{"id":385,"date":"2011-09-05T12:41:34","date_gmt":"2011-09-05T02:41:34","guid":{"rendered":"http:\/\/www.fractalthoughts.com\/blog\/?p=385"},"modified":"2011-09-05T12:41:34","modified_gmt":"2011-09-05T02:41:34","slug":"experiments-with-a-9-stop-nd-filter","status":"publish","type":"post","link":"http:\/\/www.fractalthoughts.com\/blog\/?p=385","title":{"rendered":"Experiments with a 9-stop ND filter"},"content":{"rendered":"

A couple of weeks ago I watched a short tutorial on taking long-exposure photographs in broad daylight, using a 10-stop Neutral Density (ND) filter. The long exposures smooth out slightly-moving textures (such as water), resulting in a dreamy-quality photograph that I found very attractive. I filed it under “must try out at some point”, largely because two weeks ago I didn’t own either an ND filter, or a cable release. Both are absolutely required to try this out, as is a tripod, obviously.<\/p>\n

This morning I found that the Obsessive Mountain Biker<\/a> had stopped riding trails for long enough to order the two missing pieces of equipment for me! My little surprise package contained an ND400 filter and a cable release.<\/p>\n

ND400 is a 9-stop (rather than 10-stop) filter, and even that was hard to come by. Still, only 1 photon in 400 reaches the camera so that should surely be fine, right?<\/p>\n

I attached the filter and the cable release and tried to take a picture. The first two learning points presented themselves immediately:<\/p>\n

    \n
  1. 1 photon in 400 reaching the sensor means you cannot frame a shot with the filter attached. For all practical purposes that’s like trying to frame a shot with the lens hood still on.<\/li>\n
  2. For the same reason, autofocus is right out as there is not enough light to use it.<\/li>\n<\/ol>\n

    So, I take the filter off again, frame the shot, put the filter on again, take off the eye piece, attach the eye piece cover. This is a sequence I will shortly become very good at.<\/p>\n

    Cable release, 1s. That’s about as short as I can manage using bulb exposure. This shot serves as comparison. The water shows clear ripples. (Click the thumbnail to see a full-size version.)<\/p>\n

    \"Paddleboats<\/a>
    1s exposure<\/figcaption><\/figure>\n

     <\/p>\n

     <\/p>\n

     <\/p>\n

     <\/p>\n

     <\/p>\n

     
    \nOptimistically, I tried the 2-min exposure recommended in the tutorial. Result: A completely white “picture”. It would seem that the difference between a 9-stop and a 10-stop ND filter does actually matter. So, I try again, using a 60s exposure. Success:<\/p>\n

    \"Paddleboats<\/a>
    60s exposure<\/figcaption><\/figure>\n

    Note how the water has taken on a smooth, silky texture.<\/p>\n

    Since I was still getting far too much light I switched from using my colossal light bucket (er, I mean, 50mm prime lens) to a 18-55mm kit lens. It is far inferior to the prime lens, among other things because it captures less light, which, in this case, is exactly what I wanted. Here is the same shot taken with the kit lens, also at 60s.<\/p>\n

    \"Paddleboats<\/a>
    Paddleboats - 61s kit lens<\/figcaption><\/figure>\n

    This is looking good. Time to have some fun. This is Eagle St Pier, taken with a 90s exposure:<\/p>\n

    \"Eagle<\/a>
    Eagle St - 90s<\/figcaption><\/figure>\n

    And finally, a ferry docked at Thornton St during this 60s exposure. You can see its ghosted image.<\/p>\n

    \"Ferry<\/a>
    Ferry Movements - 55s<\/figcaption><\/figure>\n

    All photographs in this post were post-processed with the exposure turned down in Aperture. This is to get decent exposure for the buildings in the backgrounds without losing the silky water texture.<\/p>\n","protected":false},"excerpt":{"rendered":"

    A couple of weeks ago I watched a short tutorial on taking long-exposure photographs in broad daylight, using a 10-stop Neutral Density (ND) filter. The long exposures smooth out slightly-moving textures (such as water), resulting in a dreamy-quality photograph that I found very attractive. I filed it under “must try out at some point”, largely … Continue reading Experiments with a 9-stop ND filter<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-385","post","type-post","status-publish","format-standard","hentry","category-photography"],"_links":{"self":[{"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/385","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=385"}],"version-history":[{"count":0,"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/385\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=385"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=385"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.fractalthoughts.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=385"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}