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SharpCap live stacking


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OK, so PS3 Eye at 0.1fps, 24bit, 640x480, gain 0%, exposure 100%, colour all 100%, lens cap on.

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Minging!

10 hours ago, Bruce Leeroy said:

very noisy images ... alot of distracting colour noise.

Anything like mine above?

 

I had SharpCap capture a dark frame, average of 10 frames. By applying that, it improves a fair bit...

image.png.0e9e679dabd879107752021642f61f9b.png

 

Increasing the frame rate to 0.5fps and dropping the exposure a bit, gain at 0, pointed at a dark corner (I can barely see the upright chair as brown) and stacked for 10 seconds or so...

image.png.e5c1384462740ea1290501337c6fd857.png

I can't use the same dark I used above as the settings have changed, so capture new dark, average of 7 frames, apply it and try stacking again:

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Tried a new dark with 20 frames instead of 7, improved it a bit as shown below but perhaps law of diminishing returns...

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Tried again with a new dark with 50 frames averages, let it stack for a while:

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Not a huge improvement with the 50 frame dark over the 20, but a HUGE improvement using dark subtraction than not.

 

Increasing the frame rate to 2fps, maxing out the exposure and raising gain until image looked about the same brightness around 60%, horizontal banding visible:

image.png.8b1d26f4b913b55337b14c35fc359e0b.png

Take a new dark, 50 frames and apply... better but still showing the banding in a single frame:

image.png.3df017420cbaef14f899d27297074503.png

 

Let it stack up 50 frames:

image.png.66c05199f9eee603fc14c04046264a30.png

 

Compare that to the 0-gain 0.5fps from before:

image.png.202b22ecd4ac85feb58177eef1bd94bf.png

Bit hard to tell, really, as the tone and brightnesses are slightly different, but I think I prefer the latter... does that mean in general that 0 gain better than +ve gain? I don't know, makes sense though.

But dark subtraction is definitely a good thing... worth the small donation for SharpCap Pro, IMO.

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3 hours ago, furrysocks2 said:

off-topic for live stacking.

Yes totally off topic apologies!!

Very good results...Yes I had a similar noise as you have in the 1st image you posted but I never put the RGB sliders upto max like you have.

Reading the attributes to my Red channel images I read "something like":

Flat applied = 0

Dark applied = 0

And the penny dropped later in the day as to what exactly darks/flats/lights are all about, reading your latest post just confirmed it. thanks !

2 hours ago, furrysocks2 said:

But dark subtraction is definitely a good thing... worth the small donation for SharpCap Pro, IMO.

Agreed, I'll look into it as I intend on using the live stacking option after seeing your results and my experiments with the PS3 cam have been hit and miss.

It was almost 2 months ago that  I tried live stacking  and if memory serves me right it bugged out with a message relating to a tracking error but I'm not 100% on that.

Can you apply/subtract a dark frame to the live video feed without using the live stacking option?

The Jupiter image you posted, is that a stacked image made from 1 of my videos? If it is then cheers it looks pretty good.

I need to read video astronomy for dummies, thanks for making the thread it's cleared a few things up for me:icon_biggrin:

 

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Darks are applied to each incoming frame, irrespective of stacking... and when you then do live stacking, you're stacking cleaner frames! They're not ideal cameras for long exposures though, clearly. ;)

All new to me... glad it's struck a chord. ;)

 

(Jupiter went from one of your videos through PIPP, AS!2 and GIMP. Not bad aye, shame it was from an iPhone.)

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20 minutes ago, furrysocks2 said:

Darks are applied irrespective of stacking, but stacking works a lot better when you subtract the darks first! They're not ideal cameras for long exposures, clearly

Thanks for clearing up the darks query and debayering should improve the long exposure/live stacking experiments? :)

 

20 minutes ago, furrysocks2 said:

(Jupiter went from one of your videos through PIPP, AS!2 and GIMP. Not bad aye, shame it was from an iPhone.)

Cheers for that, the iPhone was gifted to me if that helps lol.

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5 hours ago, Bruce Leeroy said:

... debayering should improve the long exposure/live stacking experiments? :)

The sensor should get more light so exposure setting can be lowered for same brightness, though obviously at the cost of colour.

Ah... but SharpCap might not be able to configure the camera in raw mode. I'll have a think.

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