New Update causes my photos to be low size?

I see the same bug in Sequoia 15.4.1 Preview.app > Tools > Adjust Size...

It might be most apparent in the "new style" iOS 18.2 iPhone 16 Pro .heic, but the same happens also in old .heic and .jpg although there the change in file size is not so noticeable:

With such new iOS 18 .heic without any adjustments the "Resulting size" remains original for a split second, and is then about halved (in the example below 3.3 → 1.6 MB). Press OK, and when Preview.app then closes, it re-saves and compresses the image to a smaller size (resolution remains the same) without asking if the user wants to save changes (bad!). And XMP metadata such as XMP-dc:Subject holding the Keywords is deleted (bad!) while XMP-dc:Description is preserved.

seana12 wrote: … I export my photos and drag them to my desktop,

I'm not sure what that means. File>Export allows you to save the picture to your desktop, no dragging.

On the other hand, Drag & Drop are not really supported by Photos. By that I mean that you can't ever be sure what you get-- it sounds just like your situation. In one macOS, drag & drop may give a full, edited picture, and in another, drag & drop may produce a preview size (like you seem to be getting) or maybe a thumbnail. The thing is, Photos can make many versions of a picture and, if you don't tell it which version you want, then you can't be sure which version you get.

So, if you want the Original file, no added edits, comments, or keywords, then you should use File>Export>Export Unmodified Original. If you want a file created according to your specifications, then you should use File>Export>Export nn Photos.

Is this it? Are you trying to use Drag & Drop from Photos?

"New Update causes my photos to be low size?: Hi, I export photos from my lightroom and they are automatically very small size now on my Macbook Air. I just installed MacOS sequoia, however I am unsure if this is the reason it is happening. What I mean by this is; I export my photos and drag them to my desktop, and I check the image size and they are low in size (KB).[...]I have thought that maybe the new Sequoia update I got has something where it reduces image sizes in able to save storage? I checked storage optimization and it does not appear to be turned on. Macbook pro, running most recent sequoia"

-------

Images Being Downsized After Sequoia Update:

Change the view menu, and see if they are seen as they should.

1. Go to: View Menu
2. Select: as Key Photo

Screenshot:

"I don't have a as key photo option. Should be noted that when I right click and press "get info" it shows the normal image size. However when I open the image resizer (and do not change any parameters) it tell sme that it will be low size, very low KB. Did not have this issue until I updated so im thinking the update turned on an austere setting?"

-------

Strange.

Click on this, and all would be expanded:

seana12 wrote:

Any idea on how to fix? Do you think it will be fixed?

Preview.app and Photos.app have some other long-standing issues <cough bugs> so I would not hold my breath.

But use that "Adjust size" if you really need it and do not mind losing existing Keywords (or maybe some other metadata).

But I'd use other apps like GraphicConverter, Photoshop, Lightroom etc to resize images and then re-save with the desired settings.

"I also don't have that button, i'm on macbook pro"

-------

Which App are your Using:

I'm using the Photos app here for my screenshots. And I am using a MBP, just like you.