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Firecapture Focus Help Feature

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5 replies to this topic

#1 Mikedora

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Posted 07 October 2024 - 09:55 AM

Hi All,

 

And please forgive if this has been asked before, but I can’t find anything on it.

 

Question is simply, how does the Firecapture “focus help” feature work?

 

When I activate it, eg pointing at Saturn a couple of nights ago, I see a screen with red at the top, green at the bottom, a black dividing zone in the middle, and a graph line marching from left to right in time with the camera’s exposures.

 

The faster the exposures, the faster the graph updates, and vice-versa. As I adjust the focus, the graph’s trend line shifts up or down accordingly.

 

What I do not yet understand, is what is the optimum location for this trend line for optimum focus. Should it be in the middle (intuitive), in the green zone (also intuitive), or in the red zone (counter-intuitive)?

 

And yes I know some may say just eyeball-focus using the planet’s image on-screen, but even with good seeing and a fast exposure (tried 0.1s, 0.2s and 0.3s with Saturn the other night), the screen image still bounces a bit and shimmers in and out of focus a lot.

 

What I’m hoping to do with the focus help feature, is “load the dice” for the lucky imaging method by finding an optimum focus point.

 

Thanks

 

Mike



#2 kevinbreen

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Posted 07 October 2024 - 10:01 AM

For me, experimenting with Jupiter's moons last year, it seemed that the higher the graph line was the better was the focus. Or was it the lower? Definitely not the middle anyway. Sorry to be vague

#3 Tapio

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Posted 07 October 2024 - 10:05 AM

https://www.cloudyni...ecapture-focus/

Personally now I prefer SharpCap focusing tools.

#4 RedLionNJ

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Posted 07 October 2024 - 10:31 AM

Hi All,

 

And please forgive if this has been asked before, but I can’t find anything on it.

 

Question is simply, how does the Firecapture “focus help” feature work?

 

When I activate it, eg pointing at Saturn a couple of nights ago, I see a screen with red at the top, green at the bottom, a black dividing zone in the middle, and a graph line marching from left to right in time with the camera’s exposures.

 

The faster the exposures, the faster the graph updates, and vice-versa. As I adjust the focus, the graph’s trend line shifts up or down accordingly.

 

What I do not yet understand, is what is the optimum location for this trend line for optimum focus. Should it be in the middle (intuitive), in the green zone (also intuitive), or in the red zone (counter-intuitive)?

 

And yes I know some may say just eyeball-focus using the planet’s image on-screen, but even with good seeing and a fast exposure (tried 0.1s, 0.2s and 0.3s with Saturn the other night), the screen image still bounces a bit and shimmers in and out of focus a lot.

 

What I’m hoping to do with the focus help feature, is “load the dice” for the lucky imaging method by finding an optimum focus point.

 

Thanks

 

Mike

Those are not fast exposures.  You should be looking at something like 60fps or higher.


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#5 dcaponeii

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Posted 07 October 2024 - 10:47 AM

Hi All,

 

And please forgive if this has been asked before, but I can’t find anything on it.

 

Question is simply, how does the Firecapture “focus help” feature work?

 

When I activate it, eg pointing at Saturn a couple of nights ago, I see a screen with red at the top, green at the bottom, a black dividing zone in the middle, and a graph line marching from left to right in time with the camera’s exposures.

 

The faster the exposures, the faster the graph updates, and vice-versa. As I adjust the focus, the graph’s trend line shifts up or down accordingly.

 

What I do not yet understand, is what is the optimum location for this trend line for optimum focus. Should it be in the middle (intuitive), in the green zone (also intuitive), or in the red zone (counter-intuitive)?

 

And yes I know some may say just eyeball-focus using the planet’s image on-screen, but even with good seeing and a fast exposure (tried 0.1s, 0.2s and 0.3s with Saturn the other night), the screen image still bounces a bit and shimmers in and out of focus a lot.

 

What I’m hoping to do with the focus help feature, is “load the dice” for the lucky imaging method by finding an optimum focus point.

 

Thanks

 

Mike

A couple of things.  1)  This is not rocket science.  GREEN is good.  RED is bad.

 

Grant is right you're not using very high fps.

 

There is a drop down menu next to the focus help which allows you to choose the number of frames you will average over to get the data point.  20 frames or even 50 frames reduces the excursion.  Also if you lose the planet partially, the focus help intreprets the sharp edge at the side of the ROI as really good focus and wrecks your data set so also in the drop menu is a reset button so you can srub that bad data and start anew.  For the most part it's worthless but fun to play with and it does clearly demonstrate why EAF is also a waste of time in planetary for the most part.

 

Just look at the fine details with the preview window zoomed to at least 100% (150% or higher is better) and pre-process averaging turned on to 25 frames or so.   When the fine details appear more often than not that's your focus point for THAT capture.
 



#6 Mikedora

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Posted 07 October 2024 - 02:19 PM

Thanks all,

 

BTW I misquoted my exposure times, they were actually 10ms, 20ms & 30ms (too much multitasking today).

 

Presumably that makes a difference?

 

Cheers

 

Mike


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