Just to add on Bernard's comment: the best way of doing what he suggests is to add a few oscillation images (using for example the ccp4 idiffdisp). Now, how well you'll be able to detect zones that lead to proper indexing, a-la good old precession images, depends on the geometry of your data collection of course. If you collected around one oscillation axis with a randomly mounted crystal you should be very lucky to come across zones that really lead to proper indexing. Certainly you would be luckier if you recorded images around several zones. Still, it would be useful to do what Ian suggested, i.e. a program for obtaining precession like pictures from raw data (a non-commercial one, I mean).
Cheers, Boaz ----- Original Message ----- From: "Santarsiero, Bernard D." <b...@uic.edu> Date: Thursday, June 25, 2009 20:42 Subject: Re: [ccp4bb] From oscillation photographs to seeing specific sections of reciprocal lattice. To: CCP4BB@JISCMAIL.AC.UK > I think you should just grab a copy of Stout and Jensen, and use the > oscillation photographs directly. What's so special about a precession > image? You can still index the spots and follow along rl lines. > > Bernie Santarsiero > > > > On Thu, June 25, 2009 1:38 pm, Francis E Reyes wrote: > > Yes this is exactly what I wanted. I'm embarking on an educational > > pursuit of determining the space group from the diffraction images > > directly. Unfortunately it seems like all the solutions > insofar are > > only commercially available as part of large packages that > don't list > > their prices directly on the website and, therefore, are > probably too > > much for a single person to afford for just this purpose. > > > > Cheers > > > > FR > > > > > > > > On Jun 25, 2009, at 10:41 AM, Ian Tickle wrote: > > > >> But I thought what you wanted was to reconstruct the diffraction > >> pattern > >> (i.e. streaks, TDS, ice rings, zingers, warts & all) as a > >> pseudo-precession image, not just display a representation of the > >> integrated intensities. That surely would be much more > useful, then > >> one > >> could see whether the apparent systematic absence violations > were just > >> streaks from adjacent spots, TDS, ice spots etc that have > fooled the > >> integration algorithm. That would be much more > useful! In the days > >> when we had real precession cameras this was how you assigned the > >> space > >> group. > >> > >> Cheers > >> > >> -- Ian > > > > --------------------------------------------- > > Francis Reyes M.Sc. > > 215 UCB > > University of Colorado at Boulder > > > > gpg --keyserver pgp.mit.edu --recv-keys 67BA8D5D > > > > 8AE2 F2F4 90F7 9640 28BC 686F 78FD 6669 67BA 8D5D > > > Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Phone: 972-8-647-2220 ; Fax: 646-1710 Skype: boaz.shaanan
