1” CCD sensors

[pmrid (Peter)]

I’m curious! Why are ccd sensors described as “1””? For example, the ASI533 MC is a 9MP SENSOR IN A 11.3 x 11.3 square array (3008x3008) with a diagonal of just under 16mm.

What makes it a 1inch sensor. That’s how ASI describes i. See their blurb at https://astronomy-imaging-camera.com...33mc-pro-color

[Startrek (Martin)]

Sometimes they refer to the old video camera tube dimensions of years ago
A 1” video camera tube had a diagonal of 16mm , hence they refer the 533 having a 1” sensor

Agree it’s a nonsense comparison

Look up Wiki , it shows you the old video tube sizes in inches and their diagonals

Cheers
Martin

[pmrid (Peter)]

Originally Posted by Startrek

Sometimes they refer to the old video camera tube dimensions of years ago
A 1” video camera tube had a diagonal of 16mm , hence they refer the 533 having a 1” sensor

Agree it’s a nonsense comparison

Look up Wiki , it shows you the old video tube sizes in inches and their diagonals

Cheers
Martin

Had a look at Wiki. Apparently, it is about format rather than size. Like 4/3 sensors - so called because of ratios not dimensions. It probably means more to many but I remain among the ignorant.

[AstroApprentice (Jason)]

The video tube dimensions may now be irrelevant, but the measure can make for a quick relative comparison between sensor sizes for those familiar with it. Sensors can be categorised by nearest fit to size charts like the one attached.

[Peter Ward]

Originally Posted by pmrid

I’m curious! Why are ccd sensors described as “1””? For example, the ASI533 MC is a 9MP SENSOR IN A 11.3 x 11.3 square array (3008x3008) with a diagonal of just under 16mm.

What makes it a 1inch sensor. That’s how ASI describes i. See their blurb at https://astronomy-imaging-camera.com...33mc-pro-color

I'd also point out the IMX533 is a CMOS sensor.

CCD's are rare and expensive birds these days.

[pmrid (Peter)]

Originally Posted by Peter Ward

I'd also point out the IMX533 is a CMOS sensor.

CCD's are rare and expensive birds these days.

Yes, but even so, why the 1 inch designation. It bears no relationship to the size of the sensor (of whatever type) as far as I can see.

[Peter Ward]

Originally Posted by pmrid

Yes, but even so, why the 1 inch designation. It bears no relationship to the size of the sensor (of whatever type) as far as I can see.

Martin has already answered this, the 1" refers to the video tube size that the CCD/CMOS sensors replaced.

It has little to do with sensor size. It is simply an equivalent solid state sensor format, which I suspect allowed video lenses
to be used interchangeably from tube driven to solid state camera backs.

[AstroApprentice (Jason)]

Excerpt from https://en.wikipedia.org/wiki/Video_camera_tube

The size of video camera tubes is simply the overall outside diameter of the glass envelope. This differs from the size of the sensitive area of the target which is typically two thirds of the size of the overall diameter. Tube sizes are always expressed in inches for historical reasons. A one-inch camera tube has a sensitive area of approximately two thirds of an inch on the diagonal or about 16 mm.