[Update April 27th, 2014] Rough Profiler 1.7 now runs on Mac OS 10.9. I’ve tested it and it seems to work great. Thanks Howard for sending me the tip.
[Update May 8th, 2014] Another tip from Howard that I’ve been testing. He read through Agryll CMS SCANIN document and discovered when scanning in “RAW” gamma 1.0 should be used instead of gamma 2.2. The difference is subtle, but gamma 1.0 does provide a small amount of extra colours in the shadows. More colours are definitely great to have. If you are archiving your film and want to get the most out of your scans gamma 1.0 is the better choice. The colour shift is small, and would probably only be noticeable in large prints.
[Update October 16th, 2014] I’ve added an extra step after assigning a profile: converting the working colorspace to AdobeRGB or ProRGB. This will provide a proper working colorspace for editing your scan. It also decompresses the shadow detail. Thanks so much to James for discovering this. He also has a few more great tips in his comment below; like using a lower dpi scan, and that manually exposing your film target may not actually increase the accuracy of the profile. Great stuff!
This is a follow up to a post that I wrote over a year ago about how to
properly what I thought was properly profile your scanner with Vuescan, Vuescan: how to profile your scanner/film. After much discussion in the comments I realized that my process of profiling and scanning was completely wrong, and most of what I wrote in my post was useless. But the thing about great discussions, are great solutions. I feel we found the best way to profile and scan film in Vuescan. I want to give a special shout-out to Martin Jericho who really was the catalyst in creating this process.
Achieving good scans with just Vuescan is not an easy thing to accomplish. Vuescan is one of the most powerful scanning softwares available today. And with the resurgence of film, programs like Vuescan play a very important part in creating digital files for todays industry. If you’ve arrived here frustrated after hours and hours of trying to get a good scan from Vuescan, or trying to colour-match your slides to your scans to no-avail, you are not alone. Everyone who has collaborated to create this profiling and scanning process has been in your shoes.
Right off the bat, there are two things you should know about Vuescan. The first is Vuescan does a really lousy job of creating scanner profiles from film targets. Secondly, Vuescan doesn’t like 3rd-party ICC profiles. Which means all that time we spent creating and testing different profiles in Vuescan was a waste of time. This is why every result didn’t look right.
This process of creating a proper profile requires some patience. By utilizing Vuescan’s ability to scan raw files and a 3rd-party program to build an ICC profile, creating a profile is fairly simple. Just so you don’t think something has gone wrong or you’ve done a step incorrectly, initial raw scans from Vuescan will appear very underexposed. The explanation for the underexposure is that the proper gamma has not been applied. Another important note, this process uses raw-tiff files not raw-DNG files. You will most likely have to perform the steps below a few times before you have created a proper ICC profile.
Here’s what you’ll need:
– An IT8 scanner calibration target on the specific film you want to profile (you can buy them from Wolf Faust, one of the only guys who still creates them)
– An ICC profile generating program. If you have a PC, LProf or the beta version of Rough Profiler are available to use. If you have a Mac, Rough Profiler is the program I use. Rough Profiler’s website is in spanish but the program is in english. Rough Profiler 1.7 is compatible with Mac OS 10.5 to OS 10.9.
Also, Rough Profiler is only compatible with OS 10.5 and 10.6. It will not work with Lion or Mountain Lion. Unfortunately Rough Profiler is one of the only functional GUI containers for Argyll CMS (the code that actually profiles) for Mac. If you are running Lion or Mountain Lion I suggested creating a virtual machine that runs OS X 10.6. You can create a virtual machine using VirtualBox. A lot of Apple repair shops (not the Apple Store) will have old versions of OS X kicking around if you don’t have the disc buried in a desk drawer.
– Photoshop and Vuescan
Step 1: Scanning your IT8 target
– Create a scan of your IT8 target in Vuescan. If you are using a medium format scanner, try your best to make sure the target is straight on the glass.
– Input Tab: Set the input like a normal scan. I don’t scan targets at the max resolution as the files tends to be really big, 2000dpi works fine for me.
– Select the target area. If your scanner allows, leave some grey around the target.
– Exposure Lock: Select Exposure Lock and record the value that is shown. You will need to reference this value if exposure adjustments are made.
– Multiple Exposure: This option is not available for all scanners. For profiling do not select this option.
– Filter Tab: Infrared Clean > Light (if this option is available to you)
– Color Tab: Color Balance > None, Scanner Color Space > Built-In, Output Color Space > ProRGB
– Output Tab: Make sure you have selected Raw file. Raw File > Selected, Name your scan (for profiles, I usual reference the film type), Raw Size Reduction > 1, Raw File Type > 48bit RGB, Raw Output with > Save, Raw save film > Not Selected, Raw Compression > Off, Raw DNG Format > Not Selected
– Scan your IT8 Target
Step 2: Create an ICC profile
– Open your ICC profile program. (I will be using Rough Profiler as my example.)
– Input: Preset > None, Chart Type > IT8.7, Reference File > Select the text reference file that accompanied your IT8 target, Test Chart > Select the IT8 scan you created, Gamma >
– Click Create Ti3 (required to create an ICC profile)
– Once Rough Profiler has created a Ti3 file the preview window will display your target with the sample squares
– Output: Quality > High, Force cLUT Absolute > None, Algorithm > XYZ cLUT, Profile Name > The name that will appear in Photoshop, File Name > The name that will appear in your finder
– Click Create ICC
– The ICC profile will be saved to the same folder as your IT8 target scan. There will be three files created; ICC profile, Ti3 data, and a diag.tiff file showing your the chart overlay
– You have now created an ICC profile!
Step 3: Placing your ICC profile into your system
– Place your newly created ICC profile into your system so that Photoshop can find it.
– Mac: Library > ColorSync > Profiles. (I create a folder called Film just to keep things organized. The folder doesn’t show up in Photoshop)
– Mac OS 10.7+ users: The Library is hidden by default. The quickest way to access it is: Click the Go menu and hold down the Option key, Library will appear.
– PC: I am unfortunately not a PC guy, so I do not know the ins-and-outs of installing profiles. The guys at Red River Paper explain how to install profiles for a PC and Mac, How to Install Profiles on your Computer.
Step 4: Assigning your ICC profile to the IT8 target scan
– Open Photoshop
– Open your IT8 target scan
– Assign your new profile: Edit > Assign Profile > Select your profile
– [New Step] Covert your working colorspace: Edit > Covert to Profile > Select a Destination Space Profile – I’d suggest either Adobe RGB or ProPhoto RGB
Step 5: Checking the accuracy of your ICC Profile
– Open up the Information Palette in Photoshop.
– Bring your curser over the first white box on the greyscale chart, box 0.
– The RGB values of this box should be around the 240 to 250 zone. You don’t want to any of the values creeping up to 255 (clipped).
Step 6: Repeat to achieve a proper ICC Profile
– If your RGB values are not hovering in the 240 to 250 zone, repeat steps 1 through 5.
– Adjust the Exposure Lock or RGB Analog Gain values in Vuescan by +/-0.05 depending on your RGB value, and rescan your IT8 target.
– Once you are satisfied with the RGB values, go back to Vuescan and record the Exposure Lock value.
– Use the Exposure Lock value when scanning the particular film you are creating the ICC profile for.
– You have now created a proper ICC profile.
Scanning: A good base but not perfect
Creating a custom ICC profile is the best way to achieve the most accurate representation of the film you are scanning. Setting the Exposure Lock value in Vuescan will give you a great base exposure to start with. That said, it does not necessarily mean that it will be a “perfect” images. Depending on the light used to create the photograph you will most likely have to do some colour correction, especially with slide film. Also remember different film companies have different colour casts in their film; Fuji blue/green, Kodak red/orange. Light meters measure the exact amount of light directed towards it, properly exposing for highlights. This can cause images to appear under-exposed. Adjusting the Exposure Lock value will create a scan closer to the exposure you had in mind. [Tip: I usually do a quick low-res initial scan to gauge if I need to adjust the Exposure Lock value.]
The profile is embedded in the image’s metadata, you can catalog it in Lightroom or Aperture or any other processing program you like. Just remember, this is a tiff file not a camera raw file – you will not have the same raw editing controls as a digital image. The definition of a raw-tiff scan is Vuescan capturing all of the data that the film has, this is different than a camera sensor capturing light coming through a lens. The DNG file setting in Vuescan utilizes the Adobe DNG file format to create archival files that allow you to reload the image into Vuescan and adjust settings like curves or white balance, this saves you from re-scanning the film. If you do decided to create archival DNG files, I would suggest using 64bit RGBI colour space. 64bit RGBI is 16bit Red, 16bit Green, 16bit Blue, and 16bit Infrared.
That’s how you profile and scan with Vuescan. In the end, Vuescan is just used as a power scanning program. Profiles are created in a 3rd-party ICC profile generating program, and you apply the profile itself in Photoshop. Scanning raw files in Vuescan ensures that you are capturing all of the information the film can provide without having Vuescan applying any of it’s adjustments to it.
I find it interesting that no one is sharing scanner ICC profiles online, especially since film is coming back. I understand there are a lot of different scanners out there and even between the same scanners there are differences, but properly created profiles should get you pretty accurate colours. I want to change that. I have created a full set of film-specific scanner ICC profiles for the two scanner that I use; Nikon LS-8000 and Epson 3200. These profiles will only work properly if you have the same scanners. You are free to download them and use them. All I ask is that you pass along this post to a frustrated film photographer who can’t seem to get their scans to match their film so that we all can be happier film shooters.
Films include: Fuji Provia 100F, Provia 400X, Velvia 50, Velvia 100/100F, Astia 100/100F, Sensia, Sensia 100, RTP II; Kodak Ektachrome family; Agfa RSX, RSX II, CT Precisa.