How to convert DNG to JPG on iPhone
A DNG is not really an image. It is a negative — the raw, undeveloped readings from the camera sensor. Converting it to JPG is not a format change so much as a development: an irreversible decision about what the photograph should look like.
What a DNG actually contains
When a camera sensor captures light, each photosite records a single brightness value behind a coloured filter — a mosaic, typically a Bayer pattern of red, green and blue. That mosaic is not a viewable picture. To become one it must be demosaiced (each pixel's missing two colours interpolated from its neighbours), white-balanced, tone-mapped from the sensor's linear response into something perceptual, sharpened, and finally compressed.
A DNG (Adobe's open raw format, and what an iPhone writes when you shoot Apple ProRAW) stores the mosaic before most of that happens, usually at 12–14 bits per channel. That is the point: nothing has been decided yet. Exposure, white balance and highlight recovery remain adjustable because the underlying measurements are still intact.
A JPG is the opposite: 8 bits per channel, every decision baked in, lossily compressed.
This conversion is strictly one-way, and no software can reverse it. You cannot convert a JPG (or a PNG, or a HEIC) back into a DNG. The sensor data does not exist in a developed image, and it cannot be inferred from one — you would be manufacturing measurements that were never taken. Any tool claiming to convert to RAW is producing a fake raw file wrapped around an already-developed image. Convexy does not offer that direction, because it is not a real thing. Keep your DNG files.
What you give up
- Editing latitude. This is the big one. A DNG lets you pull back a blown sky or lift a black shadow because the data is still there in the highlights and shadows. Once it is an 8-bit JPG, those regions are clipped — pushing them produces banding and grey mush, not detail.
- Bit depth. 12–14 bits per channel becomes 8. Smooth gradients lose their headroom.
- White balance as a free parameter. In a DNG, white balance is metadata you can change at will. In a JPG, it is baked into every pixel; correcting it afterwards is damage control.
What you gain is the entire rest of the world: a DNG is large, slow to open, and unreadable by most apps, websites, messaging services and upload forms. A JPG works everywhere.
How Convexy develops it
The DNG is decoded through Apple's Core Image RAW pipeline — the same machinery Photos uses — which demosaics the sensor data and applies a sensible default development based on the camera's own metadata. The result is then encoded as a JPG at your chosen quality.
Be clear about what this is and isn't: it is a good, neutral default development, not a substitute for a raw editor. If the shot needs recovering — a blown highlight, a badly-off white balance, an exposure two stops out — do that work in a proper raw editor first, and convert afterwards. The whole value of shooting raw is that the file will tolerate it.
Not just JPG. A DNG can also be developed to PNG, TIFF, HEIC or WebP. If you want the smallest file that everything can read, JPG is right. If you want to keep a high-quality intermediate for further editing, TIFF or PNG is the lossless option and HEIC is the efficient one. What you cannot do is go back to raw.
Which files count as raw
Convexy recognises DNG and the common proprietary raw formats camera manufacturers use. iPhone ProRAW files are DNGs, so they work directly. Expect them to be big — a ProRAW frame is roughly ten times the size of the HEIC of the same shot, which is exactly why people convert them.
Everything happens on-device using Apple's imaging frameworks. No upload, no server, no account. That is worth something here specifically: raw files are what photographers shoot when the picture matters, and they are the last thing you want sitting on a free web converter's disk.
How to do it
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Do any real editing first
If the photo needs exposure, highlight or white-balance work, do it in a raw editor while the latitude still exists. Converting to JPG throws that latitude away permanently.
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Bring the DNG in
Tap Browse files, or pick it from Photos — iPhone ProRAW shots live there. Select several at once to develop a whole shoot as a batch.
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Choose JPG
Convexy offers the formats a raw file can be developed into: JPG, PNG, TIFF, HEIC or WebP. Tap JPG for the universally readable option.
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Set the quality
Keep it high. You have just discarded a great deal of image data by developing the raw — there is little sense saving a few more kilobytes by compressing hard on top of that.
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Convert, then keep the original
Save or share the JPG. Do not delete the DNG: it is your negative, and it is the only thing you can ever re-develop differently.
Common questions
Can I convert a JPG back to DNG or RAW?
No — not with Convexy and not with anything else, whatever it claims. A raw file contains the sensor's original measurements. A JPG contains a developed, compressed, 8-bit interpretation of them. The measurements are not recoverable from the interpretation; recreating them would mean inventing data that was never captured. Tools that advertise JPG-to-RAW wrap a developed image in a raw container — the file has the extension and none of the benefits.
Does converting DNG to JPG lose quality?
It loses latitude, which matters more than the word “quality” suggests. The visible picture may look identical. But the JPG is 8-bit and lossily compressed, so the room you had to recover highlights, lift shadows or fix white balance is gone. Do your editing on the DNG, then convert.
Why is my DNG file so enormous?
Because it stores the sensor's raw readings at 12–14 bits per channel with little or no lossy compression — that is what makes it editable. An iPhone ProRAW file is commonly around ten times the size of the HEIC of the same photo. Converting to JPG is the standard way to reclaim that space once you are finished editing.
Should I develop to JPG, HEIC or TIFF?
JPG if it needs to be readable everywhere — sharing, uploading, printing at a shop. HEIC if it is staying in the Apple world and you want roughly half the size at similar quality. TIFF or PNG if you want a lossless intermediate to carry into another editor. All are one-way from raw; none of them can be turned back into a negative.
Will the JPG look the same as the DNG preview in Photos?
Close, but not necessarily identical. The preview you see is itself a development of the raw data, and different pipelines make slightly different choices about tone and colour. Convexy uses Apple's Core Image RAW pipeline with the camera's own metadata, so the result is a neutral, sensible development — but if you have a specific look in mind, produce it in a raw editor rather than expecting the converter to guess.