Objective vs. Lens

Question

I'm working at a German company that is building production machines. These machines are using cameras and microscopes to align small structures. Because we sell them worldwide we have to properly name the parts in English.

We have a long ongoing discussion about weather to use the word "objective" or the word "lens" for the exchangeable package of optics that are in front of the camera.

I already noticed that for instance camera companies are using the word "lens" but Wikipedia is using "objective".

So we have a camera looking through an optical device. And the question is: Is it a lens or an objective? Or anything else?

Answer 1

Among "non-photographers" in English speaking countries, I would think that "lens" would be much more understandable than "objective". Pretty much anyone who understands the technical meaning of "objective" used in the context of an optical system would also understand what "lens" means. The obverse would not be the same case, not everyone who understands what a "lens" is would also understand what "objective" means when used in the same context. There are many English speaking photographers who have not a clue where their camera's "objective" is located. They all know what "the lens" is.

As someone who is an English speaker and has been doing photography for almost 50 years, I'd say that a compound lens system is usually called a "lens" when used in the context of creative photography, which is what Photography.SE is mostly about. We even call catadioptric mirror + lens systems used on cameras "mirror lenses."

Back in the late 20th century among photographers, at least in the U.S., "objective" tended to refer to the first lens element or group of elements in a compound lens system. For example, with a 70-200mm f/2.8 lens with 23 elements in 19 groups, the first 2 lens elements would be considered the "objective group".

Though it is true that in the nomenclature of optical physics, lens refers to a single optical element, in the nomenclature of cameras, "lens" can and does often refer to the entire light gathering optical system made up of many lens elements and even mirrors.

Based on one quarter (as opposed to semester - if that doesn't date me as a fossil nothing does) of 'German Language and Culture' back in my college days, I'd say that the way most German speakers use das objektiv is very similar to the way most English speakers use the lens.

Answer 2

In microscopes and telecopes, the objective lenses are the elements of the optical system closest to the specimen or viewed thing. In cameras, the whole optical system of lenses used for focusing the image onto a film or sensor, informally called a 'lens', is formally called a 'photographic objective'.

Objective (optics)

Photographic objectives

Answer 3

If the predominant aspect of the optics is lenses, you lose nothing by writing 'lens'. If they are a mirrors or a mix of mirrors and lenses, you might say 'optical elements'. Of course, if the buyers are technically savvy, you could say 'objective'.

Answer 4

The Wikipedia article you refer to uses the word 'object lens' at the end of the first paragraph.

But the Ngram 'lens' against 'object lens' up to 2008 shows no usage of 'object lens'.

The Wikipedia article on lens shows that the lens itself is contained within the objective apparatus.

So if you are distributing the apparatus which contains a lens, then the apparatus is called the 'objective'.

Answer 5

As I tech writer, I understand your concern. "Lens" refers to a single optical element. A compound lens is a single optical element with multiple focal properties, such as a bifocal lens. An "objective" is an assembly of multiple lenses.

Any English speaker who has worked with microscopes and similar devices is probably aware of the term "objective."

Because your audience is technical, you should use the most precise term -- and include an explanation or definition. For example: "The objective is the part of the device that gathers and focuses light to produce an image. The objective is composed of multiple lenses." (It might include other devices too, such as mirrors)

And of course, a picture (diagram) "is worth a thousand words."

Answer 6

In the jargon of optics an objective lens is the lens (can be compound) that is the first to receive the image-forming rays from an object being examined or imaged. This lens or lens group is often called the objective lens.