pask replied to the topic 'Re:Plate solving issue in EKOS' in the forum. 5 years ago

Hello everybody,

My turn to jump to this thread as well, let me expose my "little" issue which is a problem in plate solving also :
Well, i spent two nights trying to solve this plate unsolving but in vain :'( ... i stayed at 1hr from my home in the middle of a field from 6PM to 6AM this morning (a bit hard for me to have my eyes open now loool) ...very frustrating to spend all nights trying to get the first step done ...but welll this is also why we like astronomy ;)

Issue :
- doing a capture & solve will never solve the capture.
- starting even a polar algnment is the same, not solving
- doing a capture ( in the module of capture, in a sequence or a preview that i saved) and then use "load & slew" will work in about 5sec !! (with the exact sky portion captured on both way)

-> from both test it is the exact same position and same exposure etc....

my setup is this one :
- skywatcher 254/1200 (+skywatcher coma corrector) with only canon EOS 5D3, no guiding.

one curious fact about the canon is, you can find 2 data for its resolution :
- 5760x3840 for a 36x24mm sensor giving 6,25microns
- 5796x3870 / 36x24mm then 6,22microns
Calculatin FOV gives : (103' x 68') - for both characteristics

I noted one weird thing :
- when i do a load&slew : it shows in the status zone that it starts the solver with that options : -H 108.966 -L 65.8275
- when i do capt&solv : options are mostly the same ...except H & L : -H 113.446 - L61.8794
Seems that from capture&solve it allows a bigger window...why ?
-> i tried to modify the options line in the "solver option" part of the aligment module, but it gets erased each time i start a capture&solve (i did not find from where it erase it)
-> I tried in the astronometry option (from the "option" button in the bottom right part of the aligment module) : i tried to uncheck "auto-update FOV" and modify the value of the FOV there but i did no see any change, each time the option line ("-o ....") is erased ... just like it was computing the FOV tolerance directly from the fresh capture
-> Is there a tolerence in the code that is different from "capture&solve" to "load&slew" ? Reversing the data gives me a +/- 5% for "capture&solve" and +/- 10% for "load&solve" !

-> so I try directly the solve-field command on the terminal ... from the same picture and just changing the H or L options ... the issue is on the H size ... the bigger one allow the picture to be directly solved in 5sec ... the initial H value does not solve at all (i increased the timeout to 5 and 10min..)

-> Then i noted the astrometry version was 0.67 ... i went to the website and in the middle of the night downloaded the latest sources (0.74) i did all the procedure from the website to install it : the short version failed at some points (i suppose some dependencies for compiling were missing) but the long version worked fine... i restarted kstars/ekos etc.. and ... well the version displayed in the status bar at launch of the alignment module is still 0.67 !! :'( :'( :'( i can't understand ... anyway no more time for that... :

As the sun was rising :'( ... i was short in options ... so idid trick the latest thing i could => i reversed the FOV formula to modify my telescope Focal length to match a option H of 113 !!
The focal was then 1146mm (instead of 1200mm) ... it solves !! but i have a warning saying "the calculed Focal length is 1082,x please change for better accuracy), i change the length, i redo the solving, then it ask me to change a little more the focal length, but still around 1082-1084mm ..(and 1082 is the exact value that gives directly a FOV of 113 .. strange)

Well ... that"s all my investigatio ... i ended up doing a polar alignment with the sunrise.. it was beautiful .. and i got my vector to adjust my alignment ! (well i missed it coz i was really too exhausting ... so i packed up everything and drove back home to sleep a few hours !!

Well ... thank you for reading me (long email, i tried to make it the most detailed and explain all i did .
@Niki and others : did you check the H & L options the solver gets to solve your picture ? (maybe it's same thing ?)

Any help will be more than welcome ... we have a big astro event tomorrow with all association of my region ... i would very love to be able to participate and most of all i would love to show the great bundle kstar/ekos/indi which is for me just a pure diamond of open developpment !!!