Images acquired with the Collins Electro Optics I-Cubed (I3) Intensified Eyepiece

A couple of years ago I purchased an I Cubed (I3) intensified eyepiece from Collins Electro Optics on the recommendation of some fellow amateur astronomers in Denver. Although the price of the eyepiece at the time I purchased it was $2000+, I have thoroughly enjoyed using the device and it has enabled me to see objects that I could either not detect at all or only with averted vision under the darkest of skies. Other objects that are detectable by eye in the telescope show varying increases in brightness and detail when viewed through the I3 device depending upon the object. Some views through the eyepiece are stunning, some are just plain cool, but all of them are interesting.

In general I have found the I3 device most useful for direct real time viewing. In my opinion, that is it's real strength. In fact, I expect that, in the future, devices like this will be as common and as affordable on consumer telescopes as computerized drives are today.

Although real time views of many objects are quite spectacular, it is also possible to do photography and videography as well. I am still playing with the system (and probably will be as long as I own it), but a few results of my photo and video experiments are below.

The I3 eyepiece is based on ITT generation 3 image intensifier technology that provides a gain of 30,000 to 50,000 in light intensity. The image intensfier tube has a receiving photocathode plate that converts photons of light striking its surface to electrons which are then amplified and projected onto a phosphor screen. The phosphor screen image is then either magnified optically for direct viewing by eye or projected into a film, digital or video camera. In this way a real-time intensified image is presented to the user for either direct viewing or for recording.

Overall, the device is a remarkable piece of equipment. I can easily recommend it to anyone who is serious about their astronomy. I only wish the price were lower. I'm sure that someday the price will be more affordable, but right now it's a bit steep.

The results of some of my imaging experiments using the I3 device are below.


Single images of M42 and M82 as viewed through the intensifier and photographed on 35mm ISO 1600 color film. The images depict reasonably well how the objects actually appear when viewed directly on the image intensifier screen. Although the color of the screen image is green, the color is not objectionable at all. In fact, because the human eye is sensiitive to light in this range of the visible spectrum, the green tint causes the images to be easily viewed under low light conditions.

This is another test image of M42 taken with a 35mm camera coupled to the I3 eyepiece using a homemade adapter. Note that there is some coma in the star images at the edge of the field. The homemade coupling device allows the 35mm camera to "look through" the I3 eyepiece. That is, eyepiece projection was not used. This approach to coupling the optics probably gave rise to the coma. Collins Electro Optics offers a 35mm camera adapter which would likely reduce the coma effect.
M47 captured March 14, 2004 on video using a CCD video module coupled to the I3 device with the Collins Electro Optics video adapter. The adapter allows the intensified image to be projected onto a CCD video device. Approximately 100 frames were composited using Registax software to create this image. Note that there remains a slight ringing or faint halo arund the brighter stars after processing. This is an artifact of the I3 device and the multiple image processing.
An image of an unidentified star cluster to the east of Orion. The image was captured on video using the equipment configuration described above. The image is a composite of approximately 100 individual frames.

An image of M35 captured in 2007
M13 - Globular cluster in the constellation Hercules. The image captured on ISO 3200 film using a 35mm camera coupled to the I3 device.

More images of M57.

These images are composites of 3 images captured on 35mm ISO 1600 film, scanned from the negatives and composited using Registax. The camera was coupled to the eyepiece of the I3 device using the homemade adapter descried above. Since taking this image, I improved the coupling and choice of camera lenses to decrease the coma effect.


NGC2331 - Open star cluster in Gemini

A depiction the sensitivity of the image intensifer tube used in the Collins I3 Eyepiece as a function of wavelength. In my experience, the higher infrared and lower blue/green sensitivity tends to strongly enhance visibility of objects such as emission nebulae, stars, star clusters, galaxies, comets and meteors while being somewhat less effective on reflection nebulae. The device does enhance the visibility of reflection nebulae, but not to the degree that it enhances the view of emission nebulae and other objects that are stronger infrared emitters.

The technical report containing this graphic may be found at:

Collins Electro Optics - Technical Report


Collins Electro Optics - Image Intensified Astronomy

Link to Collins Electro Optics

Collins Electro Optics - Overview

Technical description and specifications of the I3 system