Podcast Video (37.8 MB) [24:50m]: Download (12056)
Torrent: Play in Popup | Download (180) The images used: Play in Popup | Download (256)
In this last episode (for now…) about monochrome con- version I show you a way to get full control over the process of making a monochrome image.
I “decompose” the RGB image into three layers, each containing one of the three colour channels.
By adjusting the opacity of the three layers I mix the channels as with the channel mixer. But I have the full image as “preview area” and can change the values as long and often as I want.
Each of the layers can be further modified with the curves tool, other tools or partially masked off. Don’t forget to make a safety copy of the layer.
The image on the top of this page was done in this way. It’s an enhanced version of the one I showed in the video. I have added a masked red layer for the background and a bit red layer for all of the image. This version is in the files for downloading - just two layers more than in the video.
The challenge
You can use this technique in the current challenge. Do a monochrome conversion with GIMP, post the image in the meetthegimp.org photogroup at 23 and be sure to use the tag “mtg-monochrome”. The challenge ends March 31 1600GMT and I’ll draw a winner by random choice.
The TOC
00:34 Introduction
02:50 The leaf picture again
03:26 The colour channels
04:40 Decompose
06:26 The colour layers
08:00 Mixing the layers
09:20 Understanding the layer mixing numbers
10:15 Examining the layers
11:57 Adjusting the layers
13:00 - Curves on the blue layer
15:00 - And a layer mask
16:50 Summary
18:50 The Black and White Challenge
19:30 - Slide show
22:36 The web-site
24:49 The End
TOC made by paynekj
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Tags: b&w, layers, monochrome
you made a mistake in the video, when you say that for average of the three layers it must be put 33% 66% and 100%. Thats not that way: the good way is putting the top layer to 33% the middle one to 50% and the one on the bottom to 100%.
In this way, starting at the bottom one, it first have the 100%, when passing through the second one is 50% of each other, and in the third one it is a 33% for the top layer, and the lower ones have 66% to divide in equal parts (50% each) so 33% each one.
You can do a test with the circles you draw, if you try to adjust the opacity when the result is gray is ok (that is with 100-50-33,333)
nice screencast, it discovers me a thing or two about the gimp!
Of course you are right! Just another case of podcasting without thinking.
It is so logical, using the decomposition for mixing channels. and yet, I have never thought about that. Something to try for the challenge.
Thanks for the show!
Stimulating as ever and takes me back to my days in the darkroom. The challenge you have set is problematic in that I believe the sort of images we now go for are based not only on composition but also on colour and may not be suitable for converting to monochrome. Although it is great fun to convert from colour to black and white only certain images would make great photographs. In the old days composition was paramount and colour hardly entered into consideration.
Norman, you are right there. I’ll be out and look for my black and white eye….
Thank you for another great podcast. I am a recent fan of yours and over the past 2 weeks I have watched all of your podcasts often while commuting to work. I appreciate the many tips I have gotten from your podcast it has made my adventures with Gimp easier.
I have been in photography as a hobby for about 50 years now and the recent podcasts about black and white remind me of the early days for me as all was black and white due mostly to cost. I’ll be watching for shots I can take to convert to black and white.
Neues vom GIMP…
Neuigkeiten für Freunde des Open Source Programms GIMP. Die Version 2.4.5 ist freigegeben, ein Build für Windows sollte damit dann in den nächsten Wochen verfügbar sein. Dort ist auch das elektronische Handbuch verfügbar - das muss jeder GIMP-Nut…
[...] Episode 034: Full Control! - Monochrome conversion (3) [...]
Gimp-Anleitung auf Deutsch…
findet Ihr hier als PDF. Achtung, es sind rund 706 Seiten, die da auf Euch zukommen. Aber sicherlich wird diese Anleitung eine gute Hilfe sein, das Programm zu “beherrschen”.
Im übrigen gibt es zur Zeit einen kleinen “Monochrom”-Wettbewerb, aus…
Hi Rolf,
Thanks for the tutorials! I found another very interesting way for monochrome conversion, but the tutorial is for Photoshop not GIMP. It is found here: http://intphotos.7.forumer.com/viewtopic.php?t=25&sid=2b7b707f8fd6b5a7bbe56c352adfe702 This way allows to adjust colours individually and you can change the range each colour encompasses. It would be great if this could be done in GIMP!