Did the Romans have any sort of visual projector technology?

I have been looking at some passages, in translation, from the Neoplatonist philosopher Proclus (412-485 AD), where he is apparently using an analogy of projecting images onto a screen (to describe the way a geometer uses his imagination). See here (some are passages from the editor/translator’s introduction, but some are from the text).

It struck me that this is very anachronistic (and thus, probably, a bad translation), but is it? Obviously the Romans did not have movies, but is it possible they had something like the “magic lantern,” or perhaps just a system for casting shadows, silhouettes, in some sort of artistic way. Is there any evidence of such things? (And, if so, would they have been common enough to form the basis of a useful analogy, that readers could be expected to understand?)

Proclus was actually Greek, and was based in Athens, so the work was presumably originally written in Greek, but as he lived in the late Roman Empire era it seems appropriate to speak of Roman technology here.

Ever hear of a pinhole camera?

Any small hole in a thin substance will act as a lens and project an image of whatever you see.

Find a window which gets bright sunlight and cover it completely with foil or other opaque covering. Poke small hole and hold a piece of paper up behind it.

According to Wikipedia, the camera obscura was known to Aristotle.

I have not read the OP’s cite. But the metaphor of visual projection on a wall in discussion of thought of course dates from at least Plato

They may have done some shadow puppetry.

The most relevant passage, I think, is this:

So, at least in the translation, we explicitly have a screen and active projection. That certainly sounds like something beyond mere shadows on a cave wall to me; it sounds like an analogy to some sort of specific apparatus, and I would not have thought that projection was the appropriate word to use about an essentially passive apparatus like a camera obscura, where you really do not get to choose the images that appear (especially as, back then, presumably, a camera obscura would literally have been a dark room, not something you could steer in any way). Here we are talking about mathematical (geometrical) reasoning, so we cannot be satisfied with any old images, it has to be the image (some geometrical diagram, presumably) that “the understanding” wants to visualize.

Shadow puppetry seems a bit more like it to me, but even there, “projection” hardly seems the right word.

It seems to me that the author of this passage was thinking of something more like a magic lantern, a device of some sort for throwing specific images, as chosen by an operator, onto a screen. The question is, could that author have been Proclus (who may indeed have been thinking of nothing more than passive shadows on a wall), or is it the modern translator putting words in his mouth?

How difficult is a pin hole camera to make anyway, school children make it today.

School children today have stuff like paper - even translucent paper - and cardboard readily available; not so in ancient Rome and Greece. Maybe they could in principle have had hand held pinhole cameras, as opposed to camera obscuras [camerae obscurae?] that were actual rooms, but no-one has yet shown that they actually did

Anyway, my point is that a pinhole camera does not really project an image in the sense in which Proclus is apparently saying that the understanding projects an image (of some geometrical abstraction) onto the screen of the imagination. If the analogy is to a pinhole camera, what plays the role of the understanding in the analogy? A pinhole camera only gives you an image of whatever physical scene you are pointing it at, even assuming you can construct one that can be freely pointed where you will.

I haven’t read the original Latin passage, but “proiactare” (sp?) literally means to “throw forward.” Perhaps the original analogy was something as simple as throwing paint on a canvas or other surface.

I doubt this is right – it would require that “screen” be a pretty poor translation of some word – but I thought I’d, ahem, throw it out there.

As a light source for “projection” they would have only sunlight or fire. Shadow puppetry can involve color transparency: thin parchment-like leather stained with dyes was used to make jointed puppets that could be quite elaborate. The audience watched from in front of a screen. The puppeteers and light source were behind it.

I wrote a piece about this entitled “The Magic Lantern of Omar Khayyam” a couple of years ago. The Rubaiyat mentions a “Magic Lantern” in one of its stanzas (which was used as an epigraph by Mark Twain for his Autobiography, but which he ultimately cut. Robert E. Howard used the same verse as an epigram for his story Skull-Face) The point of the title was that the “Magic Lantern” as we know it wasn’t invented , according to the current ujnderstanding, until centuries later by Athanasius Kircher. The use of the term seems to be an imposition by Edward Fitzgerald (and other translators), who wrote when the Magic Lantern was popular. Most people think Khayyam was writing about either shadow plays or shAdow-imagtes from s[pecially made lamps.
The notio of shadow-plays goes back a long time to India, China, and Egypt, although there isn’t direct evidence for great antiquity (although I suspect it IS of great antiquity). It seems evident to me that Plato’s “Analogy of the Cave” must be based on his knowledge of shadow-plays. He describes an involved allegory of men seeing shadow-shapes projected by lamplight on the wall of a cave and think it’s reality. It’s possible that he made all of that up from scratch, but it seems more likely that he was using his knowledge of shadow-=plays he had seen to make the argument about whether what we see is reality or not (the same point, really, that Khayyam was trying to make).
It’s true that the ancient Greeks knew of the idea of the camera obscura, but I doubt if they used it in amny sort of projector technology. In the first place, images even from sunlight are pretty dim. Anything using fire- or candle-light would have been even dimmer (abnd high-intensity light sources, like Limelight, were far in the future). The craze for camera obscura in the 18th-19th centuries catered to small groups. In the second place, anything project would have been upside-down. This would be fine with “transparencires”, but mnot with trying to image real people. And “transparencies” on most materials (parchment, etc) would cut the light down even farther.

edited to add: reading the cites from Proclus, he seems to be using language that recalls Plato’s Allegory of the Cave from The REpublic.

If everyone knew about it, shouldn’t it be called the “camera non-obscura”?

In distinction to the camera obscura, a device that Henry Hyde Wollaston invented in the early 19th century was called the camera lucida, since it didn’t involve a dark room, but could be used in the light. It became an artist teaching tool (affectionately called " 'luci" s). at one time they sold them cheap from ads in comic books, but nowadays they cost a couple of hundred dollars each.
Wollaston invented it as an aid to drawing for the non-artist (like himself), and it was used for a long time for drawing not only from life (astronomer John Herschel drew hundreds of Camera Lucida pictures), but for images from telescopes and microscopes in those pre-photography days.
But, even though this was a device for the non-artist, some people (such as scientist Fox Talbot) were inept with it. Talbot went on, in consequence, to help found the science of photography. (So did Herschel, who invented hypo = sodiujm thiosulphate as a fixer)

It is thought the Egyptians used projections to draw out large scale stone decorations, small drawing projected onto a big stone etc

News to me.

Very seriously – do you have a cite? It would be a great time saver to do this, but I’ve never heard of such a thing.

Several other “iacto” verbs have come to us in English:

reject - throw back
inject - throw in
eject - throw out
deject - throw down
subject - throw under
interject - throw between

So the next time you “reject” something, imagine yourself beaning the person who gave it to you with it.

If you’re feeling dejected, you’re feeling like someone grabbed you and threw you down onto the ground.

If you interject into a conversation, you’re throwing words into the middle.
We also have the noun “trajectory”, literally a “throwing across” (trans-iacto).

dash it all i searched and searched but i can find on on line cite… my information was from a TV program and by projection i meant a projection of shadows from a platform to provide and outline maybe of a small version. I will continue to search!

After a lot of searching i must conclude that either i or the tv program misunderstood “projection” what Egyptians appear to have used is a old graphic artist trick oft known as “projection” but in fact squaring up drawings drawing a corresponding grid in bigger size on the stone and “projecting” and increasing the size by dint of brain power…thanks for pulling me up on that, i would have been confidently saying that for years!

I am pretty sure the original was in Greek, though. Although Proclus lived in the Roman Empire, he was a philosopher, based in Athens, and, in any case the lingua franca of the eastern part of the Empire was always Greek, not Latin

Thanks, that is very interesting.

I am sure that, being a Platonist, Proclus would have had Plato’s cave in mind, but I thought that the language of “projection” and “screen” (if accurate translations), seemed to imply something more, especially as, IIRC, Plato’s cave did not have a screen, but rather the shadows were cast onto the rough cave wall, and thus distorted (and so yet one more step removed from reality). The other issue is that in Plato’s cave the shadows are delusive and misleading, whereas Proclus is apparently talking about how mental images help us to understand and reason geometrically. Unlike Plato’s shadows, Proclus’ images lead us towards truth, not error. However, it makes more sense if both Plato and Proclus were making an analogy with “shadow theatre” as you suggest.

Is your article available anywhere?