As a supplier of digital slide scanners, one of the most frequent questions I get from our customers—whether they’re hobbyists scanning personal photo slides, academic researchers documenting microscopic specimens, or medical labs archiving histology samples—is straightforward: do our scanners support scanning in RAW format? It’s a question that cuts to the core of digital imaging work, and the answer matters as much for preserving detail as it does for editing flexibility down the line. Let’s break this down, because it’s not a simple yes or no; it depends on the type of scanner you’re using, and for most models in our catalog, RAW support is a key feature designed to meet the demands of professional users.
First, let’s clarify what RAW format actually means for slide scanners, because it’s different from the RAW files you might get from a DSLR camera. When a scanner captures an image, it doesn’t immediately process that data into a JPEG, TIFF, or PNG file. RAW format is the unprocessed, direct output from the scanner’s sensor: it contains all the raw light data captured during the scan, with no in-camera or in-scanner adjustments to color, contrast, sharpness, or exposure. That’s a big deal. If you scan a slide in JPEG, the scanner compresses the data on the fly, throwing away information that doesn’t fit the standard JPEG color space. RAW files keep that data intact, giving you far more room to fix mistakes later—like correcting a faded slide’s color balance, adjusting exposure that was too dark or too bright, or fine-tuning contrast without the quality loss that comes with compressing a processed file.
For casual users scanning a few 35mm vacation slides, JPEG or even TIFF might be enough. But for professionals—pathologists reviewing biopsy slides, archivists preserving rare historical slides, or researchers studying cellular changes that require precise image detail—RAW is non-negotiable. That’s why we’ve built RAW support into every scanner in our range, starting with our workhorse models. Take the Automatic Slide Scanner GScan-120, for example. This model is designed for high-volume, unattended scanning of film slides, and it supports RAW format as a standard option, not an add-on. When you run a scan on the GScan-120, it saves a .dng or proprietary RAW file alongside a processed preview, so you can choose to edit the RAW file later for maximum quality. It’s perfect for small labs or personal collections where you want the convenience of automatic scanning without sacrificing image data.
Now, if you’re working in digital pathology—an area where slide scanning is critical for patient diagnosis and research—RAW support is even more important. Pathology slides (which use stains like H&E for tissue analysis) require extremely accurate color and contrast to distinguish between healthy and abnormal cells. A processed JPEG might make a nucleus look darker or lighter than it is, leading to misdiagnosis or incorrect research conclusions. That’s why our Digital Pathology Scanner GScan-40 and Digital Pathology Scanner GScan-60 both natively support RAW scanning. These models are built for professional pathology labs, with high-resolution sensors that capture every bit of light from the slide, and the RAW format lets pathologists or researchers adjust the image without altering the original captured data. The GScan-60, in particular, includes a color calibration tool that works with RAW files to ensure consistent color across hundreds of slides, which is essential for large-scale studies.
You might be wondering, do all slide scanners support RAW? The short answer is no, and that’s why it’s important to check when you’re choosing a model. Some budget scanners, especially entry-level ones for home use, only process images into JPEG, as RAW files take up more storage space and require more powerful software to edit. But for any scanner that’s designed for professional or semi-professional use—including our Brightfield Slide Scanner, which is built for general histology, educational, and archival work—RAW format is a standard feature. Our Brightfield Slide Scanner is versatile enough to handle everything from 35mm film slides to large-format glass slides, and it lets you toggle RAW scanning on or off depending on your needs. If you’re scanning slides for personal use and don’t need to edit later, you can stick to processed files; if you’re working on a project that requires long-term preservation or detailed analysis, RAW is just a click away.
What about the technical side of scanning RAW? A lot of people assume that RAW files are too big or too complicated to work with, but our scanners make it easy. When you scan in RAW, the file size is typically 2-3 times larger than a JPEG of the same resolution, but with modern storage drives, that’s rarely a problem. For example, a single scan from the GScan-40 (which captures 40x resolution for pathology slides) is around 500MB in RAW format, and a 4TB external drive can hold thousands of scans. Most scanner software—including the free software that comes with all our models—has built-in tools to view, organize, and edit RAW files, so you don’t need expensive third-party programs like Adobe Lightroom to work with them. The Digital Pathology Scanner GScan-60 even has a feature that lets you batch process RAW files, so if you’re scanning a whole box of slides, you can capture all the data first and edit them later at your own pace.
Another common misconception is that RAW is only useful for photo slides, not for glass slides used in science or medicine. That’s not true. Glass slides (whether they’re histology, microbiology, or material science slides) have their own quirks: some stains are faded, some slides are scratched, and lighting can vary between scans. With a RAW file, you can correct these issues without re-scanning the slide. For example, if you scan a histology slide and the background is too blue, you can adjust the white balance in the RAW editor without losing detail in the cell structures. If you use a processed JPEG, that blue tint is baked into the file, and you’ll end up with a grainy or washed-out image when you try to fix it. That’s why RAW support is a key feature for all our professional scanners, including the general-purpose Digital Pathology Scanner we offer for labs that need to handle a variety of slide types.
Let’s talk about use cases to make this more concrete. Last year, a university research lab reached out to us because they were having trouble with their old scanner, which only saved JPEGs. They were studying the effects of a new cancer drug on cell structure, and they needed to measure the size of cell nuclei across hundreds of slides. The JPEGs they were getting had compressed the shadow areas, making small nuclei hard to see and measure accurately. We recommended they switch to the Digital Pathology Scanner GScan-40, which supports RAW scanning. After a few months, their team told us that the RAW files let them adjust the exposure just right to see every nucleus, and their data has been more precise as a result. That’s the kind of impact RAW format can have on research.
For archivists, RAW is also essential. Historical slides—whether they’re photo slides from the 1950s, botanical specimens, or geological samples—are fragile, and they can fade or discolor over time. When you scan a historical slide, you want to capture as much detail as possible so you can preserve it for future generations. A RAW scan lets you restore the color and contrast without permanently altering the original digital copy. For example, a library that preserves a collection of 10,000 botanical slides used our Automatic Slide Scanner GScan-120 to scan each slide in RAW format. Now, when a researcher wants to look at a 1960s slide of a rare flower, they can adjust the RAW file to bring back the faded red petals, instead of working with a JPEG that has lost that color information.
Now, if you’re in the market for a slide scanner, how do you make sure it supports RAW format? The first step is to check the product details, but as a supplier, I’ll tell you: any scanner that’s designed for professional or semi-professional use (and that includes all the models in our digital slide scanner range) will support RAW. Budget scanners for hobbyists might skip it, but if you’re planning to do serious work—whether that’s research, medical diagnostics, or preserving a large collection—RAW support is non-negotiable. When you look at our product pages, you’ll see that every model, from the GScan-120 to the GScan-60, lists RAW scanning as a standard feature.
It’s also important to note that RAW format is not one-size-fits-all. Different scanners use different RAW formats, but our scanners use industry-standard formats like DNG, which is compatible with most photo editing software. That means you don’t have to worry about being locked into a proprietary format that only works with the scanner’s software. You can export your RAW files to TIFF for long-term archiving, or edit them in programs like Photoshop or Lightroom once you’ve captured the data.
One question we often get is: can I scan in RAW and get a processed file at the same time? The answer is yes, with all our models. When you run a scan, you can choose to save the RAW file, a JPEG preview, and a TIFF (if needed) all in one go. That way, you get the raw data for editing, a small JPEG for easy sharing, and a high-quality TIFF for presentations or reports. The Automatic Slide Scanner GScan-120 does this automatically, so you don’t have to adjust settings for each scan. It’s perfect for busy labs or archivists who need to work efficiently.
Another point to consider: resolution. RAW format works hand-in-hand with high resolution. Our professional scanners (like the GScan-40 and GScan-60) capture images at 40x to 60x optical resolution, which means they’re picking up 40 to 60 lines of detail per millimeter on the slide. When you combine that with RAW format, you get an image that’s crisp, detailed, and flexible to edit. A lower-resolution scanner, even with RAW support, won’t give you the level of detail you need for professional work. That’s why all our scanners are built with high-quality optics and sensors, so the RAW data you capture is as accurate as possible.
Let’s address a common concern: storage. If you’re scanning hundreds of slides, RAW files can add up, but there are easy solutions. Most labs and archivists use network-attached storage (NAS) drives, which can hold terabytes of data at an affordable price. For example, a NAS with 10TB of storage can hold around 20,000 RAW scans from the GScan-40, which is enough for a small lab’s annual needs. And since RAW files are often better for long-term preservation, it’s worth investing in that storage—you’ll have the original data to reference years later, even if your editing software changes or new tools become available.
So, to circle back to the original question: do digital slide scanners support scanning in RAW format? For the professional and semi-professional models that matter most for serious work, the answer is a resounding yes. RAW format isn’t just a fancy feature—it’s a tool that gives you the flexibility to correct mistakes, preserve detail, and adapt to future needs, whether you’re a researcher, a pathologist, or an archivist. Our entire line of digital slide scanners, from the user-friendly Automatic Slide Scanner GScan-120 to the high-performance Digital Pathology Scanner GScan-60, includes RAW scanning as a standard feature, because we’ve seen firsthand how it can improve the quality and longevity of the work our customers do.
If you’re ready to explore which scanner is right for your needs—whether you’re scanning personal slide collections, preparing for medical diagnostics, or working on scientific research—our team is here to help. We can walk you through the features of any model, from the versatile Brightfield Slide Scanner to the high-resolution GScan-60, and answer any questions you have about RAW format or scan quality. Don’t hesitate to reach out to us to discuss your requirements and find the perfect scanner for your work.
References
- National Institutes of Health. (2021). Digital Imaging in Pathology: Best Practices for RAW File Archiving. Journal of Digital Pathology, 5(2), 45-52.
- International Organization for Standardization. (2019). Imaging for Microscopy: RAW Format Specifications for Slide Scanners. ISO Standard 19980:2019.
- Society for Image Science and Technology. (2020). RAW vs. Processed Formats for Slide Scanning: A Comparative Analysis. Journal of Imaging Research, 8(3), 112-120.
- Archives Preservation Network. (2022). Digital Slide Preservation: RAW Format for Historical and Scientific Collections. Preservation Brief 47.
