Stephane's problem with the MRC map written by ChimeraX looking like noise in Coot was because the map origin was not correct.

Tom

Begin forwarded message:

From: Stéphane ROCHE 
Subject: RE: [chimerax-users] Troubles when saving a map
Date: June 18, 2021 at 5:37:12 AM PDT
To: "Vadim Kotov" , "Tom Goddard" 

Thanks to both of you for your help !
 
I have finally understood what was happening, the origin of my map was changed and it was a very long way from its old position given that the box was quite large. So basically, when if I was looking around for densities, I was only scrolling inside the solvent.
 
Thanks again,
Stephane Roche
 

On 17.06.21 10:07, Stéphane ROCHE via ChimeraX-users wrote:
Dear Mr/Mrs,
 
I am new to ChimeraX (v 0.7) and I have a trouble when saving a map.
 
I am working with a .ccp4 map from an electron microscopy project. I would like to slightly change the pixel size that was inaccurately estimated during data processing and chimeraX seems to be the program for doing that. 
-          Opening the map is fine.
-          Then I change the pixel voxelsize which is also fine.
-          I then save the modified map (I use the .mrc format here given that I do not find a .ccp4 format).
-          However if I then use the map with my usual softwares (phenix, coot) it looks like pure noise. But the map looks normal with some other softwares (e.g. pymol). I also have no problem usually with my .mrc maps with any software so I would assume the problem is with the .mrc map I created
 
Do you know what I could do to solve this problem ?
 
Thanks, 
Stephane Roche
Institut de Biologie Intégrative de la Cellule
91198 Gif sur Yvette
France