Creating RAW DNG files with Vuescan

[nate]

UPDATED 12/1/2019: As of version 2.1 of Negative Lab Pro, there is native support for converting RAW DNG files made from Vuescan from ANY scanner.

When done correctly, this process should give you excellent, versatile scans, which can be non-destructively edited in Lightroom using Negative Lab Pro.

The process for creating a RAW DNG file in Vuescan is as follows:

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1. Set Vuescan Input Settings

a. If using a flatbed scanner, set the mode to “transparency”. If using a dedicated film scanner, use whatever mode is listed.
b. Set “Media” to “Image”
c. Preview the image if you haven’t already done so
d. Crop to show the exposed image (and a small amount of the film border if possible), then hit the “lock exposure” button. NOTE: You should only need to lock exposure once per roll. The reason for doing this is you want a consistent exposure for all your scans. Otherwise, small variances in auto-exposure could create issues later, particularly if using the “sync scene” function of Negative Lab Pro.

What’s the difference between “Color Negative” mode and “Image” mode?
“Image” mode should be an accurate representation of the underlying raw negative without any color balancing. This is recommend because it will give us the ability later to control how the colors are balanced (especially true as of the new raw profiles in Negative Lab Pro v2.1). You can also experiment though with setting the media to “Color Negative”. In Color Negative mode, the gain on the blue channel and green channel are being increased in the RAW DNG file. This will happen somewhat differently depending on your scanner model, but this is mostly being done on a software level (i.e. Vuescan is simply pushing the gain up on the green and blue channels after scanner), with the exception being some Nikon Coolscan models. Also note, even though the “preview” in Vuescan will change to a positive image, the underlying data you will get back in your RAW DNG file will still be a negative, just with increased gain int the blue and green channels. The biggest difference in terms of result is that using Color Negative mode will typically result in more muted colors after the conversion.

What is “lock exposure” doing?
There is a lot of misunderstanding on what lock exposure does and its purpose in this case. Lock exposure is similar to using exposure lock on a camera… it locks the CCD sensor exposure level based upon it’s evaluation of the current scene (in this case, the currently selected crop area). This keeps Vuescan from reevaluating exposure after each re-crop (which can lead to inconsistent exposure across scenes). Ideally, you want your whole roll to be scanned at the same gain level, which is necessary for features like “sync scene” to work properly in Negative Lab Pro.

What about setting the “film base” color like I read about in the Vuescan guide?
That’s something different. You don’t want to do that.

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2. Set Vuescan Filter Settings

a. If you’d like to (and your scanner is capable of it), you can include infrared cleaning in your RAW DNG file. You can also set grain reduction. Other settings will not have an impact on your RAW DNG.

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3. Set Vuescan Output Settings

It’s important that you get these settings exactly as shown.

a. Make sure “Raw file” is the only file type selected
b. Set the “Raw file type” to 48 bit RGB (do this even if your image is black and white)
c. Set “Raw output with” to “Save” (this will allow for IR cleaning to work, if you’ve enabled it)
d. Select “Raw DNG format”

NOTE: Do NOT set the raw file type to 64 bit RGBi - Lightroom won’t be able to interpret the 16-bit IR channel. Because you have “RAW Output with” set to “Save”, the 48bit RGB output will already include the dust removal from Vuescan.

That’s it for scanning!

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Converting and editing your RAW DNG in Lightroom with Negative Lab Pro

[UPDATE: The process has been amended as of v2.1 of Negative Lab Pro to incorporate the advanced profiles and compatibility.]

1. Import your RAW DNG file into Lightroom

2. After import, select all the files, and go to “file > plugin-in extras > Update Vuescan/Silverfast DNGs” - then follow any instructions it gives you. (This step ensures compatibility, and may not be necessary for all users depending on your scanner model, but is recommended)

3. If step 2 has gone correctly, you should see the profile in Lightroom showing as “Negative Lab v2.1”, and there should NOT be any kind of profile warnings.

4. Use the white balance tool in Lightroom and sample off the film border. (Alternatively, you can use the “auto” WB setting in Lightroom, which is useful when there is no film border showing.

5. Crop your image to crop out the film borders (or use the “Border Buffer” setting in Negative Lab Pro to ensure the film borders are not included in the image evaluation.

6. Open Negative Lab Pro, and set the “Input” to "Vuescan/SF RAW DNG"

7. Go ahead and set your other pre-conversion settings in Negative Lab Pro and hit “Convert”. Then continue to edit using Negative Lab Pro’s settings.

[Matroskin13]

Hi there!

During discussion on Facebook group, I was told to measure exposure using unexposed strip between neighbour frames and then lock exposure. Isn’t it correct?

[nate]

UPDATE: See updated explanation here with better info on this and it’s effects:

Hi @Matroskin13!

It’s important to understand that Vuescan is using the brightest point in your current cropped area to determine exposure.

So when you say “measure exposure using unexposed strip”, do you mean changing your cropped area in preview to show only the unexposed strip between frames in it, and locking from there?

In theory, sure you could do this. But it seems cumbersome to have to crop in on such a tiny area and then re-crop. And you will get the exact same result by just cropping a single frame as you normally would and just leaving a little film border in it. To me that is much faster because I only have to crop once for that shot.

Also, as noted in the instructions, if your negatives are very dense (i.e. you have overexposed the film by more than 1 stop), you may actually find that including the film border in the Vuescan exposure calculations will cause your scan to be underexposed (because the least dense part of the film will still be multiple stops denser than the unexposed film border).

SO… all that to say, the advice on Facebook could work OK in some situations, but it requires more steps than necessary, and won’t always produce the best results

[Matroskin13]

@nate

misunderstanding on what lock exposure does and its purpose in this case. Lock exposure is similar to using exposure lock on a camera… it locks the CCD sensor exposure level based upon it’s evaluation of the current scene (in this case, the currently selected crop area). This keeps Vuescan from reevaluating exposure after each re-crop (which can lead to exposure mistakes and inconsistent exposure across your scene).

Should I always include film border in my crop before locking exposure?
If you shoot very dense negatives (i.e. you overexpose your film by 1-3 stops), you likely get better results by NOT including the film border in your crop. The reason for this is that

Yes, I ment changing crop area to unexposed part of the film.

Thanks for the detailed answer!

Then the second question - why should one lock the exposure? Isnt it useless in the case you don’t have perfectly exposured film (during photographing)?

[Matroskin13]

@nate

It’s important to understand that Vuescan is using the brightest point in your current cropped area to determine exposure.

Also I want to mention that I did’t get this result . I made a crop including only unexposed strip and pressed Lock exposure and remember the value. Then I made a crop including the whole frame and some unexposed boarder, pressed Lock exposure and had different exposure value.

[aperturepriorities]

I do something slightly different that I find helps with my workflow.

I set Media to “Color Negative” then check the box for “Raw save film”. In addition, I tick the box for JPEG file.

What this does is that it will output the RAW DNG containing the negative (for use in NLP), but also creates a positive JPEG version of each scanned images (converted by Vuescan).

The reason I find this useful is that Finder cannot display DNG files, so having a JPEG sitting along side each RAW DNG file makes it possible to examine the contents of each scanned negative in the Finder. I find that Vuescan will sometimes forget what crop settings have been made for each image halfway through a batch scan or decide suddenly to use the List batch from the previous can session. Having JPEGs right there in a finder lets me quickly check that all the images were scanned correctly.

Because the JPEGs are only used as a quick reference, I don’t spend any time making adjustments in the Color tab.

[nate]

@aperturepriorities

I set Media to “Color Negative”

^ Yes, the “Color Negative” media mode works really well, too! It basically increases the gain in the blue and green channel (in most cases this is done via their software, but some scanners have separate gain controls per color channel in the hardware, which is pretty cool). I’ve been debating if I should change the official recommendation to this setting… in most cases it won’t make much of a difference, but sometimes it will give truer colors later in conversion with Negative Lab Pro.

@aperturepriorities

then check the box for “Raw save film”

^ You should NOT do this. At best it will have no impact, but at worst, it will create a file which is positive and can’t be converted with NLP. Leave this option un-checked.

[aperturepriorities]

Thanks for the extra information about the effect of the ‘Color Negative’ media option. I’ll have to experiment with it some more, and I’ll also avoid the ‘raw save film’ option from now on.

[mattdoerr]

What is the reason for saving as 48bit when scanning a black and white image? I have traditionally scanned at 16bit for B&W using ‘other’ scanning systems.

[nate]

In this case, it’s just because of the way that LR works with RAW camera profiles. If you save as 64i or 16bit black and white, the profile will not be set to work correctly.

[nate]

UPDATE: 6/4/2019

6/4/2019 - This issue will be fixed as of Negative Lab Pro 2.0. If you were using the v1.3.1 pre-release, you will need to replace the old vuescan profiles with the new ones included in the package.

Original response:

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@Matroskin13

Also I want to mention that I did’t get this result . I made a crop including only unexposed strip and pressed Lock exposure and remember the value. Then I made a crop including the whole frame and some unexposed boarder, pressed Lock exposure and had different exposure value.

Just to close the loop on this… you are correct that Vuescan is using the entire cropped area to evaluate exposure lock values. I guess what I meant is that in most cases, if you are cropping for the image itself, it shouldn’t make much of a difference if you also include part of the frame. However, I would STRONGLY advise that you NOT try to lock exposure on just the unexposed film border… This will not result in a good image for conversion later by Negative Lab Pro.

For example, this is a RAW DNG done after locking exposure on just the image border, and using “image” media type. Notice that blue channel is clipping in the shadows (which will be the highlight region in the converted image:

Because there is clipping in the scan, there will be some issues with lost channel information during Negative Lab Pro conversion.

Here, it causes funky blue-color banding issues in the sky and on the shorts of the subject:

If we were to go back on the same scan, and lock the exposure on a crop on the exposed image itself, we end up with a much more usable file, with a histogram that isn’t clipping on either side (note: I also changed media to “Color Negative” on this scan, which helps blue channel gain).

That looks much better! Now when we convert, we won’t have any of that weird color banding in the highlights, because we’ve got plenty of info!

Ah! So much better!

Hope that helps!

[mattdoerr]

In the interest of file size: is it possible to use 16bit on the initial input stage in vuescan, then save out as 48bit?

[nate]

Yes, you can do that. Although I just did a quick test and it did not reduce file size.

[Carmen]

I will try colour negative going forward as I have been using image for the last batch of scans. Will try this again. Cheers!

[asephx]

When I set Media to ‘Color negative’ the scan comes out of Vuescan green, as if the film base is green rather than the expected orange colour. Then when I convert it with NLP the shot converts with a blue tint.

I’m not sure exactly when it happened, but the Mode option in Vuescan only shows ‘35mm Film’ or ‘35mm Slide’ as options with Transparency completely removed. If I select either of those options and set Media to ‘Color negative’, the DNG comes out green.

Keeping the Media as ‘Image’ results in an output that resembles a proper orange DNG and similar to Nathans No Clipping example above… but I’m concerned that this is different to the steps above and different to everyone elses results and I may be missing something? Has anyone else experienced this?

Vuescan v 9.6.36
Scanner: Reflecta RPS 10M

[asephx]

Edit: It looks like the Color tab is having an effect on my DNG output when I set Media to Color Negative. I didn’t think this was the case when outputting a RAW DNG from VueScan but it might have something to do with my inability to set the Mode to Transparency. If I set Color Balance to None in the Color tab, then Color Space to Adobe RBG the DNG won’t clip in Lightroom but still has the green tint

Here are some screenshots of the issue I am having when selecting Color Negative as Media in VueScan. It looks like selecting Color Negative clips in Lightroom but I’m unsure as to why it would be doing that. What am I missing?!?

Above: Everything the same as tutorial… Media is set to ‘Color Negative’

Above: Everything the same as tutorial… except Media is set to ‘Image’

Setting Media to Slide Film gives similar results to Image.

[nate]

@asephx

When I set Media to ‘Color negative’ the scan comes out of Vuescan green, as if the film base is green rather than the expected orange colour.

The “color negative” mode is just increasing the gain on the green and blue channels. In this case, it looks like it increased it a bit too much. If you are getting good histograms with “image” mode, that is fine as well. I’ve gone back and forth a bit in my recommendation between these two, and certainly on some scanner models / images, one may work better than the other.

@asephx

Then when I convert it with NLP the shot converts with a blue tint.

You can try your scan again at a lower RGB exposure value to make sure no data is clipping (or use the “image” mode image. In most cases, you will need to use the film color correction module in NLP… should make it pretty easy to correct for the residual effects of the original mask.

[asephx]

Than you for the reply. I think I’ve settled on using Image for my particular scanner.

I know Ed from Vuescan has been making some changes for Reflecta scanners and I think removing the Mode > Transparency is having a negative effect on the Media option on this scanner.

I was a little concerned that using a different Vuescan options may have been an issue for future NLP releases but it’s reassuring to know that options are flexible and I should be happy as long as the end result is good

Thanks again for the reply and the amazing plugin!

[nate]

Thanks @asephx! Just to follow up on this, I found an issue with how Lightroom was interpreting the RAW data that was causing some of the issues users were experiencing with the “image mode” (particularly with clipping in shadows). There will be corrected profiles for Vuescan RAWs in Negative Lab Pro v2.

Based on the updated, corrected profiles in Negative Lab Pro v2, I think that “image” mode will generally be best, but that could differ a bit based on scanner model.

More to come!

-Nate

[dia3olik]

What about using it with the LS5000?
Do you still recommend using “image” mode?

And also in Vuescan, do you suggest to keep “restore colors” and “restore fading” disabled??

Thanks Nate!