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Wednesday, 13 July 2011

Peripheral Illumination Correction on Canon 5D, Canon 7D, and other recent Canon dSLR cameras

Most lenses will create a certain amount of corner shading or vignetting - especially clearly seen in skies or similar backgrounds.
Canon has measured how much fallingoff there is for each Canon lens and defined a profile for each. The Peripheral Illumination Correction will correct for this unevenness.

The setting process is quite easy. Enter the menu of the camera and find the utility in the bottom of the first red tab. You can enable/disable the function here and see whether the data for the attached lens is available.

With the camera connected to the computer you run the programme EOS Utility (part of the programme package delivered with the Canon camera). Select "Camera Settings / Remote Shooting" and select "Peripheral Ilumin. Correct" from the menu. Now you can define the Canon lenses you would like to use the Peripheral Illumination Correction with. Many lenses are already chosen for you - you can remove some lenses you are not likely ever to use. Do you have a 1.4 Canon Extender or a 2.0 Canon Extender - these are also available for the most obvious lenses.

The camera will either correct for the vignetting immediately in the creation of the JPEG image or will store the information in the RAW file for later use in the DPP (Digital Photo Professional - Canon's RAW conversion programme).

Have a look at this very illustrative video by David Newton.

Saturday, 25 June 2011

Customizing the white balance - particularly on the Canon 5D Mark II

Most dSLRs come with pre-programmed settings for the white balance for use in the different light types. (Daylight, cloudy, shade, tungsten, flourescent, or the exact Kelvin colour temperature setting) Or the camera can be set to automatic white balance (AWB).

If you only shoot in RAW the automatic white balance setting (AWB) will probably be a good solution - as the settings do not influence the RAW image data - but the white balance information can be used in your RAW processing programme later on.

However, if you shoot in JPEG, or JPEG and RAW - or especially a VIDEO, a correct setting of the white balance can be essential. The white balance of a RAW image should be corrected in the editing phase - but a colour cast on a video recording is troublesome - and will take a long time, even if you have got the proper video editing programmes for this.

Here is a video showing a quick and low tech way of customizing the white balance - you only need a sheet of white paper, a white t-shirt, etc.:

Customizing the White Balance on the Canon 5D Mark II


This video explains a lot more of the various opportunities for WB settings:

Canon 5D Masterclass in Depth White Balance Settings

Friday, 20 May 2011

The different licensing types in stock photography

If you want to sell stock images it is vital to understand the different types of licensing for your photos.

Basically we are talking about the difference between Royalty Free (RF) and Rights Managed (RM) - often also called Licenced. They both have their benefits and drawbacks.

Royalty Free images will not be exclusive and are often sold by size - which means you will obtain a higher price the larger the image. However, the buyer can use the photo again and again for a certain period - if not for ever.

Rights Managed images are sold for a certain purpose - and will sell again if the buyer needs to publish it again.

It is, of course, necessary to distinguish between micro stock and macro stock. In recent years the micro stock agencies have destroyed the price level for images seen from the photographer's viewpoint. Images are often sold for a few dimes with very little earnings for the photographer unless the amount of images is constantly increasing. Micro stock always sell images as Royalty Free.

A Royalty Free image at a macro site will not sell as often as from a micro site, but the price will be much higher (has been even higher a few years ago - the micro stock market is influencing this price level). Seen over a period the photographer will often earn more from the macro sites - but this may be opposite for the most plain and iconised images which will only sell as micro stock.

Selling the same Royalty Free images from both macro and micro sites is generally not a good idea.

Selling the same photo as Royalty Free and also as Rights Managed is an absolute no-no.....

These links from f.57.com and thephotographybiz.com are informative on these matters - and the viewpoint is selling from a macro site, of course:

Stock photo licensing

Understanding licensing types: Royalty Free Image Licences

Understanding licensing types - Rights Managed Image Licences

Selling on Alamy: Royalty Free or Licenced?

Can you sell an image as RF and RM at the same time?

Sunday, 15 May 2011

Travel Blog from Digital Photographer

Good advice on photo journeys - though not always possible to fulfill all the requirements. Andrew Newey's ten top tips for aspiring travel photographers:

Tips for aspiring travel photographers

200th Anniversary of the First Danish Balloon Voyage

In the evening of April 24th 2011 - 12 large hot air balloons ascended from the grounds of the Royal Rosenborg Castle in Copenhagen to celebrate the first Danish balloon voyage 200 years ago.


Canon 5D Mk II - Focal length: 24mm - Aperture value: f9 - Shutter speed: 1/160 - ISO: 200

Photos Alamy                                                                               Story and photos Demotix

Sensor cleaning

A lot of bull is said about sensor cleaning. Products are being promoted without having the promised effects, etc. And you could easily make things worse or even harm the surface of the sensor.

Practical experience and different view on cleaning from experienced people:
http://www.alamy.com/forums/Default.aspx?g=posts&t=8500
http://www.alamy.com/forums/default.aspx?g=posts&t=11032
http://www.alamy.com/forums/default.aspx?g=posts&t=9499
http://www.alamy.com/forums/default.aspx?g=posts&m=102493
http://www.alamy.com/forums/default.aspx?g=posts&t=12458

Instructional videos can be found at YouTube.

Histograms

If you are in doubt how to use histograms and colour histograms for a correct exposing of your digital photos - then learn more from Ken Rockwell's excellent blog on this subject:

http://www.kenrockwell.com/tech/histograms.htm

- great page - unfortunately some examples are with Nikon cameras - I am a Canon man, of course.

Hot, but somewhat misty and cloudy

More mist and haze than expected in the Bavarian and Austrian mountains and valleys this July. Often very hot though. But a photographer sure values a crisp and clean air. The mornings and evenings at the camp site in Sölden was unexpectedly cold, though, due to the shallow valley and height. On the last morning in Sölden, Austria, when packing the tent, a big helicopter was suddenly seen transporting heavy gear on the nearby mountain sides for the new mountain gondola to the top of Gaislachkogl peak, opening in December. Amazing to see how quickly this big helicopter could operate and transport big and heavy lifts in a long wire on the steep and inaccesible mountain sides. The towers for the mountain gondola were transported and kept in position by the helicopter for the land crew to secure. This was a matter of minutes. The tasks had surely been prepared carefully beforehand. I got a few shots with my Canon 70-200mm. But should, of course, have stayed another day and entered the mountain that morning to get shots from under the chopper. You can never do enough research on the areas you want to visit and take photos of. Had I known, I would have been there.




Later research revealed that it was a Swiss company specializing in these special and heavy lifts - and the helicopter was a Russian built Kamov heavy-transport helicopter with a double-rotor system (yes, you are not necessarily intoxicated - there are six rotor blades on the chopper).

More about the new Gaislachkogl Mountain Gondola

Depth of Field Simulator

An excellent DOF simulator - a Java applet - that gives immediate, visual feedback showing the effect of various configurations.

http://www.liquidsculpture.com/dof.htm

Hyperfocal Distance Guide / DOF Calculator

Dofmaster's guide to hyperfocal distance:

http://www.dofmaster.com/hyperfocal.html


Dofmaster's depth of field calculator:

http://www.dofmaster.com/dofjs.html

Artifacts in digital images

Mike Berceanu is going through the basics of the artifacts that occur in digital photographing:

http://www.dpcorner.com/topics/