kevin dowie

    Photographed in Tanzania,  the lilac breasted roller is a fairly common species.  I've seen numerous pictures of these birds taken by travellers over the years and was pleased to get some shots of them myself.    Technically nothing too special about this shot really,  long lens used at wide aperture to isolate the bird against an indistinct background.   With the bird's head in profile,  all the points of interests are acceptably within,  or close to,  the plane of focus.   I like the colours and the detail in the feathers which were the point to taking the shot.   Enjoy KD.  

           Canon 5D  with 500mm lens at F5.6   shutter speed 1/500 second ISO 400,  cropped image.

    Over the last couple of weeks I've presented mostly close up wildlife shots,  today I thought I'd take a different tack and show some wildlife within the context of the landscape.  The first shot was taken in Tarangire National Park whilst the second one was in Ngorongoro Crater a couple of days later.    Notice that in the first shot the zebras are up to their bellies in grass,  whereas in the second shot the grass is quite a bit shorter.   Tarangire is a fairly open landscape whereas Ngorongoro, being a crater,  is more enclosed and more heavily grazed.  

Cropping factors.

    Both shots were taken with a Canon 20D SLR.   The 20D is a reduced frame camera with a cropping factor of 1.6x.   Notice it's a "cropping" factor not a "multiplying" factor as some people suggest.   Some people are under the impression that,  if you use a lens of say 100mm on a camera with a cropping factor/multiplying factor of 1.6,  the lens then behaves like a 160mm focal length on a full frame camera,  not correct.   The depth of field characteristics of the lens don't change,  but the angle of view changes.   The effect is the same as if you use a full frame camera and then crop the image after the event.

Sharpening in Photoshop.

     A little while ago I commented on the use of digital sharpening in Photoshop,  indeed I presented an article with some examples on my main site.   Regular readers may recall an architectural shot I took in Antigua, Guatemala, and presented, unsharpened,  on this blog a couple of months ago.   I commented at the time on artifacting that digital sharpening introduced in really fine details (window shutters) in that image.   The same effect was evident when processing the first image here.   With the zebras small in the frame,  their stripes appear really closely spaced together and so sharpening,  at what I regard as normal levels,  produced really bizarre looking artifact.   For those that are using Photoshop and are interested,  the image was given smart sharpening at 50% and 1.0 pixel radius, normally I would consider 150% and 1.5 pixel radius as a starting point for most images.

    As usual,  if anyone has any comments or questions, fire away.     Cheers KD.   

             Canon 20D with 24-105mm zoom lens at 28mm,  shutter speed 1/125 second at F11,  ISO 100.

             Canon 20D with 24-105mm zoom lens at 24mm,  shutter speed 1/200 second at F7.1,  ISO 200.

     Some links to explore;  

     Taking a break from processing my wildlife shots,  I went cruising through one or two or my favourite websites and found out about a site now set up by NASA which displays a series of pictures sent back by the Mars rover as well as by satellites.   Some of the images are quite intriguing and naturally enough "other worldly".  Some are taken using thermal imaging cameras and some appear quite abstract,  including a shot of what scientists have dubbed the "Grand Canyon" of Mars, a canyon the length of which is similar to the distance between New York and Los Angeles,  mind boggling.        NASA "Mars as Art" http://www.nasa.gov/externalflash/Mars_as_art/index_noaccess.html

        Another site for those interested in space/astronomy photos  http://www.space.com has been running for quite some time.  It has some great shots taken by the Hubble space telescope,  I'm currently using one of their shots as my computer screen saver!    

       Enjoy KD.

       Captions anyone?    I think maybe this shot needs a couple of cartoon like speech bubbles.    Perhaps;  "Why are they staring at us mum?"   "It's the way of the world son,  while we're out here eating grass,  millions of humans are just sitting,  staring at computer screens."    Maybe you can come up with your own variations or themes!    ;-)   KD

           Canon 5D,  500mm lens at F8.0,  shutter speed 1/400 second at ISO 320.

      Well I hope that following my last post readers had the opportunity to click through on the link I provided to iDC Photography.  Recapping,  iDC's creator/host Bruce Dorn posted a series of my pictures from our recent Tanzania trip and has also been displaying some pictures from some other members of the group,  so check it out if you haven't already.   I submitted about 20 shots which Bruce then edited down to 11 for display.   Interesting to see which ones he picked and which one he chose to lead the article with.   The lead shot was the one which I'm presenting here today,  shot in the Serengeti National Park,  the Masai Giraffe was feeding on the foliage of a nearby tree,  but I chose to ignore the nearby tree and show the face of the animal juxtaposed against another tree on the horizon.   

       This is not the full frame but has been cropped down,   the telephoto lens gives a limited depth of field when used at a wide aperture allowing for the selective focus effect seen here.   I like the fact that the distant tree is out of focus to the extent that it's clear the giraffe is the main focus of attention,  but the tree still has enough form that it is immediately identifiable.    enjoy KD www.kevindowie.com

                     Canon 5D  500mm lens at F5.6  shutter speed 1/1250 second ISO 200.