manfromcolumbia asked:
You see heirloom photos in albums and frames that had a variety of custom sizes, mostly smaller. Standard today is 4×6. How can digital cameras or software take the same types of images with the same size range?
You see heirloom photos in albums and frames that had a variety of custom sizes, mostly smaller. Standard today is 4×6. How can digital cameras or software take the same types of images with the same size range?

It is just a matter of printing them smaller or even cutting a portrait out of a 4×6 print.
Most labs offer prints as small as 2×2″ (wallet) from your digital files.
The size of the print is today a matter of the size of paper the printing machine takes, and then your desire to trim one or more sides.
Today’s store-front machines use rolls of paper: a 4″ roll can produce prints 4×6, 4×8, 4×10, etc Each lab tries to find the optimum mix of paper size 4″, 5″ and so on, and surfaces (glossy, lustre, etc) that keeps clients coming through the doors.
The paper is cut after the image is printed, so the image can be printed any length, and is only limited by the width of the paper.
A hundred years ago, the image might have been made by placing the negative directly on the printing paper, then exposing the sandwich to light, then processing the paper. The paper came in single sheets.
In the 19th century, the photographer also made the negative material. Some processes required that the image be exposed while the “film” or plate was still wet!
So, the print size was limited to the size of the plate or film in the camera. The quality of image capture (film or plate) a hundred or more years ago often wouldn’t allow for enlargements – the blown up image would show film or lens shortcomings.
Historically, there were always many cameras using many different negative sizes – far more varied than film today – so there were many different print sizes.
The 4×6 convention is just that – a convention, not a direct result of cameras or digital imaging.
A standard print size allows for large-scale production of frames and albums for that size, reducing the costs.