AXIOM Beta
1 Printed Circuit Boards
Boards:
The AXIOM Beta uses a Microzed as main image processing platform:
AES-Z7MB-7Z020-SOM-G
2 AXIOM Beta Generations
Voucher holders get at-cost hardware upgrades and replacements. But any voucher holder can decide it which stage to actually acquire the current AXIOM Beta hardware. Software upgrades are and will always be free and publicly available. You can at any time upgrade or downgrade your camera software.
2.1 AXIOM Beta I - Developer Edition (Early Beta)
Intended for developers and early adopters - first generation that is currently being shipped - small production batch size of around 15 - 20 cameras.
Limitations:
- no enclosure yet - skeleton only (3D View)
- CMV12000 image sensor only
- passive sensor cooling only
- passive E-Mount only (passive Canon / Nikon adapter available)
- screw on UV/IR cut off filter instead of camera internal one
- Interface Board limits image sensors throughput to 150FPS@4K (faster Interface Board replacement will be available later)
- Dual 5V 3A AC power supply only
- 1x HDMI 1080p60 output module and PMOD debug module are the only plugin modules available currently (AXIOM Beta has two slots)
- Solder-on area on AXIOM Main Board not populated with gyroscopes/magnetometer/accelerator yet (will be available later on)
- Power Board requires manual reconfiguration (trimmers) switching to a different image sensor module
- no power switch on camera yet (camera turns on when power is connected)
3 AXIOM Beta Topics
3.1 Active Battery Mount
Battery mount for NP-F970/F750/F550 batteries to power the AXIOM Beta. Includes power usage and capacity monitoring to estimate remaining charge and time remaining.
More Thoughts on Power.
3.1.1 InfoLithium Protocol
Proprietary protocol from Sony that exchanges metadata between batteries and devices. Expected data inside the protocol includes: charge cycles, battery ID, remaining total capacity, remaining current capacity, etc. Only official Sony batteries incorporate this protocol, cheap replacement parts don't and some Pro Sony cameras refuse operation with batteries without InfoLithium communication. Decrypting this protocol could give us more insight into the battery but is not essential as we can measure the discharge curve and estimate remaining capacity rather accurately that way.
3.1.1.1 Hacking References
http://randybuildsthings.wordpress.com/2013/02/25/sony-infolithium-m-teardown/
http://www.dpreview.com/forums/post/4296759
3.2 AXIOM Remote
Still in concepting phase of development.
https://apertus.org/axiom-remote
3.3 Image Processing Pipeline
Draft pipeline taken from AXIOM Alpha for now.
Image Acquisition Pipeline:
HDMI Image Processing Pipeline:
3.3.1 Image Processing Nodes
3.3.1.1 Debayering
A planned feature is to generate this FPGA code block with "dynamic reconfiguration" meaning that the actual debayering algorithm can be replaced at any time by loading a new FPGA binary block at run-time. This tries to simplify creating custom debayering algorithms with a script like programming language that can be translated to FPGA code and loaded into the FPGA dynamically for testing.
3.3.1.2 Image Overlays
Full HD framebuffer that can be altered from the Linux userspace and is automatically "mixed" with the real time video from the image sensor. (https://www.apertus.org/pong-project on the AXIOM Alpha was implemented exactly with this method)
We still need to decide if a color palette here is sufficient or how many colors we would need. 32 bit image with Alpha channel might be an unnecessary overkill here.
This feature could also be used to draw live histograms/scopes.
3.3.1.3 Peaking
Peaking marks high image frequency areas with colored dot overlays. These marked areas are typically the ones "in-focus" currently so this is a handy tool to see where the focus lies with screens that have lower resolution than the camera is capturing.
Handy Custom Parameters:
- color
- frequency threshold
Potential Problems:
- there are sharper and softer lenses so the threshold depends on the glass currently used. For a sharp lens the peaking could show areas as "in-focus" if they actually aren't and for softer lenses the peaking might never show up at all because the threshold is never reached
3.3.1.4 Image Blow Up / Zoom
Digital zoom into the center area of the image to check focus.
As extra feature this zoomed area could be moved around the full sensor area.
This feature is also related to the "Look Around" where the viewfinder sees a larger image area than is being output to the clean-feed.
This re-sampling method to scale up/down an image in real-time can be of rather low quality (nearest neighbor/bilinear/etc.) as it is only for preview purposes.
3.3.1.5 Matrix and LUTs
3x3 / 4x4 Matrix
AXIOM Alpha uses one LUT per color channel.
Maybe a 3D LUT (17×17×17) is possible at a later point: http://en.wikipedia.org/wiki/3D_lookup_table
3.4 Lens Mounts
AXIOM Beta is outfitted with an E Mount currently. Adapters for Canon, Nikon, PL, etc are widely available.
| Mount | Nikon F | Canon EF | Micro Four Thirds | ||
|---|---|---|---|---|---|
| Type | Bayonet | ||||
| Compatible Lenses | Nikkor FX | Nikkor DX | EF | EF-S (optionally) | |
| Image Circle Size | Full Frame ø 43.3 mm |
DX ø 28.4 mm |
Full Frame ø 43.3 mm |
Canon APS-C ø 27.3 mm |
"Half Frame" ø 21.6 mm |
| Throat | 44 mm | 54 mm | ~38 mm | ||
| Flange focal distance | 46.5 mm | 44 mm | 19.25 mm | ||
| Axiom Beta Sensor Compatibility |
16mm Four Thirds Super35 |
16mm Four Thirds | |||
More Details: Lens Mounts
3.5 4K RAW PC recording option
This has been renamed to "AXIOM Bridge" and is currently still in the concept phase of development.
3.6 Enclosure Design
Notes:
Switchable ND Filters not planned currently
3.6.1 Skeleton
https://github.com/apertus-open-source-cinema/beta-hardware/tree/master/Enclosure/Skeleton_E-mount
Infrared Cut Off Filter (IR Cut Off)
Proposal: Buy 100x100mm filter from http://www.uqgoptics.com/catalogue/Filters/IR_CUT_OFF_FILTERS.aspx?subCatOrCatName=ir_cut_off_filters and cut into 3x3 pieces
3.6.2 Simple Enclosure
3.6.3 Full Enclosure
3.7 Electronics
3.7.1 AXIOM Beta PCB Stack Concept
Version 4:
All dimensions are still not final! Work in progress...
File:PCB Stack Concept V03 02.pdf
3.7.2 Image Sensor Frontend
3.7.2.1 Image Sensors
| Axiom Beta Model | 16mm | Four Thirds | Super35 |
|---|---|---|---|
| Brand | CMOSIS | ON Semionductor (prev. Truesense/Kodak) |
CMOSIS |
| Model | CMV2000 | KAC12040 | CMV12000 |
| Type | CMOS | ||
| Shutter Type | Pipelined Global Shutter | Global & Rolling Shutter | Pipelined Global Shutter |
| Color filter Array | Bayer (Color model) None (B/W model) | ||
| IR filter | no | ||
| Anti-Aliasing Filter (OLPF) | no | ||
| Size | 10.6 mm × 5.94 mm ø 12.1 mm |
18.8 mm × 14.1 mm ø 23.5 mm |
22.5 mm × 16.9 mm ø 28.2 mm |
| Crop Factor | Full Frame ∕ 3.56 16mm Film ∕ 1.05 |
Full Frame ∕ 1.84 Four Thirds ∕ 0.96 |
Full Frame ∕ 1.54 Super35 ∕ 1.10 |
| Aspect Ratio | 16:9 | 4:3 | 4:3 |
| Pixel Resolution (h × v) | 1920 × 1080 | 4000 × 3000 | 4096 × 3072 |
| Pixel Size | 5.5 µm | 4.7 µm | 5.5 µm |
| Dynamic Range | 10 stops 15 stops (HDR mode) |
9.3 stops (Gobal Shutter) 12 stops (Rolling Shutter) |
10 stops 15 stops (HDR mode) |
| Sensitivity | 200 ISO | ~ 400 - 1250 ISO | |
| Max Frame Rate @ Bit Depth | 340 fps @ 10 bit 70 fps @ 12 bit |
110 fps @ 8 bit 70 fps @ 10 bit 30 fps @ 12 bit 10 fps @ 14 bit |
300 fps @ 10 bit 180 fps @ 12 bit |
| More info | |||
3.7.3 Shields
The AXIOM Beta has 2 medium speed IO interfaces to be used with "shields".
- One 200Mbit/s shield interface
- One 1Gbit/s shield interface
- Shields are not hot plug-able
3.7.4 Plugin Modules
There are 2 high speed IO interfaces where "plugin modules" can be hot plugged
- 6.2Gbit/s each:
- 6 ✕ 950Mbit/s
- 500MBit/s GPIO
- Two modules can be combined in one 12.4 Gbit/s double height module
- Hot pluggable
- 2x PCIe connectors (not using PCIe signaling)
3.8 Beta Naming Scheme
Versions of the AXIOM Beta will be named AXIOM Beta plus the according roman number.
eg. AXIOM Beta I - Developer Edition