Fire-i monochrome cameraaka OLI - Oliver's Lunar Imager
|
CCD | 1/4" Sony ICX 098BL |
Resolution | 640x480 pixels |
Pixel size | 5.6µm x 5.6µm |
Frame rates | 1/30s, 1/15s, 1/7.5s, 1/3.75s with windows software |
Gain control | Automatic or Manual Control 0-30 dB |
Shutter speeds | Automatic or Manual Control 1/3400s-1/31s |
Gamma controll | on/off |
Black level | Adjustable |
Sharpness control | off / 6 modes |
Available data formats | Y8 |
Power supply | 8-30 V DC by 6 pin 1394a port or power jack |
Power consumption | 0.9 W typical, 0.4 W sleep mode |
Size, weight | 59.0 x 53.5 x 19.5 mm, 35 gr |
Interface | IEEE-1394a (FireWire) 400 Mbps, IIDC-1394 Digital Camera, V1.04 specification compliant |
Lens mount | M12x0.5 |
![]() |
![]() |
Top side of board | Bottom side of board |
I mounted the board into a standard plastic case. A mechanical drawing of the board is available as a .pdf file on the Unibrain website. I printed it 1:1 to have template to cut the hole for the lens mount and drill holes for the screws to fix the board:
Two plastic standoffs are screwed into the case to hold the PCB.
The LEDs on the board are covered with duct-tape to avoid parasitic light in the case.
The firewire cable is squeezed into a hole in one case part as a pull relief, the power cable ist fixed inside the case for the same purpose.
DISCLAIMER:
I'm not taking any responsibilites for damages of any kind that can happen
by copying the shown modifications. See bottom of page for possible damages!
The longest exposure time of the Fire-i out of the box is ~1/31s = 32ms
- a true value compared to the driver settings of a ToUcam which aren't
correct times and which change with the framerate.
The measurements of Don
Bruns for a ToUcam:
|
5fps | 10fps | 15fps | ||||
1/25s | 200ms | 100ms | 67ms | ||||
1/33s | 100ms | 50ms | |||||
1/50s | 33ms |
Imaging with a ToUcam pro and scopes around 8" aperture integration times of at least 50ms or longer are required to image e.g. saturn at reasonable scales. 32ms results in too dim images even at maximum gain. For most planetary imaging purposes with smaller scopes longer integration times are required.
A hardware modification of the Fire-i board has been published by Anthony
Wesley aka "Bird". It disables the shutter control of the Sony CXD1267AN
vertical clock driver so that exposure/integration times are directly
coupled to the framerate.
The modification is done by cutting a copper trace on the bottom side
of the PCB connecting pin 17 (VSHT) of the Sony IC (reference designator
U4) and one pin of capacitor C34
If the trace is cut, shutter controll is disabled, integration times are determined by framerate, so 1/30s, 1/15s, 1/7.5s and 1/3.75s are possible with the Unibrain fire-i windows application. Using other capture software like Coriander under Linux gives more possible framerates and integration times like 1/25s, 1/12.5s, 1/6.25s, and 1/3.125s.
Just cutting the trace totally disables direct shutter control by software, all intergration times shorter than 1/30s are lost!. To regain the shorter times the cut can simply be bridged by a switch to enable or disable shutter control.
Warning:
After two imaging sessions the modified cam "died". The hostcomputer
link works ok, data is transfered but no signal from the CCD is picked
up. This behaviour has been reported from other modified cams but also
from an unmodified unit. Maybe static buildup the cause for the damage,
grounding the CCD side of the cut trace with a 10kO resistor might prevent
this. Please keep this in my when modifiyng a cam.