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Post by Dragon Man on Apr 14, 2017 12:58:28 GMT
I have become fed up waiting for some clear sky, and because we had a group of Uni Students here at our Observatory last night, I gave in and fired up the new Advanced 224 Kit regardless of the heavy fog we had! They came to see objects in the night sky but the fog ruined that for Visual, so I wacked in the Revolution 224 camera and showed them the Moon, Jupiter, Saturn through the Fog The results were pretty good considering what the camera had to look through! And the images of Joop and saturn show a distinct glow around the edge of the planets from the glowing fog So, these first attempts aren't as good as it gets, but it was fun anyway. I'm not usually interested in Imaging Solar System objects, but because of the conditions I had nothing else to show them So, here's my first attempt on Solar System objects with the Revolution 224 camera. Firstly, these are single frames from the original Video showing how foggy it was and how the camera works on Live observing in these conditions: and then after a very quick stack of 10 seconds of Video on each object in Registax, and a tweak on brightness, and a reduction of saturation on the Moon:
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Post by ChrisV on Apr 14, 2017 13:54:48 GMT
They look excellent Ken. A bit of fog isn't going to stop you !
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Post by davy on Apr 14, 2017 15:02:23 GMT
They are fantastic ken and shows just how well video does in it's class of astronomy.. visual astronomers at your club should be lined up to buy this camera.. it is live and visual just an electronic eye has replaced the basic human eye,, to me it's the progression of man looking at the stars without a telescope to the first astronomers looking through a scope
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Post by Dragon Man on Apr 14, 2017 15:45:02 GMT
Thanks Chris and Davy Here's a quick Video:
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Post by Deleted on Apr 15, 2017 3:06:13 GMT
That's nice detail for a 10s stack.
Price of 224 cameras (and others) has come down a lot too over the last year or so.
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Post by Dragon Man on Apr 15, 2017 7:25:11 GMT
Thanks Robert. Popularity and a large range of vendors is driving prices down, They all want our custom, and that benefits us
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Post by Rick in NWArk on Apr 20, 2017 15:46:51 GMT
Simply fantastic Ken! I don't think that we talk enough about how cameras can push thru fog and haze and some clouding. This shows that not only can you do it for observing, but you can get some nice stacked images as a result too!
Great job!
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Post by Dragon Man on Apr 20, 2017 17:49:12 GMT
Thanks Rick, Yep, these cameras certainly work through thin cloud and fog. But you can see in my stacked images there is a weird ghostly glow around the planet from the glowing fog Oh well, at least I know it will work great on a clear night
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Post by Dragon Man on Apr 24, 2017 13:07:04 GMT
The weather is still terrible and we are getting heavy fog every night (tonight we have been put on flood alert because of the torrential rain that won't stop!), but I am determined to try this Revolution 224 on DSO's, so rather than keep waiting for a clear night, last night I decided to just go for it and shoot through the fog Well, what a pleasant surprise!!!! Here is the Keyhole Nebula inside the larger Carina Nebula, through FOG, using the Revolution 224, IR filter, Minus Violet filter, Skywatcher 6" f/5 Achromat refractor. 20 second frames x 3 stack (Averaged, not Additive) using ToupSky software stacking and 'Frame Align' feature. A fantastic near-Live view in only 1 minute: I am impressed with the detail in the Bok Globules sitting just above the lower dark dust cloud When our floods are over I will try again, and hopefully the fog will go away too
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Post by Dragon Man on Apr 24, 2017 13:38:55 GMT
And here's Trifid Nebula using the same gear as above except I used a #12 Yellow filter instead of the Minus Violet filter. Notice how the Yellow filter has killed the Blue in the Reflection Nebula side of Trifid turning it pale yellow I'll try it using the Minus Violet next time: Same image stats as Carina above: 20 seconds x 3 frames:
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Post by Rick in NWArk on Apr 24, 2017 15:52:01 GMT
Would something like 5 stacks @ 12s eliminate the need for the filter? Those stars may still be bright enough to produce an achro halo.
Love the detail from the smaller pixels!!
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Post by Dragon Man on Apr 24, 2017 15:59:28 GMT
No Rick, I tried that. I started at 2 seconds and stacked. The image stayed faint and couldn't see the nebula. At 5 seconds carina showed up faintly, but stacking didn't improve anything except to clean up the background noise.
10 seconds was getting better but the stars were already bright by then, and displaying halos.
Plus, the filters are needed because this is an Achromat. I tried without, to see how the CMOS would handle it compared to CCD, but everything was a mess.
What I have discovered though is that the CMOS is more sensitive to the Yellow filter than a CCD is. In my CCD cameras the yellow can't be seen, and the blue in Trifid stays blue, and the Violet fringing disappears. But with these CMOS cameras the yellow shows up really easily and no amount of fiddling with Hue, Contrast etc could get rid of it. That's why I used the Minus Violet filter which worked OK in the CMOS, but doesn't work in my CCD cameras.
Weird huh!
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Post by Rick in NWArk on Apr 24, 2017 23:04:17 GMT
No Rick, I tried that. I started at 2 seconds and stacked. The image stayed faint and couldn't see the nebula. At 5 seconds carina showed up faintly, but stacking didn't improve anything except to clean up the background noise. 10 seconds was getting better but the stars were already bright by then, and displaying halos. Plus, the filters are needed because this is an Achromat. I tried without, to see how the CMOS would handle it compared to CCD, but everything was a mess. What I have discovered though is that the CMOS is more sensitive to the Yellow filter than a CCD is. In my CCD cameras the yellow can't be seen, and the blue in Trifid stays blue, and the Violet fringing disappears. But with these CMOS cameras the yellow shows up really easily and no amount of fiddling with Hue, Contrast etc could get rid of it. That's why I used the Minus Violet filter which worked OK in the CMOS, but doesn't work in my CCD cameras. Weird huh! As I understand it - both the CCD and CMOS are sensors of monochrome pixels that just read the light intensity after it passes through a color filter. So the real difference is that the color filters are different and reacting to the light coming thru the minus-Violet or Yellow filters differently - one is leaving more blue and showing little yellow and the one with the CMOS is having the opposite effect.
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Post by Dragon Man on Apr 25, 2017 6:55:21 GMT
Yes Rick, that seems to be the effect.
The IMX224 CMOS is RGB The ICX811 CCD in R1-b, R2, and sensors in Mallincam Xtreme, Xterminator and other analogue cameras is CMYG
So the Colour filter Bayer Matrix is the difference.
In the CCD Analogue CYMG cameras the Bayer Matrix is allowing lots more CA and Violet through. The CMOS RGB filters seem to block a percentage of Violet, and CA is almost non-existent even without the filter!
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Post by Rick in NWArk on Apr 25, 2017 20:21:59 GMT
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elpajare
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Post by elpajare on Apr 26, 2017 6:16:22 GMT
Thanks to Ken and Rick for this fantastic master class.
Helps to understand a little more how this modern cameras works.
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Post by Dragon Man on Apr 26, 2017 11:47:05 GMT
Here is an interesting graph showing the diffrerent wavelengths between CCD (CYMG) and CMOS (RGB) sensors. Note how each one sees different areas of the spectrum, with CMOS being more responsive in the Visible, similar to the Human eye: See here for a helpful read: www.fen-net.de/walter.preiss/e/slomoinf.html#COLOR
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Post by Deleted on Apr 27, 2017 23:39:03 GMT
Wow, I didn't realise there was such a difference in response. Interesting and useful...
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Post by ChrisV on Apr 28, 2017 8:01:12 GMT
That difference is really interesting. Now it makes sense why the infinity images people show have that orange tint. They have a bias towards that end of the spectrum while cmos sits more on rgb ??
Edit: well they are both biased .... Not just the CCD
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Post by Dragon Man on Apr 28, 2017 11:36:13 GMT
That difference is really interesting. Now it makes sense why the infinity images people show have that orange tint. They have a boas towards that end of the spectrum while cmos sits more on rgb ?? Probably right Chris. CCD's do need a lot of either filtering or colour balancing. Now I can see why. That graph probably explains why CMOS doesn't need as much IR cut filtering either because it isn't as heavily into the IR as much as CCD is. Yes Robert, very interesting.
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