Opticstar PL-131M CoolAir Monochrome Camera

High-speed, computer controlled planetary camera.

  • Planetary video camera
  • Sensor 1/2-inch CMOS Monochrome
  • Sensor Resolution: 1280(H) x 1024(V)
  • Frame Rate: 22 FPS @ 1280x1024
  • Region of Interest: 220fps @ 320x240
  • Long Exposure mode: 10 seconds max.
  • USB 2.0/USB 3.0 port (USB powered)
  • No Infra Red filter
  • Software for video capture
  • Software for longer exposure capture
  • For Microsoft Windows 7/8/10/11
  • UK warranty
Opticstar PL-131M CoolAir Monochrome Camera
  • Product code: PL131MCA
  • Availability: In stock
  • Despatch: 2 business days
  • Retail Price: £ 149.00
Shipping rates
England & Wales
£ 6.00
Scotland Central & South
£ 6.00
Scotland North
£ 6.00
Northern Ireland
£ 6.00
UK islands (from)
£ 6.00
European Union (from)
£ 12.00
Worldwide (from)
£ 18.00


Caution: When using any camera to image the Sun, always use appropriate solar filters with your telescope.

The PL-131M CoolAir fan-cooled camera offers performance and versatility, outperforming cameras costing considerably more. The camera excels as a planetary (Solar and Lunar) camera with frame rates of up to 220fps. It can also be used as a guider with the optional Shoestring GPUSB. Gain, Region of Interest (ROI) and binning are all features implemented in the hardware to deliver high performance.

The PL-131M camera has been designed to deliver high image quality at unusually high frame rates. The camera is capable of capturing an image even at a minimum 1ms exposure (10secs max in single shot mode) at all supported resolutions and with frame rates of up to 220fps.

The PL-131M camera requires a fully featured, full speed USB 2.0 port to take advantage of all the camera’s advanced features. See the computer requirements on this page for details.





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Noise reduction and cooling

Thermal noise is reduced due to a fan that draws the heat out of the camera fast. Enclosed camera cases will typically show temperatures of around 10°C above ambient temperature, these can rise dramatically during extended exposures. Air-cooled cameras such as the PL-131M will show internal temperatures of around 3°C above ambient temperature under normal use, thermal noise halves for every 6 degrees of drop in temperature which means that a similar non-air-cooled camera with have higher noise levels.

Region of Interest – ROI

ROI has been implemented in hardware and offers fast frame rates at the expense of field of view. Frame rates of up to 220 frames per second are possible. In addition, the position of the ROI window can be set by the user via the supplied software and repositioned as required.

Demonstrating the Region of Interest (ROI).

The above example shows the ROI in action. The user can resize (1280x1024, 640x480, 320x240) and reposition the ROI over the planet in this example so as to dramatically increase frame rates from 22fps to 80fps and to 220fps respectively without reducing the actual size of the planet, this remains the same in all three images i.e., 306x204 pixels approximately. In practice the ROI reveals and sends to the computer only a portion of the total sensor area.

As such considerable amounts of detail can captured at these extreme speeds. The size of single frames and video files are also greatly reduced resulting in singe frames and AVI video files of 1/4 and 1/16 in size without compromising image quality.

R.O.I. Size
(in pixels)
R.O.I. Position Frame Rate * Frame Size
1000 frames
AVI File Size
Total Time for
1000 Frames*
1280x1024 whole sensor area 22fps 1.3mp 1300 MB 46 seconds
640x480 user definable x, y 80fps 0.325mp 325 MB 12.5 seconds
320x240 user definable x, y 220fps 0.081mp 81 MB 4.6 seconds
* maximum (depends on computer hardware & assumes 1ms exposure time)

Binning modes

Binning is implemented in the camera hardware for improved performance and is useful when you need to increase the camera’s light sensitivity. Binning increases light sensitivity at the expense of resolution, the field of view remains the same in all binning modes. The camera uses the whole of the sensor surface to collect photons and outputs the image at different resolutions depending on the binning mode selected. The table below is for illustration purposes and shows the effect of binning as light sensitivity increases and resolution/image size decreases, exposure time remains the same.

Demonstrating binning in long-exposure mode.
Binning Mode Resolution Sensitivity Binning Frame Rate
1x1 1280x1024 x1 not applicable 22fps
2x2 640x480 x4 hardware 80fps
4x4 320x240 x16* hardware/software 80fps
* maximum

Hardware Gain

Gain is implemented in the camera hardware and is useful in amplifying the incoming signal. This feature is particularly useful when minimum exposure times and/or maximum signal levels are required.

Planetary, Lunar and Solar imaging

When imaging the Sun, Moon and planets atmospheric turbulence will have an adverse effect on the quality of the image. As such the best way to capture a high-quality image of say a planet is by capturing hundreds or thousands of frames in succession and in the minimum amount of time possible. The resultant AVI video file can then be imported in say AstroArt or the freely available Registax where the image frames can be stacked by the software in a single final image of superior quality.

At a maximum frame rate of 220fps the PL-131M CoolAir is the ideal planetary and Lunar camera offering high quality video streams while dramatically reducing hard disk space requirements and the size of captured video AVI files.

For planetary imaging we recommend running the camera at 1280x1024 with the ROI set at 320x240. This ensures the highest image quality at the highest speeds possible, i.e., 220fps. When long focal lengths are used (i.e. over 6 meters for the larger planets) the camera ROI can be set to 640x480 (80fps) to comfortably fit the planetary disk inside the ROI window.

The 1/2-inch format sensor will accommodate focal lengths of around 12 meters for the largest planets so that the projected planetary disk remains smaller than the size of sensor. If the focal length used is around 12 meters you would use the camera at full resolution (22fps, ROI set to OFF).

For Lunar imaging setting the camera at 1280x1024 and the ROI at 320x240 will suit smaller Lunar features and/or when you want to draw out that extra detail. Otherwise for medium sized Lunar features running the camera at 1280x1024 with the ROI set at 640x480 will offer the best option. If you are interested in capturing as much of the area of the Moon as possible in a single shot you will need to run the camera at its full 1280x1024 resolution at 22fps (ROI set to OFF). What applies to the Moon also applies to the Sun (full aperture Solar filter required).

Finally the camera’s high speed makes it ideal for imaging (and viewing) in real time ‘fast moving’ targets like the International Space Station.

Image quality

The ability of the camera to capture and store high quality video to disk in real-time provides the data required for stacking any number of frames to create a single greatly enhanced quality image using image stacking software, these include Nebulosity (Nebulosity Lite is bundled with the camera), the excellent AstroArt, the freely available Registax and others.


The PL-131M CoolAir camera can be used as a guide camera and offers a number of features useful in auto-guiding sometimes not found in dedicated guiding cameras.

Hardware binning allows your guide camera to reveal and guide on fainter stars. Its ability to bin makes it ideal for guide scopes with shorter and longer focal lengths as you can better match the guider scope’s focal length to the size of the pixels. An on-board camera frame store ensures the highest image quality and S/N ratios.

The camera needs an auto-guide controller like the Shoestring GPUSB unit to be able to auto-guide with any ST-4 compatible mount. PHD Guiding software is bundled with the camera.

Other applications

The PL-131M CoolAir is very well suited to microscopy and machine inspection in particular due to its high frame rates combined with high image quality. The camera will perform well even under not ideal lighting conditions.

Hardware requirements

The PL-131M CoolAir camera requires a fully featured, full speed USB 2.0 port (USB 3.0 compatible) to take advantage of all the camera’s advanced features. Fully featured USB2.0 ports are rare in older laptops and not always present in entry level laptops. PCMCIA/CardBus USB 2.0 cards typically do not deliver full USB 2.0 speeds and will not work with USB 2.0 high resolution video cameras including the PL-131M CoolAir.

To resolve such issues an ExpressCard (with a USB2.0 port) could be used instead of a PCMCIA/CardBus card due to the ExpressCard's superior speed of 2.5Gbit/s (480 Mbit/s through USB 2.0) per slot.

Express type cards use a 34mm slot where PCMCIA/CardBus cards use 54mm slots. An ExpressCard should be connected directly to the computer and not via a PCMCIA/CardBus card.

Please note the ExpressCards will resolve USB related issues assuming that the laptop data bus can support full ExpressCard speeds and is fully implemented

Computers with slower USB 2.0 ports may still be able to capture at full resolution but may be able to only transfer a user selectable area (ROI 640x480 or 320x240) to the computer while sustaining image resolution and high frame rates. This does not have a real effect when imaging planets where video capture should ideally take place at the smallest ROI size possible, typically 320x240 @ 220fps for focal lengths to around 6 meters for planets like Jupiter or Saturn.

Always download and install the latest Windows updates.

This does not have a real affect when imaging planets where video capture should ideally take place at the smallest ROI size possible, typically 320x240 @ 220fps for focal lengths to around 6 meters for planets like Jupiter or Saturn.


Optionally, the PL-131M CoolAir incorporates a removable x0.5 focal reducer nosepiece that can double the field of view if required. An extension 5 metre USB lead with a USB repeater (amplifier) is also available in cases where the camera will be used further away from the computer.

The camera comes with a C/CS ring and a 1.25-inch telescope adaptor threaded for filters. A C/CS to T-thread adaptor is available as an optional extra. The camera will accept standard C and CS mount lenses as well as T-thread lenses (with the optional adapter).

Bundled software

In addition to EMAMCAP, the camera is bundled with a number of software applications including Opticstar View, Nebulosity Lite and PHD Guiding. Also, there are software plug-ins for third party applications such as AstroArt and MaxIm DL. The most appropriate software to use depends on the particular application.

If maximum frame rates are required then the camera should be used with Opticstar View or EMAMCAP. Alternatively, if maximum light sensitivity is desired then it should be used in native mode. The PL-131 CoolAir is supported natively in Nebulosity Lite, Nebulosity, PHD Guiding, AstroArt and MaxIm DL. In this mode the camera is capable of increased exposure times of up to 10 seconds.

View camera control software

The camera is recommended for lunar and solar (with a solar filter) imaging. It includes Opticstar View software for image capture and camera control with a point and click interface.

It can capture single frames, a series of single frames in BMP format or in AVI video format. The captured video data can optionally be compressed if required in MPEG-4 format.

A computer running Microsoft Windows and a spare USB port are required to operate the camera.

A brief outline of View’s image processing functions is listed below:
Opticstar View software for image and video capture.

  • Basic operations including Crop, Mirror, Flip, Invert, Rotate, Bright, etc.
  • Copy and paste user defined regions.
  • Distances can be measured between user defined points, circles, etc.
  • Angles can be calculated by defining three points on the image.
  • Operations can be performed on any user defined region.
  • Colour operations can be performed on individual R, G, B channels.
  • Data combine of two images.
  • Data calibration.
  • Image-zoom as a per cent of the original image.
  • Linear filters to soften, sharpen, emboss, blur and Gaussian.
  • Non-linear filters for median, erode, dilate, contour, edge and jitter.
  • Transform filters for pinch, punch, twirl and cylinder.
  • Fluorescence filters for gamma, colorize, mix and combine.

EtAMCAP camera control software

EtAMCAP is the second program bundled with the camera. It can be used to control the camera and capture video in AVI format. This program does not include any image processing functionality but the captured video files can be processed in other software such as Deep Sky Stacker, Registax, Paintshop, Photoshop, etc.

EtAMCAP software for image and video capture.

Package contents

  • PL-131M CoolAir monochrome camera.
  • USB cable.
  • Nosepiece (for 1.25-inch telescope drawtubes).
  • CD with software and drivers.
  • Printed setup guide.

Carries full one year UK warranty.

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Opticstar PL-131M CoolAir Monochrome Camera
Attribute Specification
Opticstar Product Code (SKU) PL131MCA
Universal Product Code (UPC) n/a
Warranty 1 year UK warranty
Experience Level Intermediate
Sensor Micron MT9C001
Optical Format 1/2-inch CCD monochrome sensor
Resolution 1280(W) x 1024(H)
Pixel Size 5.2µm x 5.2µm
Sensitivity 1.8v/Lux-sec at 550nm
Frame Rate   • 22fps @ 1280x1024
  • 80fps @ 640x480 (ROI) region of interest
  • 220fps @ 320x240 (ROI) region of interest
Region of Interest (ROI)   • 640x480 user definable
  • 320x240 user definable
Binning 1x1, 2x2, 4x4 (Binning available in native long-exposure mode only)
Shutter Electronic Rolling
Window Glass Clear, no Infra Red cut-off
Exposure Time Automatic or Manual
Manual Exposure Time Minimum 1ms; Maximum 10 seconds in native long exposure mode
ADC 8-bit, dual on-chip
Cooling Air-cooled by internal fan (USB powered) with on/off switch
Gain In hardware
Computer Interface USB 2.0 (USB 3.0 compatible) with 1.8 metre cable
Power Requirement USB Bus Power
Sensor Distance to Camera Front 10.5mm (requires removal of internal spacers), 12.5mm & 17.5mm
Mounting to Telescope C/CS to 1.25-inch (included)
Mounting to Lens C to T-thread, M42 x 0.75
Mounting to Microscope C to 23mm, C to 30mm, C to 30.5mm
Operating temperature 0°C to 60°C
Bundled Software Video & single-shot capture software for high frame rates:
  • Opticstar View
  • etAMCAP (with DirectShow)

Single-shot long exposure software (up to 10 seconds exposure):
  • Nebulosity Lite
  • PHD Guiding (auto-guiding requires optional Shoestring GPUSB unit)
  • Plugin for Nebulosity, Nebulosity Lite and PHD Guiding
  • Plugin for AstroArt
  • Plugin for MaxIm DL
Data Format AVI video with or wihthout MPEG compression; BMP
Computer Requirement   • Microsoft Windows (64-bit & 32-bit) 7/8/10/11
  • USB 2.0 port (or higher)
Dimensions Ø=70mm x 65mm (L)
Weight 240 grams
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