{"id":10163,"date":"2015-09-16T21:35:18","date_gmt":"2015-09-17T01:35:18","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/?p=10163"},"modified":"2015-09-16T21:35:18","modified_gmt":"2015-09-17T01:35:18","slug":"016366-depth-of-field-follies","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2015\/09\/16\/016366-depth-of-field-follies\/","title":{"rendered":"016\/366: Depth of Field Follies"},"content":{"rendered":"

I’ve been doing a lot of opining on my blogs of late, and much less science-ing that I would like. So I thought I’d try bringing a little science to the photo-a-day project, by playing around with f-numbers<\/a>.<\/p>\n

I put the camera on the tripod, with my fastest lens (a 50mm f\/1.8 prime) and set up an array of SteelyKid’s Lego minifigs to be targets. Then I shot pictures of the scene at different aperture settings spanning the full range I could select. The two extremes are shown here:<\/p>\n

\"Lego<\/a>
Lego minifigs shot with the two extremes of my fastest lens. Top is f\/22, bottom f\/1.8.<\/figcaption><\/figure>\n

I had to put it on manual focus, otherwise it went nuts trying to decide what to autofocus on, and as you can see, I didn’t get it quite dialed in on the frontmost minifigs. I kind of like the fact that it’s got that one bit of dog hair on the wagon zeroed in perfectly, though. The lens is a bit over 20cm from the table, because the tape measure I have here doesn’t have SI units on it, so I put it about 8 inches away (about the closest it would focus on). Each Lego set-up is 8 inches behind the next.<\/p>\n

Because I’m a great big nerd, I took photos all the way through this sequence, and here’s a representative set of f-numbers (I left the exposure time on auto, which means some of the smaller apertures had rather long exposures, and a few of those pictures got some motion blur from me pushing the button; I left those out):<\/p>\n

f\/22:
\n\"f22\"<\/a><\/p>\n

f\/16:
\n\"f16\"<\/a><\/p>\n

f\/11:
\n\"f11\"<\/a><\/p>\n

f\/8:
\n\"f08\"<\/a><\/p>\n

f\/5.6:
\n\"f056\"<\/a><\/p>\n

f\/4.5:
\n\"f045\"<\/a><\/p>\n

f\/3.5:
\n\"f035\"<\/a><\/p>\n

f\/2.8:
\n\"f028\"<\/a><\/p>\n

f\/1.8:
\n\"f018\"<\/a><\/p>\n

Kind of impressive how rapidly the depth of field shrinks as you get toward the bottom. The factor-of-2 difference between f\/22 and f\/11 doesn’t make much difference, but going from f\/3.5 to f\/1.8, wow. which, you know, is not that surprising on an intellectual numbers-on-paper sort of level– it’s optical physics, after all– but it’s something else to see the effect on the images.<\/p>\n

Anyway, there’s your highly nerdy photo-of-the-day. Next time I feel the need to do this, we’ll play with ISO values in the dark basement…<\/p>\n","protected":false},"excerpt":{"rendered":"

I’ve been doing a lot of opining on my blogs of late, and much less science-ing that I would like. So I thought I’d try bringing a little science to the photo-a-day project, by playing around with f-numbers. I put the camera on the tripod, with my fastest lens (a 50mm f\/1.8 prime) and set… Continue reading 016\/366: Depth of Field Follies<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":10164,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[684,238,7,50],"tags":[],"class_list":["post-10163","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-684","category-optics","category-physics","category-pictures","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/10163","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/comments?post=10163"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/10163\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media\/10164"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=10163"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=10163"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=10163"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}