Tuesday, July 29, 2008

Eastern Frogfish

By Bjorn Landfeldt

I saw this nice little Eastern Frogfish (Halophryne queenslandiae)at Bare Island last Sunday.

I was happy about finally being able to get a decent photo of them. Every time I have seen one, it has been hiding well under a ledge or in silt so photos have turned out dark, blurry or silty. This one was lying in-between two rocks on sand waiting for that cover shot.

Cuil search engine

By Bjorn Landfeldt

I just tried Cuil, a new search engine from some former Google people. The interface is nice, the search results are laid out side by side in columns with example pictures from pages. I found a curiosity though, simple searches such as "Sydney university or "Cuil" yields replies in no time whereas complex searches such as "Salvo rebel 12w LED" yields an error message saying something like our servers are overloaded at the moment. Could it be that the search algorithms are somewhat complex and this is the price to pay?

Sunday, July 27, 2008

Paragon Dry Suit

By Bjorn Landfeldt

I saw the paragon dry suit down at a local dealer after the dive today. It seems to be quite similar to the Northern Diver Cortex I have but there were some differences.

1) The suit is made of tough cordura as the ND suit is but this one felt softer and more pliable. The ND suit is tough as nails but it is also a bit restrictive. Without trying the Paragon on, I assume it is nicer in the water.

2) It has socks instead of boots. I think this is a good thing actually, it is better to put a decent boot on for rocky shores.

I have a problem that the ND suit traps quite a bit of air so that I need a lot of extra weight when diving dry. I suspect the Paragon is a bit better in this regard.

Thursday, July 24, 2008

Nice or Nuisance

I remember when I started to dive, how fascinating the Eastern Blue Groupers (Achoerodus viridis) were. For those of you who don't know them, these fish exist all around the coast of NSW, they are big, blue and extremely friendly.

Nowadays I am not sure. Since I started to take photos underwater I have realised that they more common than not just swim between you and the photo object, wrecking that one in a lifetime photo opportunity of the extra rare species. Are they a nice friendly part of our oceans or the hobby photographers worst enemy I wonder?

Salvo Rebel 12 W LED review / opinion

This page contains my opinions of the Salvo 12 W LED canister light. I am putting this information on line since I couldn't find much in terms of testing before I ordered it. I am not in any way a light professional and I don't have access to proper light meters so I cannot provide any hard numbers on the output. What I can do is to provide my own thoughts and experiences with the light.

First, the cannister is very small and very light. There is no problem mounting it on a back plate or on the webbing of a harness, it will not be in the way or feel heavy. In fact, I will try to mount it under my Ikelite housing at some stage for night dive photography and see how that works. The light feels very solid. Since there are no parts to open apart from the light head for recharging it all looks like a light that will last many years and the LED will not break easily either so overall, a solidly crafted package set to last for a long time with minimum maintenance. I will need to use the light for a while before being certain about the quality of the steel etc. but it all looks good.

Some facts:

Battery pack, 5.2 Ah Li-Ion
Burn time, 5 h
Output, 750 Lumen
Temperature, 5600 K
Cannister weight, 1.1 kg
Cannister size, 19 cm x 5 cm (diam)
LED manufacturer, Ostar

Light beam:

When switching the light on I was surprised at how much light was leaking outside the 6 degree beam listed on the Salvo site. Personally, I don't mind since I believe this will just help illuminate the reef around me and help me spot interesting critters. However, it also means the output is not concentrated on the spot so people who want a strict pencil beam for wreck diving etc. may get a bit disappointed.

The picture above shows the 6 degree spot in the center and the surrounding illuminated ring. In my opinion, the surrounding ring should be bright enough to illuminate a reef quite well (compared with my old c4 1 W LED torch). The photo is very much underexposed to bring out the center spot.

The below picture shows the spread from the light head. The head is about 50 cm from the wall and the large ring about 1m in diameter which shows that there is quite a large illuminated area. The camera can't separate the spot from the outer ring in the photo since the illuminated area is completely overexposed and all highlights are clipped. Also, this photo shows better than the top photo how bright the outer ring is.

In order to get a feel for how strong the torch is, I put it next to my backup torch, a Salvo Rat 3 W LED. Now, when I got the Rat I thought that was really good with a beam that went far in under ledges and nice bright light. As can be seen from the photo below, the Rebel on the right copletely kills the Rat on the left. It is hard to see in the photo but there is a wider ring around the rat spot as well but compared with the Rebel it is almost invisible. The two torches were placed side by side about 1m from the wall in the photo.

In the Water

I went diving with the torch for the first time on July 16. My immediate reaction was that the light was very bright. Greg brought his old 20 W halogen cannister light and at first I thought he was running low on batteries when he turned it on and after having seen the Salvo on. For Sydney divers who are familiar with Bare Island in order to get a feel for how bright it is, it clearly illuminates the fort on Bare Island from the boom gates (200-250 m).

I tried to take some photos from under water but it was impossible to hold the torch and take meaningful photos. Since the light source was so close to the camera all I got was a coplete whiteout from the beam, backscatter and nothing of the target wall. However, if looking at the photo below one can see the sand bottom and get an idea of the light spread. The torch would have been about 1 m above the sand at this point.

The torch is brilliant for reef diving. As I suspected the outer ring illuminates a wide area enough to see the night critters so as you dive, fairly much the entire field of vision is lit up decently. The center spot is strong enough to penetrate deep into caverns and light up the insides of caves. It was difficult to tell how far the torch penetrates since this is dependent on some quantifiable measure of visibility and particles in the water at the time. However, the reach was much further than the halogen spot (focusable).