TRIED & TESTED GEAR
The best optics and outdoor products tried & tested for you
THERMAL IMAGERS
ZEISS DTI 4/35
£2,850
Matt Merritt
Thermal imaging cameras are taking off in a big way in the world of birdwatching. Not only do they allow you to look for birds and wildlife at night, but also have had a major impact in the viewing of those species – Jack Snipe, for example – that tend to remain well hidden by day. Their use has revealed that there are often larger numbers of such birds present than previously thought.
The DTI 4/35 is Zeiss’s latest entry in the market, and the marketing stresses that it’s ideal for wooded and overgrown areas. So how does it perform?
Let’s take the design first. It’s compact and lightweight, and fits snugly into the hand. Plenty of thought has gone into the placement of the controls. In use in the field, I found it easy to find what I needed, first time, every time, with the buttons well separated, and the zoom controls in particular logically placed.
It has a high-resolution 640×512 sensor and ZSIP technology, and that helps to deliver an image that is sharp and high-contrast at all distances. Field of view – 26 metres at 100 metres – feels wide and certainly does the job in woodland, as claimed.
You do lose some detail as you zoom right in, but a lot less than I’ve seen on some thermal imagers, so it’s easy to watch for long periods, even at long range.
There are eight different colour modes – ‘Black hot’ and ‘white hot’ are high-contrast, while ‘red hot’ is probably the one to go with for fast detection of heat sources.
‘Rainbow’ aims to pick out even small differences in temperature, while ‘red hue’ helps adjust your eyes to darkness, ‘dark hue’ felt easier on the eyes when using for long periods, and ‘green hue’ and ‘night eye’ offer further options.
One feature I really liked is that you can customise the settings to suit yourself. You can select to keep only certain colour modes active, and to limit the maximum zoom, so that you don’t have to scroll through all the settings when you find any wildlife.
There are also three different observation modes – ‘universal’, ‘detect’ and ‘fog’ – designed to suit different situations. You can move between them, depending on whether you’re simply trying to pinpoint birds and animals, or trying to see them better.
There’s a movement alert feature that tracks the hottest heat source in the image and tells you when it moves, either by f lashing the LED on top of the unit, or by turning the display on, so you don’t have to hold the camera all the time.
There’s a ‘hot tracking’ feature that frames the warmest source in the image with a red square, helping you track them in dense undergrowth, and the Picture In Picture (PIP) lets
