PNG to PDF - some pages are tiny

[ColorMeToo]

Using Acrobat PRO I'm simply adding 6 PNG images to create one PDF file. I've tried  several times, both online and using the software. Each time, a random number of the resulting PDF pages are tiny, while the rest are the correct size. When I close then reopen the file, the problem is still there.

There is no difference whatsoever in the specs of the 6 PNG files I'm uploading. They're all the same dimensions and approximately the same file size. They're all greyscale. The pages that come up tiny are random (usually 2 or 3 of the 6) each time I recreate the PDF. The first page is always fine, second page always tiny, then random for the rest.

How do I prevent this happening?

[Bernd Alheit]

Have the files all the same resolution?

[JR Boulay · Accepted solution]

This is a typical problem when imported images do not have the same resolution.
The resolution value is a metadata embedded in each image, Acrobat takes it into account, but still doesn't let you modify it.
Before importing you need to set all images to the same resolution (without changing the number of pixels) using an image-editing software, such as Photoshop.

[ColorMeToo]

Thanks for that. No idea how the px/cm got messed up as all the images were created in the same way, but I figured out how to change it in PSP and it's working now.