Camera Matching and iPhone 5s

[Corey Beaulieu]

I am doing a quick project for a friend and he supplied me with an image of his house that he took with his iPhone. When viewed in the typical programs, there is nothing amiss about the image, but when I piped it into max, I got some pretty crazy stretching. In terms of bringing the image in and matching the safe frame, I did that correctly as I do it all of the time so I started investigating the "Pixel Aspect" in Max. Playing with this value made things look better, but I couldn't be sure which value was correct. Here is what I did:

 

The Display Aspect Ratio (DAR) of the phone is 1136 x 640 | 1136/640 = 1.775

The Storage Aspect Ration (SAR) of the image is 2048 x 1536 | 2048/1536 = 1.333

 

According to Wikipedia Pixel Aspect Ratio (PAR) is found by: PAR = DAR/SAR or in my case here PAR = 1.775/1.333, or 1.332

 

This resultant value of 1.332 did nothing to fix my problem in Max, nor did its inverse. When I opened the image in Photoshop (where it looked correct mind you) and I applied a Pixel Aspect Correction the image looked stretched. I saved this out and piped it into Max again and voila! the image looked correct. The Max settings are set to a PAR of 1.0.

 

The piece that confuses me is why max knew/knows what the other image viewers did not? Why were the other viewers able to auto correct and not max and why does the correction in Max not solve the problem the way it did in PS?

 

What am I missing? I have solved the problem, but I'd like to know why.

 

Thank you

Edited March 25, 2014 by CoreyMBeaulieu