Re: [ccp4bb] Fine Phi Slicing

James, On On 20 Jul 2017, at 19:06, James Holton > wrote: In my experience you need at least an average of 1 photon/pixel/image before even the best data processing algorithms start to fall over. I do not agree… both XDS and

Re: [ccp4bb] Fine Phi Slicing

@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Fine Phi Slicing An important aspect of fine phi slicing that has not been mentioned yet (and took me a long time to figure out) is the impact of read-out time. Traditionally, read-out time is simply a delay that makes the overall data collection take longer

Re: [ccp4bb] Fine Phi Slicing

An important aspect of fine phi slicing that has not been mentioned yet (and took me a long time to figure out) is the impact of read-out time. Traditionally, read-out time is simply a delay that makes the overall data collection take longer, but with so-called "shutterless" data collection

Re: [ccp4bb] Fine Phi Slicing

And the instrument makers (e.g., Rigaku and Bruker) currently sell multi-axis goniostats for in-house data collection--and not just for small-molecule purposes. Diana P.S. Ron, we still call 'em goniometer heads and goniostats at UT Southwestern. > On Jul 14, 2017, at 1:00 PM,

Re: [ccp4bb] Fine Phi Slicing

I'm not understanding much of this discussion, but I've noticed the use of words reminiscent of old issues concerning omega-two theta scans on four-circle goniostats (see Stout and Jensen, pages 168-173, second edition). p.s. In my upbringing, crystals were placed on goniometer heads so they

Re: [ccp4bb] Fine Phi Slicing

hi folks Just my two ha'porth - the small molecule crystallographers have been doing multi-orientation data collections since they moved from point detectors to area detectors in the early 1990's, for the very reasons that Gerard gives (their cusps are huge compared to ours...). Since they

Re: [ccp4bb] Fine Phi Slicing

Dear Leo, What seems to have happened is that an existing thread where fine phi (actually: omega!) slicing was discussed, among many other things, digressed into a discussion of data collection protocols using more than one instrumental setting (either using a 2-theta motion of the detector,

Re: [ccp4bb] Fine Phi Slicing

Reading back my email, when I mentioned 'just introduced', it is not giving justice to the reality and those who came up with the concept. I should have mentioned 'just reminded us', as the concept has been introduced quite a long time ago and few tens of communications. It is therefore a

Re: [ccp4bb] Fine Phi Slicing

inal Message- > From: graeme.win...@diamond.ac.uk [mailto:graeme.win...@diamond.ac.uk] > Sent: Friday, July 14, 2017 1:37 AM > To: Keller, Jacob <kell...@janelia.hhmi.org> > Cc: ccp4bb@jiscmail.ac.uk > Subject: Re: [ccp4bb] Fine Phi Slicing > > Jacob > > If you hav

Re: [ccp4bb] Fine Phi Slicing

Just to comment on what Graeme just introduced. We (and I know we are not the first ones and not the only ones) are pushing our user community towards this procedure as a standard: lowering the transmission (less juicy, yet...) and getting few data with various chi. It does help greatly in

Re: [ccp4bb] Fine Phi Slicing

, 2017 1:37 AM To: Keller, Jacob <kell...@janelia.hhmi.org> Cc: ccp4bb@jiscmail.ac.uk Subject: Re: [ccp4bb] Fine Phi Slicing Jacob If you have a complete 360 deg data set and your sample is still alive, and you have a multi-axis gonio, I would recommend rotating the crystal about th

Re: [ccp4bb] Fine Phi Slicing

Jacob If you have a complete 360 deg data set and your sample is still alive, and you have a multi-axis gonio, I would recommend rotating the crystal about the beam (ideally by ~ maximum scattering 2-theta angle) and collecting again. This would record your blind region as well as moving the

Re: [ccp4bb] Fine Phi Slicing

Hi Fred, fine slicing does not alleviate the count RATE limitation of photon counting detectors because fine slicing does not reduce the instantaneous photon flux on the detector when you cross the diffraction maximum. Fine slicing does help if you push the maximum counts per pixel per frame

Re: [ccp4bb] Fine Phi Slicing

I could be wrong here, but isn't the case that fine slicing is an option with a CCD and a necessity on a PAD b/c of dead time and/or counter dynamic range issues? (no current and/or former financial ties to any manufacturer) Fred

[ccp4bb] Fine Phi Slicing

I thought there was a new paper from the Pilatus people saying fine slicing is worth it even beyond the original 1/2 mosaicity rule? I would think, actually, more gains would made by doing light exposures at, say, 1/3 mosaicity, collecting 360 deg, then shifting the detector in 2theta by a