Very slow scanning on Glass. ET-3850 using Scan 2

[JonJacobs]

I've been doing some printing and scanning with my brand-new 3850. I use the Scan 2 app for the scanning. Color 1200 dpi. I expect it to be slow, and the speed seems about right when I use the Auto Doc Feeder (ADF). There are 3 choices: Auto Detect, ADF, and Glass. I don't use Auto Detect to save time for the device to figure out where the docs are. When I put a doc on the glass, it takes way longer than when I use ADF, which is weird. No time is required to feed the paper. Since I chose Glass (On Glass?) mode, it didn't have to decide where the paper was. In that mode, it took much longer than ADF. In two different scans I measured the time. Both times it was 5 minutes and 3 seconds.

Why would it take so long to scan something On Glass? I'm very puzzled and wonder if something is wrong.

Thanks - Jon

 

[thebestcpu]

I've been doing some printing and scanning with my brand-new 3850. I use the Scan 2 app for the scanning. Color 1200 dpi. I expect it to be slow, and the speed seems about right when I use the Auto Doc Feeder (ADF). There are 3 choices: Auto Detect, ADF, and Glass. I don't use Auto Detect to save time for the device to figure out where the docs are. When I put a doc on the glass, it takes way longer than when I use ADF, which is weird. No time is required to feed the paper. Since I chose Glass (On Glass?) mode, it didn't have to decide where the paper was. In that mode, it took much longer than ADF. In two different scans I measured the time. Both times it was 5 minutes and 3 seconds.

Why would it take so long to scan something On Glass? I'm very puzzled and wonder if something is wrong.

Thanks - Jon

Hi Jon
Epson is a bit elusive regarding expected scan speeds. I found below that the ADF and flatbed would be the same for B&W, yet twice as long on the flatbed for color.

Single-sided scan speed (A4 black)​

5 ipm with ADF scan 12 sec. with flatbed scan

Single-sided scan speed (A4 colour)​

5 ipm with ADF scan 27 sec. with flatbed scan

Optical Resolution​

1.200 DPI x 2.400 DPI (Horizontal x Vertical)

Optical Resolution (ADF)​

1.200 DPI x 2.400 DPI (Horizontal x Vertical)

Output formats​

BMP, JPEG, PICT, TIFF, multi-TIFF, PDF, PNG

Scanner type​

Contact image sensor (CIS)

It does not give the resolution used for this scan speed either, and I have not found any documentation of scan speed vs resolution other than expecting it to be slower. So those scan speeds may be for 200 dpi.

You could contact Epson to know what should be expected or run experiments at different resolutions.
You will want to ensure you also have a rock-solid high-speed connection from your printer to the computer, whether you use the USB 2.0 port, Ethernet, or WiFi, just in case another factor gets in the way.
Also, you can try different formats in case the printer has its computing problems with a given file format.

Note: I could guess why the flatbed is slower, yet that is moot since Epson documents that this is the case.

Just some incremental thoughts for you
John Wheeler