Am I able to covert JPEG into RAW so I can treat the images on Lightroom? Reason why is that for years I am travelling and taking tons of pics but my Nikon was programmed only to save in JPEG format.. Am I able to convert those pictures so I can do something with them now?


In my opinion, none of the other answers addresses the obvious misconception in the question:

There is no use in converting a JPG (comparatively low quality) to a RAW file (high quality), because you do not gain anything.

The reason why people shoot in RAW is that, as others have stated, RAW captures all the sensor data and saves it in a file. JPGs have less information than RAW and that is why people shoot RAW in the first place. You gain nothing by converting a JPG to a RAW, because you still have the same information as before.

(Edit: JPGs have less info compared to RAW when shot on the same camera. A high quality (low compression) JPG from a camera with a good sensor can have much better "quality" than a RAW file from an old junk camera. Thanks to @mattdm for the comment.)

But don't be discouraged: Even though RAW files are better to work with, you can still use JPGs in photo editing and improve your old photos. It will be significantly harder to make large jumps without creating artifacts, though, so maybe less is more here when you are editing.

TL;DR You can do something with your old JPGs, but you don't have to convert them to RAW for that.

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    I think this is the best answer, but I have a nitpick with "quality". A JPEG saved with low (or even moderat) compression can have very, very high technical image quality. And an image shot with a potato saved in RAW will still be very low image quality. The difference is in flexibility. – Please Read My Profile Aug 26 '19 at 6:47
  • @mattdm Good point, I will change this in my answer. – Ian Aug 26 '19 at 7:35
  • Nevertheless, they can convert to any lossless format for working - say, PNG. If a JPG is loaded and saved again and again, due to several processing steps, it loses even more accuracy with each iteration. This does not happen to PNG. – rexkogitans Aug 26 '19 at 14:21
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    @rexkogitans This is moot in Lightroom, anyway, because lightroom saves all editing actions as procedural modifications which are only rendered to a single canvas when exporting. – J... Aug 26 '19 at 17:00
  • @J... You are right. Only repeated exporting and importing increases loss on JPG, but not saving and loading. – rexkogitans Aug 27 '19 at 7:23

In the absence of real raw files, the JPG is your "raw". Most image editors, including Lightroom, can open or import JPGs. You may choose to save in another format while editing, but do not lose or destroy the original JPGs. Also take care not to save over the original files.

It is possible to convert JPGs to DNG. But it's usually used to test and develop algorithms to process raw files. The resulting DNG would not contain the original scene data that a real raw would contain. This process serves no practical purpose for ordinary users. (DPReview Forums: Creating synthetic raw files)

When I say 'the JPG is your raw', I do not mean it has all the data that a raw file would be expected to have, but that it is the best you have when you don't have raw files. It's as if film negatives had burnt in a fire, but prints were saved at a relative's house. The prints are now the nearest thing to the originals. While you could make copy negatives, they would not replace the prints.

However, I do not state there is no use converting formats because there are some situations in which it is of value to convert, as long as the original files are preserved. Lightroom is a non-destructive editor, so there is usually no need to save different versions of files, but if a different editor were used, it can be useful to save edits in a different format. This would be analogous to making copy negatives of the aforementioned prints to do additional darkroom work.

Re Doug's nit. He is incorrect in stating that conversion is not possible, or possible only under certain circumstances. He is correct that a lot of work would be required to produce good results. Something being possible doesn't mean it should be done. Also, Lightroom seems to be able to export DNG files from JPG. (Adobe Forums: Convert jpg to dng) – I am not recommending the use of DNG, only pointing out that such conversion is possible, which is what is asked.

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    Just a nit but while creating RAW files is possible as described in the link, it is only possible with synthetic or colorimetric images. it isn't possible to reverse the effects cameras make when creating jpegs because those effects are non-linear and non-stationary as transforms are adapted to each scene photographed. Synthetic images are colorimetrically specified, and can then be converted with the appropriate matrix for each filter in the CFA to produce a value that can be stored in the appropriate RAW's sensor location per the process described at your link. – doug Aug 26 '19 at 20:54
  • What you state isn't necessary unless you want or need near perfect results. It's like saying people must calibrate their monitors to be able to edit and print their photos. They don't have to. They can still edit. Their results might even look fine when shared, until it gets to a monitor that has been calibrated. – xiota Aug 26 '19 at 23:04
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    There's a misconception that it's possible to turn jpegs into RAW files that is propagated by a business selling such a product. It isn't and the problem is that one cannot come close to replicating the originating RAW file from a jpeg which has had it's tone curve, gamut and white point altered. Those changes far exceed the smaller differences in loss associated with 8 bit jpeg conversion. And not reversing those changes but creating a "RAW" file will result in doubling the applied changes in LR or PS with results similar to double profiling prints. – doug Aug 26 '19 at 23:13
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    @doug Have added a qualifier that a JPG→DNG conversion would not contain original scene data that a real raw would contain. – xiota Aug 27 '19 at 0:03
  • Cool, an example of converting a 2 stop underexposed jpeg to a "RAW" file compared to an actual RAW file, both taken at ISO 200, is that the actual RAW file can be pushed up 2 stops and will look very close to an image taken at ISO 800 while the jpeg converted "RAW" file will have the bottom of its S curve move up and produce an exaggerated effect. Similar effect on the overexposure side where the S curve reduces highlight contrast though there is less room for compensation on the high side depending on the head room before sensor saturation. – doug Aug 27 '19 at 2:25

Basically no.

To explain a bit further a raw image stores the input as it comes off the sensor, so each pixel will have a single colour and 12-16 bit value depending on your model of camera.

A jpeg file will have 3 colours for each pixel with every chanel at 8 bits. In saving as a jpeg the camera will have taken the raw data and processed it to jpeg without saving the original data.

You can still edit and play with jpegs, but as you're working with significantly less data you'll get artifacts sooner than if you were using raw data.

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RAW files contain ALL the image information that was captured by the sensor. The conversion, or export, to JPG removes some of that information in the name of making a file that is smaller in size and that (normally) looks good in its native (Saved As...) resolution. Basically, a JPG only has enough info to display the image.

Once that JPG is created, the information that might create a RAW file is gone. I know of no way to get it all back or even create a RAW file with the limited info from the JPG.

You could, however, export the JPG as a TIFF file. Most image editing applications can do this; even Preview on the Mac. A TIFF is (usually) an uncompressed file that allows extensive editing. If you stay within the resolution of the source JPG you could probably do some limited editing. How much editing capability you get and the quality of those edits will depend on the amount of compression used to make the JPG. Lots of compression; not much to be done. Light compression (saved at highest quality) will allow more leeway.

Seeing as how I'm getting so much push-back, I'll explain my thoughts and expand on this a bit: Editing a JPG file can create a cascading (for lack of better words) loss of quality. Each edit degrades from the original by some degree. If said JPG is exported or saved as a TIFF, the resulting file is like a snapshot of the source JPG and can be edited without any additional degradation or artifacts that would be associated with editing a JPG. It may pick up some new artifacts or be otherwise degraded, and this will vary depending on the quality of the original source JPG and the editing talent of the user. The TIFF and any file exported after editing the TIFF will NEVER be any better or contain any more information than the original source JPG. In the end, my point is that this would a capability for limited editing while possibly avoiding additional degradation. Should I have typed this into my original reply? Yes, I should have. Mea Culpa.

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    Converting from JPG to TIFF is pointless: you won't get back the removed data. – Antzi Aug 26 '19 at 2:11
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    The last paragraph is wrong and completely useless. Please remove it. – Eric Duminil Aug 27 '19 at 0:50
  • @EricDuminil, So if you edit a JPG a bit, save it, close it, then open it again, make an edit, save it, close it - that's something you are OK with? You would say that saving a file in a lossless format for repeated edits is useless? Maybe OP could have been clearer, but if you intend on editing a file over and over, you don't save it as a JPG. – JPhi1618 Aug 27 '19 at 17:07
  • @JPhi1618 One wouldn't repeatedly save as JPEG and reload at intermediate editing stages: I think we would all agree on that. However, for starting a new edit from the original, it is best to start from the original JPEG - it could be that an improved JPEG decoder becomes available. – Andrew Morton Aug 27 '19 at 18:02
  • @JPhi1618: We agree on this one, it wouldn't be a good idea to use a 1995 workflow in 2019. Hopefully, OP asks about Lightroom and Lightroom doesn't work this way. See this comment. – Eric Duminil Aug 27 '19 at 19:09

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