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Starlight Live V1.1

Paul81

By Paul81
in EEVA - Reports

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Paul81

Paul81

Posted
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Don - The version number should be on display in the bottom right of the main user interface.

I'd like to add support for ZWO cameras in the future, it's just a question of time to finish off all the features on the todo list first which is going to take a while as nowadays I don't have as much free time as I would like to work on the project!

Sent from my iPhone using Tapatalk

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Hibou

Hibou

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Hi Paul. If you already have a couple of command line arguments, I would like to suggest a couple more (all optional)

StarlightLive [NoDisplay] [DriverID] [FileName.FITS] [Exposure secs] [Frames] [nBin] [Temperature]

NoDisplay - run an instance in background with no display

DriverID    - specify which of multiple cameras to use

FileName  - output filename for stacked FITS image

Exposure  - the exposure time in seconds

Frames     - the number of frames to collect and stack

nBin          - the nxn binning if not 1x1

Temp.       - the readout temperature (for cameras with a cooler)

This would allow StarlightLive to be run within a script, which would open all kinds of custom possibilities. And it can't be too difficult if you have already foreseen command-line arguments :-)

As for extending it to other cameras, ASCOM would open it to most everything... including other SX cameras.

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Hibou

Hibou

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ZWO cameras have ASCOM drivers, so that would be the way to go if you really want a cheap camera with small CMOS chip.

On paper they will be less efficient and more noisy than the larger CCDs in the lodestar cameras, but they are inexpensive.

BTW it is not widely advertised but the Atik "Core" software now includes the Infinity on http://www.atik-cameras.com/downloads/ 

It is perhaps too early to compare, but the choice of otherwise comparable products can often be determined by the software.

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Astrojedi

Astrojedi

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ZWO cameras have ASCOM drivers, so that would be the way to go if you really want a cheap camera with small CMOS chip.

On paper they will be less efficient and more noisy than the larger CCDs in the lodestar cameras, but they are inexpensive.

:

:

Hibou,

That is a very broad assertion and not quite correct (even on paper). As an example in my experience the ASI224 CMOS based sensor/camera is actually more sensitive than my Lodestar X2C and has significantly lower read noise (but with more hot pixels and amp glow - which needs dark frames to correct).

Overall I have achieved better results with my 224 on my Alt Az mount vs. the X2C.

Hiten

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Hibou

Hibou

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That is a very broad assertion and not quite correct (even on paper). As an example in my experience the ASI224 CMOS based sensor/camera is actually more sensitive than my Lodestar X2C and has significantly lower read noise (but with more hot pixels and amp glow - which needs dark frames to correct).

I don't want to start an argument here, but you can easily find examples that will prove my point, not only on paper eg at the end of this comparison. 

You need to download the image files and view them with a 16-bit application like imageJ rather than just look at the 8-bits you see on the screen.

CMOS is getting better and has taken over consumer imaging, but you still need an expensive sCMOS chip to compete with CCDs for low-light imaging. Consumer CMOS is less expensive, and has faster readout. But the dark current is much higher, which makes them less suitable for longer (seconds) exposures, when the slower CCD readout is less important. It's only ~0.2s for the lodestar anyway. The readout noise is then less important than dark current or hot pixels. Amp glow just shouldn't be there. And if you need dark frames even for short exposures, that is a big disadvantage for cheap CMOS. 

I have seen a lot of discussion about "sensitivity" on astronomy forums. First there is "quantum efficiency" which is just the efficiency of detecting a photon; it ranges from 50% to 75% for inexpensive chips - not a big difference, but the Sony CCDs win there. Then there is the area of the pixel; the number of photons collected depends directly on that area, and there are big differences.  OK, if you have a fixed focal length, a bigger chip will just give you a bigger Field-of-View, not necessarily a brighter image, and big pixels may not give you the resolution you need. But you just need to increase your focal length to compare different chips using the same FOV. The bigger Sony chips are then much more "sensitive" as well as having much lower total noise, dynamic range etc... and they are more expensive.

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Astrojedi

Astrojedi

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No argument just discussion.... That link talks about the 120MM not the ASI224. Very different sensors. Also 120MM is an older generation CMOS sensor.

The QE for ASI224 is estimated between 75-80% same as the 825/829. More critically for stacking the read noise is 0.75e - 1.5e vs. ~6e for the 829 based cameras (and 5-6e for the 825 based cameras). And in actual use I have achieved better images/dynamic range in shorter exposures vs. the LX2C (I have both cameras so have the benefit of a direct comparison). The difference diminishes as you use longer exposures but the point is that you cannot say the ASi224 is any less "sensitive".

I agree with you on dark current and long exposures (I don't think at present the CMOS sensors are well suited for very long exposures but even that is changing quite quickly). But here we are talking about relatively short exposures for stacking (typically 10-60s sub exposures).

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Hibou

Hibou

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The QE for ASI224 is estimated between 75-80% same as the 825/829.

I agree with you on dark current and long exposures (I don't think at present the CMOS sensors are well suited for very long exposures but even that is changing quite quickly). But here we are talking about relatively short exposures for stacking (typically 10-60s sub exposures

Well, you stack your noise as well :-) even if you use dark frames to subtract dark current, hot pixels, amp glow and whatever... But I agree that the new Sony CMOS chips in the ASI224, even if equally small and therefore gathering less light with the same QE, appear better than the older Aptina chips in the ASI120.

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JamesF

JamesF

Posted
Posted

Is this a successor to Lodestar Live or are they separate? Sorry if this has been discussed elsewhere but I couldn't find the relevant thread. Thanks. 

--Ram

It's just a new name for the same thing now most, if not all, of the SX cameras are supported.

James

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Astrojedi

Astrojedi

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Well, you stack your noise as well :-) even if you use dark frames to subtract dark current, hot pixels, amp glow and whatever... But I agree that the new Sony CMOS chips in the ASI224, even if equally small and therefore gathering less light with the same QE, appear better than the older Aptina chips in the ASI120.

Darks take care of the hot pixels and amp glow... so the issues are addressable just takes more effort. But I am in total agreement that CCDs produce a cleaner image out of the box.

Ultimately I hope CMOS based sensors get better (and I think they will given the R&D dollars being invested) otherwise we have a problem since most manufacturers including Sony are winding down investments in CCD (although existing products will keep shipping for a few years).

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Hibou

Hibou

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...most manufacturers including Sony are winding down investments in CCD...

That's true, but the reasons are more to do with consumer marketing than with amateur astronomers :-) Fortunately (?) video surveillance is also a growing market that does need low light imaging, so ordinary CMOS will continue to improve.

To get back to the subject, The Atik Infinity software can even be used to stack an existing series of FITS files from another camera. The interface is very simple, and seems to be doing some kind of noise reduction that can't be switched off. (Like SL, there's no explanation or help file :-) But it does work, and it will be interesting to compare stacked results with other software, for the same files. BTW, Point-Grey, QSI and others have good articles on CCD noise especially on fast Fourier analysis, which is revealing and very easy to do with imageJ eg on Lodestar dark files before and after stacking. 

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Dom543

Dom543

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This thread has gotten very difficult to follow for people, who are interested in information about StalightLive v.1.1.

The discussions about CMOS vs. CCD sensors and all kinds of other cameras should be conducted in threads separate from this one..

--Dom

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  • 4 weeks later...
Paul81

Paul81

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Hi Paul,

Are you planning to support binning for the Ultrastar cameras in the Starlight Live software? Also any ETA on the next version? Looking forward to trying out multi-spectral capabilities.

Thanks

Yep binning is planned for a future release!

The next release will be Starlight Live 2.0 which will have the multispectral capabilities. Work has been full-on the last few weeks (plus I have had no internet at home) but should be back on the case next week. I want to fix a couple of bugs that have come out of beta-testing and then should be good to go! Hopefully won't take too long, just a question of getting the free time!

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  • 1 month later...
MrOD

MrOD

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Posted

Would it be hard to add in next release option to increase size of left side tabs at least twice?

I am using it on tablet an it is sometimes problem to change tab with finger of pen when temperature drops.

Increase in size of up/down button for exposure time would be also nice for this purpose.

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