Interesting Articles

[lovells19]

Diver physiology

[beivied]

http://sehsuan.clubsnap.org/olympus/

DIY cleaning of PT 010, compiled by sehsuan

[luc]

Correct Exposures by Choice not Chance:

Link

[siaoon]

Hi ppl.. juz found a forum that shows quite a detailed information about sea slugs.. so u ppl may want to check this out to identify the colourful "models" u photographed...

think its good for us to find out more abt our "models".. so that they can pose better for us rite?? hehee..


Sea Slug Species List

* asked to repost here.. so.. got to guai guai.. if not kena banned cham liao..

[siaoon]

more info of our "models".. extracted from Fisher**n Scuba..

:: Nudibranchs

Nudibranchs, also known as sea slugs, are some of the most beautiful and diverse creatures in the ocean.

There are over 3000 described species worldwide.

External Morphology

- Nudibranchs are essentially snails without shells, and their name literally means "naked gill". In most species, the gills are prominently displayed on their dorsal surface.

- Some kinds of nudibranchs have a tuft of gills located on their backs at the posterior end, which are used only for respiration. Other kinds of nudibranchs have many finger-like structures on their backs called cerata, which function for gas exchange and often defense (see Defense below).

- Sea slugs have a pair of tentacles (called rhinophores) located on top of their heads, which biologists believe are used as sensory organs to assist in finding food and seeking a mate.

- Many nudibranchs are brilliantly coloured while others are subtly coloured to match their background, thereby providing camouflage.


Habitat and Distribution

- Nudibranchs are benthic organisms, meaning they live on the ocean bottom. They can be found crawling over rocks, seaweeds, sponges, corals and many other substrates.

- Sea slugs range from the lower intertidal zone to depths of over 700 m.

- They are found all over the world, including the British Isles, the tropics and even the Antarctic


Reproduction and Development

- Nudibranchs are simultaneous hermaphrodites, which means that they possess both male and female sex organs at the same time. This strategy increases the probability of finding a mate, since every mature individual of the same species is a potential partner (self-fertilization is very rare).

- After mating, nudibranchs lay their egg masses either on or near the organism on which they feed. These egg masses vary in shape, size and colour depending on species. Some sea slugs lay single coils of eggs, while others are in the shape of a thick ribbon wound into a spiral. The egg masses are often white, but they can also be red, pink, orange or any other colour depending on the species.

- Egg development can take between 5 and 50 days, and is strongly influenced by temperature. Warmer waters generally result in a shorter embryonic period.

- Usually the eggs develop first into a larval form called a veliger, which drifts in the ocean currents as plankton. Specific environmental conditions trigger the larvae to settle and metamorphose into the adult form. This larval dispersal is important in the successful exploitation of new areas, since adult nudibranchs move very slowly and cannot travel long distances.

Interesting Facts

- Some nudibranchs in tropical waters feed on corals (Phylum Cnidaria), which contain photosynthetic single-celled algal symbionts called zooxanthellae. These nudibranchs are able to remove the algae intact from the coral's tissues and store them in their cerata, where the algae photosynthesize and provide the host nudibranch with a continuous supply of manufactured sugars.

- Beachwalkers can search for nudibranchs in tidal pools at low tide - try looking under loose rocks or near animals that they are known to feed on (e.g. sponges and bryozoans). One of the best ways to locate nudibranchs is by spotting their egg masses, which are usually quite visible - the parents are likely nearby!

- If you are lucky enough to find nudibranchs in tide pools or while diving, please do not attempt to pick-up or touch them. These creatures are very soft and easily damaged, and you may hurt them inadvertently.

[sehsuan]

Meaning of Diving Flags
http://www.commanderbob.com/art9.html

[lanxx]

PT015 modifications

[sehsuan]

does anyone have this particular URL where one is taught how to totally strip down a PT010 casing? lost the url in my hard disk crash... got one guy from usa emailing me for help...

[waisj]

Home made PT-015 Base Tray with Handle
For those who like to DO IT YOURESELF

http://www.digitaldiver.net/lib_docs/build_a_tray.pdf

[waisj]

Hi all,

Since there has been a few request for strobe aiming and placement articles, i've found a useful beginner's article on strobe placement and aiming here.

I'm also in the process of coming out with a trobe aiming and placement article, till then do watch this space.

[beivied]

Emergency Assistance Plan

i know this is not underwater photography related, but i just think (and hope) every diver should at least know about things like this.

[beivied]

All night-diving fans should read this!

7 Monster sized dive lights reviewed and compared!

link does not work anymore..

[beivied]

Interesting Trivia For those new Underwater Shooters,

Interesting Trivia-C5050z settings for starters

Something for you to prepare for your First Underwater Shoot

Cheers

link does not work anymore..

[kthan]

Which U/W Digital Camera Setup Should I Get?

I am sure all of us face this dilema when we decide on taking up u/w photography. Sure, there are lots of forum discussions on this particular subject, and many times, while most advices are good, most people will recommend the system that they have. I mean, I wouldn’t expect someone, after spending thousands of dollars, to say “Do not get XXX. It’s the most crap piece of junk I get. I never manage to get a decent picture, but u know what, I am still using it because I love it!”

Most likely, you would hear people say “Get XXX, becos it can do this, this, this”. Having personally gone thru this trauma, I would like to give you a different perspective, my thought process on selecting a u/w digital camera system.

1. Budget
Who wouldn’t want to drive a Ferrari and date a Miss Universe? But we all live in the real world
2. Camera – land use vs u/w use
Some perform better on land and some better in water. So u want a serious land camera which can also take a few underwater shots or you want a serious u/w camera which allows you to take a few land pics?
3. Compatibility with existing equipment
You are a film user and there are things which you hope you can still use with your new digital setup.
4. Power options – AA batteries vs dedicated lithiums.
Do you have gadgets which can share the AA batteries?
5. Memory options
Per unit cost, vs gadgets you own which can share the same memory medium
6. Size, weight, looks, depth rating and designs.
Do you have problem handling and transporting it? Or you dive infrequently and you prefer a DC to be really small for your other travel holidays? Can the housing hold to the depth you are usually at? Do you like the feel of the setup in your hands?
7. Attachment fittings for strobes, arms, base tray and add-on lens.
Not all housings will fit all strobes and other accessories.
8. Ease of maintainance and support (accessibility of repair facility)
9. Accessibility of camera controls in housing
10. User, dealer and forum comments and the consistency of information received

The list is of course non-exhaustive but I hope by answering the questions above, you will have a better idea of what to get to suit your needs.

Further readings:
My writeup on “U/W DSLRs” @ http://forums.clubsnap.org/showthread.php?t=88700
My writeup on “Guide to Strobe Selection” @ http://forums.clubsnap.org/showthread.php?t=84605
eric

[beivied]

nudibranch food..

http://people.ucsc.edu/~mcduck/nudifood.htm

[RSU]

As discussed on another thread, here is the quotation I received from an Australian distributor for the Subal ND70 housing for the Nikon D70, plus various ports, strobe housing for the SB800 and accessories.

Smelling salts not included.


Prices are in AUD, you do the conversion.

*******************
Thank you for your enquiry

Here is the requested quotation to suit the lenses you have specified and also the freight to you in Singapore. All prices quoted are in Australian Dollars and Tax Free.

Subal D70 Housing
- $3600 Aust Tax Free

Nikkor AF-S DX 18-70mm f3.5-4.5G IF-ED
Requires the following:
Subal DP-FE2 Dome Port
Subal Extension Ring
Subal 18-70mm zoom gear
Diopter Kit
- $2310 Aust Tax Free

Nikkor AF Micro 60mm f/2.8D
Nikkor AF Micro 105mm f/2.8D
Requires the following port configurations options

Option 1 (Auto Focus Only)
FP-90B Flat Port (for 60mm lens)
Subal 33mm Extension Ring (for 105mm lens)
- $650 Aust Tax Free

Option 2 (Auto / Manual Focus switchable)
FP-FC 60 Manual / Auto Focus Port with 60mm Gear set
FP-FC 105 Manual Focus Gear Set
Subal 33mm Extension Ring (for 105mm lens)
- $1350 Aust Tax Free

Subal SB-800 Housing with sync cable included
- $1090 Aust Tax Free

Ultra Light Standard 5 piece arm to suit Subal Housing
- $350 Aust Tax Free

Tray to mount second strobe
- $100 Aust Tax Free

Inon Z-220s Slave Strobe
- $750 Aust Tax Free

Ultra Light Standard 5 piece arm to suit Inon Strobe
- $350 Aust Tax Free

Inon Sync Cable
- $150 Aust Tax Free

Subal / Pelican Focus Assist Light and bracket
- $90 Aust Tax Free

Freight will be approximately $150 Aust Tax Free with FEDEX

**************************

Cheers,
Rohan

[ScoobaKev]

ScubaCam Singapore's independent tests on 6 of the most popular strobes the us u/w photographers buy...

http://www.scubacam.com.sg/pages/Strobe%20Test.pdf

[lanxx]

http://www.kelpfish.net/strobe.swf

[sprain]

I thought this might be useful...

http://www.saa.org.uk/photography/Li...waterworld.htm

[h2o]

http://xray-mag.com/

got the above link at cts......

it is a diving mag......not photography specific....but it does contain some portfolios.....

i'm sure some of the resources can be of use to all the divers here