't publish photos of their kids much - it's an iceberg where only a little of it is visible from the surface.
I should also add that in a sense the people operating in a faster environment need to demand more from their equipment rather than less, high DR is useful when you're not in controlled lighting, higher resolutions / bit-rates are useful when you want to punch-in digitally in post instead of changing lenses and doing another take, etc etc.

$50K?! That is nothing. I've been on shoots where just a single lens costs that. 

And yeah, some folks coming from that world might do shoots they call "Situation D / C" yet from your perspective it very much "Situation A". So even simply classifying different types of shoots isn't always straight forward. 

And even within "Situation A" there is a tonne of variety, from shoots which might want to get a couple of dozen pages of dialogue done in a single day, vs others which are only aiming to complete a couple of pages worth per day. 

Vloggers aren't crazy....  but there sure is lots of debate around the topic!  
My theory is that they are making films in a different situation and the fact they have different needs is why they appear to be crazy to film-makers from other situations.  This is my attempt to explain it.
I think film-makers fall across a spectrum of the speed of film-making and the amount of control over the environment that exists.
Situation A: low-speed / high control.
In situations where things happen very slowly (eg, on a controlled set, or perhaps shooting landscapes and B-roll) you can have everything on full-manual and get the best results because you're in full control of what is happening.  This means time to level a tripod, setup whatever lights you want, use a light-meter, adjust all camera settings, setup and rehearse camera moves, etc etc.  In this setting having the camera do things for you is counter-productive because you want to have full control over everything.  Therefore things like autofocus and IBIS are unwelcome, camera weight and size might not matter, but image quality probably matters a lot, and cinema-primes are a good fit.  I think the GH5s / BMPCC4K are aimed more at this type of application.  There is always room for a sound-person and various crew here.
Situation B: moderate-speed / moderate control.
In situations where things happen faster but you have a good degree of control there is value in having some 'helpful features'.  This might be something like run-and-gun film-making where you have time to setup an interview station where you have a moderate amount of control.  Things like manual focus can still be used, but reliable face-detection would be useful.  You might set shutter speed and aperture but have auto-ISO enabled.  Camera size and weight potentially matter because you might be filming B-Roll or featuring clips of things that aren't in your control (eg, shooting an event) so having a lighter tripod setup you can carry around and shoot with quickly is useful.  Having a sound-person and other crew also works here.
Situation C: high-speed / some control.
In situations where things are happening in real-time but you have a degree of control over some aspects the priorities shift again.  This might be something like ENG film-making where when the action happens you have to capture it with no second chances, but you might also be interviewing people and have some degree of control about how the interviews are done.  For example if you were covering a building fire you have no control over when or how the fire will burn, what the responders will do about it, etc, so you need to be able to move very quickly, having a rig that can be hand-held (shoulder rig normally) and also having a tripod that is quite portable.  In this situation IBIS, reliable auto-focus, an all-in-one zoom lens, etc become desirable features. However, during the interview situation you can still have input into what is asked, where it is (interviewing the fire chief with something burning in the background makes a nice shot) but if people fumble their replies you can often ask them to repeat something or prompt them in a variety of ways.  These can have crew, but often due to the economics of the situation there isn't budget.
Situation D: high-speed / no control.
I add this mostly for myself and my home videos, where my priority is to capture what happens without directing anything, as I prioritise the experience over the film.  This is 'fly-on-the-wall' film-making in a sense.  Technically this is within the previous situation, but I choose not to exert most / all of the control I have.
I teased that this discussion was about vloggers, so I think they sit across situations A-C, but the controversy comes in when vloggers are in situation C.  There is a hierarchy of needs for vloggers in situation C:
They REQUIRE that the camera be small and not attracting the wrong attention because situation C is about shooting in public (I've posted elsewhere about being stopped by authorities when shooting in public) and they require that the camera be able to be turned on and recording at a moments notice and they are almost exclusively a self-shooter with no allowance for any dedicated 'crew'.  This is basically iPhone / RX100 territory, and creates films where the content better be great because the picture will be shaky and the audio will be noisy and full of ambient sounds. They often WANT to improve the basic quality and so they add a directional microphone of some kind (typically Rode VideoMicro or Rode VMP+) and try to make it more stable by adding a handle (typically a gorillapod). However (and this is where we get the controversy between vloggers and other film-makers in situations A and B) they LUST after having more 'cinematic' videos, which drives them towards higher-bitrate codecs and large aperture lenses (which means they're now looking at the same cameras - 5DIII, 1DXmII, A7SII, BMPCC4K, XH-1, etc), and they want 'buttery smooth footage' which means world-class stabilisation.  Film-makers in situations A and B get these by having setups that are have at least one of the following challenges: slow to setup, cumbersome to use, large and attract attention.  When a vlogger looks at a high-end DSLR and sees that it doesn't meet one of the basic things they require (small, inconspicuous, no-setup time) they see it as a fundamental flaw in the camera.  This perspective makes no sense to a film-maker who places these features of a camera quite far down their priority list, and this is where the controversy occurs.  
Of course, vloggers often don't know a single thing about how the pros do things, are often self-centred and unwilling to learn about other styles of film-making, which enrages the pros and thus flame wars ensue.  (Of course, exactly the same can be said of a minority of film-makers who are uninterested in how vloggers do things, are self-centred and self-important because they view their film-making as somehow better than other types, and are equally as responsible for the flame wars as the vloggers...). Hopefully this helps to explain some of the key differences and why we keep tripping up on these topics.
I know that this is a huge simplification of the variety of situations, that this is a spectrum and film-making can exist anywhere between the four situations I listed above, and that many film-makers have projects that are on different parts of the spectrum and require equipment that is flexible.  However, each film-maker and each purchase decision will be made by prioritising the features in one category against the others.
BTW, the entire DSLR revolution (ie, the vast majority of people on this board) probably look like vloggers in the eyes of those shooting on big-budget sets with the $50-100K setups and equipment that requires a truck to lug it around.  Anyone criticising the BMPCC4K is going to look like a spoiled millennial when we criticise a $1300 camera that shoots 4K RAW!

Your post inspired me to start a new topic about how I see the differences in priorities that film-makers have
 
Here's an example with a battery...

It's from this campaign: https://www.indiegogo.com/projects/gimbal-with-focus-control-skyvideo-pro#/

Circular argument.

Looks like Panasonic has created a new sensor technology that is earmarked for the GH6. This new sensor can adjust sensitivity of each pixel individually using the per pixel ND function. And all of this is done at 8k resolution. 
From the press release:
“Panasonic Develops Industry’s-First*1 8K High-Resolution, High-Performance Global Shutter Technology using Organic-Photoconductive-Film CMOS Image Sensor
The new technology enables 8K high resolution and high picture quality imaging without motion distortion, even in extremely bright scenes.“
You can read more here.

Panasonic GX8 has a tiltable EVF. Would nice if the next GH got this as well.
 
 

@blondini No, perspective distortion is only affected by distance from the camera to the subject. No matter what sensor/lens combination you use, if the camera and the subjects don't move, then the ratio of the size of two subjects will remain the same. I did a quick and dirty test to illustrate. It's a little imprecise (the camcorder would NOT focus on the guy in front...)
For all three images the camera is in the same place. I suspect the small discrepancies in ratio (2.2% error) are mainly due to moving parts inside the camcorder when it zooms, which changes its actual distance from the subject. But this is an easy thing to test yourself.
First image is a 4mm lens on a 1/4 type sensor

Second image is a 55mm lens on an APS-C sensor

As you can see, the ratio of the figures is the same. You could even use a wider lens and the ratio remains, because the distance has not changed:
Third image is a 2mm lens on the 1/4 type sensor.

 
Quote from Wikipedia:
 
 
 
Yes, it would. As long as the camera is in the same place, the relative size of the plane compared to the people will remain the same regardless of the lens or sensor. If you don't believe me or my Legos, go try it yourself!

Somewhere between 0.95 and 1.4 - definitely no more stopped down than that. The EXIF says ISO 200 and 1/6400th so probably closer to 0.95.
I had some video tests I shot with a model a couple of a years ago with the Voigt 17.5 vs the Pana 12-35 at 17ish, both at 2.8. The difference in 3D pop was quite remarkable but I can't find the files now. 

I go along with what Metabones says about their gear.
Oh and what do you think the difference will be if you look at (say) an M43 sensor through a 35mm f2 lens VS looking at it through a speedboosted 50mm 2.8 lens? (example not relying on exact match).
I will leave it there.

@horshack If I'm not mistaken, pixel vignetting is entirely due to angle of incidence on the sensor. Smaller sensors have less oblique angles of incidence at the corners. I could be wrong, but I bet that pixel vignetting won't be a factor in this comparison. I'd love to see evidence either way, though.

At the end of the day you can project the same image into a smaller space.
That's physics.
What Northrup was suggesting was wrong.
An F2.8 aperture is always an F2.8.
The optics don't physically change shape when you have a smaller sensor behind it.
A lens that covers a smaller sensor at F2.8 is still a wider opening than F5.6 - with the same brightness as a full frame F2.8.
So no, manufacturers should not be calling a Micro Four Thirds F2.8 lens a F5.6 lens at all.
Using equivalent aperture to calculate depth of field vs full frame, is the only useful use of it. It's for us in our heads to use. It doesn't apply to other aspects.
If you put the Canon 24-70mm F2.8 on the Speed Booster XL 0.64x on 1.86x GH5S, you get...
A 1.19x crop sensor, practically full frame.
An F1.8 effective aperture.
15-45mm focal length on a 1.86x crop sensor, so an equiv. range of 28-84mm.
Not bad I'd say.
You forgot the Sigma 18-35mm F1.8 on a Speed Booster 0.71x as well. That is a 28-52mm F2.7 equiv. on the M43 SB and Super 35.

Voigtlander vs SLR Magic:
I have the 25mm 0.95 Voigtlander and it's amazing. Only thing is it has a bit of bloom wide open but it's useable for video. The image is lovely.
The SLR Magic 12mm T1.6 is nice enough and a lot cheaper. It has a natural look (not like the Lumix lenses) and is a bit warmer than the Voigt. It's a bit harder to focus as well. What I really feel is that T1.6 is not fast enough for me at times on the GH5.
M43 vs APSC/FF
I have the GH5, a Speedbooster Ultra and the Sigma 18-35mmm 1.8 (1.2 with the Speedbooster) and there are good things to say about the combo. What I really like is the IBIS as it means I can go handheld in run'n'gun situations. The 4K 10bit and 4K 50p are great and give a lot of flexibility in post (edited in 1080p).
But....it has 4 weaknesses for me for video. Coming from a Canon C100 mk1, the GH5 really isn't great in lowlight. With the same Sigma lens I could go to 6400-8000 iso with the Canon and with the GH5 it's pushing it at 3200. Whilst the Voigtlander improves things I don't feel it's able to really compete. Another problem is focussing. The LCD and EVF are miles better in the GH5 but being able to punch in to check focus is a godsend in the C100. In the GH5 if you haven't nailed it you are punished (we won't even go into AF!). Ergonomics is another issue. The GH5 is a vast improvement over the Canon DSLRs I have used before but on a C100 everything is in the right place and works. I now find myself thinking about buying a loupe (Vary-i) or mini rig for the GH5 which is not why I bought it! I wanted to go lighter! The other thing I notice is that somehow (voodoo?) the small Canon (WDR) files seem to have far more dynamic range than the GH5 (even 10bit). The Canon is somehow able to make the image work and handles complicated lighting (colour temp or lack of light) much better. At least that's my opinion!
So last night I got very little sleep as I contemplated selling the GH5 and buying a C100mk2!
Why o why hasn't Canon produced a 4k 50p C100 mk3!!!

This is a portrait I took with the Voigtlander 17.5mm and GH4 a couple of years ago. With all these cool M43 cameras out/on the horizon I wish I'd kept the Voigty set now. . . and added the 10.5.

The Voigt is much better than it looks in that comparison, it's an incredible lens. One of the few I really regret selling.
I posted a still from my portfolio taken with the GH4/Voigt 17.5 here: https://www.eoshd.com/comments/topic/6396-lenses/?page=162&tab=comments#comment-233871 I felt like the Voigts coupled with the GH4 had the most mojo of any non medium format camera I've used for raw stills, and they made the video look a lot nicer too.
 

Wide open I don't like so much.  I typically set mine on a 1.4 - .95 split.  That looks good to me.  No doubt FF and FF lenses have a lot of advantages, (I exploit them myself) but it's not like one sensor option is wildly more impressive than the other.