\u00a0 <\/span>More on Lens*Lab later.<\/p>\nSmaller apertures (higher f\/stop numbers like f\/22) produce deeper depths of field.<\/p>\n
Focus Stacking to the Rescue<\/h1>\n It was just a few weeks ago that I finally took a deeper look at focus stacking in preparation for the Death Valley workshop.\u00a0 <\/span>Focus stacking is a simple concept.\u00a0 <\/span>Instead of taking one photograph with a depth of field to cover the entire scene (if that is even possible), take multiple photographs focusing on different focal distances.<\/p>\nThe shortest focal distance has the near objects in focus, but the distant objects are out of focus.\u00a0 Successive shots are taken at increasingly longer focal distances bringing that part of the image into focus, but the rest would be out of focus.\u00a0 <\/span><\/p>\nThen, in the digital darkroom, the images are blended, selecting the sharp part of each image and ignoring the out of focus part.<\/p>\n
Focus Stacking in the Digital Darkroom<\/h2>\n At first, I thought the digital darkroom part would be the hardest, but it turns out to be the easiest, at least with Lightroom and Photoshop.\u00a0 So we will start with that. \u00a0<\/span>Here are the steps to follow.<\/p>\n\n\u00a0<\/span><\/span>Import your images into Lightroom.<\/span><\/li>\n\u00a0<\/span><\/span>Identify the images that are focus stacked and select all of them.<\/span><\/li>\nFrom the Lightroom menu, select Photo | Edit In | Open as Layers in Photoshop\u2026This loads all of the selected images into Photoshop creating a single file with a stack of layers where each layer is one of the images.<\/span><\/li>\nIn Photoshop select all of the layers and, from the menu, select Edit | Auto-Align Layers\u2026.\u00a0 <\/span>Choose the Collage option.This will line up each of the layers, making any adjustments necessary so all of the elements are aligned.<\/span>\u00a0 <\/span>This is important because by changing the focal distance the location of each element can change slightly within the frame, causing them to be slightly out of alignment.<\/span>\u00a0 <\/span>Photoshop does a good job of making adjustments to each layer to get them all back into alignment.<\/span><\/li>\nFinally, again with all of the layers selected, select Edit | Auto-Blend Layers\u2026. Select the Stack Images option and check Seamless Tones and Colors just to be safe.Photoshop now creates layer masks for each layer, selecting the in-focus part of the image while masking out the out of focus part.<\/span>\u00a0 <\/span>When it is done, all of the layers you added will show masks and a new blended layer is added at the top of the stack.<\/span><\/li>\nFlatten the layers and save the file.<\/span><\/li>\n<\/ol>\nYou can now continue working on the focus-stacked image in Lightroom.<\/p>\n
Focus Stacking in the Field<\/h2>\n So, as you can see, Photoshop makes blending the stacked images a snap.\u00a0 <\/span>The thing you need to look out for occurs when you take your shots in the field.<\/p>\nThe process is pretty straightforward.\u00a0 <\/span>Set up your tripod and compose the image.\u00a0 <\/span>Once composed, focus on the nearest object and take a shot.\u00a0 <\/span>Then focus on a more distant object and take another.\u00a0 Repeat this process until you have enough shots so that every part of the image is in focus.\u00a0 <\/span>Keep in mind that as the focal distance increases, the depth of field also increases.<\/p>\nYou may be able to get all the depth of field coverage in two shots or it may take 50 shots.\u00a0 <\/span>(By the way, 50 shots would be common for macro photography and rare in landscape photography.) How do you know how many you need?\u00a0 <\/span>We\u2019ll get to that.\u00a0 <\/span>But first we need to talk about how to focus on a specific object.<\/p>\nHow to Focus<\/h3>\n Focusing at different focal distances requires identifying objects at the desired distances and focusing on them.\u00a0 <\/span>This is virtually impossible through the viewfinder.\u00a0 <\/span>You need to use the camera\u2019s LCD screen.<\/p>\n\nPut your camera in manual focus mode. Turn on Live View.<\/span>If you have a mirrorless camera you\u2019re always in Live View.<\/span><\/li>\nMagnify the view.Normally there will be a control on your camera with a little magnifying lens icon and a + sign.<\/span>\u00a0 <\/span>Pressing it once will magnify the view 5x.<\/span>\u00a0 <\/span>Pressing it twice will magnify it 10x.<\/span>\u00a0 <\/span>Your camera may be a little different, but you get the idea<\/span><\/li>\n\u00a0<\/span><\/span>Navigate to the object you want to focus on.Your camera has some sort of \u2018joy stick\u2019 control that lets you navigate to different parts of the image when magnified.<\/span>You may need a lower magnification to find the object.<\/span><\/li>\nMagnify the object to full magnification; e.g., 10x.<\/span><\/li>\nUsing the focus ring on your lens, bring the object into sharp focus.If you have a loupe, this will be very helpful.<\/span><\/li>\nTake your shot.<\/span><\/li>\nRepeat beginning with Step 2 for each successive shot.<\/span><\/li>\n<\/ol>\nNow that you know how to use your LCD screen to get a tack sharp focus at the desired focal distance, it\u2019s time to introduce two methods for doing focus stacking.\u00a0 <\/span>It comes back to the question, \u201cHow many shots do I need go get everything in focus?\u201d<\/p>\nThe Overkill Method<\/h3>\n One way to answer this question is to shoot way more shots that you possibly need.\u00a0 <\/span>This will insure you don\u2019t have any DOF gaps.<\/p>\n\nStart with focusing on the nearest object and taking your shot.<\/li>\n Using your camera\u2019s screen, move your focus about 1\/6th of the way up from the\u00a0bottom of the screen, refocus and take your next shot.<\/span><\/li>\nRepeat Step 2 at 1\/3<\/span>rd<\/sup> of the way from the bottom.<\/span><\/li>\nRepeat Step 2 at \u00bd of the way from the bottom.<\/span><\/li>\nShoot one more shot focusing on your distant object.<\/span><\/li>\n<\/ol>\nThese numbers are just guidelines.\u00a0 <\/span>It is better to err by taking too many shots than not enough.\u00a0 <\/span>The idea is to make sure you adequately cover the full depth of field.\u00a0 <\/span>The tricky part of this is you won\u2019t know if you are successful until you get back to the digital darkroom and blend the images.<\/p>\nThe Calculated Method<\/h3>\n This is a more precise way of determining both the number of shots and the focal distance of each.<\/p>\n
Remember Lens*Lab?\u00a0 Well, you can use it to determine the exact number of shots you need.\u00a0 <\/span>We will use this image as the example.<\/p>\nThis sharp image was shot with a telephoto lens (100 mm) at f\/8 and everything is still in focus. How? Focus Stacking.<\/figcaption><\/figure>\nThis image was shot with a 100mm lens at f\/8.\u00a0 <\/span>The longer lens was chosen to get the composition I envisioned.\u00a0 <\/span>F\/8 was to use the sharpness sweet spot of my 100-400 lens.\u00a0 But those two settings would not give the depth of field I needed.<\/p>\nHere\u2019s the process I went through.<\/p>\n
\nDetermine relevant distances.a. <\/span>The first relevant distance is the nearest object. This is at the bottom of the screen right below the start of the track.<\/span>\u00a0 <\/span>I paced it off and determined it is 40 feet.b. <\/span>The next relevant distance is to the subject of the image, the pair of rocks.<\/span>\u00a0 <\/span>Pacing it off gave a distance of 150 feet.<\/span><\/li>\n<\/ol>\nWith this information, I need to determine the number of shots I need and the focal distance of each shot.\u00a0 <\/span>Enter Lens*Lab.<\/p>\nLens*Lab is great for determining depth of field. With focus stacking, the focal length and f\/stop are constant and you vary the focal distance.<\/figcaption><\/figure>\nHere is a Lens*Lab screen shot.\u00a0 <\/span>At the bottom you see three sliders.\u00a0 <\/span>The middle one is Focal Length which is set to 100mm.\u00a0 <\/span>The bottom slider is aperture and is set to f\/8.\u00a0 <\/span>These are the two DOF factors that we know based on the composition and settings I selected. \u00a0They will not change.At the top left corner of the screen you see four numbers with colored labels.\u00a0 <\/span>These numbers are calculated from the Focal Length and Aperture mentioned and the Focal Distance of 57\u2019.<\/p>\nThe red label is Hyperfocal which says that the hyperfocal distance is 142\u2019.\u00a0 <\/span>But since we\u2019re focus stacking, we\u2019re not interested in hyperfocal distance. That would only be important if we wanted to capture the full DOF in one shot.<\/p>\nThe orange label is Dof Far , that is, the farthest distance from the lens at which objects are in focus.\u00a0 <\/span>Beyond that distance objects become progressively out of focus.\u00a0 <\/span>The value is 95\u2019.<\/p>\nThe yellow label is Focal Dist. This is the same Focal Distance as is set in the slider below – 57\u2019.<\/p>\n
The green label is Dof Near with a value of 40\u2019.\u00a0 <\/span>This is the opposite of Dof Far in that any object closer than Dof Near will be out of focus.<\/p>\nThe depth of field for this setting, then, is the distance between Dof Near (40\u2019) and Dof Far (95\u2019).\u00a0 Notice that Dof Far falls short of the two rocks which are 150\u2019 from the lens.<\/p>\n
With this introduction to Lens*Lab, let\u2019s proceed with the Calculated Method.<\/p>\n
\nDetermine the Focal Distance of the first shot.a. <\/span>From what we see in Lens*Lab, we see that the Dof Near is 40\u2019 and that is the same distance as the distance to the nearest object at the bottom of the screen.b. <\/span>The Focal Dist. to get the near depth of field the same as the distance to the nearest object is 57\u2019.<\/span>\u00a0 <\/span>This, then, is the focal distance for the first shot.<\/span><\/li>\nPlace an object at 57\u2019 and focus on it.There is no object to focus on that is at 57\u2019 so I got another rock, paced of 57\u2019 and placed it on the playa.<\/span>\u00a0 <\/span>That\u2019s what I focused on.<\/span><\/li>\nTake the first shot.I took two shots, one with the rock in place and one with it removed. I\u2019ll use the one without when I blend the images in Photoshop.<\/span><\/li>\n<\/ol>\nShot 1 – capture a sharp foreground. The small rock at the left was placed at the focal distance that ensures the bottom of the screen will be in focus. But the pair of rocks are out of focus,<\/figcaption><\/figure>\n\nDetermine the focal distance of the next shot.My first thought is to see if focusing on the pair of rocks will give me a depth of field that overlaps the first shot. <\/span>So, I adjusted the Focal Distance in Lens*Lab to 150\u2019, the distance from the lens to the rocks,Lens*Lab is used again to be sure that focusing on the pair of rocks for the second shot will have enough depth of field to overlap with the first shot. It does,<\/figcaption><\/figure><\/li>\n<\/ul>\n <\/p>\n
With the Focal Distance slider set to 150\u2019, you can see that the Dof Far is infinity and the Dof Near is 73\u2019.<\/span>\u00a0 <\/span>The Dof Far from the first shot was 95\u2019 so there\u2019s an overlap of over 20\u2019 in the two shots. That\u2019s more than enough.<\/span>\u00a0 <\/span>And the Dof far is infinity so the distant mountains will be in focus.<\/span>\u00a0 <\/span>You can ignore the red Hyperfocal line as it doesn\u2019t apply to focus stacking,<\/span><\/p>\n\nFocus on the pair of rocks and take the second shot.<\/span><\/li>\n<\/ul>\n <\/p>\nShot 2 focuses on the pair of rocks. The foreground is out of focus. But, when blended with shot 1, everything is in focus,<\/figcaption><\/figure>\nIt\u2019s important to change only the focal distance. The focal length and f\/stop must remain the same. <\/span>If you look at the image above closely you can see the foreground is out of focus.<\/span><\/p>\n\nAlign and Blend the two images in Photoshop using the steps above.<\/span><\/li>\n<\/ul>\n <\/p>\n
This turned out to require only two shots.\u00a0 <\/span>If the conditions were different it might have required more.\u00a0 <\/span>Every situation will be different.<\/p>\nSummary<\/h1>\n Focus stacking provides the ability to get sharp images when it\u2019s not possible or feasible to do so with a single shot.\u00a0 <\/span>For landscape photographers, it provides the option of using longer lenses and wider apertures.\u00a0 <\/span>Also, if you don\u2019t have a super wide-angle lens or a full frame sensor, no problem.\u00a0 You can still do those extreme near-far compositions.\u00a0 <\/span>For macro photographers it allows for unprecedented detail.<\/p>\nIt\u2019s interesting that focus stacking originated with cellular biology.\u00a0 <\/span>A microscope has extremely limited depth of field.\u00a0 <\/span>It doesn\u2019t even span from the front of a cell to its back.\u00a0 <\/span>There was no way to see an entire cell in focus.\u00a0 <\/span>So, the pioneering product, Helicon Focus, was developed to solve this problem and today it is used by biologists and photographers alike.\u00a0 <\/span><\/p>\nThere are some limitations to focus stacking for landscape photographers.\u00a0 <\/span>Nothing can move in the scene.\u00a0 <\/span>And since there is considerable time between shots, this can cause a problem. Also, because of the latency between shots, it\u2019s not a practical technique to use for portraits or macro photography involving live insects and other small critters.\u00a0 <\/span><\/p>\n<\/p>\n
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One might anticipate, however, that cameras will evolve to include auto focus stacking just like they now include auto HDR.\u00a0 <\/span>In the meantime, you can use either of the two methods described to take your photograph into new realms.\u00a0<\/span><\/p>\nJoin us on one of our exciting photography workshops. \u00a0Visit our website – Ralph Nordstrom Photography<\/a>.<\/span><\/p>\n (510)<\/p>\n","protected":false},"excerpt":{"rendered":"
A practical guide to focus stacking<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[64,1339],"tags":[92,542,1464,491,1463,288],"class_list":["post-4256","post","type-post","status-publish","format-standard","hentry","category-how-to","category-photography-workshop","tag-death-valley-national-park","tag-depth-of-field","tag-focus-stacking","tag-hyperfocal-distance","tag-near-far-compositions","tag-photography-workshop"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9Nl7-16E","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/posts\/4256","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/comments?post=4256"}],"version-history":[{"count":4,"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/posts\/4256\/revisions"}],"predecessor-version":[{"id":4261,"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/posts\/4256\/revisions\/4261"}],"wp:attachment":[{"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/media?parent=4256"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/categories?post=4256"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ralphnordstromphotography.com\/wordpress\/wp-json\/wp\/v2\/tags?post=4256"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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