Hi J, Thanks for your nice comments about ChimeraX. It uses the Python tifffile module (https://pypi.org/project/tifffile/) to open TIFF files developed by Christoph Gohlke specifically for light microscopy and that can handle BigTIFF format which is needed since original TIFF only has a maximum size of 4 GB. As a test I made a 6 Gbyte 3d random image and opened it in ChimeraX 1.10 without any trouble. I made the example file in Python with this code import numpy, tifffile data = numpy.random.randint(0, 255, (2000, 1000, 1000, 3), 'uint8') tifffile.imwrite('/Users/goddard/Desktop/temp.tif', data, bigtiff=True, photometric='rgb') then opened it with ChimeraX command open temp.tif Can you show me an example where it doesn't work? Tom 2k x 1k x 1k random BigTIFF image in ChimeraX 
On Jul 16, 2025, at 5:32 PM, José Jorge Ramírez Franco via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:
Hi there,
First of all, thank you for this outstanding piece of software. ChimeraX is truly invaluable and has become an essential tool in my workflow.
As a microscopist working primarily with light microscopy (particularly confocal and light-sheet imaging) I’ve found ChimeraX’s rendering capabilities to be far superior to most tools currently available. I’ve even recommended its use several times on the image.sc forum <https://image.sc/>, especially for rendering high-quality visualizations.
In fact, I recently noticed that there was no #chimerax tag on the forum (surprisingly!) so I took the liberty of creating one. You can find the related post here:
https://forum.image.sc/t/3d-multichannel-surface-rendering-from-z-stacks-nap...
While I have this opportunity, I’d like to suggest a feature that I believe would significantly enhance ChimeraX’s utility for large-scale light-sheet microscopy datasets: support for .tiff files larger than 4 GB.
These large file sizes are quite common in light-sheet acquisitions, and the ability to open them natively in ChimeraX would be a substantial benefit to researchers in this field. Thank you once again for all the incredible work that goes into developing and maintaining ChimeraX. It’s deeply appreciated.
Warm regards,
J -- J. Jorge Ramírez-Franco PhD Institut de Neurosciences de la Timone, SpiCCI Team Faculté de Médecine 27, boulevard Jean Moulin 13005 Marseille, France _______________________________________________ ChimeraX-users mailing list -- chimerax-users@cgl.ucsf.edu To unsubscribe send an email to chimerax-users-leave@cgl.ucsf.edu Archives: https://mail.cgl.ucsf.edu/mailman/archives/list/chimerax-users@cgl.ucsf.edu/
