S Curve for Image Adjustment

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nexusjeep
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Joined: Thu Oct 18, 2018 3:01 pm
Location: Gloucestershire

S Curve for Image Adjustment

Post by nexusjeep » Sun Sep 22, 2019 8:32 am

Hi Robin,
At the moment on the auto adjust for the image we have black / mid / white points for the curve would it be possible to introduce an extra point along the graph to allow the curve to be slightly S shaped. When imaging I tend to use the auto button then push the mid point slightly more towards the left to expose more of the nebulosity. At present this also affects the deeper black portion of the image as the is only one point between black and white so the curve fits to this and subsequently lightens the whole image.

To illustrate the question the image below is just with the black/mid/white excuse the image as it was already DDP stretched it is just to show what I am talking about. As you can see it lightens the black as well as everything else.
3 point.png
3 point.png (953.15 KiB) Viewed 461 times
Were as with the additional point on the curve the black can be held down as in the image below.
4 point.png
4 point.png (821.42 KiB) Viewed 461 times
Cheers
Nick

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Re: S Curve for Image Adjustment

Post by admin » Sun Sep 22, 2019 8:09 pm

Hi,

Actually, some wearing a previous version I did have different controls that allowed you to make an S-shaped curve, but they turned out to be clumsy to use and adjust. I'm not averse to having a way to introduce that sort of slope near the black level if I can work out a good way to represent it in the UI so that it's easy to adjust.

Cheers, Robin

nexusjeep
Posts: 206
Joined: Thu Oct 18, 2018 3:01 pm
Location: Gloucestershire

Re: S Curve for Image Adjustment

Post by nexusjeep » Sun Sep 22, 2019 8:33 pm

Hi Robin,
Thanks for the response it would be a nice to have in my case as I am monochrome at the moment so process the actual colour image outside of SharpCap. But if the QHY268C or similar ever actually becomes available to purchase then I am considering a colour camera as well in which case it would be useful to hold the black level down a bit. Thanks for all the great effort with the software as it stands currently I have tried several others out of interest but I always come back to SharpCap as I just like the experience and ease of use keep up the good work. Still need to try out the dithering change you have made as I have never dithered in the past due to frame loss but am keen to now give it a go looking forward to 3.3 whenever it arrives.

On a side note I have just signed up for the licence for another twelve months for the tiny sum of £10 is there a way to donate a bit more for the use I get out of the software.

Cheers
Nick

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