10 tips and a half for half-half underwater photos

What is a semi-half-half underwater photos? And how to take pictures half and half?

Semi-half photos are read in English as Over-Unders or Split-Shot Underwater Photography. Underwater photographers like to use this technique when there is interest in both parts of the picture, underwater and above it. In the technique of half-a-half photography, you can follow the tips here to take interesting pictures the underwater occurrence together with that above them. Since this sight is very rare and impossible for imitation of a not naked eye (for that matter, without a diving mask), it is easy to create interesting images in this way. The main problem is that beyond the knowledge of the technique, the equipment specification is very important in order to achieve the desired effect. Compact, water-resistant cameras with a relatively small lens diameter make it impossible to take a half-half image because of the difficulty in controlling the waterline and the narrow angle of vision obtained from them. In contrast, cameras with a large sensor (called FF, or NIKON FX and a KROP sensor, like most SLR cameras today, is a KROP sensor, or DX) yield images with too shallow a depth of field and require a very closed aperture or focal length too short to allow for any reasonable focus on both halves of the image.

In the list of tips below, I hope to shed light on this fascinating subject of half-and-half photography and improve the percentage your successful photos even if you do not use the most suitable equipment, thinking that if you understand the limitations, you will find creative ways to overcome them. And if you cannot creatively ?! Hey! who said that underwater photography is a cheap business …?

So here it is, a list of tips:


  1. Take a wide-angle lens or a fisheye lens – a wide-angle lens / fisheye lens with an angle of view as large as possible, allows us to capture a very broad scene on the camera sensor, thus perpetuating the occurrence fully underwater and the whole event over it. Another where a wide angle lens/ fisheye helps us for half-half scenes, is their very depth of field, derived from their vast field of vision, or rather, their short focal length.
  2. Take a picture of shallow water – because the light quickly fades under the water and the reds disappear rapidly, focusing on an underwater theme which is near the surface will allow it to be well lit and to show its true colors. As colorful and prominent as that the occurrence under water will be, the picture has a better chance to be more successful. Another thing that will make it easier is good exposure and finding a clear ground (sandy soil or light corals) so that it returns sunlight.
  3. Capture when the water surface is quiet – a quiet water surface will make it easier to control the position of the dividing line in the frame, in addition to the distribution balanced frame. In addition, it is easier to keep the port from accumulating water droplets (see below).
  4. Use the largest lens / porthole available – the larger the lens or port area, the easier it is to create a semi-semi picture successfully, for two main reasons: a) it is easier to maintain the waterline and divide the frame because the water has a larger area to pass through the Y axis (up / down) on top of the port. B) The imaginary underwater picture (on the port) is more remote than the sensor (since we have increased the distance between the sensor and the beginning of the optics) increases the depth of field and brings the distance of the undersea focus closer in relation to that of the one above the water. (Since the water is densely conditioned, different from air, the light behaves differently and affects focal length – focus).
  5. Capture with a closed aperture – When we take a half-half picture, we are essentially trying to capture two situations at different distances from the camera sensor (again, because light rays behave differently under water). By using a small aperture (high value) such as f11 or f16, we significantly increase depth of field and cause the image below and above the water to be properly targeted. Note that when a closed aperture is taken, the loss of light must be compensated in some way. It can be extend the exposure duration, but then we risk a blurry image due to camera / object movement. So as not to get exposure too long, we can increase the sensitivity (ISO) we take. Therefore, as a rule of thumb, semi-half images are made with a closed aperture and sensitivity greater than 200. With the technological improvement in recent years, you can take pictures without noise as well as with very high sensitivity without fear – depending on the size of the sensor (a large physical sensor = less noise at high sensitivity).
  6. Focus on the subject under the water – the focal point of the half-and-a-half picture will be underwater; with the background going on will be the world outside, above water. Performing a focus on the underwater object will ensure that the focus is kept on it while the background is blurred more or less, according to the aperture data, the background distance, the port used and the size of the sensor…
  7. Capture when there is an occurrence in both parts of the picture – shooting when there is something going on in both parts of the picture will ensure a more interesting picture. Underwater occurrence can be a diver, a fish, a special topography or even an interesting underwater plant. While the occurrences at the top of the frame can be sunset / sunrise, clouds, mountains, birds, a boat, etc.
  8. Film in the middle of the day, with the sun above you – a photo in the middle of the day, will ensure that the maximum amount of light will penetrate the surface of the water and illuminate the subject under water. The surface of the water behaves like a mirror (see: “complete repetition” derived from the Snell Code) when the sun’s rays hit them too sharply (beginning of day and end of day). In the middle of the day the sun’s rays penetrates better and allows a better and more correct exposure. It is best to place the sun slightly behind you, to avoid from a flare phenomenon or a reflection of light in a port / lens, but note that your shadow or camera does not hide the subject or enters the frame. In addition, shooting in front of the sun may cause contrast to decrease in the picture and make it difficult obtaining proper exposure in both parts of the picture due to too large differences between the upper and the brighter part of the frame and its lower and less illuminated part.
  9. Measure the exposure by the top of the image – in order not to burn the light parts in the image, measure the exposure from the top (bright) of the image and, if necessary, try to clear shadows in part (usually at the price of digital grain / noise in the specified parts).
  10. Use the flash to illuminate the bottom – if the subject or angle of the sun requires artificial lighting, measure exposure at the top of the image (as in section 9) and point the flashes down (under water) to illuminate the subject. Of course, in this method the illumination is limited to a few meters from the camera, according to the intensity of the flash.

Bonus Tip: (I promised 10 and a half tips not?)

Avoid water droplets on the port / lens – one of the biggest problems in half-and-half photography and photography at all when the camera inside the case (for example, when surfing) is the water droplets in the picture. Drops of water can destroy an excellent picture if they are in the wrong place … when in some cases, they can be removed in editing.

There are various methods to reduce and prevent the accumulation of water droplets on the port / lens. I’ll share some with you which I found effective.

– The method I use is spitting (sorry, I did not prepare you for this …) on the port and rotational application of spit on every port. Then I dip the case in the water and take it out a few seconds before taking the picture. In this way, there is a few seconds of port without drops, before cracking the water layer on the port.

– Some prefer to use baby soap or spray to prevent steam instead of using saliva (surely girls …) that are uncomfortable spitting on the camera in public … and the other procedure of rinsing before photography as before.

–  Another interesting method is the holding of a sponge in the pocket of the compensator and once you want to make a half-half picture, lift the camera above the water (may be quite heavy in SLR cases with flashes …) and squeeze the sponge and wiping and drying the port. After that, insert the package and the port into the water while ensuring that the top of the port is not wetted.

– Port glass is less sensitive to the formation of water droplets on it and therefore better to use semi-half photography. Anyway, most existing ports are made of acrylic (a kind of plastic) and are therefore more susceptible to the phenomenon. If you know in advance that you are filming in a semi wet environment, you should consider purchasing a glass port.

In conclusion: In order to take a successful half-half picture, we have to shoot with the widest lens available (Preferably at a focal length of 24 mm or less), with the most closed aperture possible in terms of the situation (compensating quickly and sensitively), in a camera with a medium-sized sensor (advanced compact or SLR APS-C). Keep the sun above and behind us or use the flashlights to illuminate the underwater scene, avoid water drops on our big port, focus on the underwater subject and of course, find an interesting situation for photography, underwater and above … easy is it?