SC and the New ZWO ASILive.

[Harmonious]

A caution for those who may want to try the beta release of ASILive. After I tried it and returned to SC neither of the ASI cameras I was using would work normally. Setting the exposure to 15s and the gain to way high we expected the target, M42 to show a blown out image. Instead the first frame was subdued and the second frame much darker. the trap was not blown out. It was as if the image was still being adjusted by the auto features in ASILive.

We tried all of the usual, windows app cures and we used a white feather but to no avail. The next day I removed ASILive and did a repair of the SC install. Things were back to normal and the previously reported problem with the dark frames dialog box was also fixed. Which suggests to me that the problem arose from simply installing ASILive or the SC install was already compromised. Or maybe it was ghosts.

The other reason to post about ASILive is that while the beta is rough, people are saying it reminds them of the Infinity software and they like the simple interface. What I noticed was that it seemed to handle color balance in a stack better than SC. In a way it is dumbed down with fewer options and less user control and fewer options for file formats. But I have to say that Robin might want to give it a look . The color management alone is an attractive feature.

[admin]

Hi,

Thanks for the heads up – I will try installing the software and see if I see the same problem with the exposure and also take a look at the colour balance options.

Cheers, Robin

[ippiu]

And try the undo last frame function, that substracts last frame from the stack session.
For me is the most important feature.
I look forward to seeing this function in SC as soon as possible.

Thanks Robin

[admin]

Hi,

I did notice the undo function. What I didn't see was any manual way of adjusting the colour balance in the ASIlive software. I also didn't notice any problems with SharpCap images while the ASI software was installed.

Cheers, Robin

[ippiu]

Any undo last frame future upgrade also in SC, Robin?

[admin]

Hi,

No, not yet

I've been thinking about this one and one of the problems is that the amount of memory required to allow you to undo the most recent frame in the stack can become quite large for high resolution cameras. For instance for a 20 megapixel colour camera, the stack data consists of about 240 MB if you are using the standard stacking algorithm and 480 MB if you are using the sigma clipped stacking algorithm. Adding a duplicated copy of that data to go back to if somebody presses the undo button means there's increased chanced of running out of memory. I may have to consider only adding this undo functionality to the 64-bit version of SharpCap if I can't think of some clever workaround.

Cheers, Robin

[BlackWikkett]

+1 for undo function!

I mostly use Live Stacking feature and have built a PC specifically with 16 GB of RAM that I could upgrade. Maybe make this an opt in check box with a pop up warning indicating memory usage requirement.

-Chris

[umasscrew39]

Hi Robin

Starlight Live (no longer supported by Paul Shears) has had the last frame undo function for a long time. If it would help, I can email you his Windows version of the program to see how he incorporated it into his program.

Bruce

[admin]

Hi,

I think I've worked out a way to deal with the undo functionality and the amount of memory that it might require – basically instead of remembering the state as it was after the frame before and going back to that state, remembering the last frame and then running that frame through the stack effectively as a subtraction instead of an addition. The input frames are typically six times smaller than the state of the stack, so storing one of those in memory shouldn't be an issue. In fact if you are saving the raw frames to disk as you stack then you should be able to undo multiple frames in theory.

For the simple additive stacking mode, the undo in this manner should be perfect (in the sense that it will put stack back into precisely the state it was at the frame before). For the sigma clipped stacking mode the will not be 100% exact since the standard deviation value for each pixel will have been changed by the stacking of the most recent frame and in theory when running it through as a subtraction some pixels may be rejected by the sigma clipping algorithm that were accepted when the frame was originally processed or vice versa. This would only happen for pixels that were close to the sigma clipping threshold, so the effects of it should be almost impossible to spot in practice.

Cheers, Robin

[umasscrew39]

I tried ASILive for a few hours as I wanted to compare it to SC which I have been using the past 2 years. It is a bare-bones live stacking program that performs very well. Bare-bones in that you have only 3 options for gain (low, middle, high), a couple of "advanced" stack options (e.g., FWHM) and essentially just 3 image controllers (brightness, contrast, and saturation). However, it does have the last undo feature a lot of us like ad it saves your image both as a JPEG and FITS. It reminds me a little of StarlightLive (SLL) but SLL had a few other important features. I guess the simplicity of it will be very attractive but the lack of color channel controls (note: the saturation color control was very unimpressive), no way to control a filter wheel or other autofocusers, perform dithering and polar alignment, and no advanced image management features does not put it in the the same league of SC or SLL for that matter. So, I'm not knocking ASLive at all but I just wanted to provide my impressions of it in case others were curious about it. Finally, congrats to Robin for his continued development of SC as after one tries ASILive, you immediately realize the power of his program.