Photoshop - Auto levels settings

[fwm891]

I suspect not many of you are using 'auto levels' in PS but if you do there's something to watch out for:

PS sets its default auto to use - Enhance per channel contrast (open levels / options - list on left), change to:

Enhance monochromatic contrast, then set clipping to zero for highlights and shadows and OK on set as default.

This then clips each channel separately so none of the colour info is lost when using auto...

Probably more useful for general photog rather than astro.

Francis

[kookoo_gr]

i use the auto options in my astrophotographies and half the times the results are acceptable

[JimStan]

I'm certainly no expert, but I have never found auto levels to be satisfactory for astro-images. I want to "play" with my images, too much !

Jim S.

[fwm891]

I agree - rarely leave things alone although I use adjustment layers so the image remains untouched.

What the above does though is to give you a good starting point - certainly if you're starting out, 'all' the information remains in the image rather than letting PS decide where it thinks would be a good place to clip the image in each colour.

Its akin to using a camera on full-auto rather than manual or using a spot meter. With manual or spot metering you have more control over the outcome. I've seen too many botched photos taken with auto over the last 35+ years.

Try it - take a photo in day light and duplicate it. Apply the above and the PS default autos - I think you'll find the PS defaults clip or extend the whites and blacks in each colour. Leading to some colours being raised in contrast other lowered making for a muddy looking image.