Eira, Kachea, and Groma listened intently to Jin's explanation of the pinhole camera.
"Man, that's fascinating."
"Let's try making one first."
Without delay, they gathered materials on hand and assembled a pinhole camera on the spot.
They fitted a pane of frosted glass onto one side of a square box and poked a tiny hole in the opposite side. The hole measured about 0.2 millimeters across.
When they aimed it toward a well-lit area, the outside scenery projected upside down onto the frosted glass.
If the image proved difficult to see, all they had to do was shield the glass with a hood to block out ambient light.
Replace that frosted glass with photographic film, and it would become a true film camera.
"They really don't teach this at the academy, do they...?" Eira remarked, sounding slightly disappointed.
(Did it slip through the cracks of the curriculum...?)
It caught Jin off guard as well.
He had assumed that a pinhole camera demonstration was a staple of upper elementary science classes covering the fundamentals of optics.
(I definitely remember seeing one back then.)
Jin recalled his teacher at the time referring to it as a "pinhole camera."
"So we just reverse the principle. Instead of frosted glass, we insert a stencil etched with a magic circle, then blast it with a powerful light from this side."
An electric light source generated heat as a byproduct, requiring precautions against fire. A magical light source, however, could simply be set to illuminate within a frequency band that excluded heat rays.
"Even so, wouldn't we need an extremely bright light source?"
Unlike a camera equipped with a lens, a pinhole aperture let in very little light, making the projection exceptionally dim.
Translating a standard camera lens's f-number—where lower values indicate greater brightness—to a pinhole would likely yield something in the ballpark of f/200.
"What about the focal length?"
If they wanted to cast a projection over a long distance, they would need to come up with several workarounds.
Having built a working pinhole camera, the hurdles ahead were coming into sharper focus.
"For now, let's just focus on getting it to work effectively at a distance of about ten meters," Jin suggested.
Aiming for peak performance right out of the gate was a surefire way to never finish at all.
With their immediate goal set, Jin and the group got right to work prototyping the pinhole projector.
Meanwhile, Elsa was busy demonstrating the 3D anatomical model to the medical personnel.
"...And as you can see, you can also isolate and display just the nervous system or the vascular system running through the human body."
This was an advantage unique to three-dimensional imaging—something physical models could never easily replicate.
"Furthermore, to see the progression of known illnesses, you simply do this..."
Elsa manipulated the controls, bringing up a comprehensive catalog of diseases.
Organized in a branching tree structure, the interface allowed users to navigate categories like Head — Brain — Cerebral Infarction, or Chest — Lungs — Pulmonary Tuberculosis.
Selecting pulmonary tuberculosis displayed a detailed cross-section of afflicted lungs.
In many cases, the model could even illustrate distinct stages of progression: initial, intermediate, advanced, and terminal.
Unfortunately, this was not available for every condition, as some lacked documented case studies and had yet to be cataloged as data.
With that, Elsa wrapped up her presentation.
"That is truly remarkable, Elsa-sama!"
May, who was assisting her, offered effusive praise.
"Thank you....I hope this magi-device aids in the further advancement of medicine."
Elsa offered a polite bow to the audience.
The assembled crowd responded with enthusiastic applause.
"Now then, we'll open the floor to questions," May announced to the room.
"...Go ahead, Pollyanna."
"Yes....My name is Pollyanna Pendleton....Regarding this 3D anatomical model magi-device, will everyone in the Medical Squad be permitted to use it?"
"Yes. It is being donated to Avalon. It is not meant to be kept classified; I believe it should be open for general use. It will likely be available within a few days," Elsa replied, glancing over at May.
Catching her cue, May chimed in. "Indeed. As Elsa-sama says, I can assure you all that it will be made accessible for general use."
A ripple of excited, relieved murmurs swept through the room.
"Next question, please....Yes, go ahead, Cain."
"Thank you. My name is Cain Gay....Um, you mentioned that some diseases aren't registered yet. Will it be possible to add new ones later on?"
"It will....However, not just anyone can do so. At present, only I, Jin, and... perhaps Deus Ex Machina possess the means to update the data."
"Understood."
"Next... Najas, go ahead."
"Yes....I'm Najas Kahn....Are there any case studies on internal organ damage caused by external trauma?"
While Elsa had demonstrated skeletal trauma like dislocations and major fractures, she had not covered blunt-force injuries to internal organs.
"Unfortunately, no. Trauma from external forces varies far too widely, making it exceptionally difficult to standardize into data."
"...I see. Thank you very much."
After answering a few more questions in the same vein, Elsa brought the session to a close.
"That concludes our presentation. I wish you all the best in your continued growth and endeavors. Thank you for your time and attention."
The lecture wrapped up promptly.
The clock read 11:50 a.m.
At Avalon, the hour between noon and 1:00 p.m. was reserved for lunch.
Following the schedule, Jin and the others made their way to the dining hall to eat.
"Elsa... isn't here, is she?"
To his disappointment, Elsa was nowhere to be found in the general dining hall.
May had escorted her to the guest dining hall instead.
Be that as it may, while Jin was able to eat his meal in peace, the moment he settled in for after-lunch tea, a crowd swarmed around his table.
Naturally, they were all eager for instruction and advice from the Magi Craft Meister himself.
Jin was happy to indulge them; so long as the questions were meaningful, he resolved to answer as many as time permitted during the remainder of the lunch break.
"How can I get better at magi-craft?"
"Please take me on as your apprentice!"
Vague questions and impossible requests like those he gently brushed aside. Instead, he gave his attention to concrete, technical inquiries.
"I've hit a wall developing a magi-device. I've been trying compressed syntax to improve the efficiency of my magi-sequence, but it barely makes a difference. Where am I going wrong?"
To queries like this, Jin offered precise, actionable guidance.
"I'd say your fundamental approach is off. Compressed syntax helps increase the amount you can Write In on a magi-crystal, but it does very little for operational efficiency. If you want better performance, you should experiment with multi-layering instead."
When 1:00 p.m. arrived, Jin and his group excused themselves and headed back to the Go-lab.