Scanner is hooked up to my iMac OS 10.15.7 Catalina and works fine with reflective art. When scanning 35 mm slides all I seem to be able to get are Thumbnail images. The scanning window they show in the manual allows different models inc Professional. I do not see that window on my screen. I can set it up for high quality scan, 300 dpi, but no matter what I choose, only thumbnails come out! I have the latest update drivers from Epson.
I think you are missing a lot of tings in your settings.
1. Scanner Settings: not selected
2. Is 300dpi as high as you can get?
3. What is the Advanced Settings options?
4. What options are available on the Color Management ?
5. What options are available on the Thumbnail tab?
You are most probably using Epson Scan 2 and the manual is describing the Epson Scan software. Two VERY different things (not made obvious by the naming).
You're also in Photo Mode. That's for scanning prints, I believe. You have to change the setting to scan film, either negative film or positive film (slides).
From what I see the problem is the dpi setting. You are scanning for 300 dpi at the slides 100 percent size, which on the screen will look like a thumbnail. Set your dpi to the max and try again.
Thanks all for your help. Tried scanning at higher dpi and getting the results I was looking for. Yes, am using Epson Scan 2 which appeared after setting up the scanner. Previous Epson I had did show the window with various modes like Professional. I miss that window, don't know how to get Epson Scan 1 or whatever is right to function??