{"id":2277,"date":"2012-01-14T16:36:24","date_gmt":"2012-01-14T16:36:24","guid":{"rendered":"http:\/\/www.pmstudios.co.uk\/blog\/?p=2277"},"modified":"2012-01-18T08:10:00","modified_gmt":"2012-01-18T08:10:00","slug":"how-sharp-is-this-budget-lens-a-technical-post","status":"publish","type":"post","link":"https:\/\/www.pmstudios.co.uk\/blog\/?p=2277","title":{"rendered":"How sharp is this budget lens? (a technical post)"},"content":{"rendered":"

I have read posts that suggest that, when stopped down, a budget lens can almost equal a more expensive one. I have decided to put this to the test with my old, budget, film era, 75-300mm Canon lens.<\/p>\n

For this test, the camera was mounted on a sturdy tripod, the mirror was locked up, and a 2 second self timer was used – all to minimise camera shake. In addition, the focusing point was ‘micro adjusted’ to its optimum (see this previous post<\/a>). Here are some of the results:<\/p>\n

\"75mm<\/a>This shows the corner at 75mm f4. Bear in mind that this is a full format lens, so with the cropped format sensor of my camera, this\u00a0 section is about half-way out to the edge (all lenses tend to be sharper at the centre compared to the edge). This is unacceptably soft. This next one is at F16:<\/p>\n

\"75mm<\/a>A lot sharper, but not pin-sharp. This would probably withstand printing up to A4 size. Zooming in to 135mm and looking at the centre of the frame, at F8:<\/p>\n

\"135mm<\/a>Moderately sharp, again this would probably print OK up to A4 size. But when stopped down to f32, although the depth of field has increased, sharpness has taken a hit:<\/p>\n

\"123mm<\/a>OK for a postcard size perhaps… Going now to 300mm, this shows the corner at f5.6:<\/p>\n

\"300mm<\/a>Quite blurred with purple fringing – not nice. Stopping down to F16 improves things a little:<\/p>\n

\"300mm<\/a>But this is still rather soft with purple fringing. This might print OK at A4 but it is pushing it a bit.<\/p>\n

So my conclusion? Much depends on the final use. With care, stopped down to about f11-16 and in the middle of the zoom range, with a bit of sharpening I might be able to get an acceptable A4 print. Otherwise I better start saving for an L series lens (all donations gratefully accepted!)<\/p>\n","protected":false},"excerpt":{"rendered":"

I have read posts that suggest that, when stopped down, a budget lens can almost equal a more expensive one. I have decided to put this to the test with my old, budget, film era, 75-300mm Canon lens. For this test, the camera was mounted on a sturdy tripod, the mirror was locked up, and … Continue reading “How sharp is this budget lens? (a technical post)”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[65],"tags":[],"class_list":["post-2277","post","type-post","status-publish","format-standard","hentry","category-technical"],"_links":{"self":[{"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2277","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2277"}],"version-history":[{"count":16,"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2277\/revisions"}],"predecessor-version":[{"id":2382,"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2277\/revisions\/2382"}],"wp:attachment":[{"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2277"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2277"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pmstudios.co.uk\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2277"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}