17. May, 2020

In the ever-expanding market of camera lenses, housings, and ports, it has become increasingly difficult for the beginning UW photographer to choose the right underwater system.  New technologies also bring better ergonomics,  lenses, and more megapixels which easily will make the older system look awkward and obsolete.  There are limiting factors that will make the choice easier.  Like your budget of course. And the more experienced photographer often has developed a specific interest, like shooting macro or wide-angle subjects.  Or choosing a cropped sensor instead of a full-frame sensor which will automatically limit the spectrum of lenses and housings. Then there is also the type of strobe to select, and the system to fire the strobes, electrical cables of fiber optics, in which case there is a choice between either an internal flash or LED trigger to ignite the optical system.   

For strobes and lenses, the underwater market seems to change less rapidly. The choice of the lens is  crucial for the quality of your pictures, perhaps much more important than the number of megapixels of the camera, or even the size of the sensor.  A superb lens will stay with you for many years, at least when the housings designers are so kind as to provide the suitable adapter and port for your favorite top lens

For about 20 years I  have been a faithful user of the Ikelite DSLR and Olympus PEN systems, with the Oly combo as a back up during my diving trips. The cameras (Nikon DX and E-PL5) equipped with fisheye lenses:  the legendary  Tokina 10-17  and Panasonic 8 mm fisheyes (which I later changed for the Oly 8mm with a  2 cm extension), respectively. With Precision mini domes (5 and 4 inches), allowing to get very close to the UW object. But recently I followed the urge to try something (a bit) different and more simple and switched to the PT-EP14 housing with the newer Olympus M1 Mark II camera inside. But I kept the Oly fish-eye and 4-inch dome  (see insert), which so far seems to work well on the OMD housing with a PEN/OMD adapter. Like the older PEN housings,  the PT-EP14 depends on a small internal flash to trigger the optical cables and strobes. In my case, that would be the Ikelite DS 161 strobes with optical adapters.  No LED trigger is yet available for the OLY housings, but this should not be much of an issue since the flash set to lower  (1/64) power will not easily drain the batteries. I do no regret missing TTL, since I have always been happy with shooting in the Manual mode with the Ike strobes,  even when triggered by the electrical cables of the  DSLR housing. I am now on the look for a Tokina 10-17 equivalent on the 4/3 market. Perhaps the Panasonic 7-14 or Olympus 7-14, which seem to have excellent records. And eagerly waiting for the return of diving days, to see how this will work in the real world of the Oceans. 

6. Apr, 2020

With global economic activity ramping down as a result of the coronavirus pandemic, it is hardly surprising that emissions of a variety of gases related to energy and transport would be reduced. Traffic levels in the city were estimated to be down 35% compared with a year ago. Emissions of carbon monoxide, mainly due to cars and trucks, have fallen by around 50% for a couple of days this week according to researchers at Columbia University. The Dutch weather bureau KNMI  has reported a dramatic reduction in dangerous substances such as carbon dioxide and nitrogen dioxide in the Netherlands air as a result of canceled flights, reduced traffic, and economic activity.

The future

One may wonder what will happen when the pandemic is over? Will national governments become more mindful in re-stimulating their economies? Will the post-pandemic period show signs of at least the beginning of a new, more ecologically-based, form of economy? Considering the way our economy up to the present has been dominated by principles of growth and profit, a radically different policy based on the experiences of the pandemic seems unlikely. But since modern technology was to a large extent responsible for the benefits of the industrial and agricultural revolutions, it should also be capable to repair their perversions. 

Our atmosphere contains three essential substances, Nitrogen (N2), Oxygen (O2) and water H2O (a reaction between Hydrogen and Oxygen). Over the past ages, they have merged into a relatively stable compound of gasses,  until the agriculture and industrial revolutions and the rapid growth of the world population started to change things radically. Most significant were the anthropogenic reactive carbon and nitrogen. Here follows a brief overview of the two chemical footprints that have led to an increasing concern about the future of this planet.

The 'footprints'

The carbon footprint. Carbon dioxide (CO2) consists of a carbon atom double-bonded to two oxygen atoms. It occurs naturally in Earth's atmosphere as a trace gas Natural sources of carbon include volcanoes, hot springs, geysers, and acids. Because carbon dioxide is soluble in water, it occurs in lakes, rivers, glaciers, and oceans. The carbon footprint is defined as the total greenhouse gases including the carbon-containing gases carbon dioxide and methane, emitted through the burning of fossil fuels, land clearance and the production and consumption of food, manufactured goods, materials, wood, roads, buildings, transportation, and other services. Since the Industrial revolutions anthropogenic emissions – primarily from the use of fossil fuels and deforestation– have rapidly increased its concentration in the atmosphere, leading to global warming. Carbon dioxide also contributes to ocean acidification because it dissolves in water to form carbonic acid

The nitrogen footprint  Nitrogen gas (N₂) makes up 78% of the air. Together with 21  % oxygen (O2), it forms the air we breathe to stay alive. Nitrogen is also an essential building block for amino acids, proteins, and DNA. Plant growth depends on it; animals and people get it from eating plants or other animals. In compressed air, N2  becomes toxic  (think of Scuba divers getting intoxicated when at greater depth). The same holds for O2 when its partial pressure exceeds  1 Bar (Barometric pressure). The major problems for our atmosphere come not from atmospheric  Nitrogen (N2) but from anthropogenic Nitrogen gases, in particular the Nitrogen oxides NO and NO2, together known as NOx (see insert).  NOx is considered to play an important role in global climate change. Notice that nitric oxide is a particularly potent Greenhouse gas as it is over 300 times more effective at trapping heat in the atmosphere than carbon dioxide. It contributes to the formation of smog and acid rain, particulate matter, as well as affecting tropospheric ozone. Nitrogen oxides (NOx) are typically connected with fossil burning from emissions from industrial combustion and gasoline engines.  

Ammonia is largely associated with the agricultural industry and farming. In consists of one nitrogen atom covalently bound to three or four hydrogen atoms (NH3 and NH4). It is produced naturally in the human body and in nature—in water, soil, and air, even in tiny bacteria molecules by a process called ammonification (see insert). In farming, ammonia is often produced by a mixture of manure droppings and urine in stables. Large quantities of NH4 are produced by modern  (bio) industries, including dairies, poultries,  pig stables, and manure surplus deposits. It's a major component of organic manure. In grassy meadows, where cattle were allowed to roam during spring and summer in earlier days,  the manure and urine are often more spread out, thus producing less ammonia.

Nitrification is a natural biological process by which ammonia (NH4) in the soil is gradually transformed in Nitrites (NO2) and then in Nitrates (NO3) which are released back in the atmosphere,  and converted to atmospheric N2  (called denitrification). NH3 is also present in modern commercial fertilizers. Nitrification inhibitors are now used to stop this process, to save the Ammonia (NH4). This is because nitrification may not be so good for agriculture, leading to a loss of the expensive nitrate fertilizer in the soil. Inhibitors are chemical compounds that slow the nitrification of ammonia, ammonium-containing, or urea-containing fertilizers, which are applied to soil as fertilizers. These inhibitors can help reducing losses of nitrogen in the soil that would otherwise be used by crops.

The use of artificial inorganic fertilizers has increased steadily in the last 50 years, rising almost 20-fold to the current rate of 100 million tonnes of nitrogen per year. These fertilizers are often dry inorganic salt with much nitrogen.  As said, their major constituents are the Nitrogen oxides (NO and NO2). Without commercial fertilizers, it is estimated that about one-third of the food produced now could not be produced.  Excessive use of fertilizer in farming – either in the form of manure of cattle or a commercial fertilizer saturates the soil with phosphates and nitrates which in turn produces pollution trough leakage in groundwater, ditches, lakes, canals, rivers and eventual the oceans.

A solution?

The difficult problem to solve is thus that one needs to grow more food to feed an expanding population while minimizing the problems associated with nitrogen fertilizer use. Nitrogen from fertilizers, effluent from livestock and human sewage boost the growth of algae and cause water pollution. It has also contributed to the estimated 8.2 billion damage bill to the Great Barrier Reef. Animal products carry high nitrogen costs compared to vegetable products. A high-animal-protein diet in humans appears to be driving the nitrogen footprint. For example, the consumption of animal products (in particular beef, not chicken and fish) accounts for 82% of the  Australian nitrogen foodprint.

The solution to the nitrogen and carbon dioxide challenge will need to come from a combination of technological innovation, policy and consumer action. Perhaps another lesson of the current pandemic is than mankind should reconsider the shadow sides of globalization, in particular, its effect on the current economies and creating greater health risks.  As national borders disappear and airline fares are low, people are increasingly free to move, creating new challenges to global health and the risk of spreading viruses.

Another side of globalization is that countries depend increasingly on products imported from other countries. Just think of all the electronics and textile stuff that is imported from Hongkong, Taiwan, and Bangladesh.  Profiting from cheap labor. During economical crises, national economies would also be on the safe side by using new technologies  (such as 3 D printing)  allowing them to make products close to the place where they are needed. The same may hold for agricultural stocks that should primarily serve to feed the own nation,  with eventual surpluses exported when appropriate. In Holland at least this could put an end to the massive (70%) overproduction in bioindustry with its mass chicken, cattle and pig stables, stimulated by the European Union. This would certainly be a  post-pandemic change for the better in the economy.


17. Feb, 2020

Wildlife photography and filming offer opportunities for creative and adventurous people to work outdoors in challenging environments. Professional wildlife photographers however often have to struggle to make a living,  especially since wildlife photography is becoming an increasingly popular genre among hobbyists. The introduction of low cost, high-quality HD gear did to video what digital cameras did to photography -- open the floodgates of new talent looking to work cheap,  or even for free.

Left: A Carribean reef shark. The most profitable shark from the Bahamas.

This holds for pictures of land animals such as the  ‘Big Five’ from the African steppe, as well as the great predators of the sea like whales and sharks, that often form the primary target of UW photographers.

The market The majority of underwater photographers work as freelancers. Talented individuals may sell their work to different media, such as books, magazines, and scientific journals. In rare cases, underwater photographers may be hired as staff photographers for major publications, like diving magazines. Some of them have found clever ways to augment their income. Their work deals with resorts to build websites or develop promotional materials, they lead guided dive tours, they teach photographic seminars, they sell underwater photography gear, etc. But only a very few have succeeded in making enough money exclusively shooting underwater still photographs to pay their bills and maintain their families. Some of them have used their pictures as illustrative material in educational books focusing on topics such as marine biology,  famous marine habitats (e.g. the Red Sea, the Bahamas, Galapagos)  or technical details of  underwater photography, equipment, and Photoshop  

Impact on the public In our modern world with its rapidly declining wildlife populations,  it is worth considering to what extent the economic benefits from wildlife documentaries and books are balanced with conservation and animal welfare. Photo and film documentaries of wildlife still form an increasingly growing source of income for various media as well as (albeit more modestly)  for the individual freelance photographer. Although some of the documentaries have focused on the sensational side of encounters with allegedly dangerous animals or ‘monsters’, others have stimulated a more positive attitude towards creatures living in the wild.

Ethical considerations Showing the beauty of our wildlife may indeed serve to increase the awareness of people of the value and fragility of the natural environment, as long as it incorporates not only the beauty aspect but also the factors that threaten its preservation. An example is the massive public interest stirred by the Blue Planet documentary for plastic pollution, recycling, and environmental damage. The ‘Attenborough effect’   of  Blue Planet is indeed a perfect example of a beneficial impact of nature documentaries by its emphasis on environmental protection. Ethical principles developed in the last three decades involve that individual animals are now also afforded some level of moral consideration. Accordingly, economic incentives to protect a species and or environment became an increasingly important element in situations involving various forms of exploitation of wildlife.

Profits from tourist interactions at shark feeding sites.  An emerging concern in marine wildlife tourism is the ethics of tourism activities that involve the provisioning of animals. Operators at shark ‘safaris’  often enhance the opportunity to interact with otherwise elusive wild animals, thereby improving the economic value of the site and hopefully also providing an enhanced incentive for protection. Factors that may help to mitigate the   ‘guilty pleasure’* (some of us may experience) of commercial exploitation and baiting of wild animals during holidays or professional UW activities. In the Bahamas, for example, the great national winner in the economic picture is the Caribbean reef shark, which was responsible for generating 93.7% of the revenue generated by dedicated shark dives, making this the most economically important species of shark in The Bahamas. The high site fidelity to the Bahama reefs and limited migrations suggest that these subpopulations of C.Perezi  remain relatively well protected within the Bahamian shark sanctuary as compared with other apex predators. The second and third on the revenue list are the Great hammerhead and Tiger shark.  

 *Ziegler, J.A., Silberg, J.N., Araujo, G., Labaja, J., Ponzo, A., Rollins, R., & Dearden, P. (2018). A guilty pleasure: Tourist perspectives on the ethics of feeding whale sharks in Oslob, Philippines. Tourism Management 68: 264-274. Link to original article: https://doi.org/10.1016/j.tourman.2018.04.001



8. Dec, 2019

The two golden safety principles for scuba divers are  ‘never dive alone’ and ‘always stick to your buddy’.   Here,  I’d like to briefly comment on these principles, focusing in particular  on some  drawbacks of buddy and group diving,   and conditions that may  rather spoil than enhance  the safety and  the peace  of mind of individual recreational divers.

The principle of buddy diving  First,  and most important   is  that a buddy system can  only be fully effective  when the buddies stay close to another,  and are  familiar with basic rescue operations when one of the couple gets in trouble. This could be a lack of air, getting entangled in a fishing line, problems with controlling the BCD or safety sausage,  etc.  Staying close to another,  maintaining regular eye contact and communicating with hand signals  are the crucial conditions to increase safety  of diving with your buddy.   Bob  Halstead once defined it clearly as follows: the buddy system is the situation which occurs when two divers of similar interest and equal experience and ability share a dive, continuously monitoring each other throughout the entry, the dive and the exit, and remaining within such distance that they could render immediate assistance to each other if required.  Murky water, darkness or  a  strong current may even necessitate the use of buddy line:  a line or strap physically tethering two scuba divers together underwater to avoid separation

On  recreational diving trips the buddy system often serves  as an automatic safety rule,  imposed by dive operators responsible for the safety of the group.  For example, divers that travel alone  are often coupled to new buddies, often with different experience or diving skills. To guarantee  at least the theoretical possibility that  they may assist  another when an emergency situation turns up.  When a diver is not able to stay close to his buddy, he is likely to be told to stay with the group  guided by a dive master. The guided group is a excellent option when diving  in more  difficult conditions such as  low visibility, strong currents, or when exploring new and photogenic  diving locations. Here the dive master often plays a useful role in pointing out nice subjects to macro- and wide-angle  UW photographers.

Solo diving and UW photography.  Often a diver carrying a  camera, may be the  lone camera diver in the boat. He or she will often experience the situation of being  left behind by the pack, moving faster that the photographer. This is even more likely to occur during  a drift dive, or when a diving group  is moving relatively  fast along a reef  wall or sandy seafloor. Obviously,  with  low  visibility such a situation will unevitably lead to loss of  eye contact with the group. The reason is that the  group does not allow the individual diver to linger behind.  Let’s  face it, it takes patience to get good shots, which is terminally boring for a buddy especially when he/she is not making pictures underwater. Such situations may cause tension for the UW photographer and group, and will necessitate a solo ascent for the solo diver using the sausage to signal the dinghy operator at the end of the dive. 

These situations, of course,  are less likely  to occur during UW photography workshops, where divers share  a common interest  and diving tempo,  and dive operators are more lenient in applying the ‘stay with buddy or group’  rule.

In my 40 year of diving, my best solo-diving experiences are the occasions when I went out  on my own in the early morning in my dinghy, to visit diving locations in the Mediterranean. I always selected familiar sites,  good weather conditions and viz,  with little chance of being disturbed by diving groups. Three lines with snap-hooks hanging  from  the safely moored boat allowed me hook up my camera, diving rig, and weight belt after the dive. In line with these experiences,  I’d like to end with another  Halstead quote:  Safe diving, from my personal experience, involves avoiding other divers underwater as much as possible so that I will not be troubled by their mistakes and being totally self-sufficient, with redundant systems, so that if even I make a mistake I can easily recover*.

* Of course not ruling out the more pleasant and safe forms of group diving.


Francis, John (19 October 2006). "Buddy System Breakdown". Scuba diving. Retrieved 15 October 2017.

Halstead, Bob (September 1997). "Assume the risk and take the blame" (PDF). SPUMS Journal27 (3): 153–4. Retrieved 10 November 2017

Layton, Rick (15 July 2012). "When The Buddy System Fails". DAN Europe. Retrieved 15 October 201





19. Sep, 2019

I am not qualified to provide an in-depth technical review of camera lenses.  But two interesting and relatively recent expansions of the  UW photographers toolkit seemed interesting enough to discuss here. The first concerns a (relatively) new Nikon fish-eye zoom lens.  The second the  Nikon new mirrorless cameras in the FX (full-frame) format.

Fish eye-zoom Fisheye lenses in  UW photography are superb lenses if you want to get really close to your primary target while keeping the background (e.g. the surface, other divers) in the same frame. Fish-eye lenses come in two versions:  the fixed focus prime lens and the zoomed fish-eye.  With the fish-eye zoom lens, you can change the focal length of the lens. It thus has the ability to take those forced perspective images at the shorter focal length or use a longer focal length to fill more of the frame. On a full-frame camera, it allows you to switch between frame-filling and circular fisheye. But the zoom lens is also useful to reduce its angle of coverage, for example, zooming in to fill your frame with a shark at a 2-meter distance, or with that small colorful fish at a 30-centimeter distance when using the CFWA  technique.

A popular example is the Tokina  AT-X 10–17mm f3.4-4.5 AF DX – a fisheye zoom lens designed for APS-C sensor cameras, which is also usable on full-frame cameras (see insert: top left). Then comes the newer (larger, heavier and more expensive)  Nikon-8-15mm fisheye lens (see insert: top right) that according to some recent expert reviews seems to be a must tot full frame underwater photographers. The lens produces excellent sharp pictures, great colors and offers a circular image at 8mm (floating in a black background)  as well as 180 deg diagonal view at 15 mm. The drawback might be that zooming in between  8mm and 15 mm, will show and cut off circle with black corners.  A circular view is not everyone’s favorite, but It can offer spectacular artistic images,  for example when taking over-under shots of a sunset above a coral reef.

This new lens can also be used on DX (cropped) sensors, like for example the Nikon D7200.  On the zoom ring of  Nikon 8-15 there is white marker placed at  11 mm, indicating  that with a cropped format the lens will work in the range between 11 and 15 mm: at 11 mm it will produce a 180 diagonal view and at 15 mm a 110 deg diagonal view (which is about the same range as the Tokina 10-17). At lower values than 11 values, the image will show a cut off circle with black corners. This is because the DX sensor is 1.5 factor smaller than that of a full-frame FX camera. So  10mm and 15 mm a  DX camera would be equivalent to 15 mm and  22 mm on a full-frame camera respectively. Will this lens also work in DSLR  housings for cropped sensors that accommodate the Tokina 10-17? I think it should, with the specific right zoom gear and dome port. My preference has always been the 5-inch minidome, allowing you to get very close to your UW subject. A  minidome is a half-spherical dome aligned with the nodal point of the lense.  

The question, of course, is if the new lens is worth the big investment of around 1000 Euro.  Some of us would say: only if it produces superior quality of pictures on a DX camera than the good old Tokina  10-17.  The ‘Tok’ is a much cheaper fish eye that for many years has been the workhorse for most cropped camera fish-eye adepts. As one of those, I am really looking forward to some comparative tests of both lenses on a D7200/D7500 camera. But see:   https://www.uwphotographyguide.com/content/first-impressions-nikon-8-15mm-fisheye-lens-review and https://wetpixel.com/articles/review-nikon-8-15-mm-f-3.5-4.5-fisheye-lens/P1

The advancement of the mirror-less cameras In the early days of mirrorless cameras, DSLRs simply did most things better. Mirrorless cameras were more compact and much cheaper, but that was it. Almost always, a DSLR could focus faster, shoot faster, had a much better viewfinder, and more often than not produced superior image quality. But with the increased quality of electronic viewfinders,  the much smaller weight and size and the bigger sensors the mirrorless camera seems to be gaining ground on the DSLR cameras, which make them no longer simply a more compact (but not always cheaper)  alternative.

Many UW photographers in the past including myself have been using the Nikon DSLR camera, either in the full-frame (FX) or cropped (DX) format. Nikon has been making some revolutionary changes by introducing the mirrorless Z6 (24megapixels) and Z7 (45 megapixels) full-frame cameras (see insert lower panel, to compare their size with the Nikon D850, explaining why the Z7 is also known as the 'mini D850'). When directly comparing the Z7 to the Nikon D850, the key drawbacks seem to be slower autofocus in low light settings, slightly less dynamic range, and shorter battery life. One of their best features is its high-resolution electronic viewfinder (EFV) making optical analog viewfinders (OVF) in DSLRs look ancient. While the OFV gives a view through the lens, the EFV gives you a view through the sensor and the option to present a lot of information.  The LED screen serving as an additional option to view the live scene, prior to or after your shot. In an underwater housing, the EFV image may still benefit a lot from a 45-degree viewfinder on the back of the housing (see:https://www.backscatter.com/reviews/post/Nikon-Z7-&-Z6-Underwater-Camera-Review).

The  Z mount has a larger diameter larger than the F-mount on the DSLR bodies and lies closer to the sensor because of the space saved by skipping the mirror.  When combined with an FTZ adapter the Z  will also take the new Nikon 8-15 fish-eye discussed above, and older DSLR  lenses, even those from the DX (cropped sensor, APS-C) range. Unlike with the DSLR,  the Z cameras will automatically apply a DX crop, so that the DX image always fills the finder. The latest AF-S (1984 - today) and AF-P lenses seem to work nicely. However, older DX lenses, like the 10.5mm fisheye will need a manual focus (according to the Ken Rockwell reviews). There are no tests yet of the performance of third-party fish-eye lenses, such as the Tokina. 

Nikon has just brought out an even cheaper mirrorless APS-C  (DX) camera called Z50 with an electronic viewfinder. Comparable to the D750 in resolution (20 megapixels),  but smaller and lighter and with a Z mount. No UW housings are yet available for this model. To use your old DX lenses, you again need the FTZ adapter.  So, Nikon will now be creating four separate lines of lenses: APS-C and full-frame for DSLR, and APS-C and full-frame for mirrorless cameras. So far, the big promise of the new mirrorless series is that they provide a lighter and smaller camera (allowing more compact housings, although the bigger lenses would mean an increase of weight and volume again) and a large bright electronic viewfinder, without losing much quality as compared with the DSLR full-frame Nikon workhorses. But some critics have argued that  Z-50 is is a mistake since you are not able to profit from the larger Z-mount with a smaller sensor. And that it will create extra costs because one needs to buy new lenses or an adapter for your old DX  (F mount) lenses.

 What to choose will become much more difficult for UW shooters in the near future. Since the cost of full-frame sensors has decreased dramatically over the last few years  a budget FX camera would compete head to head with a high-end DX camera