Changing photo size to 1.5MB in iPhoto on Mac

In the Photos Library, the information that makes a picture is stored in a database, so there is no actual "size" to a picture within Photos. A picture only has a "size" when it is turned into a file using the menu command File>Export>Export nn Photos. Yer_Man shows you the choices you have for the new file that's created.

The "Quality" adjusts the "size of the file in megabytes" by removing some degree of detail in the picture while keeping the same number of pixels. The "degree of detail" uses a compression technique that, in Photos, is only available with the jpeg format.

The "Size" adjusts the "size of the file in megabytes" by reducing the number of pixels.

You may want to try both adjustments to see how they affect the picture.

File -> Export,

In the resulting dialogue select JPG as your destination format and the Quality is what impacts file size.

roberta jones wrote: Thank you so much! This is just what I needed.

Great!