Devi

The non-technical half, which matters more than any of the above for people who dislike being photographed: do not show them the back of the camera between shots.

The moment someone sees a frame they dislike, they tense up, and a tense face is more asymmetric than a relaxed one - the muscles on the dominant side pull harder. So you get a feedback loop where reviewing the photo produces worse photos.

Shoot, keep talking, do not review until later, and choose for them rather than handing over the whole set. It sounds like a trick. It is mostly just not interrupting.

One thing to add because it changes what "working" means: a shop vacuum with a standard filter will pass the finest dust straight back into the room.

The visible chips are the easy half and the half that is not really a health question. The fraction that stays airborne for hours is the half that matters, and it goes through an ordinary cartridge filter.

If the vacuum is going to be your extraction, a fine-particulate rated filter and a bag inside it are worth more than a perfect seal at the port. A leaky connection loses some dust at one point; the wrong filter loses the worst dust everywhere, and it feels like it is working because the floor is clean.

On question 2, what actually happens to mismatched frames is worth knowing because the two directions are not symmetrical at all.

Overexposed - you set a lower ISO than the box, so the film got more light than needed. Colour and black-and-white negative film handle this remarkably well. A stop or two over is often fine, and some people deliberately rate 400 film at 200 for richer shadows. This direction is forgiving.

Underexposed, you set a higher ISO, film got less light than needed. This is where things are lost. Shadow areas that received almost nothing have nothing to develop, and no processing brings them back. One stop is usually recoverable; two is visible; three is mostly gone.

So if you must be wrong mid-roll, be wrong toward overexposure. And this asymmetry is the opposite of digital, where highlights clip permanently and shadows can be lifted: which is exactly the habit that catches people coming from digital.

The returning wasps have nowhere to go and no ability to start over, and that is why they thin out day by day exactly as you are seeing.

A wasp colony has one queen. Every wasp you see flying is a sterile female worker who cannot lay eggs, cannot found a nest, and has no function outside the colony. When the nest goes, the returning foragers have lost the thing that gave their behaviour a purpose. They mill around the site for a few days, this is the confusion you are watching - and then die off or drift away. It is usually over within a week.

So the answer to question 1 is: nothing, and they cannot regroup. There is no scenario where those dozen wasps rebuild.