Another Eta Carina with the QHY8L

[DJ N]

Had a bit of a longer session with the QHY8L last night, with the aim of getting "more" subs in. In addition, I have better set the gain and offset, so I was keen for another comparison shot. The ambient temperature was quite high at around 22 degrees; I had the camera running at -12.

So details are as follows,

12x 8 minutes, imaged with the ED120/QHY8L (gain at 4 and offset at 123), together with darks, bias and flats. Stacked in Deep Sky Stacker and processed in PS.

For a fairly warm night, I think the image is pretty 'clean'. Much better in regards to noise than the 400D was (for obvious reasons).

Thanks for looking

[renormalised (Carl)]

Nice shot

Yeah, this warm, humid weather isn't doing imaging much good.

[dugnsuz (Doug)]

Hi Daniel,
I think the image looks excellent - would love to see a higher res version.
Folks look at me like I'm mad when I say I can't wait for winter so that my cooled DSLR can get down to the low numbers temperature-wise.
Cheers
Doug

[DJ N]

Originally Posted by dugnsuz

Hi Daniel,
I think the image looks excellent - would love to see a higher res version.
Folks look at me like I'm mad when I say I can't wait for winter so that my cooled DSLR can get down to the low numbers temperature-wise.
Cheers
Doug

Thanks Doug. Funny you should say that about winter. I was just telling some friends the exact same thing about nice cold (and clear) winter nights.

[Hagar (Doug)]

Nice one Daniel, looks like you are getting the 8L to work very nicely. I always said the only thing lacking with the QHY8 was temp control and this camera has it so it should be a bottler.
Keep at it, getting better every image.
Well done.

[wysiwyg (Mark)]

Danny,

Good effort, but I have to say its not the best Eta you have produced. I'm sure that has alot to do with using a new piece of equipment.

Keep an eye out on oversaturating your stars, there is hardly any other colours in them apart from white and they are all saturated. You should have quite a few orange and blues in that FOV when correctly colour balanced and with optimum saturation levels.

8 minute subs might have been too long in this instance. The best way to test it, is to take for example a sequenece of 8 x 1 minute interval exposures to build up to 8 minutes or similar and analyse your star saturation.
So if at 8 minutes 99% of your stars are saturated you have gone too long.
That does not mean you cannot take longer exposures to get deeper data, but you will have to combine your short and long using HDr or similar process.

For the longer exposures its important to keep your background levels at optimum based on your imaging rig.
Exposure calculator, remember?

Mark

[multiweb (Marc)]

Nicely done indeed. Lovely colors and details.