layer blend modes - my poor head....

[Bambi]

is getting all muddled. I've been reading on the different blending modes of layers. Some are pretty straightforward like 'lighten' and 'darken'. I am confused by
1. 'Multiply'

and what the on earth does this really mean? :
Overlay Combines the Multiply and Screen blend modes. If the color channel value of underlying layers is less than half the maximum value, the Multiply blend mode is used. If the color channel value is greater than or equal to half the value, the Screen blend mode is used. The Overlay blend mode shows patterns or colors of the selected layer while preserving the shadows and highlights of underlying layers.

[edG]

don't you just love how technical writers can take simple information and turn it into a mind numbing experience

[Bambi]

don't you just love how technical writers can take simple information and turn it into a mind numbing experience

oh good. I'm not alone then.

[ericmark]

Layer blend modes are based on special algorithms, too complicated to get into here,
Am I getting anywhere near? Found some instructions on using Paint Shop Pro which seemed to have some similar wording.
I also find the change in terminology between packages confuses me. HDR Conversion in one package becomes Tone Mapping in the next.
Even something which seems simple like aperture 6.5,9,12.5,18,25,38 seems an odd set of numbers and the lens about an inch across seems far too small with a half plate camera to be f6.5.
May be between us we could develop a photography dictionary?
At least we all seem to be using the same second!

[Bambi]

I don't care about algorithms! I just want to know the effect. Maybe a podcast is in order?

[ericmark]

Never tried before but after what you said had a look and I selected two images of same size in bridge then went into tools/photoshop/load into photoshop layers this started photoshop then selected top image in layers and tool next to fx which says add layer mask then pressed G you could select gradient tool and I dragged it diagonally across screen this than produced an image where the one progressively showed through the other.
Then I tried multiply while the top image was selected and this increased the amount the bottom image showed through.
Then I just played. However as I already said different packages however Gimp does seem to work in similar way. Took ages to find controls left click then down to add layer mask then mode appears above it and as with photoshop selecting multiply seems to increase the unselected layer.
Something I need to play with a lot more and thanks for pointing the function out never played before.
If you can't find buttons I will make screen shots and make a PDF not sure if PDF will display on this forum never tried but open office will make PDF without a problem and I think Photoshop will as well?
Does seem a fun function

[Mad Aussie]

The blend modes are simply different ways for one layer to blend with the layer below it.

By duplicating a layer you can then apply different blending modes to achieve different effects.

Multiply is a way to darken. Think of it like a slide that needs light to pass through it so you can see the photo. If you had two identical slides and put one on top of the other the light would have a harder time getting through. The result would be that the slide looks darker. The Multiply blend does that and then you can adjust the opacity to control the amount of the effect.
Sometimes a blown out area can be saved to some degree by using this technique.

[Bambi]

thanks MA. that makes sense.

now what does 'screen' mean? when I played with it, it seemed to make everything lighter

[Mad Aussie]

Screen is basically the opposite of Multiply and is a lightening technique.
Take a photo like one of your landscapes that has lots of sky but also dark grass, house etc and then put one of your stone pictures under it as another layer ... then use screen and see what happens. It will compare the pixels on each and lighten the dark areas so the stones blend through.

To be honest though ... I very rarely use blend modes. Multiply very occassionally.

[Bambi]

thanks for the info and your patience.

I appreciate it.