Nightvision imaging camera


EMCCD Vs SWIR

EMCCD

SWIR

Location:

 The area used was a car park surrounded by tall trees, no background reflections. The only light was from the monitor and this was shielded from the cameras. The target cars were at 25m and both cameras could easily see these, as well as the surrounding area.

Light level:

 The weather conditions for these tests were broken heavy cloud with no moon, just starlight.

Lenses used:

 To try and keep the image a similar size we had a 25mm lens on the EMCCD and a 50mm lens for the SWIR, both were fully open at f1.4. We used both cameras in digital mode, so the EMCCD had a resolution of 1K x 1K and the SWIR had a resolution of 640 x 512. Albeit the difference is not that noticeable at this light level

Tank

Location:

 Countryside – UK woodland with armoured personnel carrier.

Light level:

 Clear Starlight plus scattered light from distant towns.

Lenses used:

 Standard 50 mm focal length set at f1.4.

Sequences:

  • Top left sequence using a colour daylight only camera.
  • Top right sequence using an intensified CCD camera Note lack of flare from bright lights sources.
  • Bottom left sequence using a colour EMCCD camera.
    Note lack of frame shift smear from bright lights with the Frame Shift Smear shutter turned on.
    Note the amount of colour still available under these light levels.
  • Bottom right sequence using monochrome EMCCD camera.

River

Location:

 Coastal – UK East Coast harbour.

Light level:

 Clear Starlight plus scattered illumination from distant town.

Lenses used:

 Standard 50 mm focal length set at f1.4.

Sequences:

  • Top left sequence using a colour daylight only camera.
  • Middle right sequence using an intensified CCD camera.
    Note lack of flare and suppression of bright light sources in the field of view.
  • Bottom left sequence using a colour EMCCD camera.
    Note lack of frame shift smear from bright lights with the Frame Shift Smear shutter turned on.
    Note the amount of colour still available under these light levels.

Harbour

Sequences:

  • Top left sequence using a colour daylight only camera.
  • Middle right sequence using a SWIR (InGaAs) camera.
    Note ability to penetrate light mist indicated by the background details not available in the other two sequences.
  • Bottom left sequence using a colour EMCCD camera.
    Note lack of frame shift smear from bright lights with the Frame Shift Smear shutter turned on.
    Note the amount of colour still available under these light levels.

Traffic

Location:

 Urban – UK main road junction with full street lighting on the junction.

Light level:

 Clear Starlight plus urban street illumination.

Lenses used:

 Standard 50 mm focal length set at f1.4.

Sequences:

  • Top left sequence using a colour daylight only camera.
  • Top right sequence using an intensified CCD camera Note lack of flare from bright lights sources.
  • Bottom left sequence using a colour EMCCD camera.
    Note frame shift smear from bright lights with the Frame Shift Smear shutter turned off. These are eliminated the sequences were the shutter is turned on.
    Note the amount of colour still available under these light levels.
  • Bottom right sequence using monochrome EMCCD camera.
    Note lack of frame shift smear with Frame Shift Smear shutter turned on.