iPhoto is Downgrading Photo Resolution

Oops, forgot to add that info, yes:

OS X 10.7.5 / iPhoto v9.4.3

I wish I could accept what you say as fact, however iPhoto has in fact downscaled my photos. They contain their original creation/modification dates (as taken), all exif data, and when revealing in finder, the option to view the modified file is grayed out.

On top of that, iPhoto does not even give you the option to scale an image in the edit pane, so there is no way I could have done that to begin with.

The only discernible pattern I can find is that this does not happen to RAW images, or JPG's taken within the last year.

It has been moved from one machine to another over the years and upgraded along the way based on new versions of iPhoto coming out. I believe I originally started the library back in 2004.

I actually noticed this glitch last year, but chalked it up to a fluke and kept adding photos (at full resolution) thinking nothing of it until I noticed that those photos have now also been downgraded by 60% (which appears to be part of the pattern as well. Photos seem to all drop to one third of their original resolution).

Fortunately, I have a separate backup of some (but not all) of my more treasured images at their proper resolution so I'm feeling alright about that.

The last time I migrated my iPhoto library to a newer version was transitioning from Snow Leopard to Lion, so that would have happened back in 2011. I've imported photos into iPhoto since though, that have gone through this 60% downscaling. I think I'm going to chalk it up to a corrupted library (and I'm the only person EVER who has experienced this issue 😉) and going forward, will always export all photos from my iPhoto library when transitioning to a new OS/iPhoto version that requires upgrading.

Lesson learned!

Oops, meant to answer the first part of your question as well Larry,

Downscaling isn't instantaneous. The photos have retained their initial resolution for a period of time before being downscaled. I suppose I could perform an experiment to check, but that could take some time, possibly up to a year as that seems on the surface to be the amount of time it takes before I noticed the most recent back losing their quality.

I have none of those programs. And no, I am not doing anything to cause this. To deliberately reduce the quality of important images repeatedly, would be illogical. I am chalking this up to a corrupted library.

I will run that first aid command and give Keith's suggestion a shot tonight.

Thanks all! 🙂

Well now THAT is interesting...

I can't honestly say I sifted through thousands of photos to confirm that all had been downscaled, but that's irrelevant given that they were all part of a batch of photos to begin that. That being said, after using option+command+= to rebuild my database, I did come across at least a couple of photos in a heretofore low-res grouping that had been restored to 4k resolution. For the most part 3:4 images were restored, but 4:3 images remained at 1280x960. I can count on one hand the number of photos that are now hi-res again.

Let's start with the first screen grab below. Here you can see an image with some of its exif data intact:

The image below it, you will see, is 1280x960 (roughly a third the size), and contains less exif data:

So, I took a gander at exporting as 'original' as suggested...

And this is what came out:

So at least we know one thing: Something must have happened 🙂

I have not yet tried the iPhoto Editor application mentioned above.