with 100ms wait in arduino i obtain 10fps and there is quite a lot of computational reserve:

Number of samples:   148
Sample interval:     0.01 seconds
Total sampling time: 1.48 seconds
Number of cycles:    0
Sampled threads:
 #<SB-THREAD:THREAD "worker" RUNNING {1005D6D153}>

           Self        Total        Cumul
  Nr  Count     %  Count     %  Count     %    Calls  Function
------------------------------------------------------------------------
   1    148 100.0    148 100.0    148 100.0        -  "foreign function syscall"
   2      0   0.0    148 100.0    148 100.0        -  SB-THREAD::%%WAIT-FOR-MUTEX
   3      0   0.0    148 100.0    148 100.0        -  SB-THREAD::%WAIT-FOR-MUTEX
   4      0   0.0    148 100.0    148 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1286 :IN SB-THREAD:JOIN-THREAD)
   5      0   0.0    148 100.0    148 100.0        -  SB-THREAD:JOIN-THREAD
   6      0   0.0    148 100.0    148 100.0        -  RUN-SEVERAL-S
   7      0   0.0    148 100.0    148 100.0        -  "Unknown component: #x1005EF34C0"
   8      0   0.0    148 100.0    148 100.0        -  SB-EXT:CALL-WITH-TIMING
   9      0   0.0    148 100.0    148 100.0        -  SB-INT:SIMPLE-EVAL-IN-LEXENV
  10      0   0.0    148 100.0    148 100.0        -  EVAL
  11      0   0.0    148 100.0    148 100.0        -  (LAMBDA NIL :IN SWANK:INTERACTIVE-EVAL)
  12      0   0.0    148 100.0    148 100.0        -  SWANK::CALL-WITH-RETRY-RESTART
  13      0   0.0    148 100.0    148 100.0        -  SWANK::CALL-WITH-BUFFER-SYNTAX
  14      0   0.0    148 100.0    148 100.0        -  SWANK:EVAL-FOR-EMACS
  15      0   0.0    148 100.0    148 100.0        -  (LAMBDA NIL :IN SWANK::SPAWN-WORKER-THREAD)
  16      0   0.0    148 100.0    148 100.0        -  SWANK-BACKEND::CALL-WITH-BREAK-HOOK
  17      0   0.0    148 100.0    148 100.0        -  (FLET SWANK-BACKEND:CALL-WITH-DEBUGGER-HOOK :IN "/home/martin/quicklisp/dists/quicklisp/software/slime-2.7/swank-sbcl.lisp")
  18      0   0.0    148 100.0    148 100.0        -  SWANK::CALL-WITH-BINDINGS
  19      0   0.0    148 100.0    148 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1210 :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  20      0   0.0    148 100.0    148 100.0        -  (FLET SB-THREAD::WITH-MUTEX-THUNK :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  21      0   0.0    148 100.0    148 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-645 :IN SB-THREAD::CALL-WITH-MUTEX)
  22      0   0.0    148 100.0    148 100.0        -  SB-THREAD::CALL-WITH-MUTEX
  23      0   0.0    148 100.0    148 100.0        -  SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE
  24      0   0.0    148 100.0    148 100.0        -  "foreign function call_into_lisp"
  25      0   0.0    148 100.0    148 100.0        -  "foreign function new_thread_trampoline"
------------------------------------------------------------------------
          0   0.0                                     elsewhere
(15 8 7 20 7 2014 6 NIL 0)
Evaluation took:
  47.723 seconds of real time
  24.576000 seconds of total run time (22.731000 user, 1.845000 system)
  51.50% CPU
  134,234,695,357 processor cycles
  179,802,592 bytes consed
60ms in arduino -> 16.9fps, real time close to run time

STYLE-WARNING: redefining PYLON-TEST::RUN-SEVERAL-S in DEFUN
(38 29 7 20 7 2014 6 NIL 0)
Evaluation took:
  3.006 seconds of real time
  2.585000 seconds of total run time (2.415000 user, 0.170000 system)
  85.99% CPU
  8,456,658,508 processor cycles
  25,417,568 bytes consed

Number of samples:   129
Sample interval:     0.01 seconds
Total sampling time: 1.29 seconds
Number of cycles:    0
Sampled threads:
 #<SB-THREAD:THREAD "worker" RUNNING {101CE7FB13}>

           Self        Total        Cumul
  Nr  Count     %  Count     %  Count     %    Calls  Function
------------------------------------------------------------------------
   1    121  93.8    121  93.8    121  93.8        -  "foreign function syscall"
   2      8   6.2      8   6.2    129 100.0        -  "foreign function __nanosleep"
   3      0   0.0    129 100.0    129 100.0        -  SB-EXT:CALL-WITH-TIMING
   4      0   0.0    129 100.0    129 100.0        -  RUN-SEVERAL-S
   5      0   0.0    129 100.0    129 100.0        -  "Unknown component: #x101F3BF1A0"
   6      0   0.0    129 100.0    129 100.0        -  SB-INT:SIMPLE-EVAL-IN-LEXENV
   7      0   0.0    129 100.0    129 100.0        -  EVAL
   8      0   0.0    129 100.0    129 100.0        -  (LAMBDA NIL :IN SWANK:INTERACTIVE-EVAL)
   9      0   0.0    129 100.0    129 100.0        -  SWANK::CALL-WITH-RETRY-RESTART
  10      0   0.0    129 100.0    129 100.0        -  SWANK::CALL-WITH-BUFFER-SYNTAX
  11      0   0.0    129 100.0    129 100.0        -  SWANK:EVAL-FOR-EMACS
  12      0   0.0    129 100.0    129 100.0        -  (LAMBDA NIL :IN SWANK::SPAWN-WORKER-THREAD)
  13      0   0.0    129 100.0    129 100.0        -  SWANK-BACKEND::CALL-WITH-BREAK-HOOK
  14      0   0.0    129 100.0    129 100.0        -  (FLET SWANK-BACKEND:CALL-WITH-DEBUGGER-HOOK :IN "/home/martin/quicklisp/dists/quicklisp/software/slime-2.7/swank-sbcl.lisp")
  15      0   0.0    129 100.0    129 100.0        -  SWANK::CALL-WITH-BINDINGS
  16      0   0.0    129 100.0    129 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1210 :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  17      0   0.0    129 100.0    129 100.0        -  (FLET SB-THREAD::WITH-MUTEX-THUNK :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  18      0   0.0    129 100.0    129 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-645 :IN SB-THREAD::CALL-WITH-MUTEX)
  19      0   0.0    129 100.0    129 100.0        -  SB-THREAD::CALL-WITH-MUTEX
  20      0   0.0    129 100.0    129 100.0        -  SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE
  21      0   0.0    129 100.0    129 100.0        -  "foreign function call_into_lisp"
  22      0   0.0    129 100.0    129 100.0        -  "foreign function new_thread_trampoline"
  23      0   0.0    121  93.8    129 100.0        -  SB-THREAD::%%WAIT-FOR-MUTEX
  24      0   0.0    121  93.8    129 100.0        -  SB-THREAD::%WAIT-FOR-MUTEX
  25      0   0.0    121  93.8    129 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1286 :IN SB-THREAD:JOIN-THREAD)
  26      0   0.0    121  93.8    129 100.0        -  SB-THREAD:JOIN-THREAD
  27      0   0.0      8   6.2    129 100.0        -  SLEEP
  28      0   0.0      8   6.2    129 100.0        -  ARDUINO-SERIAL-SBCL:TALK-ARDUINO
  29      0   0.0      8   6.2    129 100.0        -  TRIGGER-ALL-CAMERAS-SEQ
  30      0   0.0      8   6.2    129 100.0        -  (LAMBDA NIL :IN RUN-SEVERAL-S)
  31      0   0.0      1   0.8    129 100.0        -  "foreign function pthread_cond_wait"
------------------------------------------------------------------------
          0   0.0                                     elsewhere
(7 30 7 20 7 2014 6 NIL 0)
Evaluation took:
  28.683 seconds of real time
  25.040000 seconds of total run time (23.046000 user, 1.994000 system)
  [ Run times consist of 0.234 seconds GC time, and 24.806 seconds non-GC time. ]
  87.30% CPU
  80,679,344,898 processor cycles
  219,328,112 bytes consed
without acquisition only 25fps possible
without debugging 150fps
(31 38 7 20 7 2014 6 NIL 0)

Number of samples:   13
Sample interval:     0.01 seconds
Total sampling time: 0.13 seconds
Number of cycles:    0
Sampled threads:
 #<SB-THREAD:THREAD "worker" RUNNING {10132FD0B3}>

           Self        Total        Cumul
  Nr  Count     %  Count     %  Count     %    Calls  Function
------------------------------------------------------------------------
   1      1   7.7      1   7.7      1   7.7        -  "foreign function fftwf_is_prime"
   2      0   0.0      6  46.2      1   7.7        -  "foreign function fftwf_cpy2d"
   3      0   0.0      1   7.7      1   7.7        -  "foreign function fftwf_ct_applicable"
   4      0   0.0      1   7.7      1   7.7        -  "foreign function fftwf_mkstride"
   5      0   0.0      1   7.7      1   7.7        -  "foreign function fftwf_cpy1d"
------------------------------------------------------------------------
         13 100.0                                     elsewhere
(34 38 7 20 7 2014 6 NIL 0)
Evaluation took:
  3.025 seconds of real time
  5.229000 seconds of total run time (5.061000 user, 0.168000 system)
  172.86% CPU
  8,508,643,798 processor cycles
  170,179,488 bytes consed
subtracting the background and multiplying with window is extremely slow (<40fps)
(15 50 8 20 7 2014
                                                        6 NIL 0)
Evaluation took:
  0.019 seconds of real time
  0.054000 seconds of total run time (0.054000 user, 0.000000 system)
  284.21% CPU
  52,534,892 processor cycles
  0 bytes consed

Number of samples:   1
Sample interval:     0.01 seconds
Total sampling time: 0.01 seconds
Number of cycles:    0
Sampled threads:
 #<SB-THREAD:THREAD "worker" RUNNING {1012E77593}>

           Self        Total        Cumul
  Nr  Count     %  Count     %  Count     %    Calls  Function
------------------------------------------------------------------------
   1      1 100.0      1 100.0      1 100.0        -  SB-KERNEL:HAIRY-DATA-VECTOR-REF
   2      0   0.0      1 100.0      1 100.0        -  REPLACE
   3      0   0.0      1 100.0      1 100.0        -  (LAMBDA NIL :IN SB-GRAY:STREAM-WRITE-STRING)
   4      0   0.0      1 100.0      1 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-674 :IN SB-THREAD::CALL-WITH-RECURSIVE-LOCK)
   5      0   0.0      1 100.0      1 100.0        -  SB-THREAD::CALL-WITH-RECURSIVE-LOCK
   6      0   0.0      1 100.0      1 100.0        -  (FLET SWANK-BACKEND:CALL-WITH-LOCK-HELD :IN "/home/martin/quicklisp/dists/quicklisp/software/slime-2.7/swank-sbcl.lisp")
   7      0   0.0      1 100.0      1 100.0        -  (SB-PCL::FAST-METHOD SB-GRAY:STREAM-WRITE-STRING (SWANK-BACKEND::SLIME-OUTPUT-STREAM T))
   8      0   0.0      1 100.0      1 100.0        -  SB-IMPL::%WRITE-STRING
   9      0   0.0      1 100.0      1 100.0        -  SB-FORMAT::INTERPRET-DIRECTIVE-LIST
  10      0   0.0      1 100.0      1 100.0        -  SB-FORMAT::%FORMAT
  11      0   0.0      1 100.0      1 100.0        -  FORMAT
  12      0   0.0      1 100.0      1 100.0        -  (FLET #:CLEANUP-FUN-301 :IN SB-EXT:CALL-WITH-TIMING)
  13      0   0.0      1 100.0      1 100.0        -  SB-EXT:CALL-WITH-TIMING
  14      0   0.0      1 100.0      1 100.0        -  RUN-SEVERAL-S
  15      0   0.0      1 100.0      1 100.0        -  "Unknown component: #x101666ED40"
  16      0   0.0      1 100.0      1 100.0        -  SB-INT:SIMPLE-EVAL-IN-LEXENV
  17      0   0.0      1 100.0      1 100.0        -  EVAL
  18      0   0.0      1 100.0      1 100.0        -  (LAMBDA NIL :IN SWANK:INTERACTIVE-EVAL)
  19      0   0.0      1 100.0      1 100.0        -  SWANK::CALL-WITH-RETRY-RESTART
  20      0   0.0      1 100.0      1 100.0        -  SWANK::CALL-WITH-BUFFER-SYNTAX
  21      0   0.0      1 100.0      1 100.0        -  SWANK:EVAL-FOR-EMACS
  22      0   0.0      1 100.0      1 100.0        -  (LAMBDA NIL :IN SWANK::SPAWN-WORKER-THREAD)
  23      0   0.0      1 100.0      1 100.0        -  SWANK-BACKEND::CALL-WITH-BREAK-HOOK
  24      0   0.0      1 100.0      1 100.0        -  (FLET SWANK-BACKEND:CALL-WITH-DEBUGGER-HOOK :IN "/home/martin/quicklisp/dists/quicklisp/software/slime-2.7/swank-sbcl.lisp")
  25      0   0.0      1 100.0      1 100.0        -  SWANK::CALL-WITH-BINDINGS
  26      0   0.0      1 100.0      1 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1210 :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  27      0   0.0      1 100.0      1 100.0        -  (FLET SB-THREAD::WITH-MUTEX-THUNK :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  28      0   0.0      1 100.0      1 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-645 :IN SB-THREAD::CALL-WITH-MUTEX)
  29      0   0.0      1 100.0      1 100.0        -  SB-THREAD::CALL-WITH-MUTEX
  30      0   0.0      1 100.0      1 100.0        -  SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE
  31      0   0.0      1 100.0      1 100.0        -  "foreign function call_into_lisp"
  32      0   0.0      1 100.0      1 100.0        -  "foreign function new_thread_trampoline"
------------------------------------------------------------------------
          1 100.0                                     elsewhere
(31 50 8 20 7 2014 6 NIL 0)
Evaluation took:
  16.458 seconds of real time
  26.039000 seconds of total run time (25.349000 user, 0.690000 system)
  158.21% CPU
  46,291,678,635 processor cycles
  1 page fault
  203,588,800 bytes consed
code to subtract and multiply is 3 times faster in a simple test
using decalaim to describe type of *buf-cs* and so on improves performance by a factor of 3
multiplication, subtraction, fft and extract runs at 67fps now
16.5fps with 60ms delay

(38 31 13 20 7 2014 6 NIL 0)
Evaluation took:
  0.005 seconds of real time
  0.020000 seconds of total run time (0.020000 user, 0.000000 system)
  400.00% CPU
  13,957,745 processor cycles
  0 bytes consed

Number of samples:   34
Sample interval:     0.01 seconds
Total sampling time: 0.34 seconds
Number of cycles:    0
Sampled threads:
 #<SB-THREAD:THREAD "worker" RUNNING {100C448E53}>

           Self        Total        Cumul
  Nr  Count     %  Count     %  Count     %    Calls  Function
------------------------------------------------------------------------
   1     34 100.0     34 100.0     34 100.0        -  "foreign function syscall"
   2      0   0.0     34 100.0     34 100.0        -  SB-THREAD::%%WAIT-FOR-MUTEX
   3      0   0.0     34 100.0     34 100.0        -  SB-THREAD::%WAIT-FOR-MUTEX
   4      0   0.0     34 100.0     34 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1286 :IN SB-THREAD:JOIN-THREAD)
   5      0   0.0     34 100.0     34 100.0        -  SB-THREAD:JOIN-THREAD
   6      0   0.0     34 100.0     34 100.0        -  RUN-SEVERAL-S
   7      0   0.0     34 100.0     34 100.0        -  "Unknown component: #x100C57A3A0"
   8      0   0.0     34 100.0     34 100.0        -  SB-EXT:CALL-WITH-TIMING
   9      0   0.0     34 100.0     34 100.0        -  SB-INT:SIMPLE-EVAL-IN-LEXENV
  10      0   0.0     34 100.0     34 100.0        -  EVAL
  11      0   0.0     34 100.0     34 100.0        -  (LAMBDA NIL :IN SWANK:INTERACTIVE-EVAL)
  12      0   0.0     34 100.0     34 100.0        -  SWANK::CALL-WITH-RETRY-RESTART
  13      0   0.0     34 100.0     34 100.0        -  SWANK::CALL-WITH-BUFFER-SYNTAX
  14      0   0.0     34 100.0     34 100.0        -  SWANK:EVAL-FOR-EMACS
  15      0   0.0     34 100.0     34 100.0        -  (LAMBDA NIL :IN SWANK::SPAWN-WORKER-THREAD)
  16      0   0.0     34 100.0     34 100.0        -  SWANK-BACKEND::CALL-WITH-BREAK-HOOK
  17      0   0.0     34 100.0     34 100.0        -  (FLET SWANK-BACKEND:CALL-WITH-DEBUGGER-HOOK :IN "/home/martin/quicklisp/dists/quicklisp/software/slime-2.7/swank-sbcl.lisp")
  18      0   0.0     34 100.0     34 100.0        -  SWANK::CALL-WITH-BINDINGS
  19      0   0.0     34 100.0     34 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1210 :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  20      0   0.0     34 100.0     34 100.0        -  (FLET SB-THREAD::WITH-MUTEX-THUNK :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  21      0   0.0     34 100.0     34 100.0        -  (FLET #:WITHOUT-INTERRUPTS-BODY-645 :IN SB-THREAD::CALL-WITH-MUTEX)
  22      0   0.0     34 100.0     34 100.0        -  SB-THREAD::CALL-WITH-MUTEX
  23      0   0.0     34 100.0     34 100.0        -  SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE
  24      0   0.0     34 100.0     34 100.0        -  "foreign function call_into_lisp"
  25      0   0.0     34 100.0     34 100.0        -  "foreign function new_thread_trampoline"
------------------------------------------------------------------------
          0   0.0                                     elsewhere
(7 32 13 20 7 2014 6 NIL 0)
Evaluation took:
  28.670 seconds of real time
  21.486000 seconds of total run time (19.091000 user, 2.395000 system)
  74.94% CPU
  80,643,843,634 processor cycles
  192,758,112 bytes consed
24.8fps with 40ms (should give 25fps)
(37 33 13 20 7 2014 6 NIL 0)
Evaluation took:
  0.008 seconds of real time
  0.020000 seconds of total run time (0.019000 user, 0.001000 system)
  250.00% CPU
  20,865,143 processor cycles
  0 bytes consed

Number of samples:   45
Sample interval:     0.01 seconds
Total sampling time: 0.45 seconds
Number of cycles:    0
Sampled threads:
 #<SB-THREAD:THREAD "worker" RUNNING {1015717193}>

           Self        Total        Cumul
  Nr  Count     %  Count     %  Count     %    Calls  Function
------------------------------------------------------------------------
   1     40  88.9     40  88.9     40  88.9        -  "foreign function syscall"
   2      4   8.9      4   8.9     44  97.8        -  "foreign function __nanosleep"
   3      0   0.0     45 100.0     44  97.8        -  RUN-SEVERAL-S
   4      0   0.0     45 100.0     44  97.8        -  "Unknown component: #x1015F0A9B0"
   5      0   0.0     45 100.0     44  97.8        -  SB-EXT:CALL-WITH-TIMING
   6      0   0.0     45 100.0     44  97.8        -  SB-INT:SIMPLE-EVAL-IN-LEXENV
   7      0   0.0     45 100.0     44  97.8        -  EVAL
   8      0   0.0     45 100.0     44  97.8        -  (LAMBDA NIL :IN SWANK:INTERACTIVE-EVAL)
   9      0   0.0     45 100.0     44  97.8        -  SWANK::CALL-WITH-RETRY-RESTART
  10      0   0.0     45 100.0     44  97.8        -  SWANK::CALL-WITH-BUFFER-SYNTAX
  11      0   0.0     45 100.0     44  97.8        -  SWANK:EVAL-FOR-EMACS
  12      0   0.0     45 100.0     44  97.8        -  (LAMBDA NIL :IN SWANK::SPAWN-WORKER-THREAD)
  13      0   0.0     45 100.0     44  97.8        -  SWANK-BACKEND::CALL-WITH-BREAK-HOOK
  14      0   0.0     45 100.0     44  97.8        -  (FLET SWANK-BACKEND:CALL-WITH-DEBUGGER-HOOK :IN "/home/martin/quicklisp/dists/quicklisp/software/slime-2.7/swank-sbcl.lisp")
  15      0   0.0     45 100.0     44  97.8        -  SWANK::CALL-WITH-BINDINGS
  16      0   0.0     45 100.0     44  97.8        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1210 :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  17      0   0.0     45 100.0     44  97.8        -  (FLET SB-THREAD::WITH-MUTEX-THUNK :IN SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE)
  18      0   0.0     45 100.0     44  97.8        -  (FLET #:WITHOUT-INTERRUPTS-BODY-645 :IN SB-THREAD::CALL-WITH-MUTEX)
  19      0   0.0     45 100.0     44  97.8        -  SB-THREAD::CALL-WITH-MUTEX
  20      0   0.0     45 100.0     44  97.8        -  SB-THREAD::INITIAL-THREAD-FUNCTION-TRAMPOLINE
  21      0   0.0     45 100.0     44  97.8        -  "foreign function call_into_lisp"
  22      0   0.0     45 100.0     44  97.8        -  "foreign function new_thread_trampoline"
  23      0   0.0     40  88.9     44  97.8        -  SB-THREAD::%%WAIT-FOR-MUTEX
  24      0   0.0     40  88.9     44  97.8        -  SB-THREAD::%WAIT-FOR-MUTEX
  25      0   0.0     40  88.9     44  97.8        -  (FLET #:WITHOUT-INTERRUPTS-BODY-1286 :IN SB-THREAD:JOIN-THREAD)
  26      0   0.0     40  88.9     44  97.8        -  SB-THREAD:JOIN-THREAD
  27      0   0.0      4   8.9     44  97.8        -  SLEEP
  28      0   0.0      4   8.9     44  97.8        -  ARDUINO-SERIAL-SBCL:TALK-ARDUINO
  29      0   0.0      1   2.2     44  97.8        -  "foreign function _ZN5Pylon19CInstantCameraArray13StartGrabbingENS_13EGrabStrategyENS_9EGrabLoopE"
  30      0   0.0      1   2.2     44  97.8        -  "foreign function pylon_wrapper_start_grabbing"
  31      0   0.0      1   2.2     44  97.8        -  PYLON:START-GRABBING
------------------------------------------------------------------------
          1   2.2                                     elsewhere
(56 33 13 20 7 2014 6 NIL 0)
Evaluation took:
  19.164 seconds of real time
  21.940000 seconds of total run time (19.595000 user, 2.345000 system)
  114.49% CPU
  53,903,843,294 processor cycles
  225,510,960 bytes consed
start using eager-future2. hopefully i can improve speed sufficiently to run all cameras at full speed
subtraction and multiplication in c code shaves of 1s
i uselessly allocated arrays at each mirror positions (this took 1.2s)
destroy_plan is called now
i obtain ~80fps
32fps ran
39fps works
tried to implement mirror scan on arduino but have acquisition error
there was a bug in the arduino code (i didn't set the inside counter back to the start value)
29 fps
the acquisition takes 16.2s (corresponding to 29fps)
but the distance between two camera triggers corresponds to 40fps
somewhere i'm loosing time