How to Find Duplicate .MOS, .MRW & .ORF Raw Photos?

Raw photos are unprocessed images that have to be processed into the fine, end-product we all drool over. Today we will be looking at how we can scan and delete duplicate images for MOS, ORF and MRW images, which are some of the popular RAW image file formats out there.

And we will also be looking into the steps you can take to prevent duplication in the future.


Product Spotlight (Duplicate Photos): Use PictureEcho to remove 1000s of duplicate and similar photos.

PictureEcho is made by our company, Sorcim Technologies. It never asks for your email address to install the software. Download and use!


.MOS (Leaf)

.MOS is a Leaf Raw Image file type and is the default file format produced by Leaf Aptus cameras. These files are typically quite large in size compared to any other image format because they are not compressed. Different image editors can easily open .MOS files, including freeware programs such as MOSViewer and RawTherapee while premium programs that support this image format include Adobe Photoshop, Capture One Pro, PaintShop Pro etc.

.MRW (Minolta Konica)

MRW is another RAW image file format developed by Sony for it’s Minolta Konica digital cameras. The contents of MRW files are not compressed and users can easily edit the exposure, color temperature at any time using a third-party image editor program.

.ORF (Olympus)

Olympus Raw Image is an unprocessed image file format. It is the default processing image format used by Olympus Digital Cameras. As a RAW format, ORF files support changing exposure, white balance and contrast.

The company provides a free software named Olympus Workspace to edit and view ORF files. The program supports both Microsoft Windows and Mac operating systems. Depending on the model and configurations of your Olympus camera, there is a wide range of software programs available such as Olympus Master, Olympus ib.

Identify & Fix Duplicate RAW Images

If you have a large library of RAW images, it will surely contain a big number of identical images. These files are usually not required and are occupying storage space and creating a mess in the photo directory. 

There are two ways to search for duplicate RAW images. First, you can load a list of all files of a specific type using File Explorer and look for duplicates by comparing the thumbnails. Duplicate copies are generally found across different partitions, folders, and sub-folders. Hence, this is not realistic if you’ve hundreds of thousands of files with a large file collection.

The second method is to identify duplicate RAW images using a dedicated tool called PictureEcho. This is fully automated and the safest bet.

What is PictureEcho? How Does it Work?

PictureEcho is a powerful duplicate photo detection utility from leading software developer Sorcim. You can use this software to scan for your duplicate images in just 3 steps:

Step # 1: Add Directories to Scan: Download & install the program. Specify the directories/ drives that you want to scan for duplicate images.

Step # 2: Start Scan: Choose between Exact Match and Similar Match. You might also have to select the Similarity Settings if you are going for a Similar scan. Click Start Search to launch the scan and now allow PictureEcho to do the good work.

Step # 3: Review & Fix Duplicates: A list of all duplicate photos will appear on your screen. Mark or unmark duplicates yourself or use the Select Duplicates button to mark in bulk. Once the files are marked, click Select Action and then delete them.

PictureEcho Salient Features

  • Multiple Directories/ Drives: It supports adding multiple directories to the scan. You can add an unlimited number of directories for the scan and can also get a specific folder that lies within those directories, excluded from the scan.
  • Image Match Patterns: PictureEcho offers two scan modes, Exact Match and Similar Match. Exact Match looks for identical images, and Similar Match allows you to find visually similar images that were taken within a time span of 30 seconds, 1 minute, 60 minutes or simply disregard the time factor (according to your preference). You can configure the visual similarity match options by clicking on the Similarity Settings link.
  • In-house Preview: When PictureEcho loads a list of all duplicate files, you do not have to open each file. Just go through the list and select a file. A preview will appear on the right side of your screen. You also get to see other information related to the file- such as name, directory, size, extension, and creation date.
  • Selection Patterns: You can choose from a range of selection patterns to mark/ unmark files. You can select bigger/ smaller images in each group, high resolution/ low resolution images in each group, newest/ oldest files in each group. There is another pattern to select images that are located in a specific directory.
  • The Final Step: Click Select Action to either purge the duplicate RAW images or move them to a folder you will specify, just in case you think these images might be needed in the future.

Raza Ali Kazmi

Raza Ali Kazmi works as an editor and technology content writer at Sorcim Technologies (Pvt) Ltd. He loves to pen down articles on a wide array of technology related topics and has also been diligently testing software solutions on Windows & Mac platforms.