Would really like to have a look at your work Pete, however for some unknown reason 'atscope' does not load. ERR_EMPTY_RESPONSE. Any chance of a IIS preview?
Would really like to have a look at your work Pete, however for some unknown reason 'atscope' does not load. ERR_EMPTY_RESPONSE. Any chance of a IIS preview?
I checked the URL externally to my PC.
Loads fine on both my mobile devices
Maybe clear your cache and re-load?
Nice one Peter. Lovely round tight stars to the corners and lots of detail.
You got nice star colour too. What mode and settings did you use for that? That's what I had trouble with last week.
I switched to broadband mode 0 and Gain 26 offset 40. Bit of a pain to switch modes in the middle of an imaging run but whatever is needed.
Using the PME, not the Mach 2?
Greg.
Thank Greg….I am finding the CMOS adventure to be an interesting one. I’ve settled on Hi-gain mode for readout, with a gain of 64 for use with shorter than roughly 1000mm focal length instruments.
With longer FL’s I find my large pixel CCD’s do a much better job. (the math is simple: with my RC a 9 micron pixel captures 81 sq microns of well sampled flux from the sky,
even if it captures just 60% of the that flux I am getting nearly 50 microns of “photon detection area” at the focal plane.
Binning with CMOS doesn’t deliver any gains, so the IMX455 even at 90% QE only gives me tiny “photon detection area” that is massively oversampled,
picking-up 5x less flux per pixel…least that’s my take on it. Also the noise profile of the calibrated CCD frames are buttery smooth with no residual structure.
Getting back to the posted image, I keep the CMOS subs down to 3-5 minutes, as the small pixels fill quickly compared to my CCD sensors. To mitigate subtle banding I dither guiding for the sub-exposures
….a very easy task for MaximCCD which is my workhorse of choice for capture.
As for the Mach2…it’s my “portable” mount and has yet to see first light..or is that first lug?
The GTX piggybacks my RC on the PMEII in my backyard dome.
I agree, I noticed a while ago that you could instantly tell if an image taken used a CCD or CMOS by the saturation of the star colours. I posted that on CN and got attacked with others saying its all about the processing. So not everyone notices it. Nothing new in that. Not my experience so far. You do need to pay special attention to colours in stars during acquisition and processing.
My CCDs though you don't really need to worry about it. Not sure why the star colours tend to be weaker. Perhaps a consequence of smaller pixels and coloured filters attenuating the light further so best suited to larger pixels.
I agree, I noticed a while ago that you could instantly tell if an image taken used a CCD or CMOS by the saturation of the star colours. I posted that on CN and got attacked with others saying its all about the processing. So not everyone notices it. Nothing new in that. Not my experience so far. You do need to pay special attention to colours in stars during acquisition and processing.
My CCDs though you don't really need to worry about it. Not sure why the star colours tend to be weaker. Perhaps a consequence of smaller pixels and coloured filters attenuating the light further so best suited to larger pixels.
Greg.
Hi Greg,
yes - Terry Hancock seems to have some nice star colours in his pic
but I had to look at many QHY-600 pics to find that one.
I don't know if his star colors are real or
if they were boosted in some way.
So I have noticed the same as you -
less star colour with CMOS sensors.
It may have something to do with the well depth being exceeded
and in which case some special shorter subframes would fix that by
copying and pasting the star colours into the final pic.
I suspect the problem with taming star colours is the small but sensitive pixels of this new generation of CMOS sensors....admittedly a nice problem to have...but requires a different way of doing business.
I find it curious how quickly these sensors saturate stars, but given the low read noise, taking many short subs looks to be the fix for going deep and preserving star colours. But at over 100mb per sub frame, you'll quickly fill up hard disk space and processing on older PC's takes an eternity.
I dropped a motza on a custom AMD Ryzen Threadripper workstation and 24TB NAS drive...but have to say the processing speed and storage problems are well and truly solved...well almost...If you go remote shifting gigabytes of raw data is going to take a while over much of the NBN
Back to the QHY600M...it tersely shows any shortcomings or problems your optics and mechanical systems..and taming them can be a nightmare...that said, when you do, the details in single 60 megapixel frame can be amazing and are well worth the effort.
Thank Greg….I am finding the CMOS adventure to be an interesting one. I’ve settled on Hi-gain mode for readout, with a gain of 64 for use with shorter than roughly 1000mm focal length instruments.
With longer FL’s I find my large pixel CCD’s do a much better job. (the math is simple: with my RC a 9 micron pixel captures 81 sq microns of well sampled flux from the sky,
even if it captures just 60% of the that flux I am getting nearly 50 microns of “photon detection area” at the focal plane.
Binning with CMOS doesn’t deliver any gains, so the IMX455 even at 90% QE only gives me tiny “photon detection area” that is massively oversampled,
picking-up 5x less flux per pixel…least that’s my take on it. Also the noise profile of the calibrated CCD frames are buttery smooth with no residual structure.
Getting back to the posted image, I keep the CMOS subs down to 3-5 minutes, as the small pixels fill quickly compared to my CCD sensors. To mitigate subtle banding I dither guiding for the sub-exposures
….a very easy task for MaximCCD which is my workhorse of choice for capture.
As for the Mach2…it’s my “portable” mount and has yet to see first light..or is that first lug?
Looking forward to it. The Mach 2 sounds like a dream mount for a moderate payload.
The GTX piggybacks my RC on the PMEII in my backyard dome.
Same except mine is on top of the RHA which is the guidescope!
There is also a new driver which offers another extended full well mode with even deeper wells.
Also one of the updated drivers (about 4 months ago or so) is supposed to reduce banding. I can't say I have seen much banding. Higher gain reduces banding somewhat.
Same except mine is on top of the RHA which is the guidescope!
There is also a new driver which offers another extended full well mode with even deeper wells.
Also one of the updated drivers (about 4 months ago or so) is supposed to reduce banding. I can't say I have seen much banding. Higher gain reduces banding somewhat.
Greg.
Indeed QHY have lifted their game considerably with their drivers and install packages.
BTW as the lockdown has endured along with the inclement weather, I've added a synthetic luminance layer derived from all the HaRGB subs.
(I'm getting to like PixInsight...now there's a worry! )
The updated version at the same URL doesn't look too shabby, even if I do say so myself, and remarkable for a mere hour and a half of exposure time.
Yes that does look great. Adding Ha as luminance normally damages colour so adding the RGB with the Ha helped with that eh?
Star colours are very good too.
Greg.
Indeed... adding just Ha as a luminance layer totally buggers up the colour balance and brightness of the scene.
By summing all of the channels you are getting panchromatic + extended red data, which also gives you an extra level of dithering/noise reduction that CMOS really benefits from.
You can't use it as a 100% luminance layer, but at 50% it brings up the faint background stars without overly distorting the colour balance.
Also for the record...the centre of the Lagoon is not blue, it's red, but the H-beta emissions will give some Blue+ Red. i.e. magenta.
