Podcast Video (23.3MB) [26:00m]: Play Now | Play in Popup | Download
The Torrent file: Download The image used in the podcast: Download
It’s toning time again. Toning is done do black and white images to increase their “volume”, the perceived contrast range. We only have 256 values on the screen, so a bit of colour can be good.
In #39 I had shown how to make a Duotone or Tritone out of a monochrome image. And then Paul Wellner Bou showed in his Blog an easier way to do this.
It’s working, but why? To answer that, I look into the HSV colour model and try to explain the effects of the different layer modes.
A little bit about sharpening in an extra layer with “value” as the mode and a pointer to faking analog camera frames in digital images with a script and an original Hasselblad frame made by Marcus Ranum are at the end of the episode.
The TOC
01:00 Toning images
02:00 Toning enhances the visual volume
03:50 The recipe for a duotone
04:30 Adding a layer in colour mode and adding a layer mask from an image copy
07:00 Doing the same for the second tone
08:00 Inverting the mask
09:20 Switching layers on and off
10:30 Sharpening in Value mode
12:20 Unsharp mask
15:10 Explanation of Colour and Value mode
17:10 HSV colour model
20:00 A fake view camera frame
22:20 Multiply mode
23:40 A real Hasselblad frame
Meet the GIMP Video Podcast by Rolf Steinort and Philippe Demartin is licensed under a Creative Commons Attribution-Share Alike 3.0 Germany License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.
Tags: color mode, colour mode, duotone, frame, hasselblad, layer mask, layer mode, toning, value mode
Nice show Rolf, as always, deep in under the trunk .
One thing :
I can’t understand the reason to use the value layer mode for the sharped layer, who is already constitued by value information (being black and white, made of shade of gray)
There is any way to affect the image by the hue or the saturation value who is not present ??
If the trick is just to not mask the toning, than we can simply put the sharpened layer below the toning ones, just above the background and play with the opacity…
I haven’t watched the show so far so I can not say if sharpening in Value mode makes sense here. But in principle it makes sense in almost all situations. USM doesn’t work in lightness/ luminance/ value automatically but it works in each of the RGB channels. This might cause colour shifts that need to be avoided by just using the sharpened value information.
Have a look at http://www.cambridgeincolour.com/tutorials/unsharp-mask.htm, they describe this problem. You can also try it yourself by creating a test image with e.g. dark violet on the left side and bright yellow on the right side. Applying a USM with big radius and high amount will show the problem: the violet becomes blue because yellow is subtracted from it.
Philippe is right, in this case a sharpening layer below the toning layers would work. Value mode is overkill in this case, but does no harm. And it seems to be good practice in all other cases.
Any explanation for the “Nothing happens! But why?” overlays?
The first time I noticed it, you were flipping between displays which were subtle in their differences, and I
thought there really was a problem, but finally realized the overlay was essentially everywhere.
~jim
Oh, sorry!
I changed the value part of the foreground colours and was in colour mode. So no change visible.
You speak perhaps about what happens around the 15:00 point?
But the overlay begins at (I think) about 1:30 into the podcast. Ahhh, I guess it only runs during the early part of the podcast .. an editing mixup, I guess?
Just a curiosity.
~jim
Arrrrrrgh! That should have been the address of Paul’s blog! Cinelerra pitfall….
To explain Rolf’s comment: “I changed the value part of the foreground colours and was in colour mode. So no change visible.”
The layer was in Colour mode. So the hue and saturation of this layer are adapted, the value is not. In this part of the video he used the wheel colour picker. And he left the outer ring, which represents the hue, constant. Now he has chosen different colours from the lower side of this triangle and couldn’t see any results in the image. The issue is that this lower side of the triangle represents the value of a colour. The upper side changes the saturation. You could explore this by selecting different points in the triangle and have a look into the Scales colour picker to get the exact numbers of value and saturation.
Thus, Rolf left hue and saturation constant and modified the value. Unfortunately, the value is not adapted in the Colour layer mode
Exactly what I should have said….
Thanks!
Philippe: You’re right, in black and white it doesn’t matter to use Value mode or not. I am used to it, it makes sense with colour, that’s the reason I use it (almost) always.
By the way… Wellner Bou, not Weller.
Sorry! Fixed.
Another annotation: The Hasselblad frame is not made by any script, it is taken from the internet (deviant art: http://pcpb3.deviantart.com/art/Border-Hasselblad-A-73802219 ). As far as I know there are non squared Hasselblad negatives, too. But I don’t have much idea about Hasselblads…
The Hasselblad and full frame were meant to be alternative frames, not to used together. Although this can be handled as you like, of course…
Nice show!!!
I have to admit that I’m not up to date with the shows, but it is nice to see that they are as good as they have always been.
In a recent family event I took some pictures and I found that B&W was a great resource for some of them; photos that did not stood out turned to be great when desaturated. This show makes me wonder how much I’d be able to improve them by means of toning… I’ll give them a try.
Again, nice show.
Cheers!