32 replies to this topic

[Midnight Dan]

Hi scopenitout:

 

In my neck of the woods, in the winter, we get one clear night a month - at most! It's extremely depressing. :-(  I did get one partially clear night in February and was able to get a few hours on M51. So I've taken a total of 2 real images with this camera since I had it in December - Orion and M51.

 

I'm not as happy with this one, but I probably needed more time on it.  Plus, because I was anticipating clouds later in the night, I started exposing early when the sky background was a little brighter and based my 20xRN mean value on that.  As the night got darker, I realized my mean was dropping substantially and I should have used longer exposures.  In any case, it has more noise than I'd like, as well as a number of other issues.  But it's still way better than my last attempt on it a couple years back with my T3i.

 

Taken with EdgeHD 8 on iOptron iEQ45 Pro mount

Lights: 60 x 180 seconds

Darks, Flats, Bias: 50 each

Filter: IDAS LPS-D1

 

 

-Dan

[scopenitout]

Thank you, Dan!

Yeah...weather seems to be bad for this hobby just about everywhere.

But your image? It looks very nice. I think this camera is a great choice for those who want a DSLR replacement.

[mahaffm]

Very Nice Dan, thanks for sharing.

 

I'm still learning both the imaging side of things as well as the imaging processing side. From what I've been able to do so far the ASI071 is a very good camera. Just need more clear sky so I can work with this camera more.

[jgraham]

Dan; do you recall the gain and offset that you used for this?

 

Thanks!

[stargazer_ken]

Midnight Dan,

 

Your lovely graph and images have disappeared! I miss that chart telling me the settings for the ASI071. In their place is an image that says "Please update your account to enable 3rd party hosting" and it's by Photobucket.com.

 

I would be happy if you put a text version of the table up. That way it wouldn't be subject to image hosting problems.

 

Thanks,

 

Ken

 

 

[Midnight Dan]

Yeah, Photobucket started charging for any sharing of images so I dumped them.  Here's the chart.  It's been updated to include 10xRN, 15xRN, and 20xRN.  I also added 3xRNSq because some people felt that 3 times the read noise squared was a better metric.  

 

Also, I've highlighted the two rows that I use the most.  Unity gain works very well with this camera because it has such a large dynamic range.  You don't really need to go to zero gain to get enough dynamic range for most targets. 

 

 

In any case, I shoot for 20xRN, but under some conditions that's a bit tough.  If I get at least to the 3xRNSq level I'm happy.

-Dan

Edited by Midnight Dan, 11 October 2017 - 05:13 PM.

[stargazer_ken]

Thanks Dan!

 

It's good to see that there is quite a range that should work. I usually use Unity Gain as well and try to go a little above. I am able to expose M42 and not over expose the nebula or the trap so it does seem to have a good range. Processing so you can see it all is another story!

 

Ken

[clockman]

ZWO has an upgrade program now for their newer Pro version for $299.  That offer expires in December