Some small update:
1) Yes, when you check "Lock", the filter DOES change for the focus. sorry, I have said nothing.
2) I had a hard crash of Ekos. This happened when I clicked the "capture" button in the capture module. Don't know what happened here. Here is extract of backtrace and log.
GDB backtrace
--------------
Thread 1 "kstars" received signal SIGSEGV, Segmentation fault.
0x0823ccc5 in FITSData::findCentroid<unsigned short> (this=0xb8540b0, boundary=..., initStdDev=<optimized out>,
minEdgeWidth=5) at ./kstars/fitsviewer/fitsdata.cpp:1298
1298 ./kstars/fitsviewer/fitsdata.cpp: No such file or directory.
(gdb) bt
#0 0x0823ccc5 in FITSData::findCentroid<unsigned short> (this=0xb8540b0, boundary=..., initStdDev=<optimized out>,
minEdgeWidth=5) at ./kstars/fitsviewer/fitsdata.cpp:1298
#1 0x082441f8 in FITSData::findCentroid (this=<optimized out>, boundary=..., initStdDev=<optimized out>,
minEdgeWidth=<optimized out>) at ./kstars/fitsviewer/fitsdata.cpp:1168
#2 0x0824431f in FITSData::findStars (this=0xb8540b0, boundary=..., force=false) at ./kstars/fitsviewer/fitsdata.cpp:2046
#3 0x0825260c in FITSView::findStars (this=0xad66378, algorithm=ALGORITHM_CENTROID) at ./kstars/fitsviewer/fitsview.cpp:1197
#4 0x082fad89 in Ekos::Focus::setCaptureComplete (this=0xad3a388) at ./kstars/ekos/focus/focus.cpp:1144
#5 0x081c016b in Ekos::Focus::qt_static_metacall (_o=0xad3a388, _c=QMetaObject::InvokeMetaMethod, _id=44, _a=0xbffaef54)
at ./obj-i686-linux-gnu/kstars/moc_focus.cpp:373
#6 0xb568d66f in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#7 0xb568dbad in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) ()
from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#8 0x081a429a in Ekos::DarkLibrary::darkFrameCompleted (this=0xb505db8, _t1=<optimized out>)
at ./obj-i686-linux-gnu/kstars/moc_darklibrary.cpp:148
#9 0x082995ab in Ekos::DarkLibrary::subtract<unsigned char> (offsetY=<optimized out>, offsetX=<optimized out>,
filter=<optimized out>, lightImage=<optimized out>, darkData=<optimized out>, this=<optimized out>)
at ./kstars/ekos/auxiliary/darklibrary.cpp:258
#10 Ekos::DarkLibrary::subtract (this=0xb505db8, darkData=0xbdc33f0, lightImage=0xad66378, filter=FITS_NONE, offsetX=0,
offsetY=0) at ./kstars/ekos/auxiliary/darklibrary.cpp:186
#11 0x0829d1f6 in Ekos::DarkLibrary::newFITS (this=0xb505db8, bp=0xa9e99c98) at ./kstars/ekos/auxiliary/darklibrary.cpp:341
#12 0x081ae056 in Ekos::DarkLibrary::qt_static_metacall (_o=0xb505db8, _c=QMetaObject::InvokeMetaMethod, _id=2,
_a=0xbffaf144) at ./obj-i686-linux-gnu/kstars/moc_darklibrary.cpp:85
#13 0xb568d66f in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#14 0xb568dbad in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) ()
from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#15 0x081a6dca in ISD::GDInterface::BLOBUpdated (this=0xb32c1c8, _t1=<optimized out>)
at ./obj-i686-linux-gnu/kstars/moc_indistd.cpp:383
#16 0x0820011f in ISD::CCD::processBLOB (this=<optimized out>, bp=<optimized out>) at ./kstars/indi/indiccd.cpp:1703
#17 0x081f4b45 in INDIListener::processBLOB (this=0xa88b3f0, bp=0xa9e99c98) at ./kstars/indi/indilistener.cpp:374
#18 0x081c082e in INDIListener::qt_static_metacall (_o=0xa88b3f0, _c=QMetaObject::InvokeMetaMethod, _id=18, _a=0xa7cb9588)
at ./obj-i686-linux-gnu/kstars/moc_indilistener.cpp:182
#19 0xb568a3f0 in QMetaCallEvent::placeMetaCall(QObject*) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#20 0xb568e183 in QObject::event(QEvent*) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#21 0xb613c04a in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#22 0xb614184c in QApplication::notify(QObject*, QEvent*) () from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#23 0xb565d4ad in QCoreApplication::notifyInternal2(QObject*, QEvent*) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#24 0xb566036e in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) ()
from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#25 0xb5660877 in QCoreApplication::sendPostedEvents(QObject*, int) () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#26 0xb56b7e03 in ?? () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#27 0xb42ee4d9 in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#28 0xb42ee779 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
---Type <return> to continue, or q <return> to quit---
#29 0xb42ee844 in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#30 0xb56b81f3 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#31 0xb188a521 in ?? () from /usr/lib/i386-linux-gnu/libQt5XcbQpa.so.5
#32 0xb565adad in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) ()
from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#33 0xb566407f in QCoreApplication::exec() () from /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5
#34 0xb5b417b1 in QGuiApplication::exec() () from /usr/lib/i386-linux-gnu/sse2/libQt5Gui.so.5
#35 0xb6138cc4 in QApplication::exec() () from /usr/lib/i386-linux-gnu/libQt5Widgets.so.5
#36 0x08094a60 in main (argc=<optimized out>, argv=<optimized out>) at ./kstars/main.cpp:313
(gdb)
Logs:
----------
==> log_09-36-14.txt <==
2017-04-11T09:36:26.416 - WARN - "Object named NGC 78 not found"
2017-04-11T09:36:26.488 - WARN - "Object named NGC 6050A not found"
2017-04-11T09:36:27.878 - WARN - "Object named NGC 4666 not found"
2017-04-11T09:36:28.526 - WARN - "Object named NGC 7318 not found"
2017-04-11T09:36:28.816 - WARN - "Object named NGC 7839 not found"
2017-04-11T09:36:29.013 - WARN - "Object named NGC 7840 not found"
2017-04-11T09:36:29.249 - WARN - "Object named IC 1127 not found"
2017-04-11T09:36:29.542 - WARN - "Object named IC 2497 not found"
2017-04-11T09:36:29.775 - WARN - "Object named IC 4703 not found"
2017-04-11T09:36:29.992 - WARN - "Object named JupiterComet Shoemaker–Levy 9 Wikipedia page not found"
==> log_21-38-29.txt <==
2017-04-11T21:45:45.543 - DEBG - SBIG CCD : "Taking 1s exposure on main camera... "
2017-04-11T21:45:50.305 - DEBG - Focus: "Capturing dark frame..."
2017-04-11T21:45:50.326 - DEBG - SBIG CCD : "Taking 2s exposure on main camera... "
2017-04-11T21:45:55.213 - DEBG - fits MIN: 927 - fits MAX: 32639 - pixel range: 31712 - bin width 50.9021 bin count 624
2017-04-11T21:45:55.302 - DEBG - FITHistogram: JMIndex 0.999997
2017-04-11T21:45:55.317 - DEBG - Focus: "Dark frame received."
2017-04-11T21:45:55.338 - DEBG - Focus: "Dark frame saved to /home/cboy/.local/share/kstars/darks/darkframe_2017-04-11T21-45-55.fits"
2017-04-11T21:45:55.470 - DEBG - Focus: "Image received."
2017-04-11T21:45:55.473 - DEBG - SNR: 31.3477
2017-04-11T21:45:55.473 - DEBG - The threshold level is 1031.21 (actual 1031.21 ) minimum edge width 5 minimum edge limit 3