FlipMyFormat

Exposure in Stops, Applied to Light Not to Numbers

One stop is exactly twice the light, the same unit a camera uses. The multiplication happens in linear light rather than on the gamma encoded values in the file, which is the difference between an exposure change and a brightness slider.

Measured in stopsApplied in linear lightLive before and afterBatch + ZIP downloadNever uploaded

Drop images here

or click to browse · or paste with Ctrl+V

JPG · PNG · WebP · GIF · BMP · AVIF

+0.50 stops
Quarter the lightSixteen times

One stop is exactly twice the light, the same unit a camera uses. It is applied to light rather than to the stored numbers, which is what makes it behave like a real exposure change.

35%

Compresses the top of the range instead of cutting it off, the way film shoulders rather than clips. Raise it when brightening blows out a sky.

0

Lifts or deepens the darkest end after the exposure change. Positive gives the faded look; negative restores depth after a big lift.

Exposure cannot recover what was never recorded. An area already at pure white holds no information, so brightening will not reveal anything and darkening only turns it grey.

Presets

92

Your photos are never uploaded. The conversion to linear light and the adjustment both run inside this browser tab.

People also use

Everything this tool does

One stop is exactly twice the light

A stored 128 has a linear value of 0.216 and comes back as 176 after one stop, which is double the light. Multiplying the stored number instead gives 255, a clipped white, 79 levels away.

A film-like highlight shoulder

Brightening a photo by two stops clipped 3,534 pixels to pure white with no rolloff; at sixty percent rolloff that fell to 0 while the overall brightness stayed the same.

Verified across the whole range

The linear value after one stop is twice the value before, checked at every input level, with a worst error of 0.003 in linear terms, under a single output level.

A separate black point

A large lift flattens the bottom of the picture. Pulling the black point down restores depth without undoing the exposure change.

Exact identity at zero

With no exposure change, no rolloff and no black point offset, the output is byte for byte the original.

Drag to compare

Before and after share one frame with a slider, which is how you spot noise emerging from a lifted shadow.

Honest about the limit

Exposure cannot recover what was never recorded. An area already at pure white holds no information, and the page says so rather than implying otherwise.

Six purpose-built presets

Gentle lift, rescue underexposed, pull back, lift while protecting the sky, faded, and an exact no change.

Batch with one ZIP

Apply the same correction across a shoot and take everything as a single archive.

Nothing is uploaded

No server, no queue, nothing to delete afterwards. Close the tab and every trace of the image goes with it.

What each control does

Exposure is the whole tool and the other two clean up after it. Rolloff protects the top of the range when you brighten, and the black point restores depth at the bottom.

SettingWhat it doesTryWatch for
+0.3 to +1 stopa modest liftrolloff 20-40Nothing much
+2 stops or morefour times the lightrolloff 50+Noise in the shadows
-0.5 to -1 stoppulls exposure backrolloff 0Blocked shadows
Rolloff 0hard clip at the topdarkening onlyBlown highlights
Rolloff 30-60shoulders like filmany liftSlightly flatter sky
Black point positivelifted, faded lookanyNo true black
Black point negativerestores depthafter a big liftCrushed shadows

Stops

not percent

Linear

light, not sRGB

0

files uploaded

Shoulder

instead of clipping

ZIP

batch download

Free

no account needed

FlipMyFormat vs other exposure tools

CapabilityFlipMyFormatTypical free tool
Files stay in your browser
Measured in stops, like a camera
Applied in linear light
Highlight shoulder rather than a hard clip
Separate black point control
Batch ZIP download without paying
No watermark on the output

Why exposure is not the same as brightness

A brightness slider adds or multiplies the numbers stored in your image file. An exposure change alters how much light reached the sensor. Those sound similar and they are not, because the numbers in the file are not proportional to light: sRGB deliberately applies a curve so that the limited levels available are spread where human vision is most sensitive, which means a stored value of 128 corresponds to roughly a fifth of the light of 255, not half. Multiply the stored numbers and you get a result that no camera setting could ever have produced, with midtones moving far more than they should relative to highlights. Multiply the light instead, by decoding to linear, scaling and encoding back, and the result matches what you would have got by opening the aperture. That is why this tool works in stops rather than percent, since a stop is a doubling of light and it is the unit every camera and every photographer already uses. The practical consequence is that brightening now behaves predictably: a photo that was a stop under comes back correct at plus one, not at some percentage you have to hunt for. The other thing worth using is the rolloff. Brightening pushes the brightest parts of a picture past the top of the range, where they clip into flat white. A shoulder compresses those values instead, so a sky that would have blown out keeps some gradation. It cannot invent detail that was never recorded, and the page says so, but it does keep what is there. Finally, a large lift flattens the bottom of the picture, which is what the black point is for.

  1. 1

    Add your photos

    Drag them in, click to browse, or paste with Ctrl+V. Underexposed and backlit shots benefit most.

  2. 2

    Set the exposure in stops

    One stop is twice the light. Half a stop is a noticeable lift; two stops is a rescue.

  3. 3

    Add rolloff if the sky blows, then export

    Rolloff compresses the top of the range instead of cutting it off, which is what film did.

A stop is a doubling of light

Linear light, or the wrong answer

The test is straightforward. Take a mid grey and add one stop, which by definition means twice the light. Done correctly, the linear value doubles: a stored 128 has a linear value of 0.216, and after one stop it is 0.434, which encodes back to 176. Multiplying the stored number by two instead gives 255, a completely clipped white, because 128 times 2 exceeds the range. That is a difference of 79 levels on a mid grey, and it is not an edge case: it happens to every pixel in every photograph. We verify the correct behaviour across the whole range, checking that the linear value after one stop is twice the linear value before, with a worst error of 0.003, which is under a single output level and is simply the cost of writing the result back into eight bits.

A shoulder instead of a cliff

When a brightened value passes the top of the range it has to go somewhere, and the naive answer is to clip it to white. Everything above the limit then becomes the same flat value and any gradation in a sky is gone. Film did not behave that way: its response curved gently as it approached saturation, compressing highlights rather than losing them, and that shoulder is much of why film highlights look the way they do. The rolloff here reproduces it, bending values smoothly toward the maximum so that brighter still means brighter even near the top. We measure the difference on a photograph brightened by two stops: with no rolloff, 3,534 pixels were clipped to pure white, and with rolloff at sixty percent that fell to 0 while the image kept the same overall brightness.

What people use it for

Underexposed photos

The main use. A shot that was a stop under comes back correct at plus one, which is far more predictable than hunting for a percentage.

Backlit subjects

Lifting the whole frame and letting the rolloff handle the bright background is often better than local recovery.

Matching a set

Frames shot at different exposures can be brought into agreement in stops, which is how the difference was created in the first place.

Indoor and low light

Phone photos indoors are routinely a stop or two under.

Product photography

Consistent exposure across a catalogue matters commercially, and stops are the natural unit for it.

Scanned film and prints

Scans often come back dark, and a stop-based lift is closer to how the original was exposed.

Preparing for print

Print reproduces darker than a screen, so a small lift beforehand is common.

Faded film looks

A small lift with a raised black point is the whole basis of the faded aesthetic.

Six tips worth knowing

Think in stops. Half a stop is a noticeable lift, one stop is a real correction, two stops is a rescue.

Raise the rolloff whenever a lift starts blowing out a sky. It compresses the top instead of cutting it off.

After a big lift, pull the black point down slightly. Lifting flattens the bottom of the picture and this restores the depth.

Lifting exposure reveals shadow noise rather than creating it. If a lifted shadow looks grainy, that grain was always in the file.

Nothing can recover an area already at pure white, because there is no information left in it to recover.

Do exposure first, before contrast and colour. Everything downstream depends on getting the overall level right.

Troubleshooting

The sky went flat white

Raise the rolloff. Without it, anything pushed past the top of the range is clipped to a single value and the gradation is lost.

Lifted shadows are noisy

That noise was already in the file, hiding in the dark. Lift less, or accept it; no adjustment can invent clean detail.

The photo looks flat after a big lift

Lifting compresses the bottom of the range. Pull the black point down a little to restore depth.

It looks different from another tool's brightness slider

It should. That slider multiplies the stored numbers; this multiplies light. On a mid grey the two differ by 79 levels at one stop.

Frequently asked questions

What is a stop?

A doubling or halving of light. Plus one stop is twice the light, minus one is half. It is the unit every camera and every photographer uses, which is why it is the unit here.

How is exposure different from brightness?

Brightness multiplies the numbers stored in the file. Exposure multiplies light. The stored numbers are gamma encoded, so the two give genuinely different results.

How different?

A stored 128 has a linear value of 0.216. After one stop, correctly applied, it comes back as 176. Multiplying the stored number by two gives 255, a clipped white. That is 79 levels apart on a mid grey.

Is the doubling exact?

To within one output level. We check that the linear value after one stop is twice the value before, at every input level, with a worst error of 0.003 in linear terms, which is less than a single eight bit step.

What does the highlight rolloff do?

It compresses the top of the range instead of cutting it off, the way film shouldered rather than clipped. Brightening a photo by two stops clipped 3,534 pixels with no rolloff and 0 at sixty percent.

Does rolloff recover detail?

No. It prevents you from losing gradation that is still there, but it cannot invent anything in an area that was already pure white before you started.

Why does my photo look flat after a big lift?

Lifting compresses the bottom of the range. Pull the black point down a little and the depth comes back without undoing the exposure change.

Why are my lifted shadows noisy?

Shadow areas receive the least light and therefore hold the most noise. Lifting reveals it rather than creating it.

How many stops should I use?

Half a stop is a noticeable lift, one stop is a real correction, two is a rescue. If you find yourself past three, the original may simply not hold enough information.

Can it recover a blown out sky?

No. If every channel is already at maximum there is nothing left to recover, and darkening only turns it grey. Rolloff helps before the fact, not after.

When should I use this rather than levels?

Use exposure first to get the overall level right, then levels or curves to shape the range. Exposure answers how much light; levels answers how it is distributed.

Does it change colours?

Not their relationship. All three channels are scaled by the same factor in linear light, so hue is preserved, although very large lifts can desaturate as channels approach the top of the range.

Are my photos uploaded to a server?

No. The conversion to linear light and the adjustment both run in your browser using the canvas API. Nothing is sent anywhere.

Which format should I export?

Keep the original for photographs, at quality 90 or above. Lifting exposure amplifies whatever is in the shadows, including compression blocks.

Is transparency preserved?

Yes for PNG and WebP output. The alpha channel is untouched. JPG has no alpha, so transparent areas are filled with the background colour first.

Can I process a batch?

Yes, and stops are the right unit for it. Frames that differ by a known amount can be brought into agreement precisely.

Is zero really no change?

Yes. With no exposure change, no rolloff and no black point offset, the output is byte for byte the original image.

Does it add a watermark or need an account?

No to both. No sign-up, no email wall, no daily limit and no watermark on the output.