nexy

Use case

Compare two photos of the same thing over time

Is that damp patch getting worse, or are you imagining it? You cannot tell, because you see it every day and your eye adjusts. Two dated photos settle in a second what weeks of squinting cannot.

Photograph the thing whenever you walk past it, from roughly the same place, without measuring anything. Nexy lines the photos up by date and tells you in a sentence what actually changed — and when two photos are too different to compare honestly, it says that instead of guessing.

What it looks like

No tripod and no marks on the floor. The dates do the work, and both sides look at the same comparison.

How to do it

  1. Photograph it the first time you notice it, roughly straight on, with something in the frame that does not move — a light fitting, the edge of a door.
  2. Photograph it again whenever you happen to pass. There is no schedule and no measuring.
  3. Ask whether it has changed. The answer is a sentence about what moved and in which direction, not a percentage.
  4. If the two photos are too different in light or angle to compare honestly, Nexy says so and asks for one more rather than guessing.
  5. Share it when you need to. The builder, the landlord or the tenant sees the same dated pair you are looking at.

Why it works

Your eye adapts, dailySlow change is invisible to somebody who sees it constantly. This is a known limit of human vision, not carelessness.
The date is the measurementYou do not need a tape measure or a tripod. Two timestamps and the same corner of the room is enough to settle direction.
Both sides see the same thingIt stops being your word against theirs. A landlord looking at the same dated pair is arguing about the same evidence.
It flags its own doubtDaylight versus a flash, or a photo from a metre further back, can fake a change. Saying so is more useful than a confident wrong answer.
It works for anything that creepsDamp, a crack, rust, a leak, a wound healing, a build progressing, a plant, a graph on a screen you photograph each week.

Where it stops

It compares images. It is not an inspection and it will not pretend to be one.

It will not diagnoseIt tells you the patch has grown downward. Why it is growing is a surveyor's or a plumber's job.
It will not fake precision“Roughly a hand's width”, not “41mm”. No tripod means no millimetres, and claiming them would be dishonest.
Bad pairs get refusedDifferent light, very different angle, half the thing out of frame: it asks for another photo instead of inventing a comparison.
No medical judgementIt can show you that a mark has changed. What that means about your skin or a wound is a doctor's call, not its own.

Questions people ask

How can I tell whether a damp patch or a crack is actually getting worse?

Photograph it now and photograph it again in a few weeks, roughly from the same spot, and let the dates do the comparing. You cannot judge it by eye because you see it every day and your vision adapts to slow change — that is a property of human sight, not a failure of attention. Two dated photos side by side settle the direction in a second.

Do I need a tripod or marks on the floor to compare photos properly?

No. Roughly the same place, roughly straight on, with something fixed in the frame — a light fitting, a door edge, a socket — is enough to tell growth from no growth. If a particular pair is too far apart in angle or light to be honest about, Nexy says so and asks for one more photo rather than producing a comparison it does not believe.

Will it tell me what is causing the damp?

No, and you should be suspicious of anything that claims to from a photo. It tells you what changed, in which direction and over how long, which is the part you genuinely cannot see for yourself. Diagnosing the cause is a surveyor's or a plumber's job, and the dated comparison is exactly what makes that visit shorter and cheaper.

Can I show this to my landlord or my builder?

That is the main reason people use it. Instead of your word against theirs, both of you look at the same two photos with the dates printed on them and a sentence saying what moved. It changes the conversation from whether there is a problem to what is being done about it, and it works the same way for a landlord documenting a tenant's claim.

How far apart should the photos be?

Whatever rhythm the thing actually changes at. Damp after a wet week is worth a photo weekly; a hairline crack in a wall is a monthly thing; a building job is worth one at the end of each stage. There is no schedule to keep — photograph it when you walk past, and the dates sort themselves out.

What else do people use this for besides damp and cracks?

Anything that creeps slowly enough to be invisible day to day: rust on a gate, a leak stain under a sink, subsidence, a tree getting close to a roof, a renovation's progress, a plant, a repair that is supposed to be settling. People also photograph screens with it — a dashboard or a chart each week — to get a plain-language read of whether the line is actually moving.

Can I use it for a wound, a mole or something on my skin?

You can photograph anything and it will describe what changed, but be careful about what that means. It can say a mark looks larger or darker than it did three weeks ago. It cannot and will not tell you whether that is harmless, and a change it describes is a reason to show a doctor rather than a verdict from one.

What makes two photos not comparable?

Mostly light and distance. A flash at night against daylight can make the same stain look twice as dark, and standing a metre further back can make it look smaller. When the pair is compromised that way, saying so is more useful than a confident wrong answer, so it asks for one more photo in better-matched conditions.

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How to compare two photos of the same thing over time (damp, cracks, progress)