Mini-Histogram Stretch Button

[admin]

Hmm,

would it help if the live stack histogram displayed statistics for each channel (a bit like the main histogram does)? Mean, Mode, etc?

cheers,

Robin

[MarMax]

I've been paying more attention to the mini-histogram the last couple of nights (actually the first clear nights in three weeks). Something that I was not regularly doing until I started using the ±0.1dB changes in the live stack histogram by clicking on the slider and using the up-down arrow keys. When zooming in 200-400% on the live stack image and making ±0.1dB changes with the R-G-B sliders the best indicator of proper color balance is the mini-histogram.

I'm not sure if a number would relay this information to me in the same way the graph does. It's the down sloping right side of each color after the peak that I'm using to visually make the final R-G-B settings. Is there a number that correlates to this part of the mini-histogram? To me the live stack histogram does not provide the same visually.

I also don't think this is an issue for folks in relatively dark skies like B5 or darker. I think this is only an issue for those doing EAA in light polluted skies. My home site is where I'm working 95% of the time and the SQM-L the past two nights was 17.88 and 17.94.

[Borodog]

Robin,

I for one would love a "hover over" magnification of the display histogram. Make it at least a second or two that you have to be over it so it isn't accidentally popping in and out as you move the cursor past it, though.

[MarMax]

[thinking out loud a bit more based on the last couple EAA sessions where I spent a lot of time making final R-G-B color adjustments]

The ±0.1 dB color adjustment seems to be the maximum allowable late in a stack with higher histogram stretch settings. That is, even a 0.1 dB adjustment can make an extreme change in color balance. Clicking on the bar is out of the question as the adjustment is too extreme. It may be necessary to add a -10x selection box on the live stack histogram to reduce the color adjustments. This would make clicking on the color bar a 0.1 dB adjustment and clicking on the slider and hitting the up/down arrow keys a 0.01 dB adjustment.

The above seems most important when using higher histogram stretch levels in light polluted skies. Perhaps the selection box is only available with the higher stretch levels (like 5 and above).

[admin]

Hmmm,

perhaps the size of adjustment for colour could automatically vary as the stretch changes, so for a strong stretch the 'click' adjustment is smaller? Before I go too far down that route though I want to experiment with the idea of a separate subtractive colour balance in live stacking to balance the background (ie remove colour cast of light pollution). I think that would make the current multiplicative colour adjustments less hair trigger...

cheers,

Robin

[MarMax]

The last two EAA sessions I spent a lot of time late in the stacks adjusting the color balance. My laptop with the trackball mouse (which I like) is just not ideal for making these important last minor adjustments. About every other time I try to use the 0.1dB adjustment I mess it up. Either the tool tip falls off the slider handle or I breathe on the trackball and/or hitting the arrow down causes a massive color change.

An easier way to make 0.1dB color adjustments would be really nice. Something that does not involve clicking and holding and pressing tiny keyboard keys. My arrow up and down keys are really small and it's easy in the dark to miss them. I'm also usually wearing a pair of thin running gloves in the winter.

I'll go back to the suggestion of a direct 0.1dB adjustment and propose something like this. Up and down arrow at the base of each slider that make fine adjustments.

FineColorAdjSlider_ExampleCropped_04232024.jpg (196.99 KiB) Viewed 151 times

[admin]

Hi,

not a bad idea, but I would be tempted to put the buttons above/below the slider rather than both at the bottom if I did this.

Are you aware that holding down the <SHIFT> key while dragging the colour adjustment sliders (and the other adjustments in the live stack histogram) reduces the speed of movement by a factor of about 10, meaning it's much easier to get a small adjustment correct with the mouse.

cheers,

Robin

[MarMax]

Robin,

Yes, I'm aware of the <SHIFT> key options. My problem is the dragging part because I only want to make a 0.1dB adjustment and usually the trackball does more than one. That is why I started using the arrow keys in hopes of making only 0.1dB adjustments but I'm having trouble with both methods involving multiple actions. Perhaps as the temps go up and I stop wearing gloves these multiple action adjustments will become more accurate.

The above and below location of 0.1dB arrows would make more sense and not be prone to a mis-click. I'm surprised others do not find the final 0.1dB color adjustments to be a critical part of the process before saving a stack. My goal is "save as seen" with the best balance of color and contrast with the least noise and the only changes I'm making at the end are 0.1dB.

Because the histogram shifts left as you make the final 0.1dB adjustments you also need to keep bumping the black level to the left. This takes a bit of time working back and forth between the 0.1dB color adjustments and black level adjustment. This is where the fumbles happen for me.

I'm not sure if it's possible to set the black level to follow its relative position on the white curve. This would greatly reduce the number of final color adjustments.

Thank you,
Mike

[Borodog]

I would like to 2nd the idea of 0.1 dB nudge buttons above and below the sliders. I rarely enjoy trying to find my keyboard keys in the dark. And imagine how difficult these small adjustments would be running SharpCap on a Surface tablet, as I know some people do.