API 2.0 Version 1.0
The PhotoId can be used to create an image url with a specific size.
Size (pixels) Format * URL (replace X with a photoid value)
50 Scaled https://s3.amazonaws.com/photos.instantencore.com/X/X_50.jpg
75 Scaled https://s3.amazonaws.com/photos.instantencore.com/X/X_75.jpg
150 Scaled https://s3.amazonaws.com/photos.instantencore.com/X/X_150.jpg
300 Scaled https://s3.amazonaws.com/photos.instantencore.com/X/X_300.jpg
750 Scaled https://s3.amazonaws.com/photos.instantencore.com/X/X_750.jpg
1024 Scaled https://s3.amazonaws.com/photos.instantencore.com/X/X_1024.jpg
50 Squared https://s3.amazonaws.com/photos.instantencore.com/X/X_50s.jpg
75 Squared https://s3.amazonaws.com/photos.instantencore.com/X/X_75s.jpg
150 Squared https://s3.amazonaws.com/photos.instantencore.com/X/X_150s.jpg
300 Squared https://s3.amazonaws.com/photos.instantencore.com/X/X_300s.jpg

* Format

SCALED images are scaled to have a height and width no larger than the size specified while maintaining the aspect ratio of the original image. If the original image was smaller than the pixels specified then the image is not changed at all from the original (i.e. it will be smaller than the size specified).

SQUARED images always have the height and width specified. The images are cropped to fit inside a square. If the original image is smaller than the size specified the image is "blown-up" so that it fits the square.