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Winnipeg, Manitoba
Canada

​Offering 3D services for film, advertising, web, corporate and birthday parties

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Building the Bomber Cam with 3d printing and scraps

Patrick Letourneau

​My Kodak Aero Ektar with the focus adapter i built

Originally produced for the US military in WW2, the Kodak Aero Ektar 178mm f2.5 is a large format monster of a lens. Mounted in bombers, facing down at Europe, this lens was sold to the US government for the price of a family car. It found its way into military surplus after the war, and was widely used in journalism and by professional photographers.  

All images in this post are expandable

I managed to come into one of these lenses through my uncle, who was director of the radiation protection bureau of Canada. I mention the radiation part, because the rear element is made of thorium glass, which happens to be radioactive! That's right kids, it's giving off all sorts of tasty rays. ​Luckily the danger is negligible unless you make contacts out of it, or grind up the glass and snort it. One side effect of the composition is the browning of the glass over time, which can be reversed (not that i want to. Such a nice tint of brown!)

​Panasonic 20mm f1.7 with reverse mount adapter. 

​So i have this lens, and i want to use it to close to its full potential. I dont do film, and just placing it in front of my GH2's cropped sensor would make it a super telephoto, so instead i decide to built a focus adapter. 

Bust out the 3d printer

So i decide on a ground-glass style adapter, only i cant find frosted glass fine enough to resolve a lot of detail. What i end up using was the diffuser from an old LCD I had. Diffusers are super fine-frosted sheets of plastic that spread out and even out the backlight on your monitor. I cut a piece to size and knew i had to build a housing for it. I started off with a pair of aluminium square tubes, as knew i wanted to build an adapter that could host my digital camera. The lens would throw onto a ground plane, and the camera would photograph the flipped image from the diffuser. Luckily, i have access to an Up! Personal Portable 3D Printer. I started measuring the lens and designing a support bracket in Cinema 4D

​This thing is huge

​The print was accurate to within 200 microns

​Printing in progress

​boom. The quality was so high that i printed a friction-fit ring to seal the lens to the bellows. 

 

​A handy man would have crafted a beautiful box out of mahogany, with dovetail joints, lined with fine black velvet and decorative brass hardware. I had matte black spray paint, epoxy, and little regard for proper ventilation. I set off putting together an aluminium frame to act as an epoxy magnet, and painted the crap out of it to cover up my shame. 

​the frame that holds this poorly thought-out design together

​More epoxy than i care to admit to

​The finished box. This is the length my camera needs to focus on the ground glass plane

​I then folded a bellows out of stiff paper and cloth tape. The bellows provides me with a push-to-focus functionality

​A diagram

​Here, with the top and back removed, you get an idea of what my camera is seeing. Note the shallow DoF and flipped picture

​Photos

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I took the completed setup to my favorite creative meetup, Secret Handshake. It was taking place in a dark pub and there were about 75 people that night rubbing elbows. I had the whole assembly on a tripod with a Nikon flash bouncing off the ceiling. The atmosphere was perfect for this vignetting and graininess 

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Popcorn Garlands and Movie Magic

Patrick Letourneau

Click to play

This ad was created in about 5 weeks for Cineplex Entertainment. It played on 1400 screens in Canada before every movie shown for a full month, and was sent out by the entire Cineplex organization (right up to the CEO) as an e-card, for which i made an alternate ending title. 4 versions in all. I didn't get much sleep, and there were at least 2 meltdowns over technical hiccups, but i'm extremely happy with the result, and the client was over the moon. I try to practice constant communication with a remote client during big projects, so i used Skype screen sharing heavily as well as a shared dropbox to keep in sync with the client's feedback. The client had creative prepared, so  my end was squeezing those creative brains until some concrete imagery dripped out. Avoiding constant changes to assets in the scene is a must, and the term "Ok, this is locked" gets thrown around a lot to keep me sane. Managing 13 shots without using Xrefs means i had to lock the kitchen build before moving to any rendering 

Lighting and rendering were a huge part of the work on this project, as there are hundreds of individual lights, most with Area Shadows, reflections, 4k textures ETC. Avoiding flicker, artifacts, aliasing, moire and noise are where my years of playing around with every button in Cinema 4D came in handy. Animating Global Illumination is, as any 3d artist will tell you, a stupid and impossible thing to do on a tight deadline. Animated GI (bounce lighting) is subject to A: massive pre-render caching and B: Soul crushing artifacts when it goes wrong

It went wrong

I ended up rendering out tests about halfway through the project with the Full Animation mode in Cinema 4d, and let me tell you about terrible glitchy flickering artifacts. They were *everywhere*. After a stressful few tests and more that one email to my producer proclaiming possible doom, i ended up using the standard static image lighting model for the GI, and lo and behold, it eliminated all flicker. This was the complete opposite of what C4D AR is designed to do, but holy crap did it save the day. GI pre-cache times were cut by 75%, and i didn't have to deliver a plasticy render with no bounce lighting. 

​Character help came from Pixel Reborn for design and reference animations. I did the hair based off of his sketches in Cinema 4D, and it came out at roughly 10-20 seconds per frame to render the hair, which is a really really fantastic result considering how great it looks. I had to exclude most lights from affecting it, so shadows dont fall quite right on his forehead, but the deadline shows no mercy. 3ds max FBX export issues plagued the project for days and really threw a wrench in the production schedule, so hopefully Alembic will be able to solve that on the next character heavy project.

​All images are lightboxed. Click to expand 

​The scene contained 100s of individual lights. Optimization was a huge priority to keep render times sane

Diffusion, depth of field and a bit of color go a long way

​Blocking out camera moves over Skype screen sharing with my producer really made the project manageable. It's difficult to use the standard email loop for feedback on something with as many variables as a camera move

​An example of the sub-optimal hair render. With a few more weeks i would have preferred more occlusion around his forehead -- But damn, does that oven look fantastic

​Compositing a 5000px sky with animated star twinkles and Aurora Borealis i 16bit colour quickly maxed out my RAM