I refuse to call it the Running Chicken Nebula

[Mosc_007 (Charles)]

Originally Posted by dylan_odonnell

That's true, the same object can look wildly different depending on how much of the outer details are resolved.


Thanks! The pieces are finally coming together.

d

I used DSLR's for about 18 months. Only this year I bought the QHY10 and the Hyperstar.

I am still learning about using the CCD. It is so different to my 100D and Modded 1100D.

I have a heap to learn about using a CCD. Much better detail but MUCH less sensitive than the DSLR. The Exposure time are hugely longer than the DSLR was.

It was all the extra detail you captured that thru me. When i did it with the QHY10 it looked a lot like a running chicken. Maybe Rotating it 90 degrees will help


Looks like I have to have another go at processing. I have only very limited processing skills with very limited software.

Great shot.


Charles

[dylan_odonnell (Dylan)]

Originally Posted by Mosc_007

I have a heap to learn about using a CCD. Much better detail but MUCH less sensitive than the DSLR. The Exposure time are hugely longer than the DSLR was.

It was all the extra detail you captured that thru me.

You know I had the exact same problem when I got the QHY12 and I was worried it was broken. At first I thought there was something wrong because the subs are so dark, but with DSLR you've got big bright images straight off the camera.

It's normal for the subs to be dark from a CCD, very very dark. You won't see any nebulosity or faint stars until you start stretching the data. But the data *is* there, and in more detail and dynamic range than the DSLR can capture.

The first thing you need to work out are the GAIN and OFFSET settings. It took me ages to figure out the sweet spot. In the end I imaged M42 Orion over and over, changing the GAIN and OFFSET and watching the histogram on each image. When the big hill on the histogram is close to the left - but not clipped - then you are on the right settings. For me it was Gain 27 and Offset 145.

I hope this helps!

d

[Mosc_007 (Charles)]

The DSLR was so easy to use compared to the CCD. Bright images straight from the Camera as you say.

I keep reading that CCD is more sensitive than CMOS. To date my experiance is that CMOS is at least 50 times more sensitive than CCD. But the CMOS doesn't have the fine detail.

I went with the Hyperstar when I bought the CCD as I knew the CCD was not as sensitive. But I wasn't expecting it to be this bad. Hyperstar at F/2 is 25 Times faster exposure time than using F/10. I was expecting the CCD to be pretty short images at F/2. Big mistake.

It is amazing the data is their though. I have taken subs with almost no Nebula in it, after processing, Wow, Its realy their.

5 Mins at F/2 is like 125 Mins at F10. And with the CMOS 5 Mins at F/10 was ok for almost all Nebula. The Helix was mildly saturating on the CMOS at 5 Min exposures using F/6.3

Now I am finding with the CCD at F/2 even 5 Mins (125 Mins F/10) is not long enough.

I did do some 30 Min subs on Rosetta with the QHY10 because I thought nothing was their. At F/2 the CMOS gets saturated after about 15-20 Seconds on objects like that. But even 30 Mins and the CCD wasn't even near saturated at F/2.

The main reason for the CCD was to get my Colours correct. After 12 Months I was getting sick of Red images from the Modded 1100D. Although some Nebula like Trifid look great with the stock 100D.

Biggest problem this year has been the Weather. We go to Linden 2 Sats a month when the moon is hiding. I think we have had 2-3 nights this year. Not much time to play !



Charles

[Retrograde (Pete)]

That's a really great image!

Interesting to read your comments regarding CCD vs DSLR - good comparison for those of us still at the DSLR stage.