Guess the Vintage Device

We are back to celebrate the new year with a new installment of Guess the Vintage Device where I tear down a piece of classic hardware, and then present photos as clues while you try to guess the device.

Today we bring a classic design from the early 80's. I'll note that this device represents some transitional technologies bridging the analog and digital electronics worlds.

We'll bounce around a bit so as not to give away too much at once.

Let's get started.

Packaging and Construction

Here are some shots to give an idea of the number and size of the assemblies and components involved.

Notice the extremely small spring!

Yep. It's a thing with parts and frame held together with screws.

The Central Component

This is the workhorse of the device.

This is a Vidicon Tube which is used to convert an optical image into an electronic signal.

For it to work, it needs some optics.

Optics

We'll start with the primary optics.

Between the primary lens group and Vidicon sensor, we encounter the following:

We've got a beam splitter. This means the image comes through the primary lens group, follows through the main path of the beam splitter on to the Vidicon. A fraction of the image is directed upwards to a mirror and then through some viewing optics.

In image recoding devices, there are a several typical ways to get an idea of what is being recorded. These include:

• No viewer - You point and shoot and basically have no idea about the framing etc. This might be something like a hidden pen camera, an unconnected spy camera, or something else where you just don't have the space for a viewer of any sort. These will typically be used on wide angle photography since you can't frame your subject with any real accuracy.
• Viewfinders - These give you a separate viewing window to look through which approximates what the optics will see. The wider the view angle, the better these will work. Some even adjust their viewing angle to match the zoom factor of the camera optics.
• SLR (Single Lens Reflex) - A more advanced viewer type that typically uses a mirror and a prism to allow you to view through the same lens that is exposing the recording surface. One looks through the prism, across a mirror and then through the lens. When you take the photo, the mirror moves aside exposing the recording surface (film or sensor) for some time until the mirror returns to the default viewing position. But this typically can't be used for recording video since the light is either going through the viewer, or to the film/sensor. But it can't do both at the same time.
• Electronic viewfinder - If you are using an electronic system, you can send the image data to both a display as well as the recoding medium simultaneously. The drawback in 1980 was that you needed a small CRT with additional power for it. The small CRTs were also somewhat bulky as they were a a vacuum tube and needed an additional power supply, etc.
• Pellicle Viewfinder - A viewfinder that uses a thin transparent film as a mirror which acts as a beam splitter to direct a portion of the light from the primary image path up to the viewfinder.
• "Beam Splitter Viewfinder" - I could not find much about this, but it is employed here in this device. Hopefully you've guessed it by now, this is a video camera.

Below is a photo of the complete optical assembly, minus the main lens and Vidicon image sensor.

At the top we have the beam splitter viewfinder. This allows a full color image to be seen through the viewfinder without requiring an additional bulky CRT display. The brightness seemed fine for what I'd consider normal lighting situations. But beam splitters and pellicle mirror systems are always going to reduce the available light to the film or sensor.

Below the viewfinder are optical elements to control exposure and filter the light for the system. It looks like there are two orange filters. The small one on the upper left seems to be an IR cut filter immediately in front of the Vidicon sensor. The orange one on the lower right filters light that goes to both the image sensor as well as the viewfinder. Perhaps this is for white balancing fluorescent light? The white filter's function is unclear to me. Perhaps a polarizing filter?

PCBs & Electronics

There are two main PCBs on either side of the camera frame.

Mostly Together

And here is the first image of it fully assembled.

This is a Toshiba IK-1900C Color Video Camera NTSC compatible video camera. It was released in 1982. It uses a 2/3" Vidicon tube. The lens is a Nikkor 12.5mm~100mm f1.6 Macro Telephoto lens.

As you can see, there is no room for any sort of video cassette. This unit would be used in conjunction with a separate recording unit that would be slung across one's back. I couldn't find any specifically compatible portable recorders, but the TT-X340 from 1985 looked close. The V-9030T might be another possibility.

It was a really interesting piece of technology during a time when imaging had not gone fully solid state with CMOS and CCD technologies.

A few modern digital cameras recently used something to this beam splitter viewfinder. Rather than a fully glass beam splitter, they use a piece translucent film at an angle called a "pellicle mirror". (Pellicle means film in French.) In addition to weight advantages, pellicle mirrors have improved optical qualities with regards to ghosting and chromatic aberration when compared to traditional beam splitters.

Sony used pellicle mirrors as part of their SLT (Single Lens Translucent) System in some of their Alpha cameras as recently as 2016. But it seems the light loss across the mirror or beam splitter was too much for modern applications and consumers' performance expectations in low light.

Here is one of those Sony cameras from 2010:

Thanks for joining this teardown in reverse.