M42 with Canon 6D that has dirty Sensor ... how to tell..!

Discussion in 'My Astrophotos' started by ROBERT T SCHAEFER JR, Jan 27, 2020.

  1. ROBERT T SCHAEFER JR

    ROBERT T SCHAEFER JR Cyanogen Customer

    Joined:
    May 13, 2018
    Messages:
    303
    I was reading in the MaximDL Pro Manual that you can control the amount a 'correction' will happen for
    1 second in the Settings after you Calibrate and then there are two controls , one for RA-X and Dec-Y
    and the manual shows a -4 and a -3 being used . This I think means how much of a pixel the 'correction'
    will do in 1 second of time … so if RA-X-Axis has increasing RA errors the maybe if you dial up the
    RA-X statistic numbers to a +1 value or higher the 'correction' will move 1 or 2 pixels in 1 second and could
    help with 'guiding' problems …. I was looking for a way to control the Mount's 'motor' speed but there isn't
    a command to do it so you rely on a Calibration at the 'object' you're at with an Astro-Physics 1200GTO Mount
    at 1xSiderealGuideRate . You can dial down these settings and dial down the Dec Aggressiveness to ' 0 ' and
    the RA Aggressiveness to 1 or less and then image relying on the Mount's PEC Error correction and acquire
    images drifting a little bit for about 2 minute images …. or like with the SBIG 'Track and Accumulate'
    and start with a "PinPoint Astrometry" 'solved' image and put the 'solved' coordinates in the Telescope Tab
    and do a GoTo to get back to the original 'solved' position ; also the 'guide' star if it's being use if it can use
    the larger than 32x32 sub-frame will show it's drift across the sub-frame and when it gets close to the edge
    you can use the GoTo of the 'solved' coordinates to get the star back to the center of the subframe … but I
    don't know yet if this idea will work but it might … without letting 'corrections' happen to the Mount .

    [next theory]
    152mm A+M Refractor(OfficinaStellare-1200mmF/L) and CanonEOSII 6D'stock-new 2017 model from B+HPhoto' using PrimeFocus 1200mmF/L and a BreakThrough X4-UV 49mm filter . The purpose of this image which is two 20secISO50 RAWMonochrome and two 255secISI4000 RAWMono Autosave images done with MaximDL Pro V6.20 was to try seeing what the Astro-Physics 1200GTO Mount would do with just it's 'PEM-ON' pec correcting curve I made and up-loaded to the Mount's PEM ... I Scaled it up 1.50 and re-loaded it and this is the result at four images Sum stacked . What I did was I was doing images before the clouds covered the good imaging sky and I capped the Guider Scope and I did a 10sec Bin2 to the already Calibrated for Guiding M42 area and I used the 'screen-stretch' to darken the image so only a 'STUCK' pixel would be visible and the was one there and then I press the 'Track' radio button and 10sec went by and the 'STUCK' pixel was in the sub-frame for 'guiding' and I dialed down the Dec Y-Axis Aggressiveness to ' 0 ' and the RA X-Axis to ' .5 ' which is less than ' 1 ' and there isn't any correction happening to the Mount but the 'motor' should be moving at the Calibrated 1xSiderealGuideRate speed and the Mount's PEM-ON is doing the RA corrections as PEC Corrections to prevent the RA wiggle which might have oblong stars ... but this theory seems to be working to keep the stars round for 5minISO5000 exposures . With better sky and a real good 'Polar Alignment' this idea can be helpful and might help eliminate 'guiding' errors when not at the Telescope for awhile so less images will be lost due to un-known or un-monitored large RA or Dec 'guiding' foul-ups . { Here is ' A Simple Plan ' with this image after Sum stacking two short exposures and two longer exposures , and after stacking I put the 'screen-stretch' to Max-Val and then I 'opened' the "Histogram Specification" command and selected the 'Gaussian' radio button and a fully illuminated area can be seen... and in my case with the Canon 6D's dirty sensor it shows round globules in the corners and other places besides showing the stars in the image ; then if you put the 'screen-stretch' to 'Planet' the low light areas will decrease.. leaving the stars and the 'object' .. in this case M42 which can show a lot of spatial light for this kind of test . I know the Anti-Alaising filter on the DSLR needs to be cleaned on both sides because while I was attempting to clean is quite a few times yesterday ... some of the Isopropyl Alcohol seeped in and got around to the underside of the filter and dried with a remaining watermark and I get at it because watching videos on the internet and other pictured demonstrations on how to take a Canon 6D apart to modify it shows there are about 20 different screws to remove and about 8 different ribbon type electrical connections to un-hook and the take out the Sensor and remove the Anti-Alaising filter to get at other filters and if you get the camera back together again it might not 'Turn-On' and then it must be sent to Canon to get it going again ... so "Spencerscamera.com" seems like the best idea for around $50.00 to remove the Anti-Alaising filter permanently ; so till then it is useless except for PEMPro Curves ... so' I'l have to send it to get it fixed . The Canon RebelT7i doesn't seem to have this problem yet but these cameras aren't air and water-tight forever so this is what it came to with a 3 year old CanonEOS 6D'stock-new 2017 model from B+HPhoto' ..otherwise the camera is real good .} . x
     

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