Tareq, I don't actually think you are doing something "wrong", but two things need to be separated here:
First, your remark about the Noritsu:
You are talking about a professional minilab. I don't know what the prices are, but I bet it is in the tens of thousands of dollars. So YES, there is a very high quality scanner in there. You can not compare a 700 dollar flatbed like Epson V750 with that. The Epson has at the most 2400 ppi max, the Noritsu might do 5000 or maybe even 8000 ppi, similar to a Hasselblad X5 or drum scanner. It is like comparing apples with pears... can't be done.
So now you wonder why that guy DID get proper results of 8x10. Well, easy, even my cheap Canon 9950F flatbed, with a maximum true optical resolution of 1200 ppi can do it.
What is the case, is that the larger the film format, the lower the needed optical resolution to get a good scan.
As a consequence:
The bigger the film format, the lesser the requirements needed for the scanner to create a good image
So even cheap flatbed CAN make good scans (at least in terms of total image size and captured megapixels of image data), of large format source material.
I know some people here on Hybridphoto may object to my bold generalizations, but my only aim here is that I make it hopefully a bit more clear to you...
Just do the math:
35 mm,
4000 ppi scanning resolution (pixels per inch) = 4000 x 6000 = 24 MPixel scanned image
8x10,
1000 ppi = 8000 x 10.000 = 80 MPixel scanned image
To understand the above calculations, just look the MPixel count and compare it with your H3DII-39 that has 39 MPixel. What is your conclusion? YES, the 1000 ppi scan of the 8x10 image has BETTER image quality than your current digital Hasselblad, and surprise, the higher resolution scan at 4000 ppi from 35 mm has LESS image quality than your hassy...
Maybe a bit counter-intuitive, but as you can see,
both scanning resolution
and film format determine the final outcome in terms of quality and size of the image captured.
By the way, I strongly recommend you to read two articles by myself, you may find them enlightening:
-
Optimal scanning resolution
-
Kodak Ektar 100 color negative film test
Marco