Florent, Thanks for all the effort you've made to investigate this. Also for sharing the pixel math formula you used to create a scale dark. All this is way over my level of understanding but gives us good reason to believe that the current issues are all fixable. Cheers, Ray

for the flat , it is a little difficult to use them due the light leak on the left. As this light is not present during the night , it completly mess the calibration of light frame. i think the best is not use flat at all , but there is a lot of dust on the mirror. difficult

Mount is retaking darks as I type, the camera does not have a shutter so they can only be done on dark moonless nights this meant this evening was the earliest opportunity as they take 6 hours and the moon will still be out the way Flats I am thinking about a solution Steve

Phil is off on Holiday this week but I will do my best to get the new darks from last night zipped up and made available for download If I manage I will let you know in the forum but for now Pier 1 is back up and running Re flats - at present we have a maintenance trip booked for the 22nd so if all else fails we will address the light leak in flats then if you can bear with us Steve

flats in an open scope are difficult to do i think you use a flat panel ?

We have a flat panel, roof flat system and of course we can take sky flats however in this case we believe its a small amount of light leak from the ZWO OAG that's causing the issue. None the less whatever the issue we will get it solved when we are there. In the meantime we can try different ways of garnering the Flats in the hope of an interim solution Problem solving remotely is never an easy thing to do LOL Steve

Ok everyone, The flats issue on Pier 1 1, After much testing it appears 2 of the 31mm unmounted narrowband filters have slipped position in the wheel causing a small amount of off-axis light to leek in, we have checked and this appears to be a very common issue with the ZWO wheel as the holder is a lot bigger than 31mm and the filter shield/holder does not always hold the filter in perfectly. So much so that an after market solution has sprung up to fix the issue! https://buckeyestargazer.net/Store/FilterMasks.php We have order these 3d printed centring holders from the USA We are hoping they arrive in time for the next trip but just in case they do not arrive in time, I have also instigated a back up plan in the form of 1mm thickness O-rings which we can put round the unmounted filters 2, This present s a small issue in so much as I doubt we will obtain decent flats for the 2 offending filters until we get to Spain and then to make matters a little worse it will make all previous flats void because we need to remove the wheel to do the fix. 3, So there it is Boys n Girls, the solution with a slight bitter after taste I am afraid to say However once done this issue should not present itself again! Steve

Phil is off on Holiday this week but I will do my best to get the new darks from last night zipped up and made available for download If I manage I will let you know in the forum but for now Pier 1 is back up and running Re flats - at present we have a maintenance trip booked for the 22nd so if all else fails we will address the light leak in flats then if you can bear with us Steve

Hi Steve, Have the new darks been done as I cannot seem to find them. Cheers, Ray

Yes, Phil is putting them on the server now Ray They should be ready this afternoon

Just zipping now Ray - they will be in the normal calibration area and not on FTP

hello i ve test the new dark frame on the tulip dataset . The ampglow is completly remove now , i even not use flats and registered file are ok thanks for the new darks Steve , you say that there is a collimation issue on the scope that will be adressed on the next trip ?

hello i ve test the new dark frame on the tulip dataset . The ampglow is completly remove now , i even not use flats and registered file are ok thanks for the new darks Steve , you say that there is a collimation issue on the scope that will be adressed on the next trip ?

Awesome news on calibration Yes, top left corner is just a little out from memory, we leave for Spain on the 22nd so will sort it that week Steve

anybody can test the M101 dataset ? i ve got very strange behavior of L flats ? need to re test , may be i made an error but dust isnt corrected as it is on Green or Red channel

I ve found the prob . all L data before the night of 29 july are way up in median level and the Flat doesnt correct very well the dust . i didnt understand why the median level is rising on a line . it is like data are accumulated in each frame ... i v resbumit correcting L data for M101 before this object diseaper