Re - v5 and SX AO


Aug 9, 2008

 


----------------------------

#33171 Aug 9, 2008

Just to re-iterate - my concern is about the mods done to v5 of Maxim that

appear to eliminate the possibility of bypassing its inability to do dark

subtraction in the SX AO unit. This - if true (as the manual implies) would be

a **really** bad mod. I await clear skies to test it. I really hope that I am

wrong in understanding the suggestion in the manual that Cyanogen has prevented

the use of the 'fix' for their bug"!



Lawrence



----------------------------

#33200 Aug 10, 2008

--- In MaxImDL@yahoogroups.com, Lawrence Harris lawrence@...> wrote: >

Hi Lawrence

Could you let me know what the fix was in ver 4 as I have a hot pixel

on my AO guider that just wont let me calibrate on a star, even if it

is much brighter than the hot pixel. I have also upgraded to ver 5.0

and waiting for clear skies.

Regards

Steve Carmichael > Just to re-iterate - my concern is about the mods done to v5 of Maxim

that > appear to eliminate the possibility of bypassing its inability to do

dark > subtraction in the SX AO unit. This - if true (as the manual

implies) would be > a **really** bad mod. I await clear skies to test it. I really hope

that I am > wrong in understanding the suggestion in the manual that Cyanogen has

prevented > the use of the 'fix' for their bug"!

>

> Lawrence

>



----------------------------

#33222 Aug 11, 2008

Hi Steve



We seem to be the only ones acknowledging (in public) the existence of this

unbelievable bug.



The fact is that when you have the SX AO unit configured normally in v4.62, the

CCD window behaved as per the design - ie., the option 'full calibration'

actually does what it says - it calibrates the guider image - and so removes hot

pixels exactly as it should!



Unfortunately, the writers have *not* applied this to the SX AO 'locate' window

so if you use 'locate' to find your guide star, you will see a faithful

reproduction of every fault in the camera- swamped in my case with warm and hot

pixels and therefore completely preventing the algorithm from detecting genuine

stars. The second problem here is that the algorithm apparently only looks for

isolated bright pixels and assumes that they are genuine stars (I kid you not!)



Purely by chance I discovered an easy workaround in v4.62. Merely use the CCD

window to do a full calibrated guide image. Identify your genuine star and

identify its exact coords. Use the locate window to pick the same coords (and

therefore genuine guide star) by mouse click, and when this is transferred into

the locate field, use the track option. The whole process is really quite

smooth, but IMHO should *never* have been necessary.



good luck.



BTW until a clear sky lets me check whether v5 *has* actually eliminated this

workaround - as written in the manual - I shall only use v4.62........

Unfortunately this now adds a severe complication to another project of mine

that involves Maxim ............................................ ;-)



Lawrence





>Re: Re - v5 and SX AO

> Posted by: "Steve" stevecarmichael1@... steve35ukm

> Date: Sun Aug 10, 2008 8:08 am ((PDT))

>

>--- In MaxImDL@yahoogroups.com, Lawrence Harris lawrence@...> wrote:

>>

>Hi Lawrence

>Could you let me know what the fix was in ver 4 as I have a hot pixel

>on my AO guider that just wont let me calibrate on a star, even if it

>is much brighter than the hot pixel. I have also upgraded to ver 5.0

>and waiting for clear skies.

>Regards

>Steve Carmichael

>> Just to re-iterate - my concern is about the mods done to v5 of Maxim

>that

>> appear to eliminate the possibility of bypassing its inability to do

>dark

>> subtraction in the SX AO unit. This - if true (as the manual

>implies) would be

>> a **really** bad mod. I await clear skies to test it. I really hope

>that I am

>> wrong in understanding the suggestion in the manual that Cyanogen has

>prevented

>> the use of the 'fix' for their bug"!

>>

>> Lawrence



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