I posted this question on BGG but didn't receive any suggestions.

I'm wrapping up the editing of a star field image I'm creating for my 6' x 3' ProMat Kickstarter and I have a question about print output. I'm editing this giant bitmap in Photoshop, with the following image settings (suggested by the project lead):
- WIDTH: 74"
- HEIGHT: 38"
- RESOLUTION: 150 pixels/inch

If you are familiar with Photoshop, there are a few options to view your image with the "Zoom Tool". Due to my large image size, the "Zoom Tool" options for "Actual Pixels" and "Print Size" look quite a bit different and I don't know which one is representative of what the image will look like on my printed mat. In Photoshop, the "Actual Pixels" option shows much more stuff (more stars and more star density) than the "Print Size" option. With the "Print Size" option selected, parts of my star field image just disappear (stars just aren't seen). Do you know which of these two options is representative of what will be printed on my mat?

Here is a link to the image, saved as a jpg from Photoshop:

http://www.mediafire.com/view/iifajhas5l81fs8/Mat_Star_Field.jpg#

Screenshots don't showcase my problem and also don't show off the image very well so I'm including a link to the actual Photoshop file, if anyone with PS can spare some time to look at it in its original environment:
Link to Photoshop file

URL: http://www.mediafire.com/download/d7a9v4cm6ckes6m/Mat_Star_Field.psd