Hi Kevin,
Welcome to IIS.
The DSI 2 has a very small sensor. Its only 8mm diag.
I've attached an image of the horsehead neb. I took with a DSI 2 thru a ED127 and a link to an image of the same image taken with a QHY8 which has a sensor size of 28.4mm diag. Also taken using a 127mm.
The linked image was taken by Finao(Astrod00d) and I hope he doesn't mind.
http://www.iceinspace.com.au/forum/s...832#post368832
Hope this helps and gives you and idea of the size, but dont compare the quality of the 2 images, I'm only a beginner.
Cheers