Hi Barnali, The >3 data sets are all still open. It is just that the Volume Viewer dialog only shows 3 histograms at a time by default. You can increase that number using the Volume Viewer dialog menu: "Features… Data display options” and then adjusting the "Maximum number of histograms shown”. <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/frame...> <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/volum...> Even if you don’t show all the histograms at once, you can still access each data set from the Volume Viewer menu: Data… I hope this helps, Barnali ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco

On Apr 12, 2017, at 1:39 AM, Barnali Waugh <barnali.waugh@weizmann.ac.il> wrote:

Hi All, I am using Chimera volume viewer to open four volume simultaneously (*.mrc tomogram; 256 256 256 voxel). However, I can open any three volumes at a time. When I try to open the fourth one, it replaces one of the open volumes. I would be thankful for any suggestion. Regards, Barnali.