{"id":927,"date":"2010-01-29T18:21:49","date_gmt":"2010-01-29T22:21:49","guid":{"rendered":"http:\/\/www.birdsasart-blog.com\/?p=927"},"modified":"2011-02-24T14:24:46","modified_gmt":"2011-02-24T18:24:46","slug":"basic-sharpness-testing","status":"publish","type":"post","link":"https:\/\/www.birdsasart-blog.com\/baa\/2010\/01\/29\/basic-sharpness-testing\/","title":{"rendered":"Basic Sharpness Testing"},"content":{"rendered":"\n\n\n
ngg_shortcode_0_placeholder<\/td>\n<\/tr>\n
This image was created with the Canon 70-200mm f.4L IS lens with the 1.4X II TC (handheld at 280mm) and the EOS-7D. ISO 400. Evaluative metering +1\/3 stop: 1\/2000 sec. at f\/6.3. You need to have absolute confidence in both your and your camera's ability to produce sharp images.<\/td>\n<\/tr>\n<\/table>\n

Whenever I take a new camera out of the box, I head down to the lake and create some images just to make sure that the camera is capable of focusing accurately.\u00a0 I have never had a camera that did not create razor sharp images when I did everything right.\u00a0\u00a0 That said, on rare occasion, folks do get a bad camera.\u00a0 If you are relatively new to photography, reading the article below will be a great help and includes some basic tests so that you can check and see if your camera is a rare dud.\u00a0 I have never had to perform\u00a0any of the tests below\u00a0because my initial \u00a0“test” images with new cameras have always been sharp, that a result of quality products and excellent sharpness techniques.\u00a0 (See the same in ABP II.)<\/p>\n

Basic Sharpness Testing<\/h2>\n

I receive several e-mails each week from folks who state that this camera does not focus properly or that that lens is not sharp.\u00a0\u00a0In 99% of\u00a0the cases I am sure that\u00a0operator error rather than equipment\u00a0malfunction is the cause.\u00a0 That said, on rare occasion, folks\u00a0using quality equipment from Canon or Nikon\u00a0do experience\u00a0real problems with focusing accuracy.\u00a0<\/p>\n

If you are handholding, please do not complain about unsharp images.\u00a0 I was walking around in Sabine Woods on a spring trip least year.\u00a0\u00a0It was cloudy dark.\u00a0\u00a0 I was working at ISO 800 with shutter speeds of about 1\/60th second and even slower at times.\u00a0 There were two folks walking around\u00a0handholding <\/strong><\/em>500 f\/4 lenses; they might as well have gone fishing as there was no way that they could create a sharp\u00a0image without a tripod in those conditions.\u00a0 It is best to work on a tripod at all times when using your\u00a0longest lens (unless you are handholding for flight or for action).<\/p>\n

Another factor to consider is that most of the folks who write complaining of unsharp image\u00a0are using cameras with 1.6X or 1.5X multiplier effects.\u00a0 They need to realize that these cameras multiply vibrations and movement caused by operator error by the square of the equivalent focal length!<\/em><\/p>\n

If you are using a tripod\u00a0you need to\u00a0check and note\u00a0the shutter speeds of your unsharp images.\u00a0 I had one guy on an IPT complaining that none of his images were sharp.\u00a0 I checked his set-up and saw that he was working in near darkness at ISO 100 with shutter speeds in the 1\/8 to 1\/15 second range.\u00a0 Making sharp images with a long lens at such slow shutter speeds is simply not possible for most folks.\u00a0 When working at long effective focal lengths I am confident that I can make sharp images down to 1\/60 second as long as I have time to lock the tripod head and provided that the bird does not move during the exposure.\u00a0 With the prime lenses alone, I can usually get down to 1\/30 second.\u00a0\u00a0With the\u00a0relatively\u00a0new Canon 800mm lens and its new 4-stop IS system, I have made some sharp images at shutter speeds as slow as 1\/6 sec.<\/p>\n

\u00a0Below are two\u00a0simple tests to determine if you have faulty equipment.\u00a0<\/p>\n

    \n
  1. Tape a sheet of newspaper to a sunlit\u00a0outdoor\u00a0wall on a relatively still day.\u00a0\u00a0Make sure that it is as taped down as flat as possible.\u00a0 (A magazine cover with fine print or a plastic or cardboard test chart are\u00a0of course\u00a0better options.)\u00a0 Mount your telephoto rig on a tripod.\u00a0 Lock down the tripod and the\u00a0lens collar.\u00a0 Make\u00a0sure that you are beyond the\u00a0minimum focusing distance of your lens and that the distance range switch (if your lens has one) is set to full.\u00a0 Make a few images at the wide open aperture using both One-Shot or AI Servo with Canon gear\u00a0or Single (S) or Continuous (C) with Nikon.\u00a0 Then do the same thing at f\/8.\u00a0 As long as the wall is sunlit you will have more than enough shutter speed to\u00a0know that your focusing issues are\u00a0not caused by too-slow shutter speeds. Now download your images and check them for accurate focusing.\u00a0 If all of the images are sharp, then you can be sure that your unsharp images were being caused by operator error.<\/li>\n
  2. Stand well off a somewhat busy road with the sun angled so that the approaching\u00a0vehicles are coming right down sun angle.\u00a0\u00a0 Use the wide open aperture and choose an ISO that results in shutter speeds greater than 1\/2000 sec.\u00a0 Choose AI Servo (Canon) or Continuous (Nikon) and select the center AF sensor.\u00a0 As the cars approach, place the central sensor on the license plate and hold the shutter button down once focus is acquired.\u00a0 Even this simple task requires some practice so be sure to take lots of images.\u00a0 Download the images and sort them into two groups: sharp on the license plate and unsharp on the license plate.\u00a0\u00a0Now using an application that allows you to see the position of the active focusing sensor, in this case the central sensor, note the position of the sensor in the unsharp images.\u00a0 If the sensor is consistently on the\u00a0license plate and the images are unsharp, then you likely have equipment problems.\u00a0 You can\u00a0repeat this test with various camera bodies and various lenses in an effort to determine the cause of the problem.\u00a0\u00a0When you are pretty sure that you have an equipment problem it is best to send the gear to the\u00a0manufacturer along with a CD of the\u00a0test images.<\/li>\n<\/ol>\n

    In most\u00a0cases, folks will\u00a0learn that their equipment is perfectly fine\u00a0but that their\u00a0poor sharpness techniques are the cause of the unsharp images.\u00a0 Do also realize the importance of subject movement.\u00a0 While working at the Cozad Ranch probably well more than half of my\u00a0images were unsharp.\u00a0 This was due in most cases\u00a0to subject movement.\u00a0 In other cases, the unsharp images were a result\u00a0of the AF system being\u00a0unable to maintain sharp focus on the\u00a0tiny\u00a0songbirds\u00a0as they leaped\u00a0off of their perches.\u00a0\u00a0\u00a0It is important to understand and to realize the limitations of our equipment.\u00a0\u00a0\u00a0<\/p>\n

    The above text was adapted from a feature in BIRDS AS ART Bulletin #289:\u00a0 http:\/\/www.birdsasart.com\/bn.html<\/a>.\u00a0\u00a0The Bulletin Archives here: http:\/\/www.birdsasart.com\/bn289.htm<\/a>\u00a0are a tremendous free resource.\u00a0\u00a0 And there is a great Google search feature that can help you find what\u00a0 you need quickly.\u00a0\u00a0<\/p>\n

    <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    ngg_shortcode_1_placeholder This image was created with the Canon 70-200mm f.4L IS lens with the 1.4X II TC (handheld at 280mm) and the EOS-7D. ISO 400. Evaluative metering +1\/3 stop: 1\/2000 sec. at f\/6.3. You need to have absolute confidence in both your and your camera's ability to produce sharp images. <\/p>\n

    Whenever I take a […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[89,34,14],"tags":[],"class_list":["post-927","post","type-post","status-publish","format-standard","hentry","category-89","category-70-200mm-f4","category-photography-tips","odd"],"_links":{"self":[{"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/posts\/927","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/comments?post=927"}],"version-history":[{"count":0,"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/posts\/927\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/media?parent=927"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/categories?post=927"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.birdsasart-blog.com\/baa\/wp-json\/wp\/v2\/tags?post=927"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}