Part of my pre dive briefs include that you have to smile, as one of the most voracious underwater photographers in the club it is easy to spot me as you just follow the Strobe flashes. I have been using my trusty Olympus C50-50 prosumer camera since 2003 however the world of digital photography has moved on and I’ve been thinking over the last 2-3 years about upgrading to a digital SLR system underwater. As you start to research this it becomes a bit of a minefield as this is a niche area of photography where most of the major manufacturers of underwater housings are small family run businesses and therefore support for mainstream products is limited.
I had been humming and arring about whether to go for a DX or FX Format camera in particular Nikon D7000 (DX) or Nikon D700 (FX), What is FX and DX you may ask? This the size of the Sensor that the camera uses FX is equivalent to 35mm Film camera and is what professional photographers use, DX is about 1.5 times smaller than the FX Format and is mainly aimed at Enthusiasts and Consumers each. Cost is the main difference with FX Cameras typically starting from £2000 and then add the cost of professional lenses which cost over £1000 each. FX sensors have larger pixels than DX Sensors and hence they have better low light capabilities also the “Crop Factor of 1.5” has impacts on the focal Lengths of lenses for example a FX 100mm Lens on a DX Camera will be the 150mm and also each format has its own specific lenses such as the excellent Tokina 10-17mm Fish eye lens which works best on DX cameras (This is discussed at length on many review sites).
For diving photography in the UK (Green Water Diving ) creates a set of issues / problems to overcome to get the good shots:
visibility – this is typically 5-7 Metres although occasionally 30 Metres can be had both on the East and West Coasts.
Loss of Light:
- Reds are lost in the first 10 metres by 30 metres a lot of the natural light has gone so you need to use a Strobe (Underwater Flashgun)
- Camera’s Automatic Focus ( Infra red doesn’t travel at all) and range finder doesn’t work very well, so you have to use an additional light source such as a torch to light up your subject which can put them off.
Sand and silt in the Water:
- This causes the dreaded back scatter suspended sand, silt and detritus act like tiny mirrors underwater so when you use a strobe the light bounces back from the particles in the water giving you a dandruff effect in the picture.
Few tips for the new underwater photographers.
- Get closer – even powerful strobes only work up to 2-3 metres so if your subjects are appearing Green or Blue (In Warm Water) with your Flash going then you are too far away.
- Use macro setting and get closer than 20cm to your subject – be careful not to disturb it.
- Using a wide-angle lens allows you to get closer to your subject
- Try shooting slightly upwards this allows more ambient light into the frame
- Move your light source away from the camera ie. buy a strobe (Or use a torch) which can be used or a arm 40cm – 60cm to the side or above, this will reduce back scatter so you can angle the light to not bounce straight back at the camera, be careful not to set the strobe too close to the edge of the picture otherwise you will get a bright spot from the Flash.
- You can use a Green or Blue water (Tropics) filters which brings back in the natural colours of red, this works only for depths to about 20 metres and for slow or static subjects not in shadows, you need good light.
Well last weekend thanks to our local photography shop in Perth, I was able to borrow a Nikon D700 (FX Camera) and a F2.8 24-70mm Nikon Lens to compare against my Nikon D7000 (DX Camera) and my Nikon 20mm F2.8 lens and I also tried my Nikon 60mm Macro Lens (Nikkor Micro). To make the trip more challenging and fun I invited my two nephews along and Tara for crowd management.
Shooting Photos at an Aquarium has its challenges Low Light and you can’t use flash as it bounces off the glass ruining the shot, it is a good idea to shoot close to the glass straight on and you may have to switch to manual focusing if the lens locks on to the glass rather than the Fish or Crustacean. I use aperture priority on my camera opening the lens up to F2.8 which allows the most light in and then as fish tend to move you need a fast shutter speed 1/60th or ideally 1/125th so the image doesn’t blur. In this low light not using a flash the ISO (Speed at which the film or Sensor absorbs light) wash pushed up to 3200+, unfortunately the faster the ISO the more noise occurs in the image. The developments the last two generations of digital cameras in low ISO capabilities has been huge and I now wanted to see how the best DX Camera stacks up against a professional FX camera.
Using the wide angle lens, I noticed that both the Nikkor F2.8 24-70mm and the Nikkor F2.8 20mm both had issues with automatic focusing and I set the focusing manually. Both the cameras performed well at ISO 3200 and on the wide angle the D700 when zoomed in showed slightly less noise, but not much in it. After taking the boys through the aquarium and buying them a few toys and juice I headed back around the aquarium with my 60mm Macro (Nikkor) Lens on both cameras I was happy with the results from both cameras see below: