Experiences using the Pentax Optio W30 amphibious camera

Guido Zsilavecz

Cape Town, August 2008

The Pentax Optio W30



Sample shots using the Pentax Optio W30: slow shutter speed (forced by using lowest ASA setting) on a waterfall, and dawn over Oudekraal and Camps Bay, Cape Town.

The author taking photos in a rock pool.







Sample shots of fish taken in a rock pool using the Pentax Optio W30 using only the internal flash. The top photo shows some of the problems with darkness to the right of the image. The fishes are all between 3 and 5 cm long. Top two are Clinus cottoides, bottom two are Clinus acuminatus).

Diffuser for the Optio to improve flash coverage using macro.



Optio with the Pixtreme PX21 housed strobe.





Sample shots taken in a rock pool using the Pentax Optio W30 using the internal flash and external Pixtreme strobe. These are uncropped, showing the much more even lighting, and no burn-out due to internal flash being used as well. (Top fish is Clinus superciliosus, bottom is Clinus cottoides).

Introduction

The Pentax Optio W30 is a small and simple to use point-and-shoot 7.1 mega-pixel digital camera. It is unusual in that range of cameras in that it is dustproof and more importantly, waterproof to 3m. The latter is achieved by not having an extending lens, and the use of rubber gasket-style seals on the two opening doors. It is aimed at the more adventerous user who may encounter water, rain, snow or other damp environments. The size and shape of a large candy-bar, it is easy to hold, with all of the few buttons in a logical place. A large screen (there is no viewfinder) is easy to see in most lighting conditions. Macro focusing is superb, allowing the user to focus down to 1 cm! The user interface and menu system is quite obvious, with the liberal use of cute graphics to indicate what mode the user is in. Start-up time is short and focusing is quick in most conditions, and writing to the SD card is moderately quick, giving the user access to the camera before having completely finished writing, allowing the user to start framing the next shot. Picture quality, stored in jpeg only, is acceptable, and pretty much along the lines of what one would expect from this type of camera. Battery life, using the standard Lithium-ion battery is remarkably good, although I do carry a spare with me at all times.

Intended usage

I bought this camera because of a need of a small, compact camera, which I could use in shallow water rock pools. My housed cameras which I normally use underwater - my older Canon A75 or my current Olympus SP350, were found to be a bit too big for the often shallow and small rock pools, although this could be overcome with some careful selection of rock pools. Where these setups came short was in the need to use an Inon close-up lens: as water is required between the housing lens and the close-up one, it had to be removed each time before use in order to get rid of the air. This meant frightening the fishes and often stirring up sand. As these problems could not be overcome I started researching amphibious cameras.

Alternatives

The only real alternatives I could find were the range of Olympus Mju-SW cameras. These are more robust than the Pentax, with the top model, the SW-1070, boasting of being shock-proof, temperature-proof, dust-proof, and, most importantly, water-proof down to 10m. These cameras are shaped quite differently to the Pentax, being more square, with the lens in one of the top corners. Where the Olympus cameras came short is in their comparatively lacking close macro focusing ability. Only the top of the range SW-1070 allows for very close-up focusing, but, and this is something which seems to be an Olympus trait, once in super macro mode the flash will not fire! This is most likely because the flash would not be able to cover the subject well enough - a problem found with the Pentax, but instead of allowing the user to deal with that problem, removed any ability to do so. Instead, they offer a white LED light. I tried this out, and found it to be only moderately acceptable. What clinched the deal for the Pentax was the price, which was about half that of the SW-1070!

The Pentax Optio W60 had not been released at the time I bought the W30, and I did not evaluate it.

Likes and dislikes

Many point-and-shoot cameras have the annoying distinction of not allowing users to over-ride settings. The Pentax, which offers only a "Program" mode, apart from the multitude of preset modes I never use, thankfully allows for sufficient over-ride to be useful, especially in certain areas, such as exposure metering, focusing area, white balance and ASA setting (which I rarely change from its lowest value). While one cannot change aperture or shutter speed, the camera software does not default to a fully opened lens when it is dark but the flash is on, allowing for some depth of field. What I experienced and researched satisfied me sufficiently to buy the camera, so I was rather happy to find a couple of rather useful features:

  • Settings storage My land camera is a Canon A590is. When you put it into macro mode and switch if off and on, it has forgotten that. As I used Canon A-series underwater where much work was done in macro, this annoyed me endlessly, as I have a habit of switching off when not using the camera, to conserve batteries. The Olympus SP350, as indeed other Olympus', have their brilliant "My Mode" settings, where you can store four sets of settings, including zoom setting! Using this camera underwater is a dream, as I have a macro mode setting and a wide-angle setting, between which I can switch very quickly. This means I at most adjust flash output, and occasionally aperture. The Pentax does not offer quite this flexibility, but it is better than the Canon in that you can specify what settings to remember when switching off, and which ones to default. As this includes all the useful settings, during rock pooling I can switch off and on with the camera coming on in exactly the way I want it. It is a small thing, but not having to constantly switch to macro, for example, is a real time-saver and error-preventer.
  • The "green" button The Pentax has few buttons, so to access most functions requires working through a menu system. It is already very handy that one can move the items in that menu system around, but they have improved it one step further, by allowing you to place four commonly used functions under the "green" button. Pressing that button in sequence cycles through those four settings. Other cameras, such as the Olympus SP350 and the Canon A590is have a customizable button, but both only allow one function for that button. Having four meant I could place those I use most in a rapidly accessible place: EV compensation, white balance, AE (Auto Exposure) metering and focusing area. Again a simple feature, but extremely useful.
  • Soft flash As I work usually in macro at very close range the internal flash has a tendency to over-expose. This was the same with my various older Canon A-series and the Olympus SP350. The Pentax does not offer flash compensation like the Canon A590is does, but does have a "soft flash" mode, which reduces the intensity. And in general, it works. Unless there is something bright white (like a shell), images are generally well exposed.

In the "dislikes" section there is only one - the problem Olympus avoided by disallowing flash in super macro mode: due to the closeness to the subject, the offset flash does not cover the subject perfectly. With the Pentax this leaves a darkening right side of the image. Move a few centimeters away and this is no longer a problem, but it means getting less detail. This I overcame partially by creating a diffuser.

Diffuser

Usage of diffusers is common with compact underwater cameras. Due to refraction a lens underwater tends to be "narrower" than above water. For example, the old Nikonos V 35mm lens became a 50mm lens underwater. This reduction in field angle is also applicable to the flash, so a white semi-translucent diffuser is often used to widen that angle. Generally these work best if there is some distance from the flash to the diffuser, in order to diffuse as wide a beam as possible - placing it directly in front of the flash usually has little positive effect. As the Pentax has a non-protuding lens I had little distance to play with, so instead of using such a diffuser I opted instead for an optical one, using the cover of a bulkhead light as often found on exterior walls of houses. Small prisms moulded into the plastic diffuse the beam quite effectively. I angled the diffuser so it would beam more to the right. The result was better than without it, but not sufficiently enough for my liking, forcing me to find another solution.

External strobe

This solution was an external strobe. After a dive I saw a friends housed compact digital camera with the cutest smallest strobe attached to it. It was a Fuji camera, housing and strobe, although we subsequently found that the strobe is sold under a variety of brands, with varying levels of accessories. The one I bought is a Pixtreme PX21 digital slave strobe. The unit, as can be seen from the photos on the left, is small. It takes two AAA-size batteries, and triggers optically. A sensor switches the strobe off when it deems proper exposure has been achieved. According to the manual this is approximately equivalent to providing sufficient light when ASA setting is between 100 to 400, at f2.8. A switch allows for three settings to control this, and the strobe can ignore up to three pre-flashes. The unit I bought came with a base plate and a LocLine arm. These were not to my liking for my needs. The Pixtreme, unlike some of the other variants available, comes with a little mount for using the strobe outside the housing, with a small base-plate to mount it next to your camera. This base-plate was ideal, and together with a thinner, but longer LocLine arm I had from previous usage, allowed me to fashion what I wanted. By pure chance the bolt I had on that LocLine fitted the nut on the housing perfectly As can be seen from the photos, this arrangement allows me to place the strobe directly above the lens, or move it far away. The whole unit now of course has grown in dimensions, but thankfully mostly upwards, where there tends to be the most space. Trials on land showed that the strobe lit up the subject matter extremely well, with exposure pretty much perfect, and with less over-exposure on the top left than the Pentax internal flash occasionally showed. I initially thought I would need to cover the internal flash with black tape as otherwise it might possibly interfere with the other flash, but that seemed unnecessary. On land covering the internal strobe, allowing only the top edge to show, is enough to trigger the very sensitive optical eye of the Pixtreme, but this was found not to work under water.

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