Raw DNG file from VueScan from negatives-Number of passes?

I only began using VueScan with my Minolta Dimage Scan Elite 5400 to create Raw DNG file for processing in Lightroom Classic and NLP. The guidelines do not make specific reference to the setting for the number passes, the screen capture shows 1. Over several years I have usually scanned to output as tiff or jpeg and would use several passes in the setting to achieve a high-quality output file.
In the forum, I have come across advice to leave the setting at 1 since there is no advantage to selecting several passes. Is this thinking specific to Raw DNG’s.
The negatives that I am working with are from the early 1980’s so they are over 35 years old any thoughts on this issue. The scans take a lot longer than a single pass.


In theory, increasing the number of samples will increase the usable bit depth. At least in my own limited trials, this did not produce a visibly noticeable difference (and it dramatically increased scan times). But there may be some circumstances where this could be important (for instance, if you see posterization in your final results, you may try increasing the number of samples to see if that helps). More information here: Maximizing Image Quality


Thanks for your input and the useful link. The negatives I am using are 35 years or more and my experience with multiple passes is that it’s helps reduce the scratches and “noise” from degradation of the negatives. I will try and do a comparison to post online.
The Minolta Dimage Scan Elite was very highly regarded back in the early 2000’s but it’s slow.
It’s taking 10 min per negative with 3 passes.


I use the Scan Elite 5400 and have found that unless the negative is REALLY dense, the multipass/exposure made little difference except in extra time even when scanning negatives that are 50+ years old. The grain dissolver helped reduce the appearance of scratches a little because the light is more diffuse, but it was even more helpful with Fuji films in reducing the appearance of the pepper grain. Sadly, I haven’t found that Vuescan does a particular good job with dust and scratches with my 5400 compared to the Nikon LS-50 I also have.

Where I found the multiple exposures or passes to be especially helpful was when working with old Kodachrome slides. In some cases the slides were slightly under exposed and the extra passes helped me pull just what little detail was in the murk of the shadows.

I would recommend enabling the grain dissolver in Vuescan and skip the multiple samples. The grain dissolver will increase the scan time a little because it’s a translucent material that is physically inserted between the light source and the negative to soften the light. The grain dissolver helps reduce the appearance of scratches by softening the light so it’s less directional. It can have a minor effect on the apparent sharpness because the light is uncollimated, but it’s not a real loss of sharpness but rather just a slight loss of micro contrast which is why it helps with softening the grain a little as well as the scratches.

I did a quick test, the images are from the scans converted in NLP the only adjustment is brightness -3, crop is from the image display on my iMac 27" 5K monitor at 100%. The first image is for a scan 3 passes and grain dissolver off, the second is the same brightness 1 pass and grain dissolver on.
Comments are welcome. The three pass takes 10 minuites the 1 pass 7 miniutes.

To my eyes as I flip between the images, it almost looks like the second image isn’t as well focused as the first. The grain is softer as I’d expect with the grain dissolver, but other features are softer too that look to me like the scanner was slightly defocused. Both are pretty good. Also, the Minolta scanner is multisampling, not multi scanning. You may have known that, but unlike some scanners where multi scanning means that it makes multiple passes, the Minolta is simply re-reading the ccd values multiple times, so alignment of the pixels is less of a concern.

The general school of thought on multipass/multisamplling is that the increased sampling will help with the shadow areas of a film. With negatives, that shadow area is the highlights obviously; however, negatives aren’t usually dense enough to fall into the deep shadow area that would cause most scanners to struggle.

Phil, thanks for the info and your thoughts. I definitely see benefits to using multiple passes and the grain dissolver, and will consider using both when necessary. The deciding issue is time, if I cannot clean spots, scratches and other “debris” with the scan then it’s a job for Photoshop or like applications.