Creating a JPEG from a DNG in Photos

[bs1946]

I am currently using a Mac Studio with IOS 12.6 Monterey & Photos 7.0. But this issue has been around probably since the first version of Photos.

I have two Leica M cameras and would prefer to just shoot with DNGs instead of DNGs & JPEGs or JPEGs only. I rarely need to do more than very little editing with my photos; some slight cropping or minor adjustments. I found Apple Photos perfect for this and several years ago, stopped using Lightroom, OnOne, and Photoshop. I also use Photos to store and manage my photo library. The only problem with Photos, including previous versions is there is no way that I can find to save or create a JPEG from the DNG file unless I export the photo, which creates a JPEG, and then import the JPEG back into Photos. Even worse is if I download a DNG & JPEG from the camera with the exact same date and time, because they are linked together forever and you can delete one without Photos deleting both of them. So I am looking for a simple way to create a JPEG from a DNG inside Photos if that is even possible.

 

[Andy Hewitt]

I am currently using a Mac Studio with IOS 12.6 Monterey & Photos 7.0. But this issue has been around probably since the first version of Photos.

I have two Leica M cameras and would prefer to just shoot with DNGs instead of DNGs & JPEGs or JPEGs only. I rarely need to do more than very little editing with my photos; some slight cropping or minor adjustments. I found Apple Photos perfect for this and several years ago, stopped using Lightroom, OnOne, and Photoshop. I also use Photos to store and manage my photo library. The only problem with Photos, including previous versions is there is no way that I can find to save or create a JPEG from the DNG file unless I export the photo, which creates a JPEG, and then import the JPEG back into Photos. Even worse is if I download a DNG & JPEG from the camera with the exact same date and time, because they are linked together forever and you can delete one without Photos deleting both of them. So I am looking for a simple way to create a JPEG from a DNG inside Photos if that is even possible.

It might help to understand your workflow needs a bit more. So, just asking, but why do you need to do this? At what point do you need to have a JPEG?

Photos creates a JPEG Preview image anyway, so there is one there. If you want to create a copy (for editing differently perhaps), just use 'Duplicate', which creates another version you can edit and export separately (linking to the original master).

If you shoot DNG+JPEG, and want to keep them separate, you need to import them separately. If you copy them from your media card into separate folder on your internal drive, then you can import them int Photos as separate batches, and Photos will handle them as separate images then. It only merges them into a 'pair' if you import the whole lot together.

Otherwise, it is a matter of Export as JPEG and re-import.

Photos is a consumer level app, so don't expect 'Pro' features.

Cheers.

 

[bs1946]

I am currently using a Mac Studio with IOS 12.6 Monterey & Photos 7.0. But this issue has been around probably since the first version of Photos.

I have two Leica M cameras and would prefer to just shoot with DNGs instead of DNGs & JPEGs or JPEGs only. I rarely need to do more than very little editing with my photos; some slight cropping or minor adjustments. I found Apple Photos perfect for this and several years ago, stopped using Lightroom, OnOne, and Photoshop. I also use Photos to store and manage my photo library. The only problem with Photos, including previous versions is there is no way that I can find to save or create a JPEG from the DNG file unless I export the photo, which creates a JPEG, and then import the JPEG back into Photos. Even worse is if I download a DNG & JPEG from the camera with the exact same date and time, because they are linked together forever and you can delete one without Photos deleting both of them. So I am looking for a simple way to create a JPEG from a DNG inside Photos if that is even possible.

It might help to understand your workflow needs a bit more. So, just asking, but why do you need to do this? At what point do you need to have a JPEG?

Printing and several sites, including this one, where I post my work will not accept DNGs

Photos creates a JPEG Preview image anyway, so there is one there. If you want to create a copy (for editing differently perhaps), just use 'Duplicate', which creates another version you can edit and export separately (linking to the original master).

When you export any image from Photos, the original remains in Photos and it creates a jpeg as part of the export process. That is why I said to create a jpeg from a DNG in Photos, you need to an export to create the jpeg and an import to bring it back in.

If you shoot DNG+JPEG, and want to keep them separate, you need to import them separately. If you copy them from your media card into separate folder on your internal drive, then you can import them int Photos as separate batches, and Photos will handle them as separate images then. It only merges them into a 'pair' if you import the whole lot together.

It's all about the creation date and time on the image file. If you shoot a DNG or any other RAW file plus a jpeg, both files have. the same creation date and time. Even if you download them separately, Photos immediately links them back together.

Otherwise, it is a matter of Export as JPEG and re-import.

Photos is a consumer level app, so don't expect 'Pro' features.

Photos has long since stopped being just a consumer level app and Apple even said that was their intent when they replaced its predecessor. I used OnOne because there was nothing left that I couldn't do in Photos, plus Photos contains a CRM, cloud storage, and easy file transfers between all my devices. before I moved to Photos I had to use different apps to do all of that.

Cheers.

 

[Andy Hewitt]

I am currently using a Mac Studio with IOS 12.6 Monterey & Photos 7.0. But this issue has been around probably since the first version of Photos.

I have two Leica M cameras and would prefer to just shoot with DNGs instead of DNGs & JPEGs or JPEGs only. I rarely need to do more than very little editing with my photos; some slight cropping or minor adjustments. I found Apple Photos perfect for this and several years ago, stopped using Lightroom, OnOne, and Photoshop. I also use Photos to store and manage my photo library. The only problem with Photos, including previous versions is there is no way that I can find to save or create a JPEG from the DNG file unless I export the photo, which creates a JPEG, and then import the JPEG back into Photos. Even worse is if I download a DNG & JPEG from the camera with the exact same date and time, because they are linked together forever and you can delete one without Photos deleting both of them. So I am looking for a simple way to create a JPEG from a DNG inside Photos if that is even possible.

It might help to understand your workflow needs a bit more. So, just asking, but why do you need to do this? At what point do you need to have a JPEG?

Printing and several sites, including this one, where I post my work will not accept DNGs

Ok, but I thought that was just a normal process anyway, regardless of using Photos or anything else. Unless of course you might sometimes get a direct linking plugin or something.

You can also just drag images from the library window into other apps, and it'll send a JPEG.

What I'm failing to understand is why you need to export and reimport as JPEG. You can simply create the JPEGs at the time they're needed, you don't need to be storing them as JPEGs all the time.

If you want to keep a particular version of an image intact, just create a duplicate internally, maybe stick it into an album to separate it. Then you can just save/export/use it anytime you need to. You then have an option to re-edit, or create more versions if you need to do that too, and still have the exported version left intact.

Photos creates a JPEG Preview image anyway, so there is one there. If you want to create a copy (for editing differently perhaps), just use 'Duplicate', which creates another version you can edit and export separately (linking to the original master).

When you export any image from Photos, the original remains in Photos and it creates a jpeg as part of the export process. That is why I said to create a jpeg from a DNG in Photos, you need to an export to create the jpeg and an import to bring it back in.

Yes, I'm failing to see the problem with that. Perhaps some apps might handle that internally, but it's not something I'd consider is within the needs of the average Photos user.

If you simply use the image in any apps that can use the photos media, it creates a JPEG as and when needed.

If you shoot DNG+JPEG, and want to keep them separate, you need to import them separately. If you copy them from your media card into separate folder on your internal drive, then you can import them int Photos as separate batches, and Photos will handle them as separate images then. It only merges them into a 'pair' if you import the whole lot together.

It's all about the creation date and time on the image file. If you shoot a DNG or any other RAW file plus a jpeg, both files have. the same creation date and time. Even if you download them separately, Photos immediately links them back together.

Hmm, I've not had that issue, all the ones I've imported have remained separate if I import them as separate import processes. Sorry, don't have an answer for that.

Otherwise, it is a matter of Export as JPEG and re-import.

Photos is a consumer level app, so don't expect 'Pro' features.

Photos has long since stopped being just a consumer level app and Apple even said that was their intent when they replaced its predecessor. I used OnOne because there was nothing left that I couldn't do in Photos, plus Photos contains a CRM, cloud storage, and easy file transfers between all my devices. before I moved to Photos I had to use different apps to do all of that.

That's pretty much why I use Photos, but no, it's not a pro level app by any means. Personally I think it's very good, for its intended purpose, but whatever Apple's intentions, it's never competed at the pro level.

If you really need more complex file management and image manipulation, you really do have to consider other options.

 

[allanimal]

I am currently using a Mac Studio with IOS 12.6 Monterey & Photos 7.0. But this issue has been around probably since the first version of Photos.

I have two Leica M cameras and would prefer to just shoot with DNGs instead of DNGs & JPEGs or JPEGs only. I rarely need to do more than very little editing with my photos; some slight cropping or minor adjustments. I found Apple Photos perfect for this and several years ago, stopped using Lightroom, OnOne, and Photoshop. I also use Photos to store and manage my photo library. The only problem with Photos, including previous versions is there is no way that I can find to save or create a JPEG from the DNG file unless I export the photo, which creates a JPEG, and then import the JPEG back into Photos. Even worse is if I download a DNG & JPEG from the camera with the exact same date and time, because they are linked together forever and you can delete one without Photos deleting both of them. So I am looking for a simple way to create a JPEG from a DNG inside Photos if that is even possible.

It might help to understand your workflow needs a bit more. So, just asking, but why do you need to do this? At what point do you need to have a JPEG?

Printing and several sites, including this one, where I post my work will not accept DNGs

Ok, but I thought that was just a normal process anyway, regardless of using Photos or anything else. Unless of course you might sometimes get a direct linking plugin or something.

You can also just drag images from the library window into other apps, and it'll send a JPEG.

What I'm failing to understand is why you need to export and reimport as JPEG. You can simply create the JPEGs at the time they're needed, you don't need to be storing them as JPEGs all the time.

If you want to keep a particular version of an image intact, just create a duplicate internally, maybe stick it into an album to separate it. Then you can just save/export/use it anytime you need to. You then have an option to re-edit, or create more versions if you need to do that too, and still have the exported version left intact.

Photos creates a JPEG Preview image anyway, so there is one there. If you want to create a copy (for editing differently perhaps), just use 'Duplicate', which creates another version you can edit and export separately (linking to the original master).

When you export any image from Photos, the original remains in Photos and it creates a jpeg as part of the export process. That is why I said to create a jpeg from a DNG in Photos, you need to an export to create the jpeg and an import to bring it back in.

Yes, I'm failing to see the problem with that. Perhaps some apps might handle that internally, but it's not something I'd consider is within the needs of the average Photos user.

If you simply use the image in any apps that can use the photos media, it creates a JPEG as and when needed.

I agree with Andy here - if the DNG is your master image, send that to other programs that accept it, otherwise exert the JPG or TIFF to those that don't. The master DNG will still be there. The exported JPEG or TIFF can be used to print or publish on social media or whatever, it does not need to be re-imported back into photos. If you want to have different versions with different edits, crops, etc. just do that by duplicating the master DNG (command-D) and have each version with those specific edits. There is no need to re-import. Or am I missing something here?

 

[bs1946]

I agree with Andy here - if the DNG is your master image, send that to other programs that accept it, otherwise exert the JPG or TIFF to those that don't. The master DNG will still be there. The exported JPEG or TIFF can be used to print or publish on social media or whatever, it does not need to be re-imported back into photos. If you want to have different versions with different edits, crops, etc. just do that by duplicating the master DNG (command-D) and have each version with those specific edits. There is no need to re-import. Or am I missing something here?

One of the problems with using Apple in recent years is that something that is there in OSX, Photos, or any of their other software will change or completely vanish with the next update, however minor it may seem. Apple is real good at telling what's new but not what's gone or changed. While everyone's workflow is different, to me, the DNG is basically a negative and once I have a good copy of the JPEG, the DNG is surplus to me. Beside the necessary extra steps, I don't like the export/import process because you are creating a JPEG on the export but bringing back a copy of that JPEG on the import and what most people, who have not worked in the computer industry, don't realize, is every time you copy of a jpeg, a little bit of the original detail is lost. Copy that JPEG enough times and you can tell the difference between the two. Tiff, DNG, or any of the other RAW file types out there do not have this problem, JPEGS are universally accepted by just about any program that uses photo files, but not so for the others. Plus now and days, most editing programs will allow you to just about anything with a JPEG that you can with a RAW or TIFF file, except get a color copy of a B&W JPEG.

 

[Andy Hewitt]

I agree with Andy here - if the DNG is your master image, send that to other programs that accept it, otherwise exert the JPG or TIFF to those that don't. The master DNG will still be there. The exported JPEG or TIFF can be used to print or publish on social media or whatever, it does not need to be re-imported back into photos. If you want to have different versions with different edits, crops, etc. just do that by duplicating the master DNG (command-D) and have each version with those specific edits. There is no need to re-import. Or am I missing something here?

One of the problems with using Apple in recent years is that something that is there in OSX, Photos, or any of their other software will change or completely vanish with the next update, however minor it may seem. Apple is real good at telling what's new but not what's gone or changed. While everyone's workflow is different, to me, the DNG is basically a negative and once I have a good copy of the JPEG, the DNG is surplus to me. Beside the necessary extra steps, I don't like the export/import process because you are creating a JPEG on the export but bringing back a copy of that JPEG on the import and what most people, who have not worked in the computer industry, don't realize, is every time you copy of a jpeg, a little bit of the original detail is lost. Copy that JPEG enough times and you can tell the difference between the two. Tiff, DNG, or any of the other RAW file types out there do not have this problem, JPEGS are universally accepted by just about any program that uses photo files, but not so for the others. Plus now and days, most editing programs will allow you to just about anything with a JPEG that you can with a RAW or TIFF file, except get a color copy of a B&W JPEG.

Yes, DNGs, and indeed Raws, are your digital negatives (hence DNG). That’s not different for anyone.

How Apple have conducted their evolution of software over the years, hasn’t changed the way they handle Raw and JPEG images at all, they’re were one of the first to start using non-destructive workflows.

You seem to be missing an understanding of how that works though. Copying a JPEG does not lose any detail at all, unless you’re changing the image itself each time. Making a copy, bit for bit, should be identical. However, if you export to JPEG, then reimport, apply some more edits, then export again, then it will change and lose detail.

By storing everything in the non-destructive workflow, that Photos and many others apps use, those edits are only applied once. As long as you keep that image within the Photos ecosystem (or any other similar app), you can make duplicates, re-edit, or place in albums, as you please, and that image remains at the same quality. Photos uses JPEGs as a Preview to show edits made onto a Raw image, but recreates it behind the scenes if you change anything, and it remains a top level edited JPEG.

You only need to export that image if you need it outside Photos, for example, printing, sharing with others, or for website displaying.

And you certainly cannot do just about anything with a JPEG that you can with a Raw. There may be some clever AI algorithms out there now that can do some wonderful trickery to give you a falsely improved JPEG, but they can’t really give you back anything that wasn’t there in the first place. Once you create a JPEG, you will lose any highlight/shadow detail that the Raw might have retained, it will introduce artefacts, and you will reduce it to 8-bit data. Once you’ve done that, it’s gone. You can only get all that back by going back to the Raw image, and starting again from there.

Or you could just use the non-destructive workflow as it was intended to be used.

Try this:

https://tidbits.com/2019/06/14/the-...estructive-editing-in-photos-for-mac-and-ios/

Regards

 

[bs1946]

You seem to be missing an understanding of how that works though. Copying a JPEG does not lose any detail at all,

I spent 47 years in the computer industry as a tech, engineer, and product design manager and jpeg degradation is a hard fact. You have a DNG or any other raw file and you want a jpeg. With photos, you have to export the file and you will be asked do you want a jpeg, tiff, or png, along with quality you want, which will also determine the file size, and the location you wanted it exported to. Photos creates the jpeg and exports it to the location you specified. Now you request Photos to import the jpeg. It doesn't move the jpeg it just created back into Photos, it creates a copy of the original jpeg and puts in your Photos library. The original jpeg is still back at the location you told Photos to use. So you just created your first copy of the jpeg and if you duplicate it or export the jpeg somewhere else, you have a copy of the copy of the copy and each copy will degrade slightly.

 

[robgendreau]

You seem to be missing an understanding of how that works though. Copying a JPEG does not lose any detail at all,

I spent 47 years in the computer industry as a tech, engineer, and product design manager and jpeg degradation is a hard fact. You have a DNG or any other raw file and you want a jpeg. With photos, you have to export the file and you will be asked do you want a jpeg, tiff, or png, along with quality you want, which will also determine the file size, and the location you wanted it exported to. Photos creates the jpeg and exports it to the location you specified. Now you request Photos to import the jpeg. It doesn't move the jpeg it just created back into Photos, it creates a copy of the original jpeg and puts in your Photos library. The original jpeg is still back at the location you told Photos to use. So you just created your first copy of the jpeg and if you duplicate it or export the jpeg somewhere else, you have a copy of the copy of the copy and each copy will degrade slightly.

I'd like to see some proof that simple copying, say by Finder, causes generation loss in JPEGs. Numerous sources online say that isn't the case, vs making generations by transcoding, editing and saving, uploading and sharing via social, etc. Not doubting your experience, but it would be important to have data about such since we all store them and have to copy them.

I suppose bit rot could be a problem, but that's different.

And I'm not sure what Photos does internally if you export an imported JPEG; it migh copy it, it might generate a new JPEG since it is a non destructive editor, although I seem to recall an "export original" function that should just copy.

As to the original problem, this is one reason I use LrClassic. As Andy noted, Photos is a consumer app. LrC has the publishing feature, designed to keep track of exported jpegs so you can continue to manage them. I need to have exports of them for various uses, like thumbdrives of them, or some on a media server. But I do NOT want to import them back into Lr, nor would I want to Photos. Needless duplication. LrC also has other means of dealing with these, including Snapshots.

If the problem is Photos seeing it as a paired jpeg something might be wrong. I just exported a raw with "large" settings, with all metadata, and with the same file name but jpg extension. Reimported, and it shows as a separate image in my copy of Photos.

 

[Brewse]

. . . request Photos to import the jpeg. It doesn't move the jpeg it just created back into Photos, it creates a copy of the original jpeg and puts in your Photos library. The original jpeg is still back at the location you told Photos to use. So you just created your first copy of the jpeg and if you duplicate it or export the jpeg somewhere else, you have a copy of the copy of the copy and each copy will degrade slightly.

Respectfully, what you have said is incorrect.

It is possible to faithfully copy a jpeg without degradation. The trick is knowing when you are copying, and when Photos (or other software) is taking additional action.

So, terminology is key here. You know from your work experience that computers routinely copy files without error. Jpegs are no different, in that they are just a collection of bits that can be copied.

Next time you export images from Photos, take notice that you have the option to "Export photo" or "Export Unmodified Original" (or "Export Original"). If you choose "Export (Unmodified) Original", Photos will make a Copy of that image file in the location you choose. Data loss (image degradation, in this instance) is no more common than any other copying of computer files.

If, on the other hand, you choose "Export photo", Photos will make a new image file and put it in the export location you choose. This process involves interpreting the original file, any edits you made in Photos, and applying any new instructions (file type, size, compression, etc.) you have given it. Re-applying jpeg compression would be the big worry here, since it would happen every time you handle a file this way even if you have made no changes.

Notice that File/ExportOriginal does not give you the option to choose a different file type. You are not asked what jpeg quality (compression) you want applied. Photos will not interpret the file, will not convert the file. A bit-for-bit copy will be made.

It might have been more obvious if Apple had chosen to call "Export Original" something that did not re-use the word "Export".

 

[Andy Hewitt]

You seem to be missing an understanding of how that works though. Copying a JPEG does not lose any detail at all,

I spent 47 years in the computer industry as a tech, engineer, and product design manager and jpeg degradation is a hard fact. You have a DNG or any other raw file and you want a jpeg. With photos, you have to export the file and you will be asked do you want a jpeg, tiff, or png, along with quality you want, which will also determine the file size, and the location you wanted it exported to. Photos creates the jpeg and exports it to the location you specified. Now you request Photos to import the jpeg. It doesn't move the jpeg it just created back into Photos, it creates a copy of the original jpeg and puts in your Photos library. The original jpeg is still back at the location you told Photos to use. So you just created your first copy of the jpeg and if you duplicate it or export the jpeg somewhere else, you have a copy of the copy of the copy and each copy will degrade slightly.

Blimey, I think you really do have things mixed up here. I’m not any kind of computer professional, but I have been a user and hobbyist for about the same amount of time. As a background, I started using 8-bit machines in the early 80’s, and writing some programs in Basic a little. I’ve also been capable of repairing systems and hardware, and have even built up a few PC over the years, and have been using Apple systems for 28 years.

I’ve been handling digital photos for over 20 years, and Raw images for 16 years, and have used all the Apple software from iPhoto, through Aperture to Photos. As well as a few alternatives too (spent quite a while using Lightroom too).

I’ve been taking photos for over 40 years.

I think looking at your comments here, you have either misunderstood what is happening with Photos and its file management, or you have a very weird workflow.

I'd like to see some proof that simple copying, say by Finder, causes generation loss in JPEGs. Numerous sources online say that isn't the case, vs making generations by transcoding, editing and saving, uploading and sharing via social, etc. Not doubting your experience, but it would be important to have data about such since we all store them and have to copy them.

Yes, indeed.

I suppose bit rot could be a problem, but that's different.

And I'm not sure what Photos does internally if you export an imported JPEG; it migh copy it, it might generate a new JPEG since it is a non destructive editor, although I seem to recall an "export original" function that should just copy.

Photos ‘copies’ the original image into its database, it’s a bit for bit identical copy, there is no degradation here. At this point you will have two identical copies. As you would if you copied any file on your computer.

If it’s needed, i.e. a Raw image, then a JPEG Preview is created (although I’m not sure if it uses an embedded JPEG preview if available). This also applies if you edit any image (regardless of file type). This maintains a non-destructive workflow whatever image format you’re working with. You can always revert back to the untouched original. It will be in the condition it was when you imported it.

There are a number of ways you can share/export/save an image. This is initially regarding any image that is simply imported, edited and exported within Photos.

You can either use Export… which will save an edited version of the image as displayed on the screen in Photos. This will be a first generation saved image, so will have the highest quality possible for a JPEG.

Or you can use Export Unmodified Original… which will simply copy out the original image back to the location of choice. This will be exactly the same quality as the original image you first imported.

You can also drag images from the Photos window into apps, or the desktop. As I understand it, these are lower resolution ‘edited’ images, but still a first generation export. I believe using the Share menu to send the image to other apps does a similar thing too.

Now, if you, say, reimport the image you Exported (as in the above process for Export…), then that will be a newly imported image that is an exact file copy of the image you exported. Which will be an edited version of the first image you originally imported.

If you edit that image now, and then ‘Export…’ it again, *then* it will be a degraded copy. But it will be you that has created that yourself, it’s nothing special about Photos, it will happen with whatever app you use.

Otherwise, those extra copies are identical to whatever you exported. But they are also superfluous within Photos, and you now have the original non-destructive version of the image, which you could easily duplicate, if you wanted different versions of it, or export again at any time you needed to. But also now have another ‘fixed’ copy, that looks identical, but has lost it’s nondestructive editing capabilities.

As to the original problem, this is one reason I use LrClassic. As Andy noted, Photos is a consumer app. LrC has the publishing feature, designed to keep track of exported jpegs so you can continue to manage them. I need to have exports of them for various uses, like thumbdrives of them, or some on a media server. But I do NOT want to import them back into Lr, nor would I want to Photos. Needless duplication. LrC also has other means of dealing with these, including Snapshots.

Indeed so, the exported images are usually intended for a specific task, otherwise they simply reside in the library until they are needed.

If the problem is Photos seeing it as a paired jpeg something might be wrong. I just exported a raw with "large" settings, with all metadata, and with the same file name but jpg extension. Reimported, and it shows as a separate image in my copy of Photos.

The merging of paired Raw and JPEG images usually happens if you import them at the same time. I too have imported these separately, and the remain as separate images in Photos.

Have a look at that link I posted. Nik develops Raw Power, and was on the Aperture team at Apple, so knows his stuff.