Horsehead 1st light QHY600m

[gregbradley]

I got an excellent adapter from Joshua Bunn on this forum so I could use the camera I have had for a while. I was waiting on the free adapter that was supposed to come with the camera from Cyclops Optics but it hasn't arrived. I received the camera over 2 months ago.

The camera is extremely sensitive and highly resolving. It seems it will be a good match to my scopes.

This is only 1 hour (12 x 300 seconds Gain 26 Offset 10). Still a bit of noise but way ahead of what would I normally would get with 1 hour of Ha.

AP Riccardi Honders scope F3.8.

I used darks, flats, biases for this image.

https://pbase.com/image/171407366/large

https://pbase.com/image/171407366/auto

Greg.

[Retrograde]

Wow that's impressive for only an hour.
Congrats on first light!

[gregbradley]

Thanks Pete. Yes I was impressed at how deep it goes very quickly.

I still have some tilt to work out not really seen here but visible in the RGB.

Greg.

[strongmanmike]

Yeah cool Greg, cooking with..?..gas? literally! :lol:

Mike

[ChrisV]

Totally excellent! So much detail, but like, how the hell does something like those gas clouds take shape?

[gregbradley]

Hehe Thanks Mike.



Yes the forces behind that are somewhat of a mystery.

Greg.

[Peter Ward]

Gotta be happy with that :thumbsup:

I've been exploring binned modes with the 600M recently. No revelations there I'm sorry to report.

They seem to excel with short fast optics, but when oversampled...say at 3400mm...(who would do that?? ... :whistle:)
and with faint targets, I get banding at the noise floor. ...hence I suspect M&T are correct: for ultra faint large image scale work, CCD's still rule.

That said...that puppy with the RHA...humm...very tidy indeed.:thumbsup::thumbsup:

[gregbradley]

Thanks.

Banding has been reported as an issue with the 294M. I have only seen it in very short underexposed images.

This IMX455 is more like the CCDs than the earlier CMOS models though. 16 bit, smooth, very little noise, no amp glow and very high QE in narrowband as well as LRGB.
It calibrated like a CCD image. Some have had a lot of trouble calibrating 294M images. I haven't had that yet but I don't use bias's with that camera.

But I agree, I am not planning on selling my CCDs either. I do plan to try it on the CDK17 and try 2x2 and see how that goes. Probably with the reducer.

Otherwise its a good match for shorter focal lengths.

Greg.

[multiweb]

Awesome shot Greg. Plenty of details. :thumbsup:

[gregbradley]

Thanks Marc.

I have an HaLRGB version I am just putting the final touches on as well.

If we ever get clear skies again I think I will add to this.

Greg.

[Peter Ward]

I just had another long look at you h-alpha data...It's really, really, good, but does indeed show subtle banding in the extremely faint/ shadow areas
....no deal breaker....but I suspect CMOS requires a different way of doing business to mitigate this annoying artefact.

[gregbradley]

Yes I can see that too.

2 points here to handle it. One would be to use a higher gain so the banding is pushed further down by the signal.

Recommended settings for narrowband are Gain 56 and 50 offset (mode 1). I didn't use that simply because it was first light, I only have a dark library for 26/10.

The other solution if this does not work well would be too expose for longer.
I'd keep an eye on highlights blowing out and use Mode 3 for extended full well if it needed it. I used an ASI183 with 600 sec subs high gain and did not see bright areas blow out in narrowband nor banding.

I really only plan to use 3 sets of settings:

Mode 1 56/50 for narrowband and 300-600 sec subs.
Mode 2 26/10 for broadband
Mode 3 extended full well setting for really bright stars like Mr Alnitak.

If the above don't work then we are fresh out of luck.

Greg.

[Placidus]

An amazing result for just one hour.

[gregbradley]

Yes I thought so too. The camera is up around 74% QE for Ha and similar for O111.

Greg.