Conversion Issue- Mac vs. PC

[defaultzczdd3lk6bdr]

I've been converting PDFs to .tiffs using Adobe.  I'm using a particular program to process .tiff files that need to be in grayscale.  When I convert PDF to .tiff on my PC, they come out in color, even if the PDF was in grayscale to begin with.  However, if I convert the PDF to .tiff on my Mac, they come out in grayscale.  I'm unsure why this is the case.  Does anyone know what's up here, and whether there's some way I can fix this?

[Dave Creamer of IDEAS]

Did you click on the Setting button when exporting to TIFF?

You will see this dialog box:

Worked for me--my PDF showed as grayscale in Photoshop.

[defaultzczdd3lk6bdr]

Where do you get that dialog box?

Here's what I'm looking at:

[Dave Creamer of IDEAS]

Option 1: Export PDF tools

Option 2: Export menu

Choose TIFF, then: