Scan Dual IV and Digital Noise

[Swift1]

Hey all,
I did a google search and couldn't find what I was looking for, so I figured I'd ask here.

I scan all my film primarily with an Epson V500. I'm mostly quite happy with the Epson, but there are times that I'd like a bit more resolution, so every once in awhile, I pull out my Minolta Scan Dual IV. Usually when I do this, I end up being somewhat disappointed, and I put my Scan Dual IV back in the drawer and forget about it for another 6 months.

It seems to me that the Scan Dual produces a fairly excessive amount of digital noise.
Below are two 100% crops. The first is from my Epson, scanned at 2400 dpi, the second is from my Scan Dual, scanned at 3200 dpi, then downsampled (just for comparison) to 2400 dpi.

Is this typical of the Scan Dual IV, or is there a problem with mine?
I should mention that with color slide film, there is virtually no noise, it's only an issue with color negative and B&W film.

 

[Highway 61]

The scanner is a machine, it doesn't know what either slide film or color negative film is.

If you decide to tell the scanning software that you have a color negative film then the software you use to scan will modify the file which the scanner had produced (which can't be anything else than a digital image of what you see on the film when you look through it).

If the scanning software isn't capable enough, when it converts the file color chart from what is (for you) a negative so that it becomes (for you) a positive image on your computer screen, then some chromatic aberrations may appear.

The remedy (and this is particularly true with Minolta film scanners, otherwise truly excellent) is to always scan your films as if they were slide films, then to export the file into PhotoShop, then post-process using this software.

There is tons of tutorials about this on the Internet, and dozens of threads documenting this on this very forum.

For a basic example :

http://www.computer-darkroom.com/tutorials/tutorial_6_1.htm

Pretty "old" (by nowadays' standards about what is new and what is old) but still very useful...

 

[Swift1]

The scanner is a machine, it doesn't know what either slide film or color negative film is.

If you decide to tell the scanning software that you have a color negative film then the software you use to scan will modify the file which the scanner had produced (which can't be anything else than a digital image of what you see on the film when you look through it).

If the scanning software isn't capable enough, when it converts the file color chart from what is (for you) a negative so that it becomes (for you) a positive image on your computer screen, then some chromatic aberrations may appear.

The remedy (and this is particarly true with Minolta film scanners, otherwise truly excellent) is to always scan your films as if they were slide films, then to export the file into PhotoShop, then post-process using this software.

There is tons of tutorials about this on the Internet, and dozens of threads documenting this on this very forum.

For a basic example :

http://www.computer-darkroom.com/tutorials/tutorial_6_1.htm

Pretty "old" (by nowadays' standards about what is new and what is old) but still very useful...

Actually, the above Minolta sample was scanned as a positive and then inverted it in PSE.
As far as I can tell, the noise is present on the unedited positive scan.

 

[Highway 61]

Actually, the above Minolta sample was scanned as a positive and then inverted it in PSE.
As far as I can tell, the noise is present on the unedited positive scan.

If you don't tell us which scanning software you are using, and which kind of file you're creating (ideally you must create some 16bits per channel TIFF files without any compression at 3200dpi before exporting them into PS), and which film you're scanning (brand, type, ISO speed) we're discussing in the blue I'm afraid.

 

[Filzkoeter]

It's no noise, it's grain/dye clouds. Your minolta is simply _much_ more resolving then the Epson.
If you look close, your "noise" is in the exactly same spots on those two scans. It's just much more smeared on the Epson one.

I tried to make it more obvious by changing levels & curves on both scans and then overlaying them:

some Gaussian blur on the Minolta-scan and some adjustments and both can look nearly the same:

 

[Swift1]

If you don't tell us which scanning software you are using, and which kind of file you're creating (ideally you must create some 16bits per channel TIFF files without any compression at 3200dpi before exporting them into PS), and which film you're scanning (brand, type, ISO speed) we're discussing in the blue I'm afraid.

The Minolta scan was done as a 16 bit linear tiff using the Minolta software. The Epson scan was done as a jpeg in Epson Scan.
I tried the Minolta using Vuescan, and results were worse.
I figure the film is less relevant because both scans are of the same negative, but FWIW, the film is Lomo 400. Also the noise is prevalent in any scan from any negative film.

 

[Dan Daniel]

Miko is right- that is grain, not noise.

I had the same confusion at first when I went from a V700 to a Scan Dual IV for 35mm film- what the heck is all this noise?!!??? Then I remembered from working with film and darkroom printing- it's grain. If you doubt it, scan the film in the Minolta, then turn it 180 degrees in the holder. Scan again. Now see if the noise aligns when you overlay them. Digital noise is a semi-random thing, while grain is grain and isn't going to move.

The V500 might have a true resolution of 1200dpi? The v700, about 16-1800. The San Dual IV- 3100dpi. Print them out and see what you get.

Also, Epson Scan will be stepping on things as it makes a jpg. There is an option to save as a tif, which should have a bit more detail.

 

[Swift1]

Miko is right- that is grain, not noise.

I had the same confusion at first when I went from a V700 to a Scan Dual IV for 35mm film- what the heck is all this noise?!!??? Then I remembered from working with film and darkroom printing- it's grain. If you doubt it, scan the film in the Minolta, then turn it 180 degrees in the holder. Scan again. Now see if the noise aligns when you overlay them. Digital noise is a semi-random thing, while grain is grain and isn't going to move.

The V500 might have a true resolution of 1200dpi? The v700, about 16-1800. The San Dual IV- 3100dpi. Print them out and see what you get.

Also, Epson Scan will be stepping on things as it makes a jpg. There is an option to save as a tif, which should have a bit more detail.

Okay.
Thanks for all you guy's input.

 

[Ranchu]

I said once, as long as I'm looking at grain, I'm OK with the V500. I also have a coolscan V.

Guy replies, it's likely you're looking at artifacts, not grain, V500 doesn't have the resolution. I didn't agree. I know what grain looks like. But I needed something like this, and it'd be a lot of trouble just to prove an artifact debate.

Ha ha.

 

[Swift1]

I said once, as long as I'm looking at grain, I'm OK with the V500. I also have a coolscan V.

Guy replies, it's likely you're looking at artifacts, not grain, V500 doesn't have the resolution. I didn't agree. I know what grain looks like. But I needed something like this, and it'd be a lot of trouble just to prove an artifact debate.

Ha ha.

I actually prefer the results I get with my V500.

 

[Ranchu]

Me too.

😀