Laurin Dave

Are you using the ZWO filter wheel? If so vignetteing with either 1.25 or 31mm easily correctable with flats.. I've used both and saw very little difference.. 31mm just slightly better Dave

Fabulous image, how good is he going to be when he grows up ! Dave

Turn the gain down .. it’s in the camera control tab

Its 6.5mm

With ASI1600 to get 55mm backfocus its flattener then 11mm and 16.5mm spacers FW then camera ie take the 11mm spacer off the front of the camera and connect camera direct to FW. There are diagrams on their website showing how its done. At the moment you have 65mm. Dave

Canon lenses have 44mm backfocus and the distance from the front face of the camera to the sensor is 6.5mm so the camera adapter plus spacer should total 44-6.5mm i.e. 37.5mm to obtain focus. Have you measured it? Looks like the zwo diagram for the 183 is incorrect in that you do need to use the 11mm female to female spacer as it shows in the diagram for the 1600. For what it worth I have the 1600mono and filter wheel and the appropriate version for Nikon lenses and it focuses fine. Dave

Surely Darkframe should have sorted that out as part of their Stellardrive mod. I'd get in contact with them and ask them to fix it. Dave

Thanks Steve for your excellent write up, I shall add it to my copy of your Dark Art or Magic Bullet book which arrived yesterday .. I did notice that in this post Deconvolution now starts on page 51 rather than 45 as in the book.. What other gems are you working on? Dave

Hi Nigel, Nice image, I had a look at your data last night whilst waiting patiently for my power supply to fail as I imaged the Fireworks galaxy in Ha. To me Dynamic psf in Pixinsight seems to show that the minor elongation gets worse on the Red from top left to bottom right and on the Green and Blue in the opposite direction, also the Blue and Green are generally more elongated. Also when combining RGB and after background neutralisation there is a pronounced red to green gradient left to right... So these make me wonder whether you did a meridian flip between red and green/blue and whether you have balance and polar alignment/field rotation issues, I don't know whether you are using an OAG or guidescope or are on a on a permanent pier. Hope this helps Dave