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Olympus C-8080 Camera,
Underwater Housings, Ports and Wide-Angle Lens.

Olympus PT-023
40m

Ikelite #6130.80
60m TTL
Dome Port option

PT-023 housing PPO-05 port Ikelite housing Dome port Comparison

Olympus C-8080 Wide Zoom Camera:
8.00M pixel 2/3" Bayer CCD.
3264 x 2448 pixels max. image size.
5x optical zoom 7.1 - 35.6mm
(35mm equiv: 28 - 140mm).
RAW output.
Max aperture: f/2.4 (wide), f/3.5 (tele).
Electronic reflex viewfinder with diopter adjustment.
TTL hot-shoe (Olympus protocol).
xD and CF card slots.


Olympus software and RAW files:
Advanced users will probably prefer to use the Olympus RAW import Photoshop-plugin available from Olympus' website. C-8080 owners must otherwise use the 'RAW development' feature of the supplied Olympus Camedia Master 4.2 software. The Olympus software falls somewhat short of what can be achieved by adjusting 48bit data in Photoshop, particularly because it lacks a histogram display and allows only stepwise adjustment of contrast and colour balance, but images can be adjusted so that they are good enough to allow final adjustment of the 24bit output files in Photoshop without significant loss in quality. The best saving option after adjustment in the Olympus software is 24bit uncompressed TIFF; and for those who wish to file their pictures sensibly, the files produced must be rescued from C:\Documents and Settings\All Users\Application Data\OLYMPUS\Camedia Master 4\Album\Samples\[album_name] (on the author's computer at least - use the Windows Explorer search utility if you can't find 'em). After retrieving the image files you can use Photoshop to give final tweaks and re-save them with LZW compression and thumbnails. Note that in some cases, it may be necessary to log on as administrator to locate the Album folders and enable user-access.

One of the annoying features of the Olympus software is that it does not allow users to decide where image files will be saved, and insists on putting them on the C: drive under 'Application Data' (see above). If you have a fairly small disk drive, and you save your files as uncompressed TIFFs at full camera resolution (23.4MB), you will quickly fill up your boot partition and run out of virtual memory. Fortunately however, Camedia Master does not use its own database, it just uses the normal file system; which means that it is possible (using Windows Explorer) to cut files from an Album folder and paste them elswhere, or even paste files into an Album folder provided that they are of a type that Camedia Master can understand, and the software will simply list and work on what is there. Note incidentally, that instead of having to pay for an upgrade so that you can indulge in such rare and specialised activities as 'e-mailing pictures to other people', you can simply cut or copy pictures from the Album folders and deal with them in the normal way. Note also, that if you do decide to let Camedia Master manage your image files, you must edit your backup routines to point at its Album folders.

Note: If you are running Windows 2000, and you have previously installed software for other Olympus cameras, you may discover on connecting the camera to the USB port that the computer cannot detect the camera or gives an error message saying that a driver is unavailable. In this case you may need to install Microsoft update 822831:
support.microsoft.com/default.aspx?scid=kb;en-us;822831&Product=win2000
then remove and reinstall the camera software.

Memory card corruption:
The author has experienced, and others have reported, that the C8080 and C5060 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-023 Housing for C-8080wz

Depth Rating: 40m
Filter thread M138 x 1.5
Interchangeable lens port.
Control for all camera functions.
1/4" UNC tripod socket.
Double O-ring seals at port and back door.
Removable diffuser-box allows internal flash to be used with standard port.
TTL flash connector allows optional use of Olympus flash.
Materials: clear polycarbonate housing, red polycarbonate control knobs, Ni-plated brass control shafts, Fluorite tempered glass lens port, Anodised Al lens ring & sync connector cap, Stainless steel buckles, Silicone main O-ring, NBR LCD hood.
Dimensions /mm: 181w, 188h, 200d. Weight: 1475g , excluding LCD hood, lens cap & strap.
Kit includes: Wrist lanyard, grease, Silica gel, O-ring remover, ballast weight, LCD hood, lens cap, sync connector cap.


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 frequently 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.


Olympus PT-023 Housing and C-8080 Camera
Test Pictures using Standard Port
Internal Flash:
Standard Port, Full Wide, ISO 50, aperture as indicated.

The Diffuser-box of the PT-023 housing gives the best internal-flash underwater performance (flatness of illumination) seen by the author to date. The light-trap design is good and there are no signs of light leakage into the port. Note however, that the flash output is very low, and the pictures above were taken at close range in perfectly clear water. In conditions of moderate visibility, backscatter is likely to be a problem, and an external flash unit is (as always) strongly recommended.

External flash, corner detail vs aperture:
Standard Port, Full Wide, ISO 50, Ikelite DS-125 flash with 4100.5 TTL slave sensor, aperture as indicated. Corner detail image is full size (same resolution as original).


Radial Correction (removal of pincushion distortion and chromatic aberration):
Same photograph as immediately above, corrected using Panorama Tools (see the software optical correction article for an explanation of the method).

PanoTools
Radial Correction
Coefficients

The chromatic aberration visible in the uncorrected pictures is almost entirely due to the air-water boundary and is unavoidable when using a lens with 75° coverage behind a flat port. The effect will be reduced at longer focal length settings of the zoom lens.

Radial correction allows complete elimination of chromatic aberration and pincushion distortion. This will be beneficial if large prints are required, but is not essential for small album photographs.

PPO-05 Wide Port and WCON-08D Conversion Lens
PPO-05 Wide Port:
For use with CLA-8 bayonet adapter and WCON-08D wide converter lens.
Depth Rating: 40m. Double O-ring seals.
Underwater photographs will exhibit noticeable optical distortion (but pictures taken in air are not affected). Software optical correction is recommended. See test pictures for details.
Materials: Fluorite tempered glass optical port with anti-reflection coating. Clear polycarbonate body, Silicone O-rings, Other parts: ABS, NBR, red polycarbonate.
Dimensions: Max dia 156mm, overall length 90mm. Weight: 600g, excluding lens cap.
Supplied accessory: Grease, O-ring remover, lens cap.

WCON-08D Converter Lens:
Magnification: 0.8x.
Coverage at full wide in air: 88° (35mm equiv: 22.4mm)

Optical Data*
Lens System
(zoom setting = full wide)

35mm equiv.
focal length

Coverage
in air

Coverage UW
(flat port)
Standard lens.

28mm

75°

54°
Std. lens + WCON-08D

22.4mm

88°

62.5°
* Angle of coverage figures are nominal, i.e., on picture diagonal when lens is focused at infinity.

PPO-05 Wide Port and WCON-08D Lens
Test Pictures


Distance, camera to test card: 3m. Zoom setting: Full wide. Aperture: f/5.6. ISO: 50.
Light source: Mixed daylight and Ikelite DS-125 with 4100.5 slave sensor.
(The white measuring stick attached to the bottom of the test card is 1m long).

Close-up, corner detail vs aperture:
PPO-05 wide port, WCON-08 wide lens, Full wide, ISO 50, Ikelite DS-125 with 4100.5 slave sensor, aperture as indicated.


Radial Correction (removal of pincushion distortion and chromatic aberration):
Same photograph as immediately above, corrected using Panorama Tools (see the software optical correction article for details of the method).

PanoTools
Radial Correction
Coefficients:

To find out how to obtain, install, and use Panorama Tools, see the software optical correction article in the optics section.


The addition of the wide conversion lens gives the C-8080 an effective 35mm equivalent minimum focal length of 22.4mm. This gives a nominal angle of coverage of 88° in air and 62.5° underwater. The use of such a wide angle lens behind a flat port underwater results in a degree of pincushion distortion and chromatic aberration which will be noticeable even in small album prints. Hence, for underwater photography, software optical correction is strongly recommended. Correction will not be needed if the port is used merely for water protection, e.g., for surface water-sports photography.

Ikelite Housing for Olympus C-8080


#6130.80
Depth rating: 60m.
Interchangeable ports, with dome port option.
Standard port fits Ikelite 4.2" push-fit UWCC filter #6441.43 B/G.
TTL flash via cable with optional DS-series Substrobes. Conserves camera battery by avoiding use of internal flash for slave triggering.
Pop-up flash cannot be used..
Controls for all camera functions.
Battery and memory card can be changed without removing camera from internal tray.

Weight: less than 3.2Kg with camera.
Dimensions: width: 10.25", 7" without tray; height: 6.5" including buttons; depth: 8" including standard port and back knobs.

Flash interface circuitry built into the housing allows TTL exposure 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.


Additional Lighting for Ikelite Housing

Triggering via 5-core Ikelite sync. cable gives maximum system functionality.

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. Camera AF system does not work in low light conditions.

Shown left: Ikelite housing with DS-125 TTL Substrobe, 5-core sync cable 4103.51, and SA-100R ball-joint arm (Substrobe package #3944.75).

Fittings for the Quick-Grip socket on the top of the handle are made by Ikelite, Ultralight, and GreenForce.

Ikelite 6130.80 Housing and Olympus C-8080 Camera
Test Pictures
Standard Port (54°):
Zoom setting: Full wide. Aperture: f/2.8. ISO: 50.
Light source: Mixed daylight and Ikelite DS-125 with diffuser.
(The white measuring stick attached to the bottom of the test card is 1m long).


Standard port. Image geometry, and corner detail vs aperture:
Standard Port, Full Wide, ISO 50, Ikelite DS-125 flash with diffuser, aperture as indicated. Corner detail image is full size (same resolution as original).


Radial Correction (removal of pincushion distortion and chromatic aberration):
Same photograph as immediately above, corrected using Panorama Tools (see the software optical correction article for an explanation of the method).

PanoTools
Radial Correction
Coefficients

(for flat port,
full-wide zoom)

Discussion:
The use of a flat air-water boundary always introduces some pincushion distortion and chromatic aberration (colour fringing in off-centre detail), and these effects worsen as the angle of coverage of the camera lens increases. The uncorrected photographs above demonstrate these effects in the worst case, i.e. with the lens at its most wide-angle setting, which corresponds to a coverage in air of 75° (35mm equivalent focal length = 28mm). The pincushion distortion is less than expected, being partially offset by barrel distortion of the lens, and is not sufficient to require correction except when photographing subjects with obvious straight lines and right-angles. Chromatic aberration will however be noticeable in large prints and displays with significant edge detail if the full-wide zoom setting is used. Fortunately, the RGB separation in the camera is accomplished with very well-behaved filters, resulting in a perfectly apochromatic system if the user is prepared to take the trouble to apply software radial correction to the pictures produced. If radial correction is applied, the camera will give exhibition quality prints of up to about 22.7 x 17" (i.e., 3264 x 2448 pixels at 144 pixels/inch). Note incidentally, that the radial correction for the Ikelite standard port is exactly the same as for the camera in the Olympus PT-023 housing with standard port.

Dome Port for Ikelite C-8080 housing.


#9306.38
High precision injection moulded acrylic optical dome.
True 88° wide-angle: Dome port preserves the 88° coverage of the Olympus WCON-08D conversion lens underwater.
Gives 76° coverage when used without the wide-converter lens.
Two-part lens housing holds the conversion lens without the need for the Olympus CLA-8 adapter tube - allows the camera to be removed and installed without disturbing the port.
Port obscures internal flash, but slave triggering is still possible.
Dome port is not recommended for macro photography (curvature reduces magnification, use the standard flat port in preference).
Strap wrench for port removal and refitting is included.
Optical data: Port material: Acrylic, nD=1.492. Inside radius: 3", 76.2mm. Nominal thickness: 0.218", 5.537mm.


CLA-8


WCON-08D
Olympus WCON-08D
Magnification: 0.8x.
Coverage at full wide in air: 88° (35mm equiv: 22.4mm)

Adapter tube CLA-8 is required when using the camera and wide converter without the housing. It is not required when using the Ikelite dome port.

Optical Data*
Lens System
(zoom setting = full wide)

35mm equiv.
focal length

Coverage
in air

Coverage
UW
Standard lens. Flat port.

28mm

75°

54°
Std. lens, Dome port

76°
With WCON-08D, dome port

22.4mm

88°

88°
* Angle of coverage figures are nominal, i.e., on picture diagonal when lens is focused at infinity.
With dome port, some coverage is lost in practice underwater due to lens extension, but optical distortion due to the port is eliminated in wide-angle photography.
Flat port is recommended for macro-photography, due to strong de-magnifying effect of dome port underwater.

Dome Port: Test Pictures
Dome Port and WCON-08D (88° wide-angle):
Full Wide, ISO 50, Ikelite DS-125 flash with diffuser, aperture as indicated.

Softness of corner detail at f/2.8 is due to curvature of field. This effect will be less apparent at greater lens to subject distances.

Radial Correction (removal of barrel distortion and chromatic aberration):
Same photograph as immediately above, corrected using Panorama Tools.

PanoTools
Radial Correction
Coefficients

(for DP with WCON-08D,
full-wide zoom).


Dome Port without converter lens (76° wide-angle):
Full Wide, ISO 50, Ikelite DS-125 flash with diffuser, aperture as indicated.

The Ikelite dome port for the 6130.80 C-8080 housing is intended primarily for use with the WCON-08D wide-converter lens, but can be used without it. In this case, slight corner vignetting may occur at the full wide zoom setting. Vignetting may be eliminated by zooming in slightly, or by cropping the final image; or, for preference, by applying radial correction for barrel distortion.

Radial Correction:
Same photograph as immediately above, corrected using Panorama Tools.

PanoTools
Radial Correction
Coefficients

(for dome port,
full-wide zoom).


Comparison of Ikelite and Olympus C-8080 housings.
 

Ikelite 6130.80

Olympus PT-023
Depth rating

60m

40m
Use in rough conditions

Yes

No
(port mountings too delicate)
Includes tray

Yes

No
(but too bulky for use without)
Use internal flash

No

Yes (standard port only)
TTL flash converter

Supplied as standard

Optional, HeinrichsWeikamp
Supermacro mode with flash

using Ikelite DS-series SubStrobe

FL-20 + PFL-01*
FL-36 + PFL-E01
HeinrichsWeikamp converter
Slave triggering**

Not recommended

Yes
Accessory shoe.

No

Yes
* TTL flash is possible with the Olympus FL-20 flash and PFL-01 housing, but this flash system is too low-powered for wide-angle UW photography and has no focusing light.
** Slave triggering requires the internal flash to be swiched on; in which case supermacro mode will be unavailable. Since neither of the housings can be fitted with an external macro lens (and there is no room for an internal macro lens either), supermacro mode with flash is essential if the user is to realise the full capabilities of the C-8080 camera.

UW coverage (full wide)

Ikelite 6130.80

Olympus PT-023
Standard port:

54°

54°
PPO-05 + WCON-08D

-

62.5° *
Dome port:

76°

-
Dome port + WCON-08D

88°

-
Needs CLA-8 to mount WCON

No**

Yes
* The PPO-05 Flat port with WCON-08D converter gives pronounced chromatic aberration and pincushion distortion underwater. Consequently it unsuitable for large prints and displays unless software radial correction is used.
When the WCON-08D wide converter is used with the PT-023 and the PPO-05 port; the port must be opened and the CLA-8 unscrewed before the camera can be removed from the housing. Changing batteries and memory cards aboard an open boat may be difficult.
** The WCON-08D is held inside the Ikelite dome port assembly and the CLA-8 adapter tube is not required. Hence the camera can be removed from the housing without disturbing the port setup.

D. W. Knight © Cameras Underwater 2004.