FUJINON A20x8.6BRM

The A20x8.6BRM is a lens, of which there are tens of thousands and about which hardly anyone writes. It is the standard ENG zoom that was on practically every news camera in the nineties and noughties. Precisely for this reason, it belongs here: anyone who wants to understand the broadcast look must understand this lens, not the exceptions.

Twentyfold — and why it works

8.6 to 172mm is a twentyfold range in a lens that weighs 1.4 kilos and is 19 centimeters long. This would not be buildable on Super 35. It works because the image circle only needs to cover a diagonal of 11mm — 2/3 inch. Any optical calculation becomes simpler the smaller the image circle, and a twentyfold zoom is the reward for it.

The aperture is not constant

This is where broadcast and cine thinking diverge. Fujinon specifies F1.8, and this applies up to 115mm. From there to 172mm, the light intensity drops to F2.7. A cine zoom with this characteristic would be considered a compromise; in broadcast, it's normal because exposure is regulated via gain and shutter anyway, and nobody works with a fixed aperture. Anyone using such a lens for a film shoot must be aware of the drop, however — as you zoom into telephoto, the image gets darker, and this is not a malfunction.

Reading the name

A stands for the 2/3-inch format, the missing prefix before A for Standard Definition. 20x is the zoom ratio, 8.6 is the shortest focal length. Then come the letters: B for Bayonet, i.e., B4. R for Zoom Servo. M for Manual Focus. No E, so no built-in extender — the variant with a twofold extender is called A20x8.6BERM and weighs 1.5 kilos. In lens lists, an appended SD often appears. In Fujifilms's own nomenclature table, this abbreviation is not present — the interpretation Standard Definition is plausible but not officially confirmed by the manufacturer.

The rest of the data

Minimum focusing distance of 0.9 meters, plus a macro range. Inner Focus, meaning the front element does not rotate and the physical length remains constant. Filter thread M82 x 0.75. Angle of view in 4:3 format from 54 degrees 11 minutes horizontally at the wide end to 2 degrees 56 minutes at the tele end. The jump between these two numbers is what a twentyfold zoom means in everyday use: a wide shot and a close-up from the same position, without anyone moving the camera.