Bob Andersson

Hi Matts, NII was stronger than SII and OIII was quite weak. Yes, I am using 3nm filters (Astrodon). Even so I subtracted a small fraction of the much stronger Ha signal from the NII. Not enough to get anywhere near black clipping but enough to improve the contrast of the NII image a little without introducing unwanted Ha detail. Bob.

Hi folks, NGC7822 And here it is at 2048 x 2048. TEC 140 plus FLI ML16803 mounted on a DDM60 Pro. Ha - 8 x 1500secs, OIII, NII and SII all 18 x 1500 secs, R, G and B each 8 x 200 secs. Astrodon 3nm filters used for the narrowband subs. Processed in PI and PS. The colour palette is ordered by atomic weight with Ha = red, OIII = orange, NII = green with a splash of blue and SII = blue. White balance of the nebulosity was set in those areas where Ha, NII and SII reached their maximal values. The palette chosen may be unusual but I think it has virtue, both aesthetically and as an aid to seeing what is going on. It also means that there is a chromostereopsis effect with the whiter and bluer stars and, to some extent, the whiter nebulosity appearing to float slightly in front of the redder parts of the image. Such a 3D effect is pure fiction of course, but fun if you like to let your imagination lose. If you don't see this effect then you may need to relax your eyes slightly as you view the image. If you still don't see it then maybe you just have really good eyesight. Best seen on the larger image and, if possible, with a dark surround. The DDM60 Pro performed beautifully. At just under 2 seconds of arc per pixel the stars in the Ha subs were nice and round even thought the mount was unguided. Bob.

Hi Robert, Thanks for that, a very interesting post. I honestly have no idea whether I have the hub you describe but I'll assume for the moment that I do. Presumably the fourth port is used internally to provide the USB interface for the mount's controller? The Transcend TS-HUB3K looks close in geometry but I have a feeling it is still too big to fit as a replacement. But if the wiring is as you describe then it would seem very possible to do a USB 3 upgrade without returning the mount to ASA provided ASA can source a suitable hub. I'll contact ASA tech support directly and ask the question. Bob.

Hi Ian, Thanks for the welcome. I've checked since my last post and USB 3 is full duplex so, unlike previous generations, data can flow both ways simultaneously rather than the direction of transfer being controlled by the host (source). This is probably worth having even if, as would be likely, all the kit hanging off the hub in the DDM60 Pro is USB 2 but maybe not if the cost of upgrading were too high. If it meant replacing the PCB controlling the mount rather than a separate USB hub PCB then that would almost certainly cost too much but I thought I'd ask the question and see if anyone at ASA wanted to pick it up. Bob.

Hi folks, I've just joined the forum, not having been willing to join the social media groups previously used. I've had my DDM60 Pro for over a year now and I can't speak highly enough of it. I have the previous generation of position encoders but that isn't an issue after calibration. The only item on my wish-list would be replacing the current USB 2 hub with a USB 3 hub. USB 3 is faster and, I believe, full duplex and with the mount, camera, filter wheel and focusser all sharing a single USB port from the computer (Windows 7 32 bit) I think I occasionally see signs of congestion. Is a USB 3 upgrade something that other owners might be interested in. And would it even be possible to upgrade the DDM60 Pro without returning the mount to Austria, something I wouldn't want to do. Bob.