The amazing new GSTAR-EX4 colour camera is your passport to live viewing and imaging the night sky.

The GSTAR-EX4 is USB plug and play ready and utilises the latest high-speed USB3 technology and new generation, low light sensitive Sony Exmor image sensor. With internal thermal cooling fins and extraction fan, the GSTAR-EX4 camera uses Sony's IMX174 high resolution CMOS Sensor with high dynamic range and back-illuminated CMOS image sensor technology. The IMX174 is an "Exmor R" sensor, with significantly enhanced imaging characteristics, including sensitivity and low noise.
High dynamic range was achieved by featuring 12 bit ADC, which reduced quantization noise and suppressed dark random noise. This enables clear image quality in light and dark areas, even when imaging objects with high contrast.

With it's slightly wider field of view over its predecessors, for casual or even serious deep-sky target imaging, the new EX4 stands out. Even for live viewing in full colour, imaging the planets or the Moon, this camera will meet your needs. It is also an ST-4 compliant auto-guider.


GSTAR-EX3 uses the amazing Exmore R series sensor with STARVIS low light performance


GSTAR-EX3 High Resolution Colour camera
Image Sensor: Sony Exmor IMX174 colour (see spectral response here)
Size: 1/1.2" (13.4mm diagonal) (3:2 aspect)
Resolution: 1920 x 1200 (2.35 Mega pixels)
Pixels: 5.86μm x 5.86μm
Bit Depth: 8 bit and 12 bit (10 bit / 12 bit A/D converter)
Dust Protection: dust protective window.
Exposure: 0.244 sec ~16 mins
Cooling: Fan vented with heat sink fins (on/off controllable via software)
Connection: USB3 (also USB2.0)
Power: USB powered
Dimensions: 84 (L) x 67mm (W)
Weight: 300 grams
Thread: M42 female
Nosepiece: M42 male to 1.25 inch (threaded for 1.25" filters)
Auto-Guiding: ST4 compliant with ASCOM and WDM drivers
Cables: USB3 and Auto-guide supplied

CD Software:
Includes powerful live viewing, live stacking and capture softwares, including the latest update of GSTAR4 capture V.56 plus ASCOM drivers and auto-guiding software. Compatible with WIN XP, WIN7 WIN8 and WIN10.

Image & video formats: AVI, SER, BMP, JPG, PNG, TIF & FITS

GSTAR-EX4 front view and image sensor GSTAR-EX3 fan cooling, USB3 and Auto-guiding interface
The GSTAR-EX4 camera comes with a M42 x0.75 female threaded front housing for direct attachment to M42 male adaptors and providing more inward focus capability. It can also be used in 1.25 inch eyepiece holders with supplied M42 male to 1.25 inch nosepiece adaptor or optional M42 male to 2 inch nosepiece.

The rear of the camera features a low brightness red power LED which blinks during operation. A USB3 high-speed port for connecting the camera directly to your computers USB3 or USB2 port with supplied USB cable and and ST4 auto-guiding port for connecting the camera directly to your mounts auto-guiding port connector using the supplied 1.5 metre auto-guiding cable. The camera is kept cooled to ambient temperatures via the built-in fan and side vent helping to reduce hot pixels.


Carina Nebula with GSTAR-EX4 camera
NGC 3372 Carina Nebula - Vixen R130Sf at f/5 with GSTAR-EX4 camera - 10 second exposure - live align and dark frame subtract, live stack averaging


M20 Trifid Nebula - ProStar 127 APO refractor with GSTAR-EX4 camera
M20 Trifid Nebula - ProStar 127mm APO refractor with GSTAR-EX4 camera - stack of 10 second exposures using auto-dark frame subtract - Courtesy Rob Jocumsen
Omega Centauri with GSTAR-EX4 camera
NGC 5139 Omega Centauri - Vixen R130Sf at f/5 with GSTAR-EX4 camera - stack of 5 second exposures


M65 and M66 with GSTAR-EX4 camera
Captured using GSTAR4 capture software


IC434 Horse Head Nebula - 15 second exposure time - live stack with Vixen R130Sf telescope

M1 Crab Nebula - 5 second exposure time - live stack with Vixen R130Sf telescope
Running Man Nebula - 5 stacked second exposures - Vixen R130Sf telescope
Running Man Nebula - 5 second exposures stacked  - Vixen R130Sf telescope

One of the powerful features of the cameras software is the ability to subtract visible hot pixels from long exposures live. Cover the scope, select how many frames to capture then check the "Enable" box.


This is perhaps the key feature of the cameras software whereby deeper views and images can be displayed on screen and captured in real-time using the live stacking option. Just like the GSTAR-EX and EX2 cameras which performed co-add or summing of video frames within the cameras electronics, the images from the GSTAR-EX3 uses external software to perform this task offering a few user options. Option 1) to Co-add a number of user defined images from the camera to display the equivalent of a much longer or deeper exposure or Option 2) to average a user defined number of exposures for displaying a smoother, less noisy result. This is similar to the CSD function of our GSTAR4 capture software although far more flexible and powerful.

If your telescopes mount is fairly well polar aligned and / or tracking pretty accurately, another amazing feature within the "Live Stacking" option is aligning and stacking images in real-time. In other words, images output from the camera can be aligned as well as stacked (with dark frames subtracted for that matter) all at the same time to produce a lovely still image, sequence of still images or video recording at the same time. And, you can stack these later as well for even smoother results using your favourite image stacking software.

Select 8 bit mode or better still, 12 bit mode for greater dynamic range and detail.

Live stacking and dark frame subtraction of GSTAR-EX3 camera and software

As can be seen from the screen grab below using only a small 130mm f/5 telescope, dramatic full colour views of nebula, galaxies or star cluster is possible. And of course with shorter exposures, wonderful views of lunar vistas and the planets can also be viewed in realt-time and captured in high-speed video recordings. However, like anything, when it comes to modern computer displays, the viewing angle capability of the LED or LCD monitor is important for allowing highly impressive large group viewing.

The computer monitor view here is of NGC3372 Carina Nebula using 10 second exposure with live auto-dark frame subtraction and live average stacking and auto-align to yield a smooth photographic live on screen view. Simply select full screen mode using the viewing softwares supplied on the CD to give dramatic views on local or external projector or other monitor. 

Remember, the GSTAR-EX4 is not a large format (wide-field) or Peltier cooled camera type camera but a video camera with the ability to take short or long exposures and output as a video file or still images and it really does perform as well or better in some regards to some far more expensive cameras out there. Its image sensor yields a wider field of view over the old EX and EX2 models and is wider again than the alternative EX3 camera. It is truly an excellent colour camera for producing portraits of star clusters, galaxies and nebulae alike.


M64 Black eye galaxy with GSTAR-EX4
Black Eye galaxy M64 with 12 inch Newtonian at f/5 - Stack of 5 second exposures

NGC4564 galaxy from GSTAR-EX4 camera
NGC4565 Edge on galaxy in Coma Berenices with 12 inch f/5 telescope.  Live additive stack mode with 5 second exposures and stacked in Registax 6.


Like any camera out there, particularly when it comes to deep-sky imaging, optimal performance and contrast will be limited by sky-glow, local light pollution and sky transparency. Also, it is important to remember that the key to brighter deep-sky images with good contrast is a fast scope like f/4 or f/5. Use of a focal reducer assists greatly in producing not only a wider field of view but also brighter images.


With its fine 5.86 micron pixels the GSTAR-EX4 can record and produce wonderfully detailed lunar and planetary portraits even from a single snap shot or using your favourite stacking and image processing software.


Hardware Requirements:

CPU equal to Intel Core2 2.8GHz or better
Memory: 2GB or more
USB Port: USB3.0 High Speed port *
USB Port: USB2.0

*The camera is designed to work optimally with Intel based USB3 port controllers including NEC and many others. However the cameras software may not perform correctly with some older computers that use AS-Media USB3 port controllers in Window 7 but may be ok in WIN8 and later. If this is the case, you can simply use a USB2.0 port.

**Please note: If you do not well understand the basics of using your telescope, its optics and / or have difficulties working with a computer then this product may not be suitable for you.**



Getting the best results

Like any form of astro-photography / imaging, getting the best out of a camera depends on several factors including your telescopes optics, environmental conditions, understanding the capture software and optimal settings thereof and of course, personal post image processing skills.
When it comes to deep-sky imaging, the GSTAR-EX4 works best for live viewing in short focal length (fast) instruments like F/5 etc so, with a longer focal length instrument, consider using a focal reducer (tele-compressor) lens.

You should seriously take time to learn the capture and live view features of the software by experimenting  with various settings to see what works and what doesn't for a given celestial target as there are many combinations that will affect the on screen view and final processed image.
For example you might try using a longer exposure time (trigger mode) capturing a dozen or so frames for later stacking or use shorter exposures in Video Mode capturing one or two hundred frames for later stacking to compare the differences. Some prefer "real-time" dark frame subtraction while others want more control over this by capturing their dark frames separately and applying them later. You might prefer to stretch the gamma settings a little to reveal fainter detail and co-additively align and stacking in real-time or you might prefer to use Registax or AutoStakkert to do this later or even use both methods. 

In the end however, producing a really nice final image depends on how well you set things up with the camera and software from the outset in order to register and record the maximum pixel information from the camera and of course your own personal image processing skills.


GSTAR-EX3 (planetary & deep-sky) GSTAR-EX2 (discontinued) GSTAR-EX (discontinued) GSTAR-EX CLR (discontinued)
Software GSTAR Capture Software (V2.56)    




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