{"id":572,"date":"2010-08-12T10:27:59","date_gmt":"2010-08-12T10:27:59","guid":{"rendered":"https:\/\/www.cg-blog.com\/?p=572"},"modified":"2012-09-23T12:48:13","modified_gmt":"2012-09-23T12:48:13","slug":"depht-of-field-dof-vray","status":"publish","type":"post","link":"https:\/\/www.cg-blog.com\/index.php\/2010\/08\/12\/depht-of-field-dof-vray.htm","title":{"rendered":"How to get a nice depht of field"},"content":{"rendered":"<p>I really hate to talk about options and parameters.<br \/>\nUnderstanding through the parameters seems to me a great bullshit. It&#8217;s necessary to deeply understand things, then\u00c2\u00a0just apply to the software.<\/p>\n<p>That&#8217;s because 90% of this article is devoted to a simple explanation of what the depth of field is and\u00c2\u00a0what it depends. The softwares does not invent anything new, \u00c2\u00a0once you understood the fundamental issue so\u00c2\u00a0the application will be really simple.<\/p>\n<p style=\"text-align: center;\">* * *<\/p>\n<p>For each picture there is just one place where the photo is perfectly sharp. There also is a space in front and one behind the subject, in which blurring is so minimal as to be imperceptible.<\/p>\n<p><img decoding=\"async\" class=\"alignnone size-full wp-image-1634\" src=\"https:\/\/www.cg-blog.com\/wp-content\/uploads\/2010\/08\/dof-vray.jpg\" alt=\"vray phyisical camera\" width=\"599\" \/><\/p>\n<p>Outside of this space objects start to appear increasingly blurred.<\/p>\n<p>This space is called <strong>Depth of Field<\/strong> and the objects in this space appears perfectly sharp.<\/p>\n<p style=\"text-align: center;\"><strong>WHAT DOES AFFECT THE DEPHT OF FIELD?<\/strong><\/p>\n<p>There are 3 importants things:<\/p>\n<ul>\n<li>Focal lenght<\/li>\n<li>Distance from the subject<\/li>\n<li>Aperture (f number)<\/li>\n<\/ul>\n<p>How to increase Blur DOF effect?<\/p>\n<ol>\n<li>Using a bigger focal lenght<\/li>\n<li>Reducing the distances from the subject<\/li>\n<li>Decreasing F Number<\/li>\n<\/ol>\n<p>If you already fixed your camera\/view, <strong>the only way you have to give a strong DOF effect is decreasing F Number<\/strong>, but there is a problem: more light will came!<\/p>\n<p>So, how to balance this phenomenon?<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.cg-blog.com\/images\/more-contents-premium.jpg\" alt=\"\" \/><\/p>\n<p>You can follow 2 ways: &#8220;Exposure values&#8221; using tables or Intuitive way like this special video below!<br \/>\nWatch the <strong>Video<\/strong> , download the <strong>Files<\/strong>\u00c2\u00a0and complete the <strong>Exercise<\/strong> to fix the concepts.<\/p>\n<p>[private Premium|Premium1|Premium-1year]<\/p>\n<p><strong>VIDEO<\/strong> :<\/p>\n<p><iframe loading=\"lazy\" src=\"http:\/\/player.vimeo.com\/video\/34554589?color=ff9933\" frameborder=\"0\" width=\"599\" height=\"337\"><\/iframe><\/p>\n<p><strong>VIDEO-SUMMARY<\/strong> :<\/p>\n<ol>\n<li>Add V-Ray Physical Camera<\/li>\n<li>Try 3 ways to get a stronger Dof effect<\/li>\n<li>Use longer focal lenghts<\/li>\n<li>Use Closer Shots<\/li>\n<li>Use lower <em>f<\/em> number<\/li>\n<li>Use &#8220;subdivs&#8221; to reduce grain<\/li>\n<\/ol>\n<p><strong>EXERCISE<\/strong> :<\/p>\n<p><strong><a href=\"https:\/\/www.cg-blog.com\/files\/Premium\/dof-basics.zip\">Download this PACK<\/a><\/strong> and do the same you watched in the video.<br \/>\nStart the exercise opening &#8220;Dof &#8211; START.max&#8221;<br \/>\n( For any doubt check &#8220;FINAL&#8221; version )<br \/>\n[\/private]<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><strong>You can also do the same using \u00c2\u00a0EV (Exposure Value)<\/strong><\/p>\n<p>Basically the amount of light entering in a lens is the result of two factors:<\/p>\n<ol>\n<li>F number (the aperture)<\/li>\n<li>Shutter speed \u00c2\u00a0(expressed in thousandths of seconds)<\/li>\n<\/ol>\n<p>In this table &#8220;<strong>f<\/strong>&#8221; and &#8220;<strong>shutter speed<\/strong>&#8221; are associated with a number (EV).<\/p>\n<p><strong><span style=\"color: #ff0000;\"><strong>Keep EV value constant and you will get the same brightness!<\/strong> C&#8217;est facile! \ud83d\ude09<\/span><\/strong><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1635\" src=\"http:\/\/www.grafica3dblog.it\/wp-content\/uploads\/2010\/07\/exposurevalues-749412.jpg\" alt=\"\" width=\"475\" height=\"354\" \/><\/p>\n<p style=\"text-align: center;\"><strong>PRATICAL SCENE EXAMPLE<\/strong><\/p>\n<p>I completed my settings and I have VRay Physical Camera with: <strong>f=8 \/ Shutter speed = 250.<br \/>\n<\/strong>In the table \u00c2\u00a0I can read the<strong> EV is \u00c2\u00a014<\/strong>. (image below)<\/p>\n<p><a href=\"http:\/\/www.grafica3dblog.it\/wp-content\/uploads\/2010\/07\/render-valore-ev-1.jpg\" target=\"_blank\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1636\" src=\"http:\/\/www.grafica3dblog.it\/wp-content\/uploads\/2010\/07\/render-valore-ev-1-icon.jpg\" alt=\"\" width=\"475\" height=\"281\" \/><br \/>\n<\/a>(Rememebr: Our goal is to keep EV constant!)<\/p>\n<p>Do you want to get a blurred image?\u00c2\u00a0(I know you like thaaat!) if I decrease \u00c2\u00a0<strong>F number = 4 <\/strong>I have to check in the table the right Shutter speed value in order\u00c2\u00a0<strong>to preserve EV=14<\/strong><\/p>\n<p>The right values is <strong>Shutter speed = 1000<\/strong> (Click image below)<\/p>\n<p><a href=\"http:\/\/www.grafica3dblog.it\/wp-content\/uploads\/2010\/07\/render-valore-ev-2.jpg\" target=\"_blank\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1638\" src=\"http:\/\/www.grafica3dblog.it\/wp-content\/uploads\/2010\/07\/render-valore-ev-2-icon.jpg\" alt=\"\" width=\"475\" height=\"333\" \/><br \/>\n<\/a>( <strong>F=4<\/strong> and <strong>Shutter speed = 1000<\/strong> will keep <strong>EV = 14<\/strong> and the brightness will be constant! )<\/p>\n<p>It&#8217;s easy: I told you! \ud83d\ude42<\/p>\n<p>Now just flag <strong>depht-of-field<\/strong> (in V-Ray Physical Camera object)\u00c2\u00a0and remember that &#8220;<strong>subdivisions&#8221; <\/strong>affects the grain coming from the Dof. High values (30-40) will give a better image but the rendering time will increase drammatically.<\/p>\n<p>Remember that the distance where we \u00c2\u00a0have the perfect focus will be determined by the <strong>VRayPhysical Carmera TARGET<\/strong>.<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-1640\" src=\"http:\/\/www.grafica3dblog.it\/wp-content\/uploads\/2010\/07\/depth-of-field.jpg\" alt=\"\" width=\"475\" height=\"172\" \/><\/p>\n<p>For the application I used V-Ray but the concept is the same for any software simulating a real camera.<\/p>\n<p>Last good news: these concepts are also valid for your REAL Reflex!<br \/>\nHave a good rendering!<\/p>\n","protected":false},"excerpt":{"rendered":"<p>What does affect depht of field? There are 3 importants things: Focal lenght, distance from the target and Aperture. In this tutorial you will learn how to manage them with V-Ray Physical Camera.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false},"categories":[24,26,39,56],"tags":[40],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/posts\/572"}],"collection":[{"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/comments?post=572"}],"version-history":[{"count":0,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/posts\/572\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/media?parent=572"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/categories?post=572"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cg-blog.com\/index.php\/wp-json\/wp\/v2\/tags?post=572"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}