Hi All
Both Martin and Kay ( in a later message) have misinterpreted what I
wrote - what I meant was that it seems normal in using XDS with
Pilatus data, not the normal thing to do with data from other detectors.
I had found a number of scripts on the web that deal specifically
with processing Pilatus data with XDS that seemed to use
"PATCH_SHUTTER_PROBLEM=TRUE" - what I didn't notice was that the
commands had all been commented out, and that "FALSE", the default,
was in operation.
So, in either case I was wrong. Apologies to Kay and Wolfgang, and
all who write and use scripts for processing Pilatus data with XDS.
On 5 Nov 2010, at 18:33, Martin Hallberg wrote:
Hi Harry,
On Nov 5, 2010, at 5:45 PM, Harry Powell wrote:
I think there may be issues with collecting data too finely with a
Pilatus, even in shutterless mode. I don't know where the problems
arise (can't be shutter/rotation axis synchronisation), but it
seems to be the normal thing in XDS (which should have no problems
with fine phi-slicing) to use the "PATCH_SHUTTER_PROBLEM=TRUE"
that Martin Hallberg suggested, which looks a bit like a fudge to
me (but I expect Kay to correct me on that!).
It is not the normal thing in XDS but it is perhaps a relatively
common solution to shutter/spindle synchronisation problems
discovered afterwards (always process directly at the beam line!).
The default in XDS is indeed PATCH_SHUTTER_PROBLEM=FALSE
Compensating like this is of course not the best (go and
recollect!) but still way better than unusable data in the
meantime. In the case Sergei originally described it would at least
indicate what the problem may be. Sergei did not say which detector
was used for the data collection so we don't know if it was a
Pilatus or a CCD. Maybe Sergei can fill us in on the details?
BTW, any views in the community on crystal lifetime with continuous
data collection like on the Pilatus (or AXIOM) versus letting the
crystal rest/cool/die(?) a second between frames on a CCD?
Cheers,
Martin
Harry
--
Dr Harry Powell,
MRC Laboratory of Molecular Biology,
Hills Road,
Cambridge,
CB2 0QH
