Retro Scan Universal experiments using the gh4 in 4k

[milesandjules]

Hi film Gang- been loving the Retro Scan universal since we got it a few months back. I'm amazed by how the on board chameleon camera can take all those frames in almost realtime....brilliant implementation!

We been chatting to Roger about how to use the universal with another camera just to see what a 4k scan would look like. We been testing it out with our panasonic gh4 micro 4/3 camera. The best thing about this camera is that it has a mode for shooting with an electronic shutter. This is good because the regular SLR would die after a few hours from all those mechanical actuations of the shutter/mirror.

Roger knows his stuff and suggested using a relay with the gh4 to stop and start the film for each exposure. This is because gh4 has the rolling shutter that looks terrible if it shoots moving subjects. It looks fine for a still image with higher shutter but for animation which is what doing transferring a frame at a time is, it gets jello effects pretty quick....i tried it with very slow rpm takeup motor and it still had problems. So relay solves this problem.


heres the setup so far
https://youtu.be/R0Od2BqZK34

heres a test clip
https://youtu.be/twMDHxrE1pQ

I haven't done any post work on either clip. Other than stabilisation in after effects using motion stabiliser.

here are some comparisons

[Pj]

This is great, the gh4 video seems softer, but the colours, detail and dynamic range is very pleasent an much better. Are you saving each frame as a Jpeg and then animating the Jpegs?

Pav

[Tscan]

The images look great, but seems like a lot of modification to do the scan at 1fps. I guess i'm wondering why you didn't opt for a higher resolution Point Grey model instead? What is the white plate mounted over the light box? If it's a shield for the LED, it's a good idea. But did you put it on ir did it come that way?

[milesandjules]

Hi guys
thanks for the feedback
Roger suggested this whole triggering setup -the led on the end of the chemilion input, to trigger a circut that sets off the relay to stop the film take-up motor and also triggers the camera remote and takes a gh4 jpeg-it can do raw to but that is somthing i havent played with yet cause the file sizes are mega-then just do an sd card dump the image sequence in after effects then stabilization cause the start and stop of the motor makes the frame move around alot( about 1/2mm in up and down sporadic jitter) you definatly need to stabilise.

Yep this is a slow process and something that is for our film making experiments rather than for client home movie dvds- the good thing is this mod just unplugs and its back to factory setup in 10 mins- the only thing i perminently had to mod was cut 5mm off the y axis camera holder so the big extention tube would fit- this doesnt affect the chameleon camera operation which i was careful of...i didn't want to wreck this machine with my experiments that might not work ha ha.

Yep i think other point gray cameras would work great and cant wait to see what future upgrades Roger has up his sleave for the universal.

We own a couple of gh4 cameras for regular video work and thought we would see if we could get it to work with the universal, after all roger likes people to experiment with his machine with different cameras -thats obviously part of its design.

Yep that is a light diffuser that i 3d printed -that stops lens flare coming from the sides of the film and the sprocket hole. (Pm me and i can send you the file)

I reckon the biggest improvement between the gh4 and the chameleon is camera noise in dark areas -its not really a resolution issue- the hd that the chemilion spits out looks great especially on bright shots where you dont see any noise- which is probably why the neg footage looks so good with it cause the shadow areas are white.

Also the gh4 is completely auto - because its set to aperature priority and i usually set it to f5.6 (non active lens) - iso 400 then let the auto shutter do the rest- which is essential as a 400ft roll takes 15 hours or so.

[JeremyC]

I could be wrong but the the chameleon seems to have the edging wound up on it making it appear sharper. I'm tentative because I'm assuming these sorts of cameras do not have this sort of technique built into their processing.

[milesandjules]

I think Roger's software has some sharpening built in and higher contrast makes it looks sharper i reckon- highlights and shadows have more info on the gh4 which makes it look softer i think

[Nate Williams]

Awesome work! I wish I had the time and knowledge to tinker with my Universal like you do. Luckily we have you to do the hard work

[ncollingwood]

Ya I think the GH4 footage looks more realistic in regards to what's on the film. The Retro, while a solid machine that produces great results, is oversharpening the image in my opinion vs the 4k capture is seeing more of the original film grain and is a bit softer without any post processing obviously. A touch of sharpening in post would do wonders for the 4k footage I think.

Having gotten my first ever 2k scans of Super 8 film from CineLab recently, I was blown away by how much sharper the scans were and how much more detail there was in the film than 1080p scans I've gotten done before so I don't think that 1080 is the limit for Super 8.

[RyanH]

I hope you made sure to use the electronic shutter on the camera and not the mechanical one, otherwise you are going to kill your mechanism in a hurry doing this.

[milesandjules]

Yep electronic shutter is the reason i used the gh4- its got quite a few other tricks up its sleave and yes after transfering 26x 400ft rolls of Scot's movie it surely would be dead by now- we had a nikon d70 die after is shot 120,000 frames for our stopmotion film- gh4 is still going stong