DIY digital camera
A rendering of what I'd like the camera to look like.
10 May 2012 - Inspired by the DigiLomo by Joel Pirela, I too wanted to make a good looking digital camera for cheap. I'd be making and designing it myself, facing a number of different challenges.
This will be the page I'll post the updates and the steps I made to make this project come true. And I'm giving myself till July 6, 2012 to make a working digital camera.
If you want more information about me, ask me questions, contact me, here are all the details! I'm Charles-Axel Pauwels, industrial design student, my twitter is @cpauwels, and you can contact me at capauwels [at] gmail [dot] com.
Now let's start making this camera, shall we?
The camera you see above is the one made by Joel Pirela, which I'll use as starting point. I hope my camera won't look too similar, but I'll be using the same materials (wood and aluminium), since they are cheap, easy to use, and they look really good together. Also, without specific machining equipment, the final result might also look very box-like.
Lessons learned from the DigiLomo
Let's start with the specifications:
- 5MPix sensor
- 50mm Olympus OM lens
- Powered by AAA batteries
- 1.8" screen
Doing some research, one thing that struck me as weird from the pictures taken with the DigiLomo, is that the viewing angle is about the one of a 50mm lens, but with the sensor (a very small one, I'll get to that later), there ought to be a crop factor of approximately 4 or 5, meaning theoretically the images would be like with a 200-250mm lens.
An other detail is that the Flange Focal Distance (distance between the lens and the sensor) of OM lenses is 46 mm, and clearly from the pictures this isn't the case. From my rudimentary knowledge about optics, I believed the camera wouldn't be able to focus to infinity. I've contacted Joel and that's indeed the case. The camera will never get far objects in focus. This for me wasn't acceptable, and thus one of the requirements of my camera would be infinity focus. The sensor being much closer to the lens is also why the field of view looks normal.
Joel disassembled a Vivitar Vivicam 5025 camera to use as a base for his project. It's one of the worst cameras you can buy. I wondered why he did this, except for the fact it is very cheap and he wanted to go for the "Lomography" style. I chose to go for a better sensor and screen, and tried to disassemble a Canon compact camera with a broken lens assembly, but that still showed an image when powering on. And this is when I understood why he used a cheap compact camera: zooming lenses on compact cameras can't be removed without:
- A whole lot of effort. I was stuck with a lens+sensor assembly I didn't know how to disassemble further
- Keeping the camera working. Assuming you manage to remove the lens, the camera will throw out lens errors and power off.
The ViviCam cameras are some of the cheapest cameras you can get. And they are so cheap for one reason: they don't have a lens that focuses. They have a hyperfocal fixed lens, meaning the lens is made so that everything after a certain distance is in focus, and thus the need for a focusing mechanism is not necessary. It is really cheap, and since it doesn't have any electronics, the camera has no way of knowing wether the lens is present or not, and thus removing it doesn't change the way the camera works. Which is excellent news for a homemade camera, and the primary reason why Joel chose this camera.
"Digital Lens" -- or the most analogue lens you'll find on any camera today. No electronics whatsoever.
So I scoured the internet -- eBay -- to look for a cheap ViviCam camera. I found a Vivitar ViviCam 5024 used and in working condition, I bid 25 euros for it, got it for 14! It has the same sensor as the one used by Joel, but it has a larger 2.4" screen, which isn't too bad.
I didn't want to go the same route as Joel with the lens, being unable to focus to infinity.
So there were a couple of unknowns from the ViviCam, which would be important:
- The equivalent focal length
- The sensor size
Different sensor sizes in cameras nowadays -- note the 1/1.8" sensor isn't the smallest one!
So the next task was to find a lens that wasn't too large, that would give a 50mm equivalent focal length (so I was looking for a 10mm lens), that had a Flange Focal Distance of under 20mm (otherwise the lens would be too far away from the body, making it stick out like a swore thumb), and that wasn't expensive. Oh and a nice bright lens would be awesome (f/2.8 or better).
Guess what? Such lenses do exist!
They are called C-mount lenses, and they were originally made for 16mm movie cameras. The mount is extremely simple, it's just a screw thread. The FFD (Flange Focal Distance) is just 17.52mm. And there are plenty of lenses available, ranging from old Angenieux marvels costing a couple of hundred to a couple of thousand euros, to extremely cheap new lenses. Why new, when the mount is for old film movie cameras? Because security cameras use the same lens mount! And they are made for different sensor sizes, including 1/3" and 1/2". So I went looking for cheap C mount lenses made to cover a 1/2" sensor (the closest to 1/1.8"). And I found two I bought:
- 1/2" CCTV 12mm C Mount Lens for Security Box Camera f/1.4 @ 23 euros
- 35mm f/1.7 F1.7 C Mount Lens @ 15 euros
Attaching the lens to the camera
To attach the C-mount lens to the camera, I thought the easiest way was to buy a couple of rear caps, remove the flat part, and voila! So I did just that, bought 2 aluminium rear caps for C-mount lenses.
11 May 2012 - So while waiting for all the components to come from all over the world -- basically Hong Kong -- I decided to do some more work on the dimensions, and the best way to do so is firing up a 3D CAD application (SolidWorks) and start modeling all the elements. I started with the lens. I got the dimensions from eBay, and then used the sensor as starting point for modeling the camera. I gave the camera a thickness of 3cm, which is a lot, but I preferred starting with enough space, and once I get the ViviCam I'll see if it needs adjusting.
The body will be made out of wood, because it is the easiest to shape, but I want a good looking finish, so I'll cover the wooden structure with leather to make it look gorgeous and exclusive. The rendering has a Leica look to it which I like. The top and bottom plate will be cut out of aluminium. The shutter and power button aren't modelled right, and the whole needs a lot of refining, but I want to share every step of my process.
So here is the first rendering:
12 May 2012 - I changed the thickness of the camera from a safe 34mm to the thickness of the ViviCam+4mm to account for the thickness of the wood on both sides. The renderings look a lot more balanced now. But don't be fooled by the renderings, the size of the camera now including the lens is 112mm large, 61mm high, and had a depth of 70mm. Which, put in perspective, is the same size as an iPhone, but a lot thicker of course!
Reducing the thickness has one disadvantage: the FFD is too large, and thus the mount will stick out a bit. I don't mind actually, it'll make changing lenses easier as well as giving more space to focus (the focus ring is the first one on the lens starting from the camera body).
Other changes include:
- Modeled a shutter and power button
- Made the leather texture clearer
- Started working on the back of the camera
Receiving all the ingredients
26 May 2012 - Over the past two weeks all the ingredients I ordered slowly came into my mailbox (or rather the mailboxes of my neighbors since I'm not often at home during the day). The camera was the fastest to arrive being shipped from the UK. The lenses from HK were shipped reasonably fast too!
You've seen the camera in the pictures above, here it is disassembled. 5 screws are all that holds the camera together, with about 5 other holding several components in place (like the lens). The thickness of the camera is 28.7mm
On top you can see the front cover, which is made out of an injection molded plastic. It serves the sole function of protecting the camera. The "lens" you can see in the previous pictures of the camera is just ornament, as you can see there is a hole in the front cover. Removing the front cover, but still keeping the camera working as good as before (with the lens and all the electronics), the thickness of the camera goes down to 20.9mm (from 28.7!)
A bit lower on the right you can see the "real" lens. Vivitar states it's a "digital lens", f/2.8 with a 7.23mm focal length. Actually there is absolutely no electronic component in the lens, it's plastic and optics (plastic too! - forget glass in this case...). So the "digital lens" is the most analogue you can find, with no communication between the body and the lens. This is perfect for what I want to make, since the body has no way of knowing if I changed the lens!
In the middle below the front cover is the main board, which has the sensor, and is still attached to the back cover. The sensor is quite much smaller than expected, meaning the focal length of the lens is wrong. I guess the size of the sensor is closer to 1/3" or 1/4", which is much more realistic for such a cheap camera.
Around the sensor on the left and underneath there is a metal part attached with screws. The sole function of that is to add weight to the camera. Yes you read perfectly, it's more than 20 grams of weight added to make the camera feel heavier and less cheap.
Furthermore on the board you can see the flash, the condensator for the flash, and a small piezoelectric component that makes beeps each time you press a button. 3 1.5v AAA batteries power the camera. Underneath you can see the battery slot element that let's you swap batteries.
The back of the camera is taken mostly with the 2.4" screen, as well as several buttons you can see on the right. Not all buttons will be used on my camera, but from left to right, top to bottom here are the functions:
- Zoom out
- Zoom in
- Mode (Photo/Video/Review pictures)
- Flash/Arrow up
The SD card slides in from the left under the screen. The maximum capacity the camera recognizes is 8Gb.
Without the back cover, the total thickness of the working camera goes down to 19mm, 33,8% thinner than the camera originally was.
So, before creating a totally new body, I managed to fix the lenses to the existing body and took a few sample pictures. These are not interesting from a photographic point of view, but are interesting nontheless.
35mm f/1.7 lens pictures
All these objects - the camera, lenses and two caps - are expected to arrive soon. I'll be updating this further during the project, and I'll be tweeting when something is added. You can follow me here: @cpauwels for updates or questions!
Charles-Axel Pauwels - 2012 - capauwels [at] gmail [dot] com