PI and Background Neutralisation

[swag72]

Following Harry's tutorials in PI (Is there ever any others to follow?!!) and I am combining RGB data. All combined and cropped and now onto the Background Neutralisation tool. Harry says that prior to running the tool, check that none of the colours are over 0.1.

My red is showing 0.14 while the green and blue channels are significantly lower.

So to those who use PI and I hope Harry - What do I do about this and why has it occurred? Too much red signal compared to the other channels? (Although there were 20x300s subs for each channel).

Look forward to your help, still finding my feet with the RGB processing

[perfrej]

You should start with a simple test. Expose a flat through each filter with the same light source (as white as possible) and the same exposure time. Make it end up in the middle of the histogram.

Try mixing them wit LRGB combination tool (where you can set the balance between them) until you get a reasonably white result. L is skipped, of course.

Make note of the percentages of the channels. Now you know what the white balance of your camera and filters is. Use that balance to combine your equally exposed R, G and B. Then do the background neutralization. If values are above 0.1, you can always adjust the parameters of the neutralization settings to take that into account. Later, you may want to change exposure times for R, G and B to match the balance instead of doing it at the time of combination.

If you - in the background, mind you - find values in excess of 0.1, maybe you are not really using a preview representative of the background. Also, your balance may just simply be off. Go find it with the method above.

/per

[harry page]

Hi

What the man said will sort out future images , but ver often there is a imbalance in the channels and to get you round it in this case just raise the upper tolerance to say 1.6

Harry

[swag72]

Cheers Per, will have to try that.

Cheers Harry!