Ok, I'll bite.
Back in the day I wasted money on an adapter attempting to make my old little Canon camcorder look like 35mm shooting through Nikon lenses onto a spinning ground glass, just before the world was turned upside down by the 5DMKII, and the Nikon D800 and the Panasonic GH4. The rig was clumsy and almost impossible to use, especially as my adapter did not invert the image.
So, purely as an experiment, I may dig the adapter out, build the rail support/optical bench and mount the GH4 shooting 4K. With a Panasonic lens on the camera, the adapter's diopter so the camera lens can focus on the adapter's ground glass and a Nikon lens out front all passing the light to the sensor, the rig can't possibly be sharp, but no doubt will produce shallower DOF and a grainy image. And as I have all the pieces, won't cost anything but time.
What a pain. Like I said, purely an experiment. When I have time. Like in two years.
The most valuable point I have learned from Mr. Rosen is to use your bars generator and waveform monitor to analyze the green.
I turn on the bars on my GH4, then turn on the waveform monitor on our Panasonic professional monitor. (This can be a problem if you don't have a monitor that can display a waveform monitor, but it's really a key part.)
I look at the green bar and put a piece of masking tape physically onto the monitor where the green bar falls on the waveform monitor. This tells me what the exposure for the green screen should be. I turn off the bars and light the green screen. All I need is two 500-watt Lowel Totas about ten feet from the green and a little higher than the camera lens, off to the sides of the green, and behind where the actor/subject will sit. I look at the waveform and I should see a straight line across the waveform. If it isn't, I adjust the Totas until it's flat. I adjust exposure with the lens iris/shutter angle (I usually use 180 degrees, although Rosen suggest a slightly faster shutter speed/lower angle to reduce blur if the actor is moving about a lot) until the flat line reaches the piece of masking tap where the green bar was before I turned bars off. Now I know where the camera iris has to be for a good green.
Then I put the subject into the shot and adjust the key light until the exposure is right. I don't touch the iris. Move the light in and out instead to adjust the exposure on the face. This maintains the proper green exposure.
Keep the green way behind the actor -- ten feet at least -- so the green spill onto the actor is minimal. Yes, it requires a good-sized studio to do this, but otherwise you will get green highlights on your actor that will cause problems. Shoot in 4k -- easy to do with the GH4. This gives a lot of pixel density to pull a good key.
Two open face 500-watt incandescents for the green and one big 36x48" soft light for the key and maybe a reflector for some fill and I'm good to go. Editors love it.
The time-delay effect of a vertical shutter was shown in 1912 in the famous French Grand Prix race car shot. I believe it was taken with a 5x7 focal plane shutter that, like the Canon, traveled from top to bottom, but much slower and for a greater distance across the giant piece of film. The race car's wheel leans forward and the poles and people in the background lean backward. It was so iconic, so representative of speed that cartoonists began drawing fast cars that way.
Rolling shutters are a very old problem indeed.
Focus will be close to impossible. Have you ever tried to focus a view camera? It takes a loupe on the ground glass and a black cloth over your head even to see the image on the ground glass.
And it's hard enough to see a phone's screen in bright daylight. Now you are looking at a reflection of your phone's screen, which is looking at an insanely critical focused image on the back of a view camera.
The phone will autofocus onto the "film plane" of the view camera okay, but you will still have to rack the bellows back and forth to bring the primary lens into focus onto the projected surface.
This is a variation of the pre-Canon 5DII 35mm Depth of Field adapter systems we hassled with to get shallow depth of field, where a static or rotating ground glass was placed behind an SLR lens and your small sensor video camera shot a video of the ground glass. Letus, Redrock Micro and many others offered solutions.
Now we're asked to shoot a video of an even larger "ground glass."
When I have nothing but time, I could adapt my antique folding 5x7 wooden field camera that's been in the garage for ages. All I'd have to do is mount a lens on a 4"x4" board and drill a hole above the lens for the iPhone to peek through backwards, then put the mirror to reverse the phone's image again.
Then, after hours and hours and hours of fiddling fun, put the whole thing away.
It was originally done for the 2015 National Space Symposium. We are reformatting and tuning it a bit but it will be essentially like:
Sony and Canon both want you to buy their high end products and whatever accessories they feel you should buy. Panasonic also has the high end product, but somehow, amazingly, has allowed their prosumer still camera division (think about that for a minute) to compete directly with their supercams.
Sony dragged their heels like this before. They told us the only way to record HD was with hyperexpensive HDCAM cameras onto giant reels of 1/2" super betacam tape screaming through the camera at uncompressed recording rates. Then JVC said, "Why don't we just encode to MPEG-2 TS -- the HD broadcast signal going to everyone's TV over the air -- and record an HOUR of HD onto super-cheap Mini-DV cassettes?"
This forced Sony and Canon to create their versions of HDV. I don't think they would have done so without JVC's pressure.
Personally, I applaud Panasonic for releasing the GH4 at such a reasonable price. It's amazingly good. We just finished a show -- shot completely in 4K -- that will be playing in NASA's IMAX theaters as an intro. I'm finding new ways to use the GH4 every day.
But remember, the G line -- the whole thing, including the GH4 -- doesn't really belong in this rarefied arena of performance filled with cameras like the C500, Red, Arri and Sony F55. It is an amateur camera that performs way above its design and has done so since hacked GH2's.
Canon had no idea what they were doing when they released the 5DMkII and blew us all away, just a few years ago.
It wasn't that long ago that good cameras were $30K, good lenses were $30K, tape was a serious cost element and the edit bay (three betacam machines, titler, switcher, DVE, scopes, sync generator, etc, etc, etc) would add up to $250K or more.
We are doing better quality work on our iPhones today (which can shoot 250fps 720p slo mo, with in-phone editing) and with these little DSLR's than we could have done with 16mm or SD video or even HD video just a little while ago.
We are at the very start of a new era. Enjoy the ride and have a bit of patience. It'll get there.