Episode 201: OPSEC!

Download the video! (21:44, 43MB)
The companion file! (51MB)

Nearly all colour laser printers leave a pattern of tiny yellow dots all over the paper. These dots contain information about the printer and perhaps also about the time and date of the print, the IP of your computer and who knows what else. These codes are in there for at least a decade and the EFF has complained in vain. Reality Winner got cought with these dots – but perhaps they would have found out about her a bit later without them.

The EFF has a dorky video about that.

I have a laser printer in my office at school. What does it tell about me? I research that with help of GIMP 2.9 – which looks terrific and has a lot of nice new stuff on board.

And of course you get to see some of these new features.

The companion file contains the scan of the Ordnungsmaßnahmenverordung in different resolutions and the XCF file with the revealed code. The last paragraph on the page gives me the right to take away your phone and hand it back to your parents after a reasonable time – if it beeps again in my class. (A lot of kids would prefer the cane over this….  😉 )

I forgot about the serial number of the printer – this will be updated soon.

The TOC:

00:00:00 Intro

00:00:50 Leaking from the NSA
00:01:35 Little yellow dots on laser print
00:03:00 Gimp 2.9 fired up
00:03:30 Search for the yellow dots
00:04:20 Colour Channels
00:06:00 Extract a colour component
00:06:40 Split view – new in filter dialogs
00:07:15 Searching for the pattern
00:07:55 New things in the layer dialog
00:08:30 Searching for the pattern
00:10:10 Crop tool
00:10:30 Measuring the pattern
00:11:35 Adding a precise grid
00:12:45 30 bytes of data in the yellow dots!
00:14:00 What’s not in the code?
00:15:00 Printing leaves traces
00:16:25 Blunder of “The Intercept”
00:17:00 Anonymising a scan with the threshold tool
00:18:30 The mono mixer for getting red back in
00:20:00 Return of the Minox for leakers?
00:21:00 We need a guide about OPSEC!
00:21:44 End of video

Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 4.0 Unported License.
Permissions beyond the scope of this license may be available at https://meetthegimp.org.

How does the “Ghetto Pinhole” stand up to German Engineering?

On Sunday I took my aluminium foil pinhole and a “Monochrom Subjektiv Pancake” (link in German to a shop – I get nothing from them) with a laser drilled pinhole to the Weser and took some shots.

I’ll show the Subjektiv in the next episode in detail. The pinhole has a diameter of 0.28mm and a whopping 1/f=159. My aluminium foil should have about 1/f=240.

And now compare:

“Ghetto” (3 sec exposure – JPG direct out of the camera)

“Subjektiv” (2 sec exposure – JPG direct out of the camera)

“Subjektiv” (2 sec exposure – JPG direct out of the camera)

“Ghetto” (3 sec exposure – JPG direct out of the camera)

Not really bad for a quick hack!

The Subjektiv has 3 much more elaborate and fancy lenses – so this was really unfair…….

Episode 200: Worldwide Pinhole Photography Day

tip of the pin
Download the Video! (7:15, 63MB)

And here is the mythical Episode 200 – in a quite different form than planned. Years later, shabby audio and short. I am still on a steep conversion course with my workflow – and completely out of routine. Even the video is partly out of focus….

This Sunday (tomorrow!) is the Worldwide Pinhole Photography Day.

In the video I demonstrate a quick and dirty way to convert an expensive digitial camera to a cheap quality pinhole camera.

Episode 201 will cover the background for this stuff – but this has to go up now!
Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 4.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

I am back!

Life threw some interesting stuff in my direction – mostly positive – that consumed a lot of my time and attention. But now I have some capacity to come back to this project.

It will take some time for the next video. First I have to rebuild my production pipeline – and that is an interestimg task too. My favorite video editor Cinelerra crashes all the time – I have to learn Blender for editing. And then there is the screen recording with a lot of newoptions and some nice new ways to encode video…..

Episode 192: Look Down! – A Challenge

192Download the Video! (45:45, 86.9 MB)

Watch on YouTube
Download the template! (0.06 MB)
Download my sidewalk images! ( 18.1 MB)

There was no show for quite some time – and there will be a gap until the end of summer. I move back to Bremen – and that takes a lot of time and creativity away. But in Bremen I will have nearly 2 hours more time each day, because I can walk to school and don’t need to ride the famous Berlin S-Bahn Ring Line.

In the meantime I have a challenge for you! Present the place where you live to us – but look down on the sidewalk for that! The best results will be published in the GIMP Magazine #5 and of course here on the blog. The exact rules are below.

This Challenge is a perfect rip off from a challenge by Andrés (Twitter) (Website), an illustrator from Buenos Aires, in the now closed forum of Tips from the Top Floor. Make a mosaik of images of the sidewalks in your city and try to transport the atmosphere.
Rolf's Example
This is my take on the Silvio-Meier-Strasse around the corner from my flat in Berlin.

The Rules

  1. Make a mosaic of at least 3×3 images.
  2. All images have to be shot straight down
  3. All images are in the same scale, use the same distance to the ground and the same focal length.
  4. All images have to be linked to each other in their theme by being from one city, one journey …..
  5. Publish your image online and post a link to it before September 1st in the comments to this blog post.
  6. License your image as CC-BY or better and allow this site and the GIMP Magazine to publish your image under CC-BY (here) or CC-BY-SA (GIMP Magazine).
  7. Rules 1 to 4 may be broken, 5, 6 and 7 have to be followed exactly.

You may download the template for my version from above or build your own one. You are free to make other forms than a square – circles or a spiral anyone?

There will be hopefully a discussion in our forum.


The video uses chapter marks, you can jump between TOC entrys!

00:00:00 Pause until end of August
00:02:05 A contest for you – introduction
00:03:42 The contest rules
00:04:50 My example
00:06:04 Selecting the images
00:08:00 Scaling down and exporting in Shotwell
00:08:40 Calculating the image size
00:09:30 Create the file
00:10:20 Save as XCF.gz – compressed to save space
00:11:05 Creating a “Contact Sheet” for reference with Imagemagick
00:13:00 Make a movable layer mask with “multiply mode”
00:16:00 Building a stack of layer groups and fill it with images
00:23:00 Filling images into the layer stack
00:26:45 Isolate the layer groups with “lighten only mode”
00:27:55 What do these layer modes do? Blackboard explanation
00:33:08 The last image – a Memory to Edith and Tina Wolff
00:34:30 Fine tuning the mosaic – exchange images
00:36:08 Adjusting contrast between the images with the curves tool
00:41:05 Variations: Soften the borders between fields
00:43:08 Final words about the Challenge
00:44:15 Exporting and scaling down for publication
00:45:45 End of video

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 3.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Episode 182: A Special Day

5 Years of Meet the GIMP!Download the Video! (30:37 61.1MB)
Download the companion file! (65.5MB)
It’s a special day today, five years ago I rolled out the very first episode of “Meet the GIMP!”. And now it is #182, that’s 0.7 episodes per week. 😉 Update: An error corrected below and the comments are working again!

But the show starts with an other anniversary. Twenty years ago these days Tim Berners-Lee (still without a “Sir” in front of his name) published the first photo on the World Wide Web. Up to then it had spent it’s first year or so text only. The users and servers were somehow connected to the CERN particle collider near Geneva. What’s better to put on an image in a nerdy environment than a band? An all female High Energy Rock Band, Les Horribles Cernettes, of course. So a quick and dirty Photoshop (Version 1) hack (yes, web sites were that ugly once…) intended as a base for an in house CD publication found it’s way to the computer of Berners-Lee and history was on it’s way. There seems to be quite a dispute about this just now. Why can’t people keep proper records when they are making history? 😉


Some epsiodes of Meet the GIMP! have found their way into an education program of the Indian Institute of Technology in Mumbai (Bombay). They dub them with Indian English and publish them on their server. The project Spoken Tutorial is a great way to reach out and broaden education. And of course I am proud that my material is used that way.

I love the Greyscale Icon Theme by Eckhard M. Jäger of the “Linux for Designers” blog. Keeping the active icon in color is a nice touch.

Ramon Miranda has updated his GIMP Paint Studio. This is a collection of brushes, patterns, gradients and more, bound together by presets and dynamic settings for tablet users. (If you don’t have a tablet, get one now!)

The GIMP Magazine is taking up steam. I have seen the drafts, they are nearly complete and get better all the time. Expect the first issue in early September.

And finally I process an image of a small part of the steam engine 01 1066, which I found in the Hamburg Main Station. The processing is nothing spectacular, just cropping, curves, a bit of burning and dodging. But this time I am printing the image on my brand new printer – an Epson 1500W. An Episode about printing is coming up, just now I am just playing around.

UPDATE I made a blunder here and switched the terms dodging and burning – I got the reminder of proper dark room culture from Saul Goode in the forum.

Burning is letting more light from the enlarger onto the paper (as I told in the show) but as it is a negative projected on light sensitive paper  the image gets darker. So I burned the lower right edge of the image.

Dodging is keeping light away from the paper and so making that part lighter, no light at all would result in unchanged white. I dodged the rust on the fitting in the center of the image.

And here comes the twist. A “burned out sky” is white on the final image because it has been “burned out” the negative, resulting in solid black there. I haven’t been in the dark room lab for decades, perhaps I’ll try it again after the printing fever has gone old. 😉 (BTW, my new pigment ink and refillable replacement cartridges arrived today…. )

A very good demonstration of burning and dodging is done in the film War Photographer about James Nachtwey. Worth watching, even without interest in dark room technique.

A big thank you to all of you for the support in these five years!


00:20 Les Horribles Cernettes
03:15 20 years of images in the net
03:50 Meet the GIMP is dubbed in Indian English by spokentutorials.org in Mumbai
06:20 5 years of Meet the GIMP!
07:00 Installing a grey icon theme
08:00 Where is your personal GIMP directory?
09:00 Gimp Paint Studio by Ramon Miranda
10:50 The presets give additional value
11:20 Dynamic settings
13:00 Dampflok 101066 in Hamburg Central Station
14:45 Opening and analyzing the image
16:20 Cropping for a print with a fixed aspect ratio
18:45 Make a backup layer
19:00 Curve tool to get black black
20:45 Dodging Burning with a layer and brush
22:50 Burning Dodging with a layer and brush
26:05 Sharpening
27:30 Saving the image
28:10 Printing is new for me
29:00 The GIMP Magazine is coming in September
29:55 5 Years – a summary.

Creative Commons License
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.

Episode 181: 2.8, 2.9 and Counting!

Download the Video! (24:08 48.1MB)
A week of news: GIMP 2.8 is out, we have again a modern stable version of GIMP. Gratulation to the developers, this was good and hard work. But instead of relaxing a bit they threw at the same moment Version 2.9 into the world. High bit depth, not only the 16 bits everybody wanted, 32 bits integer and floating point modes are suddenly available. But be aware, this is a field of bugs and crashes, don’t expect any productive results yet.

In a first look at 2.8 I show the shiny new brushes, explain how to use the new sliders and the tagging system for brushes, gradients and patterns. For the lazy I add a bit of calculations in input fields.

Then nachbarnebenan takes you for a tour through 2.9, presenting the lossless operation of the layer stack and other stuff. But again, this is not for the faint at heart. If you want to compile 2.9 on Debian, here is a How To in our Wiki. (The link address says still 2.7, but it is 2.9….)


00:20 News about 2.8 and 2.9
04:40 Starting GIMP 2.8.0
05:00 Single Window Mode
05:25 A new brush set – brush controls
07:10 The new slider controls
08:10 Ressource tagging for brushes, gradients and patterns
10:45 Calculations in input fields
11:45 Goat Invasion! Outlook to 2.9 (nachbarnebenan)
11:50 A layer stack in 2.8 – 8 Bit depth
14:50 The same in 2.9 – 32? Bit Floating Point
18:20 Soft Light and Overlay – the Bug is gone!
19:20 Not all is using GEGL yet
22:30 Final words from Rolf

Creative Commons License
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.

Episode 176: Double Photivo

Download the Video! (34:04 67.9MB)
Download the companion file! (97.8MB)
It’s time for a guest again. Nachbarnebenan shows how to process a RAW image in the current (well, it was November…) version of Photivo. Photivo has a very different approach to image processing from GIMP and others. It’s more stacking up and tweaking of algorithms instead of making a series of changes one after the other. Fully non destructive and very powerful.

To isolate the model from the a bit to vivid background Nachbarnebenan produces two images from his RAW file. One is crisp and colourful – best for the model. The other one is soft and a bit dull – this tones the background down.
In the next episode he will show how to combine these two images in GIMP into one.

I am still looking for “Bad Good Images” from Phones and other not so good cameras!

Sorry, no TOC up to now.

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort and Philippe Demartin is licensed under aCreative Commons Attribution-Share Alike 3.0 Germany License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Good Bad images please!

I am planning an episode about editing images out of cheap cameras and phones. My phone takes technically really decent images and I have given away all my old digital cameras. All I have is too good for this. 😉

If you have an image that is suffering from “not so good” camera quality, either from a phone or a cheap camera, and let me take a shot at it, please mail it to info@meetthegimp.org or put a link to them in the comments. Thanks!

Legal notice: By sending me the image you give me the rights to use them in the show and publish them in the companion file under under CC BY-SA 3.0 License.

Now I am off to visiting some friends in Bremen. Next show next week!

(The original image used in this post was made by Moose G. and is published under CC-SA 2.0. Click on the image to go to the original. )