Episode 149: Lens Flares Ahead!

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[flattr /] Every time you have a bright light shining into your lens you get a lens flare. This can look nice or horrible. You can avoid much of it with a lens hood – and with paying more money for better coated lenses.

But when you have these nasty spots on the image – there are ways in GIMP to heal them. Some are discussed in the forum thread where I also got the image for this show.

My preferred way to tackle a problem is to understand the source of it. Solving the problem is often much easier then. (This is the theory, often I just poke around…..;-) ) So I start with a bit of blackboard – showing that a lens flare is only added light, the original image lies below and the flare can be (in theory) subtracted from it.

In GIMP I do this with comparing similar colours in and outside of the flare. A bit of layer magic and the flare is gone. Except for the fringe where my patience ran out.

The TOC

00:20 Greetings, Flattr
01:45 Lens flares
02:20 Origin of lens flares
12:10 Avoid lens flare with a lens hood and lens coating
13:05 “Digital” lenses
14:20 Solution: subtract light
16:00 Curves to correct the contrast
19:45 Subtracting light from the flare
19:45 How much light was added in the flare?
22:00 Sample points
23:05 Docking a dialogue
23:30 Mixing the correction colour
27:25 Correcting the second flare
33:00 Recap
35:15 A quick crop
36:30 Why layers?

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Episode 123: Pimp my Photo! (2)

The Dragon on the SofaDownload the Video! (58.1 MB, 30:32)
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The results of the Book Challenge have been so interesting that I have made two shows out of them. This is the second part.

If you want to buy Akkana Peck’s book from amazon.com in the US, go to her website and use her link. She gets a bit more money out of it and you pay the same.

The TOC

00:50 Threshold tool revisited
02:40 Ityker’s image
04:00 Selective decolorisation
05:00 Layer mask for selective decolorisation
05:00 Layer mask shortcuts
06:00 Duotone
08:45 Sample points
10:00 Preventing tonal change of the colorisation layer
11:10 Sharpening layer
12:50 Fake view cam cassete shadow
14:30 Mathias’ image
15:50 Image sources
17:00 Layers for ressources
18:40 Combining different exposures
19:25 Healing spots and bra straps
20:30 Layers for sculpting the hair
22:40 The sky – overlay mode
23:50 The sign
24:00 Layer groups
25:00 Dodge and burn on a layer in soft light mode
26:00 Unsharp mask for enhancing local and global contrast
27:20 The John Arnold Style Vignette(R) 😉

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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 073: Layers

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This week Rolf tries to explain layers, the layers dialogue  and layer modes. The image on the left is a result of a little play with layers: a layer with a screen shot of GIMP was duplicated, set to “Grain Extract” mode, shifted two pixels to the left and top and than duplicated again. Looks nice – but why? 😉

Layers are an important tool in image manipulation. You can isolate different parts of an image with layer masks and so avoid negative consequences of your actions to other parts of the image. And you can play work with different layer modes to achieve effects from a little contrast manipulation to complex changes.

We need Tables of Content for the back episodes. You can help by joining this thread in the Forum.

TOC

00:30 The helpers
03:18 The TOC Project – Help Kevin!
05:10 Layers
05:20 What’s an image?
07:00 Alpha Channel
08:30 Locking a layer
08:50 Layer modes
10:20 Documentation at gimp.org
13:10 Tips in the forum: Contrast reduction
17:10 Visibility toggling
18:00 Changing  the layer order
18:40 Protect the alpha channel
19:00 Creating new layers
20:40 Layer masks
23:30 Showing and disabeling layer masks
24:15 Text layers
26:40 Editing a text layer
27:30 Loosing the text properties
29:00 Learning by doing

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Episode 046: Getting rid of People!

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This week I’ll answer the first search term that led according to the logs someone to “Meet the GIMP!. “Getting rid of people in GIMP” was the question. And here, about 9 months later, is the answer.

I took two shots of the same scene with my point and shoot camera to remove some moving cars (the runner shown here was just an accident. But I like the idea and will do a “real” one soon). I used a technique similar to that shown in episode 44, only this time a bit more sophisticated using layer masks instead of the eraser.

But I had no tripod and no beanbag. So unintentionally I moved and rotated the camera between the shots. Registering (adjusting them to a perfect fit) is the largest part of the work to be done. This involves the selection of a point of reference, moving the top layer, setting the centre of rotation and finally rotating the top layer. With more than two layers this has to be repeated for each layer.

I hadn’t thought that this would work out so good and easy. You can just shoot any public place without moving traffic if you make enough images. Imagine a big crossing, all traffic lights red.  😉 And you don’t need the tripod. OK, it’s better with….

Some links, as promised:

The exhibition in Hannover’s Sprengel Museum and the formidable book from the museum, in German and in English. Helen Levitt in Wikipedia, an interview with her on NPR and some images on “Masters of photography”

The file with the images from the podcast is at the usual spot.

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Episode 044: Splitting myself!

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This week I am absolutely late with the show. I recorded on the weekend and had to find out later, that I had messed up the sound.

As an emergency fill in I made this. It’s a project I wanted to do for a long time – and did now without anny planning and preparation. I even forgot to take a tripod for the video camera with me. But the lab provided a clamp for Erlenmeyer flasks. Worked great. 🙂

I got the idea from Allan J. Ager and Simon Taylor from the Tips from the Top Floor Forum.

You can download the four finally used files and a shrinked xcf file as an archive. The full resolution output is here.

UPDATE: Newer versions of GIMP don’t add an alpha channel automatically to a new layer. Add one for each layer except the bottom one!

The TOC

00:24 Welcome
00:33 Introducing Simon Taylor
01:20 Taking the source images
04:23 Choosing the images to use
06:30 Select the parts to use
10:02 Fine tuning the edges
18:20 Fine tuning the individual pieces
23:40 Crop to the final size
24:30 Use copy visible to get a completed layer
25:40 Curves adjustment
28:44 The End
TOC made by paynekj

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Episode 037: The Two Minute Holiday Shot Edit

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I was in Berlin for four days last week. And I only took a point and shoot digital camera with me. So this episode covers quick editing of holiday pictures, done in two minutes.

In this short time one can only do the basic stuff. And so I give you some easy recipes for getting more out of your snapshots. If you take this small amount of time, your images will get a lot better.

  • Rotate them, so that they are level
  • Adjust the perspective to get these falling lines out
  • Find a good crop
  • Adjust the contrast with the curves tool, applying an S-curve helps in most cases
  • Double the layer and use a layer mask to apply your edits only to a part of the image. Get more light into a dark corner or dim down a bright spot
  • Double the layer and use overlay or screen mode to change the overall contrast in an image. Use the opacity slider to adjust the strength of this effect. Try other modes, sometimes they work really good.

Don’t forget the challenge! Make a monochrome image and post it in our 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.

You can find the image used in this episode here on the Download Page

Contact me!

You can leave your comments on this blog or write me a mail.

The TOC

00:23 Photos of Berlin
02:49 Photo 1
03:28 – Curves to suit part of the image
04:15 – Add a layer mask
06:00 – Add an overlay layer
06:34 – Save the tweaked version
07:00 – Resize for web and sharpen
08:04 – Save the small version
09:05 Photo 2
10:15 – Perspective tool
12:25 – Crop tool
13:33 Photo 3
14:28 – Rotate tool
15:50 – Crop tool
16:45 – Rotate tool with a different centre of rotation
18:55 Photo 4
19:34 – Image Transform rotation
20:37 Photo 5 (See episode 38)
21:04 Summary
24:59 The End

TOC made by paynekj

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Episode 036: Nightvision on a lazy Sunday Afternoon

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This week you are in for a strange show. I try to make an image out of a not so good night shot by Stuart Martin from New Zealand. Stuart had his camera for three days and was experimenting with it. He shot the Christmas decora- tion of his neigh- bour but only got a dark and a bit blurry image.
With no specific goal in mind I just played around with UFRaw and layers in GIMP and got a quite nice result. The 100% crop you see here is a bit like a painting, the full image looks like seen through night vision goggles. NightgoggleThe lesson to learn except a refresh of using UFRaw and layers: Play around! Make experiments! There is no right way – just interesting results.

Stuart has an incredible collection of links to sites about language – from fun to pure science.

Don’t forget the challenge! Make a monochrome image and post it in our 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.

You can find the image used in this episode here on the Download Page

Contact me!

You can leave your comments on this blog or write me a mail.

The TOC

00:35 Welcome
02:14 The original image by Stuart Martin
03:28 The problems with the image
06:50 Examine using UFRaw
08:40 – change the colour temperature
09:15 – change the exposure
10:18 – Make the second version of the image
13:15 – Make the third version of the image
14:03 Put the 3 images as layers
15:54 Plan the composition
17:19 Rotating all the layers together
19:40 Cropping
22:50 Combining the layers
23:49 Add a layer mask
30:25 The Blog
31:06 The Black and White Challenge
32:26 Request for help with WordPress
33:20 The End
TOC made by paynekj

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Episode 034: Full Control! – Monochrome conversion (3)

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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

Contact me!

You can leave your comments on this blog or write me a mail.

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Episode 031: A double face and more selections

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Today I have two videos made by viewers of “Meet the Gimp!”.

Torsten Kunkel made a video about the image on the left side. He had two passport images of a person taken 40 years apart. One with age 17, the other now. And he combined them in one image, showing what changes and what stays constant.

I added some tips about an easier way to paint the dividing line and about ways to further improve this image.

Michael Schönitzer sent in the scond video. He shows how to fit a selection around an object on a uniform background. Of course I had to try it too.

You’ll her a lot of rumbling noises. I have new microphone stands and forgot to isolate them acoustically from the desktop. Too much clutter…. Sorry.

You can find the files used by Torsten here on the Download Page.

Contact me!

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Episode 016: And the Winner is…. / Frames and Tryptichs in a new Way

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In this show John Arnold from Photowalkthrough draws the winner of the triptych contest. Before that we talk about why you should also listen to his podcast and about a really nice workshop. I have to work at that time (May 5th to 7th), but otherwise I would have shelled out the money and gone there.

Then I’ll show you a new way to make a frame around an image or to do a triptych. It works with layer masks. The tip to do it that way was sent by Jason from New York.

Finally you’ll see all the triptychs made by you in a slideshow to the full lenth “Surreal in Vienna” by _Ghost – the music I use in the intro. More from _Ghost at ccmixter.

The TOC

00:23 Welcome
00:34 Gimp 2.4
01:30 Meet The Gimp web site
03:28 Interview with John Arnold from Photowalkthrough
11:07 Alternative triptych method
13:00 – create a canvas
13:44 – add the images as layers
15:20 – scale the layers
19:50 – add a layer mask
20:40 – make the edges ragged
24:20 (Tip for guides)
25:05 – Change the composition by moving a layer
28:27 Triptych contest entries
33:12 The End
TOC made by paynekj

Get the files!

The files from this episode.

Contact me!

You can leave your comments on this blog or write me a mail.

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