Laurier

Move the 35mm back and this image is dramatically different. And yes it will match a 90mm since all that matters is distance to subject, not all this lens compression nonsense. This article explains/demonstrates it perfectly.
http://admiringlight.com/blog/perspective-correcting-myth/
"The perspective in a photograph is 100%, completely dependent on the photographer’s physical distance between them and their subject.  That’s it.  Not the lens, not the format, nothing but the distance.
To create an image with telephoto compression, the photographer backs away from the subject and uses a longer focal length to keep the framing the way they want.  The key point is: It’s the backing up that changes the perspective, not the lens.
If I am 1 foot from my subject, and the background is 100 feet behind, and I frame the subject with an ultra-wide angle lens, the difference between me and the subject and the subject to the background is 1 to 100.  Now, if I back up 10 feet and frame the subject so they’re the same size in the frame as my original composition by using a short telephoto lens, now that ratio is only 1:10.  This causes the background to appear much closer to my subject than in the first instance."
Shoot both lenses from 15 or so feet away and crop the 35 to match the 90, images will be identical. If you try to get the same framing in cam, the 35 will be much closer to your subject, creating the unflattering look with people, minimizing background elements - like making mountains and buildings look smaller and so on.

Lol Andrew, seriously? 

Since you have the cameras and lenses, why don't you just make a small comparison. Distortion of the different lenses will make it a little bit complicated so  try to stick to simple designs.
Take the GH5 with a 28mm lens at 2.8 and the hasselblad h3d 39 with the 80mm and f8. Same lens front (lens nodal point would be better) to object distance. Let's say 3 meters headshot with plenty of things going on behind, post the images here and let's see about that compression.
 

To be fair, most camera will do a ok job in controlled environment, but if you go shoot in uncontrolled mixed light environment, or outside in high contrast situation, the gh5 will fall apart compared to the ursa 4.6k. That what you pay for.
Also the motion is not even comparable, it s just ugly on Gh cameras, it s fine if you do documentary/corporate work but for fiction or music video the aesthetic is not very appropriate .

The DP1 and your DP2 has the best manual focus for zone focus in any premium compact camera Ive ever used. And I own the Leica Q... 
That's pretty usable imo
 

I had a DP2 and a DP3 Merrill, loved the look and the leaf shutter, but autofocus was terrible and dynamic range so so.
 
I did try the sd quattro , but autofocus is still bad, the viewfinder is really average for 2017, dynamic range is still so so.
And let s be honest, usability is quite limited on those camera .

To be fair, most camera will do a ok job in controlled environment, but if you go shoot in uncontrolled mixed light environment, or outside in high contrast situation, the gh5 will fall apart compared to the ursa 4.6k. That what you pay for.
Also the motion is not even comparable, it s just ugly on Gh cameras, it s fine if you do documentary/corporate work but for fiction or music video the aesthetic is not very appropriate .

Well the Kinefinity Terra is pretty much a Chinese knock off of a Red for nearly Red prices. I don't see the point of having one. Best to just buy a later model Red used, and hey it works, and you have a upgrade path.
Once you get above 8 grand well 2 grand more for a established product is the way to go. You can buy a Sony FS7 for that much money. I just don't see how they can survive. look what happened to Cion, and others. You can't sell cameras for nearly the same money as the top dogs and last.
And you can't show up at a shoot someone is paying you 50 grand to shoot without having a Red or a Arri, is a sad reality of the business. Even a FS7 doesn't cut it, you have to at least have a F5, preferably a F55. I would be the same way if it was my money hanging out.
Heck even the old original Red MX can get the job done if you can stand the boot up times, and the weight of it. You can't beat a Red for the money. A Arri, well rent one or be rich, Way out of most peoples budget.
And sad to say the Panasonic Varicam is not hardly even mentioned. Pretty good camera, well a great camera, that does not get much love. I guess they Need to lower the price pretty big time on it, only thing I see for them to do. I have a comparison video up in the Shooting section that shows it may be too good!
Sort of the same problem Canon seems to have with there top stuff, seems Way overpriced. The C700 is crazy money, and the C300 mkII well they have lowered it, and now the C100 mkII is Reasonable. But it sure as hell wasn't to start with. But then there was the Sony F65, WOW, now that was Expensive new! Might still be the best video camera ever made for the output on it. F35 no slouch either output wise.
I am talking all this stuff I think 90% of us, or more, could never afford. Maybe the older Reds, the Canon mkI that's about it. Nice to dream about them though LoL.

On the camera front yeah. Two things I'm super excited about are the Teradek iOS wireless feed, and the Aputure 300d.

Hi had a preorder on the 5k, canceled it and got a ursa mini 4.6k.
I had good experiences with blackmagic consumer services, they replaced my pocket in a week back then.

Having to ship your camera back and forth to china is a no go for me., If your BM camera break it s easy to replace/rent one to finish your production. If you plan to do serious work with your camera that something to consider.
I prefer the color science from Bm but the one from the terra is nice too.

I was considering waiting for it, but went for a URSA mini 4.6k ( I know it s not the same price range).
I had a pocket, a a7s and a GH4/vlog.
For docu and corporate work I think the GH4 was a nice camera but the motion cadence/DR was bad ( the motion cadence is also quite bad on the varicam apparently )
SO... yeah the gh5 is a better GH4, is it a cinema camera, no , is it worth 2k ? maybe , but for 2k you can get a second hand ursa mini 4k and I would probably go for that, especially if you do narrative/ music video work.

I was considering waiting for it, but went for a URSA mini 4.6k ( I know it s not the same price range).
I had a pocket, a a7s and a GH4/vlog.
For docu and corporate work I think the GH4 was a nice camera but the motion cadence/DR was bad ( the motion cadence is also quite bad on the varicam apparently )
SO... yeah the gh5 is a better GH4, is it a cinema camera, no , is it worth 2k ? maybe , but for 2k you can get a second hand ursa mini 4k and I would probably go for that, especially if you do narrative/ music video work.

I was considering waiting for it, but went for a URSA mini 4.6k ( I know it s not the same price range).
I had a pocket, a a7s and a GH4/vlog.
For docu and corporate work I think the GH4 was a nice camera but the motion cadence/DR was bad ( the motion cadence is also quite bad on the varicam apparently )
SO... yeah the gh5 is a better GH4, is it a cinema camera, no , is it worth 2k ? maybe , but for 2k you can get a second hand ursa mini 4k and I would probably go for that, especially if you do narrative/ music video work.

Well since you have a Sony A7s I would assume you have lenses for it so why not buy a used Sony A6300? I have seen them for 800 bucks used once in awhile. Probably better than m4/3 with low light ability.
Has 4k, really good autofocus, especially eye focus. 1080p sort of sucks on them, but if you shoot 4k and down sample they look great. And you would know the horrible menus they have, just like the A7s has. So that is a plus, sort of. 

The problem with HDR with a A7s/R is that your video feed will be 8 bits only, So what ever you do you won t have a lot of information to display, HDR displays are 10 or 12 bits usually.

It s a bit like displaying 720p on a 1080p TV, it s fine but you won t use the full spectrum of resolution.

If you output a video in rec2020 color space it will look like crap on a normal display, your display monitor also need to be set up in rec2020 space
Ideally you can work in something like davinci in ACES mode and apply the Lut at the end for exports.

As for the pro not adopting them.... Well a lot of high end pro go to rental houses, who invested tons of money on expensive system.
A red epic package is usually around 1k usd per day , for the price of a week of shooting you can buy a 4.6k mini package, so I won t be surprised if some rental house are being protective toward their equipment by saying that the ursa mini is not usable for pro work. It s probably the same thing for operator/owner of red/arri.

If people hire you for your past work they won t care much on what you shoot. If they hire you just to operate they will probably expect something else.

At the end of the day, the image coming out of the 4.6k is on par with arri and red, for a fraction of the price.
The camera is flexible enough to do what most jobs require, without being too big or need to many batteries.

People usually have a distorted view of what arri and red do, they create solid production cameras, but they don t do miracle, if you underexpose, all camera sucks.

I think blackmagic have their own market, a weird niche, but IMO they have the best company philosophy .

As for a new pocket/micro camera, I m not sure it s very useful, maybe replace the S16 4k sensor  as the DR is low.
Blackmagic released fair amount of cameras over the last years because there was a lot of improvement to be done, but today, they have a solid lineup.

Yeah the truth is, one can put a 20mm on the pocket cam and with a monopod shoot cinematic footage like no other camera anywhere near its price point. The footage still holds up today and is better than footage coming out of cameras 2 or 3 x its price.
With that being said, BlackMagic is out of their mind if they don't release a Pocket Mark II or a similar camera with a few upgrades at a similar price point... if they want to stay in the camera business. 

I had one with a set of mamiya on a a7s, sold it quickly.

First the focal reducer add a fair amount of barrel distortion,
Second, as stated by others, focal reducer.... reduce focal so your 80mm 2.8 become a 56 mm f2.... It s not so exciting, you can t go super wide either .
The only good point for me was that the lenses where bigger with a good focus throw, so quite production friendly.
Due to the modern market full frame lenses got a lot of improvement compared to medium format, today you can get pin sharp lenses wide open at 1.4, so getting medium format glass with a speedbooster on full frame is not such a good idea IMO. 

Using it without can be decent as you only use the center of the image circle but you will be mostly stuck at F2.8.
Keep in mind that the alexa 65 sensor size is not far off full frame either.

If you want the medium format feel on smaller format, just use lenses a bit longer and faster than you are use to, something like the Nikon 105 f1.4 

Well perspective compression is relative to your distance to your subject ( that why people speak about equivalence , a 42.5 on micro four third and a 85mm on full frame will produce the same compression at the same distance from the subject) 

The test you show simply say that the Leica are more corrected in term of distortion than the Cooke.

If you like distortion, get the Kippon, you will get a lot of it. But in term of compression and dof your 80mm f 2.8 will act like a 52mm f 2 .

The point of larger format is I guess that wide angle are a bit easier to manufacture.

Are you going to use it in controlled environment or not ? are you going to shoot all day long with it ?

If not nothing beat the versatility of a a7s/2 , you need to expose it properly and have decent skills to grade it , but for complex production the battery is a bit a pain in the butt.

Otherwise get a blackmagic pocket or the 2.5k one.

I had gh4/a7s/bmpcc and shoot a feature on the bmcc 4k.

Panasonic motion and image is not pleasing at all, the best images a I saw out of it, were when used with some lomo spherical to cut the sharpness. and still the colors/motion are so so...but a small versatile camera
Sony colors and rolling shutter suck on the a7s...but you can shoot everywhere anytime.
The pocket was way better in term of color/motion/look, but beware the moire.
The blackmagic 4k is unusable pass iso 400. otherwise pleasing image.

I personally now have a ursa mini 4.6k nothing to complain about....you get what you pay for.

Some people have made their own Nikon F mounts I believe?

People have definitely found ways to mount other glass on it. Besides, there's plenty of affordable PL lenses these days. It can shoot 48fps iirc, which is half speed, and I've talked to people on DVX User who use the camera completely solo. The F35 gives you a much better image then the RED One--just not better specs. Hollywood films are still being shot on F35, not RED One.

That camera is gigantic and heavy , you also need an external recorder, and pl glass only . 
Sure it as global shutter but no slow mo at all .
This camera is still overpriced as it s very hard to use if you don t have a full crew with you , they should go for 2k not 4/6k , I d rather for for a red one if I had to pick one of the two.
 

My overall personal experience after having a Bmpcc , GH4, a7s + recorder and some production with them are that ... I m done with dslr style camera .
Either the codec or the battery or the colors are issues (or rolling shutter ect)...
 
So I decided to move to something more professional and also considered a red one , a kinefinity terra and a Ursa mini
( I m doing creative work so I need a bit of slow mo, so no canon)
 
At the end of the day I went with the ursa mini 4.6k .
The red one is just too heavy, won t have warranty and the accessories are not transferable with the more modern red cameras,  it s fine if you have small crew around you , but as the solo operator it s too hard to manage IMO ( and no 4k 60fps ) But the image is great and the workflow too.
I actually pre ordered the terra 5k, but canceled it after so many delays, also one of my a7s died on shooting and made me realize how important it is to be able to send your camera for repair easily, with Kinefinity you have to send your camera back to china ...so also a no go.
 
 
Red mx brains (either scarlet or epic ) prices are dropping but the accessories are still quite expensive .
 


 

You should reconsider the ursa mini you can get a second hand one for cheaper , get faster glass or some extra light with the money saved.

A red mx won t be better in low light, and other than a F55/F65, sony colors....sucks period , panasonic is barely better outside of the varicam range.

Personally I  find external recorders to be a pain to use . More battery to carry , more potential issues , ect....

A ursa mini will be all in one .