Celestron NexImage Burst Colour and Monochrome Cameras
The recent total Lunar eclipse has certainly been very popular with many thousands of people here in the UK, and overseas, viewing as well as imaging this celestial event. For the UK this was the last fully visible total Lunar eclipse until December 2029! For imaging this eclipse, the types of imaging equipment that have been used have ranged from micro 4/3 cameras, APS-C and full frame DSLR's, to small high-speed sensitive planetary imaging cameras. It has been the latter type of camera that has allowed the suspected lunar meteorite impact(s) to be recorded and reported.
Although the total Lunar eclipse is over, the Moon can still be imaged whenever its visible in the sky. The same applies to the planets. The magnificent planet Jupiter is on the rise in the morning sky at present. If you want to image the Moon or the planets (or the Sun with a suitable safety filter), Celestron do a range of suitable cameras that can help.
At the moment there are some exclusive offers on these too!
The first Celestron camera we will look at in this blog is the Burst camera which is available with one-shot colour or monochrome sensors. For those wanting minimal "fuss" and to capture a colour image straight away then the colour model is the one to go for. A colour imager is a great camera for learning what is involved in Lunar/planetary imaging. For those wanting to experiment a little more and create colour images by combining monochrome images taken through Red/Green/Blue filters to get better colour rendition (and for a slightly more sensitive camera), then the monochrome version is the one to get (but you will need colour filters and a filterwheel too).
All the Burst cameras come with
- a (removable) nose-piece to allow it to be used in a telescope focuser. It is also possible to directly attach the camera to a suitable eyepiece for eyepiece-projection imaging.
- 1.5metre/5 ft USB 2.0 cable for power/data transfer.
- A CD with camera control software (called iCap) and Registax image processing software.
- User manual
Out of the box, the first thing you will notice about the Burst camera is how small and light it is. Its compact size, and weighing only ~57g (2 ounces), means that should you want to attach this camera onto a lightweight portable (travel) scope such as the Celestron 90/127SLT for example, it will not add any real significant weight to the overall set up and also not cause any balancing issues too. To do planetary imaging you don't need a GOTO computerised telescope, such as an SLT, but as long as your mount can track that is all you need to keep the target centred in the field of view of the camera.
Inside the camera body sits the imaging sensor. For the Burst models this is an Aptina AR0132 (colour/monochrome) CMOS chip - a newer updated version of the popular and very well regarded MT9M034 sensor. This AR0132 chip is very sensitive in the Blue/Green part of the visible spectrum (good for planetary imaging) and has a quantum efficiency of nearly ~75% @ ~520nm (in the green). This sensor is also used in Celestron's more expensive Skyris 132 cameras too (a future blog). The sensor has small 3.75micron square pixels, for good resolution, in a 1280x960 pixel array. So what sort of field of view will you get with the chip?
The answer ultimately depends on what equipment you are using - from what your telescope is, whether you are using the camera with or without a barlow, or using eyepiece projection. Below is an image of the full Moon with a few overlays showing the approximate field of view that you would get with a Burst camera directly attached to different popular Celestron telescopes, and without the use of a barlow or doing eyepiece projection.
Approximate field of view of a Celestron Burst camera, centred on the crater Copernicus, when connected to: Celestron 127 (5" f/12) SLT ; Celestron C8 SCT @ f/10 ; Celestron C11 @ f/10
When doing Solar System imaging, cameras are set up to record a series of images in quick succession - creating a video file. This file is then processed using alignment and stacking software (e.g. Registax - supplied with the Burst cameras) where, out of all of the individual recorded frames, only the best sharpest ("clearest") images are used, aligned and then stacked, to produce a final single image which shows much more detail than a one single exposed image. To record the individual Lunar and planetary images, exposure times are very short as the Moon and planets are bright. A high frame rate is also usually chosen. This is because during those brief fleeting moments that the air stabilises and the image becomes clear, the more images you can capture will help contribute to a more detailed final image.
The Burst cameras can read out up to 30 frames every second when it is used in full frame mode (i.e. when using the whole chip area). However if your target object is small (e.g. a planet or only a small segment of the Moon such as a particular crater) you can select to use only a portion of the chip (called Region of Interest (ROI) or subframing). Apart from reducing the individual video file size, this ROI subframing also increases the rate at which the images are recorded (i.e. frame rate). For the Burst cameras you can achieve a frame rate of over 120 frames per second when using ROI, with very low noise levels. Using the smallest chip area (104x96 pixels) a maximum frame rate of nearly 200 frames per second has been obtained.
Attaching the camera to a telescope is simple. Just screw on the supplied nosepiece to the camera body and insert it into your telescope's focuser. Alternatively, if you want to magnify the image (increase the image scale) you can use a barlow lens such as the Celestron Omni, X-Cel LX 2x or 3x or the 2.5x Luminos. Simply insert your barlow lens into the focuser first and then insert the camera with nosepiece into the barlow lens. For imaging the planets it is usually suggested that a focal ratio of at least ~f/25 is used. So for example the Celestron 127 SLT Maksutov Cassegrain has a focal ratio of f/12 so using a 2x barlow would give f/25. An SCT with a focal ratio of f/10, one could use the Luminos 2.5x barlow (making f/25) or the X-Cel LX 3x barlow giving f/30.
Image showing a Celestron X-Cel LX 3x Barlow. The 2x version looks similar.
You can also attach the Burst camera to an eyepiece -called eyepiece projection- for increased image scale using eyepieces such as the Baader Hyperion or Baader Morpheus.
Controlling the camera is very easy using the Celestron iCap software where important settings such as exposure time, frame rate etc can be set. The Burst camera can also be controlled with 3rd party software too such as FireCapture. The user interface of iCap can be as simple or as detailed as you want as there are many options to have different/as many camera controls (gain, white balance, exposure etc) on show. The screenshot below has pretty much all the camera settings shown, so it does look more busy or complicated than it needs to be but, as mentioned before, you can alter what is visible quite easily.
After you have obtained your video files you would then use Registax to process them. Using Registax is easy and there are a large number of tutorials on the web, such as YouTube, that you can view to see how to process your videos. For Registax tutorials published in the last year on YouTube see >>here<<.
Summary: It is possible for you to capture high-resolution lunar, planetary (and Solar images with suitable safety filter) with the NexImage Burst Solar System camera. It can be used with a non-computerised telescope with a motor drive, or a computerised telescope, for tracking celestial objects as they move across the sky. The Burst camera features a well regarded sensitive imaging sensor and the camera is easy enough to use (with the iCap software) and with the supplied Registax image processing software, it is possible for a beginner to produce detailed images of our Solar Solar objects.
Now these cameras are more affordable than ever. The usual list price for both models of the Celestron NexImage burst cameras was £299. However we are offering these cameras for only £129 - a saving of 57% off list price.
If you are interested in a Burst camera - see the link below where you can choose either the colour or monochrome versions from the drop down menu at the top right of the page.
If you do need any more information or help please email us at email@example.com