Post processing: lens correction / perspective correction

23 March, 2013

Tags: open source, post processing, tutorial

Last week the blog fototriss had architecture and buildings as theme. Architecture and (ultra) wide angle lenses can make dramatic images, but also cause much distortion in the image. To over exaggerate a little, walls that should be parallel can appear like the sides of a pyramid.

For example one image straight from the camera taken at 21mm with a crop camera (equiv. 33mm on full frame):

Photo of Bigfoot studios

If we trace lines along the vertical walls they will intersect. That is not how the building appears in real life. If the image would have been taken at equivalent to 16-18mm on full frame, the distortion would be much larger.

With the meta data recorded in the image and the help of the lensfun library the image can be automatically adjusted. The second image is processed in GIMP, the GNU Image Manipulation Program, which is great and free alternative to Photoshop. With the plugin GimpLensfun the image is easily adjusted by selecting Filters > Enhance > Gimplensfun. The default settings should be okay if your camera/lens is recognized.

Photo of Bigfoot studios with automatic lens correction applied

A much better result than the first image. For more advanced use or if the camera-lens combination used isn't available in lensfun, the panorama stitcher Hugin can be used. It can do perspecive correction, simulate architectural projections besides from stitching together many images and more.

Photo of Bigfoot studios with lens corrections performed manually in Hugin

The image from Hugin is not cropped compared to the one processed with GIMP and lensfun.

All the tools mentioned in the post are free and open source and part of my must-be-installed list.


Photo triplet: Buildings and architecture

17 March, 2013

Tags: fototriss, umeå

One of the more recent buildings in my close vicinity is the new train station, "Umeå Östra". It's located close to the University hospital (NUS) and the Umeå University campus area. There is also another station, Umeå Central 2km away but in my opinion it's not really needed anymore. The Umeå East train station seen from the lower entrance Escalator within the Umeå East train station Part of the wood and glass structure the station is made of Umeå Östra is mostly made of wood and glass and has a very characteristic look, specially since the walls are not vertical, but angled slightly outwards.
More triplets can be found at fototriss, also, feel free to leave comments and feedback in English or Swedish.


Documentary: Lennart Nilsson (part 2 of 2)

11 January, 2013

Tags: none

The second part of the Lennart Nilsson documentary was aired recently and made available online for streaming at svtplay. I recommend seeing it this weekend if you haven't already since it is only available until Sunday the 13th.


Refused live in Umeå!

05 January, 2013

Tags: umeå

During the 90s, Umeå had a big hardcore scene and one of the most known bands were Refused. They split up in 1998 and despite that, they are bigger than ever.

The rumours of them reuniting made me happy... and then a secret gig at Scharinska in Umeå (which me and many others would like to have seen) followed by a world tour with an epic final in Umeå. Picked up tickets for the show the same day they were released.

Refused live in Umeå, 15th December 2012: All images shot with a phone - I was there for the music and didn't have time to mess around with photo gear.

The opening acts before Refused were "Two White Horses", "Randy" and "Råd Kjetil Senza Testa" who all made it into an awesome night!


Documentary: Lennart Nilsson (part 1 of 2)

01 January, 2013

Tags: none

Swedish television recently aired the first part of a documentary about the photographer Lennart Nilsson. It is possible to see online for a five more days online at svtplay. Well worth watching! I'm waiting for part 2.


Happy new year!

01 January, 2013

Tags: none

I'll sum up the last year with one image: brio toy dog I lost my brother. I got a daughter. That toy was my brothers when he was a kid and now it has been passed on to my daughter. She loves that toy - just as much as it was loved before.

It was raining last night so we stayed indoors instead of even considering going outdoors to photograph fireworks like last year.


Wildlife: squirrel

10 February, 2012

Tags: wildlife

I'm amazed that some animals manage to find food during the winter when everything is hidden under a deep layer of snow. There are also people who feed birds etc. during the winter. Those birds are nice to look at, but I spotted a different guest the other day:
hungry squirrel
Apparently, the bird food caught the interest of a squirrel. Think it has been there before a couple of times as well since the snow has often been missing on that part of the branch where the squirrel is sitting.
acrobatic squirrel stealing bird food
Went real quick but I managed to get a shot of it, the squirrel hanging down from the branch and stealing some food, then it sat there and ate before hurrying away.


Wildlife: roe deers

08 February, 2012

Tags: umeå, wildlife

Been working on redesigning the page a bit and there are stil a few more things I want to do and this caused a small break from posting new things. That little break hasn't stopped me from photographing things.

I have a list of different wild animals I want to photo and it will be interesting to see how many of them I'll manage to get before the end of this year. Saw a couple of elks the other night, they were partly hidden behind some trees. Unfortunately it was way to dark at 1 AM to catch them - but I did have the camera at hand.

For now, some roe deers caught during better light conditions: four roe deers

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