Making a Photo Story with PowerPoint

We did the Secret Santa thing this year and The rules were
Second hand or Home Made.

I decided to make a book of photos for Dan

I went through my blog and a few other hard drives looking for pictures containing Dan.

Then I thought about how to combine them.  I tried GIMP but that was just too fiddly.  You cant easily resize and crop the way you can in word.

I tried power point and discovered you can save your slide show as a set of JPEGs.  Great!.

But now how to select resolution.

One is supposed to be able to set slide size in this dialog.

It does not seem to be consistent.

This web site says that PP operates at 96dpi
I wanted to do 6 x 4 inch photos because I could do them quickly.
Wanted to do 600 dpi output because Harvey Norman advised their photo printer was that resolution.
So I figured 6 x 600 = 3600.
The web site above indicated I could enter px as a unit.
So I tried to enter 3600px and that automatically changed to 76.2cm when I clicked out of the box.  I set the Y resolution the same way and exported some slides only to find they were 2880 x 1920 which is 480 dpi.

I tried a few other numbers and it did not seem consistent.  I was not even sure it was linear.  Gave up on trying to hit 600dpi and just took jpegs that looked reasonable and printed them and made up the book.

Then decided should try and work out the formula.
At this stage I was not even sure it was linear.  If Microsoft had made it, in my view, illogical in and inconsistent, then there was no guarantee it was even linear.
I took to just entering a size in cm and exporting the jpegs and looking at the size.
Plotted a graph

Interesting that the y intercept calculates to be negative.









Anyway then knowing m and C rearranged for X as a function of Y (the dpi) and entered those numbers and got the desired result.