Show HN: Snap Scope – Visualize Lens Focal Length Distribution from EXIF Data
7 comments
·January 24, 2025netsharc
Man, this would be so much more intuitive as a command line tool that either generates a HTML file with the summary, or a CSV file with filename, focal length. Dragging thousands of photos into the browser window seem very sketchy (OK I just tested, Vivaldi doesn't like me dragging dozens of files onto it, I can do 2 files, but if I try dragging about 20 files it just loads one of the images, replacing the page).
I can imagine a CLI wouldn't even read the entire file (I have 15MB heavy images), just the few KB's at the beginning to find the Exif tag.
rad_gruchalski
Makes you wonder if you could chop the start of the file, upload it, and get the result?
Cieric
This sounds really cool, I'm less then an amateur photographer (I have a weird camera that I like writing software for.) But most of my images are stripped of Exif data as others have mentioned, could you provide an example on the page that I could test it out with?
DarkSucker
Can anyone speak to the image processing used? In particular, how is depth inferred from a single 2D image? It seems to me one would need both depth and angle over the field of view to back out the lens focal length. The EXIF format doesn't seem to contain meta data helpful to the focal length calculation.
nanoanderson
There is a FocalLength tag in the EXIF spec. https://exiftool.org/TagNames/EXIF.html
ttoinou
Would you have an example of this tool being used ?
dboreham
Definitely a need for this. I built something similar years ago from hacky scripts so nice to see it done properly.
Hey HN, I built this tool because I wanted to understand which focal lengths I actually use when taking photos. It's a web app that analyzes EXIF data to visualize focal length distribution patterns.
While it's admittedly niche (focused specifically on photography), I think it could be useful for photographers trying to understand their lens usage patterns or making decisions about lens purchases.
Features: Client-side EXIF data processing (no server uploads/tracking) / Handles thousands of photos at once / Clean visualization with shareable summaries
This tool supports most RAW formats, but you might occasionally encounter files where EXIF extraction fails. In such cases, converting to more common formats like JPEG usually resolves the issue.
Try it out: https://snap-scope.shj.rip/?lng=en
Source: https://github.com/Gumball12/snap-scope