damians personal blog

After the aforementioned library hack I couldn't see any thumbnails from about 30-45 images, and some had the even the wrong thumbnail instead. (This might be due to an error in importing from the flash card, as some images ended up having the same file name.)

Even the right-click menu entries "Delete Preview" and forced "Generate Preview" wouldn't help. The correct image appeared on double click or entering fullscreen mode, but the preview won't change. I was always looking for an option in the mouse menu, I guess I'm working too much with windows at work -- the option I sought was placed in the "Images" menu and is called - surprise - "Generate Thumbnails".

This did solve the problem with the missing thumbs, but not with the wrong thumbs. Immediately after generating a new thumb from the image it helped. But somehow it seemed to me, generating new thumbs only postponed the problem. And I could observe files having a different original name mix up thumbs repeatedly, it was the same image that got the same wrong thumbs.

So what I tried to do

• Generate Preview on all images
• Generate Thumbnails on all images
• Delete .approject/AP.Thumbnails and other AP.* files

but nothing helped. Until I found that thread in the apple forum, where the user "firstlaunch" suggests to rebuild the database. His advice is to hold [Alt][Cmd] at startup, and then rebuild. In my case, a simple "Consistency Check" did do the trick.

Compare the screenshot below:

        24.Nov.2009, 6:32 :: photo :: Permalink :: Comments (0)

© Apple Computers

The other day I had to collect the pictures of FriScènes, a local theater festival. I freed up some 20 GB on my internal hard drive, and collected about as much data of raw photos in Aperture. After the festival I created a backup of the files on my external hard drive, and copied the aperture library also to the external drive (kind of unnecessary, but you never know).

Some days later I needed to access the photos of the festival. But Aperture (v2.1.4) won't let me set the Library path to the external drive, and I couldn't copy it back on the internal either due to lack of free space.

So after some fiddling in the terminal I found a way to leave the photo files on the external drive and access them anyways with Aperture:

1. copy the .aplibrary folder and all the files in it to your internal harddrive except the .approject files
2. create a symlink on your internal drive pointing to your external drive

In my case, the commands where the following:

 cd /Users/damian/Pictures/
 cp -rv /Volumes/wd590/Aperture\ Library\ FriScenes.aplibrary .

(which I interrupted with CTRL-C when I saw it copied actual image files)

 cd Aperture\ Library\ FriScenes.aplibrary
 rm -r *.approject
 ln -s /Volumes/wd590/Aperture\ Library\ FriScenes.aplibrary/*.approject .

This works fine, though the slower performance of the USB drive causes the thumbnails to appear one after another (instead of appearing instantly when running from the interal drive.)

        15.Nov.2009, 23:05 :: photo :: Permalink :: Comments (0)

...still better than broken ones. Hope you get the idea though, it's never as beautiful as reality. And there is no scent on the web, either!

        30.Mär.2009, 23:41 :: herzvoll :: Permalink :: Comments (0)

This is a video about a very interesting technique for content-aware image resizing, also called retargeting:

For my fellow computer science students: what algorithm would you apply? Remember travelling salesman? Tree traversal algorithms? They'll be back!

Thanx to MTN for the hint.

        23.Aug.2007, 7:29 :: photo :: Permalink :: Comments (0)

© Verner Nielsen

(Deutsche Zusammenfassung dieses Eintrags)

There is another method to combine several exposures into one called Dynamic Range Increase. The argument against HDR is that an image is created, which contains more information than the human eye is capable to handle.

This is no true, it is not the eye that is the problem, but the viewer technology. As far as I'm concerned, people argumenting like this don't understand what HDR is about.

Nevertheless some HDR Images look somewhat shallow, because the colors seem to approach grey during the HDR conversion.

My experience is that night-shots look great with DRI. But with day-shots, especially with a bright sky, nothing beats HDR.

drimaker.com:
More information about DRI and software to automate making DRI images.

Continue reading "hdr vs dri" »

        28.Jul.2007, 18:53 :: photo :: Permalink :: Comments (0)

   

A HDR image of the panorama of Fribourg (Châpelle de la Laurette) and the original images above, shot july the 6 with back light of the evening sun. It is quite amazing how the sky is blue and textured, and the houses in the foreground still show natural coloring. This image was made using Photomatix Pro and the Tone Mapping set to 'Tone Compressor'.

        9.Jul.2007, 10:04 :: photo :: Permalink :: Comments (0)

(Deutsche Fassung dieses Eintrags)

Digital cameras cannot take pictures the way humans perceive it. The human eye has a higher dynamic range than the camera.

The easiest example is an object with very bright background: the human eye can see textures on the object as well as in the background. When taking a picture of the object, the camera will make a choice: either the textures of the object appear, and the background is completely white - or the texture of the background are visible, and the foreground will be too dark.

The solution to this dilemma (except from cut-out and mask) is to increase the dynamic range of an image: the amount of data stored in the a pixel is doubled. High dynamic range (HDR) images cannot be displayed on a normal computer screen or printer prior to mapping the higher range (32-bit) to the conventional range (16-bit).

Because there are no HDR compatible cameras on the (consumer) market yet, the process works as follows: the information of two or more (usually 3-5) images of the same scenery with different exposures is combined into one image. The range of image is then 'compressed' to fit standard viewing methods.

When HDR will be implemented directly in the cameras, the photographer will not need to worry anymore about over- or underexposed pictures. The decision about the 'exposure' will be post-production. I'm looking forward to that!

More information about HDR:
wikipedia.org/wiki/High_dynamic_range_imaging
hdrsoft.com

Note: the Photomatix Pro Software from this website may be trial licensed only, but can still be used to generate pictures without watermark: use the Tone Compressor method instead of Details enhancer when tone mapping, and you will get no watermarks!

Continue reading "hdr wtf?" »

        8.Jul.2007, 17:17 :: photo :: Permalink :: Comments (0)

© 2005 Canon (Schweiz) AG

The other day I wrote about the Canon 50mm f/1.8 I bought. In that post I forgot to mention the story preceeding this buy.

I was talking with caillou about portraits I took and the problem of bad lighting conditions. He recommended me buying this objective, whereupon I laughed at his proposition, telling him "50mm ain't enough focal length for taking portraits with a small depth field". Then I continued thinking about this problem, and I thought I might give it a try. I tested with another objective and smaller aperture and found the depth field to be pretty small.

He shall be right, I was wrong. The rest ist already documented in the previous post. (tuet guet, gau?)

        18.Dez.2006, 0:05 :: photo :: Permalink :: Comments (2)

This evening I was impressed by the beautiful colors the sun painted the sky with. I took my camera, and on the way out I thought I might as well give the dog of my landlord a walk. (I'm not really sure if he qualifies as "landlord" since I will have my own appartment.)

I went a little uphill and looked for a place to use as tripod for my camera. I found those green hay-balloons and took some classic pictures like the first one. Then it crossed my mind that this might be very pretty to look at, but I've already taken hundreds of pictures alike. So, let's experiment a little with the balloons, the dog and the sunset - the result is shown above.

Unfortunately I overestimated the brightness of the sunset (in fully manual mode) so the photos turned out too dark. I could brighten them in order to recognize the dog, but I'd have preferred somewhat brighter originals.

        26.Nov.2006, 20:00 :: photo :: Permalink :: Comments (1)

I'm not talkin about a near death experience, it's about photography. I'd like to share a revelation I had yesterday: the power of an 50mm f1.8 objective.

The image above is a part of an 3456 x 2304 pixel image with the following EXIF data:

• ISO Speed 400 (Filmepfindlichkeit / Sensibilité)
• Shutter 1/50 (Belichtungszeit / Vitesse d’obturation)
• Exposure Bias -1.33 (Belichtungskorrektur / Correction d’exposition)
• Aperture 1.8 (Blende / Ouverture)
• Focal length 50mm (Brennweite / Longueur focale)
• Flash Off (Blitz / Flash)

The shot was taken in a train at night, thus very lousy light conditions. I am completely amazed by the possibilites this offers as I am used to an objective with aperture values ranging from 3.5 (18mm) to 5.0(40mm) to 5.6 (59mm) to 6.3 (195mm). In such light conditions (train at night) I wouldn't even have tried a shot because I wouldn't want to be disappointed by a motion blurred image.

Another advantage of a focal length of 50mm is that you don't have to hold absolutely still - I even took shots with 1/30 and they were just slightly blurred. The next image (400, 1/125, 1.8, 50mm) is an old lady sitting about 3m away from me to give an impression of the angle you can capture.

And finally, a test of the close-up capabilities of this little wonder of optics: my jeans at a distance of 45 cm. Though it isn't a spectacular ratio as of a true macro objective You can capture quite a lot of details. And the depth field is very small, thus giving beautiful portraits at short distance.

(I didn't say I was a beautiful model but You could take beautiful pictures!)

        23.Nov.2006, 10:54 :: photo :: Permalink :: Comments (2)

The title is in swiss german an means as much as "moving out of the stöckliacker" whereas "stöckliacker" is the name of the street.

In the beginning, my intention was to document me and my brother-in-law in spe disassembling some pretty complicated tables. I was convinced it would take us very long since the assembly was quite demanding, nevertheless we finished soon. So I decided to continue the documentation of us carrying furniture and stuff out.

The result is a stop-and-go-motion like movie with no clue but I though like the effect it gives. And it has an nifty change from horizontal orientation to vertical orientation during the "filming".

klick to open Quicktime movie!
no Quicktime? YouTube!

        2.Nov.2006, 8:44 :: life outside computers :: Permalink :: Comments (0)

continuous write MacBook Pro to flash using LaCie Universal Media Drive USB 2.0. Test command: $ date && cp -v /256mb.dmg /Volumes/EOS_DIGITAL/ && date

continuous write Canon 350D to flash 20 files RAW 7,2 MB, total size 144 MB, shot in continous mode, no AF, fixed AV (3.5) and TV (1/1000s), only starting to count after internal buffer was filled (5 pictures minimum).

When using continuous shot mode or shooting pictures in very small intervals, you can take about twice as many pictures with the Sandisk ultra II than with the IBM Microdrive.

What do we learn? It matters which CF card you use!

        21.Jun.2006, 14:21 :: photo :: Permalink :: Comments (2)