Olympus C-7070 and
C-5060 Cameras,
PT-027 and PT-020 Underwater
Housings,
PPO-02 wide port and WCON-07C Wide Converter,
Ikelite housing and Dome
Port.
Olympus
C-7070 Wide Zoom Camera
|
Olympus
C-5060 Wide Zoom Camera
|
 Memory card corruption:
The author has experienced, and others have reported, that the
Olympus C-8080 and C-5060 cameras sometimes corrupt the file
system on CF cards which have been formatted at the factory or
by a non-Olympus camera. The solution to this problem is to format
the card in the Olympus camera before using it. |
Olympus
PT-027 Housing
for C-7070 and C-5060
Materials: Clear polycarbonate
body. Red polycarbonate controls. Red anodised Al lens ring and
blanking cap. NBR LCD hood. Stainless steel buckles. Fluorite
glass reinforced lens port. Small parts in Ni plated brass. Silicone
rubber main O-ring.
Dimensions /mm: 161w, 143h,
127d, excluding projections.
Weight: 776g without LCD
hood.
Supplied accessories: Wrist
lanyard, lens cap, LCD hood, ballast weight, Allen key, waterproof
cap maintenance tool, O-ring remover, grease, silica gel. |
 |
|
Olympus
PT-020 Housing
for C-5060 Camera
Closure system: Double O-ring
back-door seal with buckle catches.
Materials: Polycarbonate
body. Fluorite Glass Optical Port. Small parts made from Aluminium,
stainless steel, and NBR. Silicone main O-rings.
Dimensions/mm: 165w, 143h,
127d (excluding LCD hood)
Weight: 600g, excluding LCD
hood & lanyard. |
|
PT-027, PT-020 System
Chart
O-rings for Olympus PT-020 & PT-027
|
Part # |
r /mm |
ID / mm |
JIS
B2401 |
|
POL-020A |
3.5 |
140 |
- |
|
POL-020B |
2.5 |
135 |
- |
|
POL-020C |
2.0 |
64.5 |
S-65 |
|
POL-101 |
2.95 |
67 |
G-67 |
|
Test Pictures
Standard Port and Supplementary Lenses:
When using the standard port underwater, rectilinear correction
is excellent and aberration is minimal in the mid-zoom to telephoto
ranges; but at the extreme wide angle end, pincushion distortion
and chromatic abberation are apparent. This is not a defect of
the camera or housing as such, but a consequence of the laws
of physics: i.e., it is unavoidable with any camera system when
using a lens with a 77° acceptance angle behind a flat port.
Screw-in 67mm f supplementary lenses
such as the Epoque DCL-20 and DML-2 can however be used with
the standard port. In these cases, vignetting occurs at the extreme
wide-angle setting (due to the wider than usual coverage of the
C-5060), and the lens has to be zoomed until vignetting is no
longer apparent. The DCL-20 wide converter then shows fisheye
(barrel) distortion (which is sometimes desirable and generally
more acceptable than pincushion distortion), and chromatic aberration
is slightly less than when using the standard port on its own.
Note that barrel distortion, pincushion distortion, and chromatic
aberration can be substantially corrected in Photoshop (or a
Photoshop plug-in compatible image editor) using the 'Radial-shift'
option of the free Panorama Tools plug-in by Helmut Dersch.
To find out how to obtain, install, and use Panorama Tools,
see the software
lens correction article in the information section. |
Telephoto setting. ~2m range. FL-20 flash. |
Mid-zoom setting. ~1m range. FL-20 flash. |
Wide setting, standard port. FL-20 flash. |
Full-size detail showing chromatic aberration. |
Epoque DCL-20. FL-20 flash. |
Full-size detail showing chromatic aberration. |
|
The macro capability of the C-5060 is already very good, but
the Epoque DML-2 macro converter supplements it, enabling a 2cm
x 3cm rectangle to be photographed in high resolution. The DML-2
is therefore recommended to those interested in extreme macro
photography. Also note that the internal flash does not operate
in super-macro mode, and so, while users of the FL-20 + PFL-01
can use flash in this mode, users of slave strobes cannot. The
DML-2 therefore restores macro functionality otherwise unavailable
to slave flash users. |
Supermacro mode. FL-20 flash. 20mm square tiles. |
Supermacro mode, showing depth of field ("f/8") |
Epoque DML-2. FL-20 flash. |
Macro mode. YS90a flash. Slave mode. |
Epoque DML-2. FL-20 flash. ~2 x 3cm area. |
Full size detail (~3mm x 2mm). |
Flash:
The PFL-01 + FL-20 combination gives excellent results in macro
photography, but the output is somewhat low for wide-angle work
(diffuser required, ISO 400 setting recommended). The housing
can however be used with slave flash units, as for previous members
of the PT-0xx series. An Ikelite DS-series substrobe with 4100.5
TTL slave sensor works correctly with the camera set in normal
flash mode. The Sea & Sea auto slave strobes (YS-90A, YS-25A),
being unable to track the camera automatic exposure system, require
the camera to be set in slave mode. A fibre-optic cable is required
for reliable triggering of Sea & Sea and Epoque strobes.
With manual and auto strobes, use of the camera image histogram
display assists greatly in determining the correct exposure.
The bulkhead TTL flash connector on the housing is proprietory
to Olympus (it is NOT a Nikonos connector, and does not use the
Nikonos TTL flash protocol). Note also that the detachable internal
lead from the connector to the hot shoe is supplied with the
PFL-01 flash housing, it does not come with the PT-020 housing.
In the photographs below, note how an increase in flash output
overcomes ambient illumination and thereby improves colour rendering: |
Sea & Sea YS90a flash. Max zoom. Slave mode. |
Ikelite DS-125 flash. Max zoom. Normal flash mode. |
Note on the bulkhead flash connector:
The metal version
of the Olympus flash connector requires maintenance even if an
external flash system is never used. Remove the cap or plug after
each day's diving and apply silicone grease to the screw thread
before reassembly. Failure to carry out this procedure may result
in seizure of the screw thread due to salt water corrosion. Attempting
to remove the connector blanking cap or sync-cable plug by force
will rip the bulkhead connector from the housing and may cause
irreparable damage. |
 |
Arms and Trays:
YS-fitting strobes can be mounted to the top accessory shoe using
an Epoque or Sea & Sea accessory shoe mini-arm. The longer
versions give a good macro lighting position.
The housing fits on Ikelite tray 9523.01 and can then be used
with the Ikelite Quick-Grip arm system. The large contoured handgrip
improves underwater handling considerably, and an articulated
arm allows optimal lighting positions in both macro and wide-angle
photography. YS-fitting strobes (including the PFL-01 housing)
can be used with the Ikelite QG system by using an Ultralight
or TLC YS-mount adapter. Other arm and tray combinations are
of course possible, e.g., for YS-mount: 10Bar slot stay with
long flexi-arm. |
|
PFL-01 Test System |
DS-125 Test System |
PFL-01 Flash housing mounted on
Epoque accessory shoe arm |
Ikelite DS-125 flash, with 4100.5 TTL slave sensor, 4086.61
ball arm, and 9523.01 tray. |
Olympus
PPO-02 Wide Port
for PT-020 and PT-027.
WCON-07C
Wide Converter
for C-5050 and C-7070.
PPO-02
Wide-angle port.
Used with WCON-07C and CLA-7 |
CLA-7
conversion lens
adapter tube. |
WCON-07C
wide-conversion lens.
0.7x mgnification |
PPO-02 Wide-Angle
Port:
 For PT-020 housing
and C-5060 camera or PT-027 housing and C-7070 camera with CLA-7
and WCON-07C.
Angle of Coverage with WCON-07C:
In air: 97° (equivalent to 19mm lens in 35mm format), Underwater:
68° (equiv. 32mm lens in 35mm format).
 Camera internal
flash is obscured (but can trigger slave flash).
 Max depth: 40m
(same as camera housing).
Materials: Flat toughened
fluorite glass optical window, Polycarbonate body, small parts
in brass & stainless steel, Silicone O-rings, NBR front protector
ring.
Dimensions: Overall diameter149mm
(excluding catches), length 78.5mm.
Weight: 552g (port assemby
only).
Supplied accessory: front
& back protective caps, PSOLG-1 O-ring lubricant. |
PPO-02 O-rings
|
Part # |
r / mm |
ID / mm |
JIS
B2401 |
|
POL-102B |
2.95 |
124 |
G-125 |
|
POL-102C |
2.0 |
118.5 |
S-120 |
|
POL-102A |
2.95 |
67 |
G-67 |
|
 |
|
PPO-02 Test Pictures
|
In normal underwater practice, use of a lens having a 35mm equivalent
focal length of much less than 35mm behind a flat port is considered
to be poor practice. With the PPO-02 and WCON-07C however, we
have the equivalent of a 19mm lens behind a flat port, a combination
so bad that chromatic aberration is even visible in the uncorrected
273x205 pixel thumbnail image below. Faced with the paradox of
how to market this device and still retain some semblance of
public credibility, the author decided to investigate the possibility
of applying radial correction to the camera output files as a
way of producing acceptable images. This investigation forms
one thread of the software
optical correction article given elsewhere. If images are
corrected according to the instructions given in that article,
the results can be truly excellent. On the other hand, those
who are not prepared to apply radial correction should avoid
this port and use the Ikelite housing and dome port instead.. |
Geometry before correction. |
After correction. |
Corner detail before correction. |
Corner detail after correction. |
|
Panorama Tools radial correction coefficients for the
maximum wide-angle zoom setting: |
 |
Ikelite
Housing for Olympus C-5060 & C-7070
 |
 Flash interface
circuitry built into the housing allows full TTL control via
the hot-shoe with Ikelite DS-series Substrobes. Microcontroller-based
interface module is powered from the DS-Substrobe via 5-core
(blue-band) sync cable 4103.51 (single strobe) or 4103.52 (dual
strobe). Reverts to manual trigger in absence of power. |
 Vignetting at
widest zoom setting will occur with external wide conversion
lenses. This is due to the wider than usual coverage of the C-5060
lens. |
Additional Lighting
|
Slave triggering
is also possible, but precludes use of flash in supermacro mode.
Strobe with built-in
light, or auxiliary torch to act as focusing light is recommended.
Shown left: #6130.61 housing with optional DS-125 TTL Substrobe,
sync cable 4103.51, and SA-100R ball-joint arm (Substrobe package
#3944.75) |
Ikelite
DP-60 Dome port
 |
Olympus WCON-07C wide-converter:
Magnification (focal length multiplier): 0.7x
In-air coverage: 97° max with C-5060 or C-7070 camera and
CLA-7 adapter tube (equivalent to 19mm lens in 35mm format).
The CLA-7 adapter tube is required for attachment of the WCON-07C
to the C-5060 when using the camera without the underwater housing. |
CLA-7 |
WCON-07C and DP60 Dome Port:
Test Pictures.
WCON-07C in air (no port). |
WCON-07C with DP-60 dome, underwater. |
Shooting information:
zoom setting: 5.7mm (35mm equiv: 27mm).
Effective air focal length with WCON-07C: 19mm.
Angle of coverage UW: 97° nominal.
Aperture: f/8.
Focusing mode: Macro.
Distance:
Object plane to entrance pupil: 337mm perpendicular, 509mm at
L/R edge of field (calculated).
Object plane to outside of dome: 256mm perpendicular, 427mm at
edge of field (nominal, calculated). |
Full resolution corner detail. |
The first point to notice is that the Ikelite DP-60 dome-port
introduces no additional geometric distortion beyond that which
is characteristic of the WCON-07C and camera. Mild fisheye distortion
is apparent but this is normal for wide-angle lenses. The chromatic
aberration visible in the corner detail is a consequence of the
air-water boundary and is not an optical defect of the dome.
The system exhibits excellent overall image sharpness. Slight
softening of focus at extreme edges is due to large difference
in lens to subject distance between centre and edge (curvature
of field) - see shooting information above. The effect will be
reduced for larger object to camera distances.
This optical system gives truly outstanding performance for its
class. Optical correction is not necessary for normal display
purposes, but due to the narrow spectral bandwidth of the RGB
sampling system used in the C-5060 camera (and Bayer mosaic sensors
in general) and the well designed Bayer to RGB interpolation
algorithm used by Olympus, it is easy to determine a near-perfect
compensation for chromatic aberration and thereby obtain the
performance of a fully water-corrected lens. Large high-quality
prints are then possible. The effect of radial
correction using Panorama Tools is shown below: |
WCON-07C + DP60, after correction |
full resolution corner detail |
The PanoTools
radial correction coefficients which were used are shown right:
These coefficients will correct all pictures
taken with the C-5060 + WCON-07C + DP60 underwater with the zoom
set at full wide. |
 |
DP60 Dome Port used without the
WCON-07C
Above left: bare camera lens in air (no port), full wide.
Above right: bare camera lens with DP-60 dome port underwater,
full wide.
Right: full resolution corner detail.
Shooting information:
zoom setting: 5.7mm (35mm equiv: 27mm).
Angle of coverage: Air: 77° nominal,
Underwater: 73° effective (measured 73.4±1.1°).
Aperture: f/8.
Focusing mode: Normal AF, with assistance from spotting
light in Ikelite DS-125 Substrobe. |
 |
|
The DP60 dome port works perfectly well underwater without the
WCON-07C installed and very nearly preserves the 77° coverage
of the camera lens underwater. Actual coverage (measured using
a method described in the angle
of coverage article), was 73.4±1.1° at a lens
pupil to subject distance of 0.75m. This lens+port combination
therefore exceeds the coverage of the Olympus PPO-02 flat port
with the WCON-07C (68°), and gives vastly less optical
distortion. The prototype dome port tested gave very slight vignetting
at the corners of the picture, but this was corrected in production
versions by slight adjustment of the port-shade cutouts. Also,
software radial correction pushes the vignette out of the picture.
Chromatic aberration at this angle of coverage with the Ikelite
port is negligible (the green-magenta fringing in the
detail above is actually due to the zoom lens), but radial correction
for the barrel distortion introduced by the zoom lens is beneficial.
The corrected underwater image is shown below: |
 |
 |
The PanoTools
radial correction coefficients which were used are shown right:
These coefficients will correct all pictures
taken with the C-5060 + DP60 underwater with the zoom set at
full wide. |
 |
|
DWK. Test
pictures and narrative © Cameras Underwater 2004. Reproduction
for commercial purposes strictly forbidden. |
|
67mm
filter ring on standard port.
Screw-fit
interchangeable ports. Optional dome port.
