This English looks clumsy and hard to follow. I hope someone can structure it more coherently.
…he cut a peephole through where the vanishing point fell on the picture, that was “the size of a lentil” on the painted side, and opening up “conically” on the back
I look forward to your feedback
He took extremely accurate sightings of the church from just inside the doorway of the Cathedral opposite to paint its picture onto his panel; next, he cut a peephole through where the vanishing point fell on the picture, that was “the size of a lentil” on the painted side, and opening up “conically” on the back. By holding up the panel with its unpainted side to his face, he looked through the peephole at a mirror to see an astonishingly three-dimensional image for the time of the Baptistery. Having a polished silver area on the panel made the reflected image even more impressive as the actual sky was reflected on the perspective panel.
Can’t say anything about the link, but the text in the op definitely sounds like a pinhole camera aka camera obscura. Mirror makes the image right size up, small hole generates the image. Why it widens in a cone not sure, either reduces image aberration, &/or gets more light back out the hole so you can see the image.
Panel - so painted on wood like many old paintings, rather than canvas. Hence the conical hole, a small hole drilled in a thick panel doesn’t do much.
The panel held a good perspective drawing of the church (I assume the church he was planning to modify with the baptistry)
He stands so that the eyehole is at the point where the perspective of the painting (where his eye) was to to draw this painting.
Place a mirror directly in front (per the diagram) to reflect exactly the panel. Behind it the real live church.
Essentially what he’s done is “pasted” the panel into his view of the church so he can see how the planned baptistry will appear with the rest of the church.
To add to the reality, the panel painting has silver where the sky would be, thus reflects the sky when seen through the hole so that he did not have to match the painting’s sky to the real sky that day.
the theory is - if you do a perspective drawing of a scene from a particular viewpoint, then you should be able to hold that picture in front of the real life and have it match up perfectly with real life behind it if your eye is where the perspective “viewpoint” was.
If your eye is in the right place, then no matter whether you look forward upward, down, left right the painting will match exactly with what is behind.
If he simply put the panel out there, there is nothing to constrain the eye to the right place. Plus, by using the mirror and silver, he reflects the sky in the silver; if he simply placed the panel in front of him, standing in the doorway, the “sky” refelected would be the interior behind him not blue sky.
I gather Bruneschelli was using this trick to see how the baptistry concept design fit into the existing structure.
Dammit I should know this, it was explicitly covered in my intro to Italian Renaissance art history ; but I don’t remember the exact details and can’t find my notes again. But here’s a short video about it, skip to 5:15 for a graphic representation of the technique.
Yes, that’s exactly it. And it was revolutionary because prior to him no image respected proportionality or perspective, there was no notion of “foreground” or “background” etc…
Yes-- he loses or ties on a big sculpture commission competition and bails out of Florence to go study architecture in Rome, and seems to have developed it to be able to back-engineer groundplans from good drawings or something like that.
This panel experiment was a way to mandate the single, unmoving point of view that the one-point perspective depends on: like reducing any confounding variables that would mess it up.
Disputed, as far as I know. But bear in mind, my entire expertise on the subject is what was covered in “Intro to Renaissance Art History”, taken as a minor elective, and which I didn’t pay overly much attention to :o.
That being said, I know there are art historians who point at trompe l’oeil fugue lines in some Roman painted wall decorations which are very close to linear perspective but not quite and suggest it’s possible there were more advanced versions that have disappeared (and it’s true that it’s very rare when a coat of egg-paint laid down two thousand years ago survives). This is to be understood in the context of what the Renaissance was, which is to say a lot of re-inventings or figuring-out-how-they-did-that based on the re-discovery of Greco-Roman art and culture. So it’s possible.
There are others who point at paintings from Bruneleschi’s era but prior to the whole mirror(s ?) episode that also demonstrate a rough understanding of perspective, scale and a similarly scientific/mathematical approach to representations and it’s possible they had their own reflections (ha!) on the subject… but unlike Bruneleschi didn’t benefit from a prolix and popular biographer friend.
But yeah, at this point I don’t believe we’ve found any conclusive proof of someone talking about linear perspective specifically nor exactly before the B man. Actual art historians who art history for a living might know more. Like, a lot more. A *lot *a lot.
There’s nothing of the Camera Obscura about this – the hole was simply to look through (although why he made it as small as a lentil – which is only a few millimeters across – isn’t clear to me). I’m sure that the hole was “conical” only to maximize the view through the hole in a thick panel (the panel must have been relatively thick, if the hole has enough depth to be perceived as “conical”) The point was (as illustrate in Burke’s series and the video linked above) that whether you looked straight through at the building, or placed the mirror in place so you saw the painting reflected you saw the same svene. The painting, made using the principles of linear perspepective, accurately reproduced the reality.