Stack Your Focus

By Roger (30 Jan 2014)

While I have Mark's light tent set up, let's talk about making some close-up, or macro, photographs.

Just so you know, the technical definition of macro photography is one in which the size of the subject on the sensor is life size or greater. Most people today use the term to mean any photograph at a very close range, whether a macro lens is used or not. I wouldn't nitpick a close-up that isn't really macro, but you should know the correct meaning.

Besides the obvious attraction of photographing very small slices of life, many photographers love the very shallow depth of field inherent with macro photography. Depending on your lens' focal length and selected aperture, the acceptable area of focus can be as small as a couple of millimeters. You can use this to drive the viewers eye to your subject; the rest of the photo will be lost in bokeh.

With a macro lens, even a weed can look nice.

With a macro lens, even a weed can look nice.

But when you want to have everything in focus, you'll have to resort to a post-processing technique called focus stacking. This technique is nothing fancy, but you'll need a photo-editing software, like Photoshop, to make it work.

I start by stealing my wife's sculpture of Neu Schwanstein and putting it inside the light tent. The light tent helps give me nice even lighting. You can see the castle is about eight inches from front to rear.

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When I focus on the front gate with my Nikon 105mm Micro lens, set at f8, you can see that only about half an inch is in focus. The front of the sculpture is way too soft, and the back is completely lost in the bokeh.

With a macro lens, your depth of field will be very narrow.

With a macro lens, your depth of field will be very narrow.

To keep everything consistent, I put the camera on a tripod and use manual mode on both the camera and lens. In any of the auto modes, the camera will calculate its settings every time you depress the button and may give you different solutions each time. That isn't what you want. You can use the camera's first solution as your starting point for exposure. Just read the back of your camera; switch to manual; and dial in the settings.

With your lens in manual, you will make a series of photos, moving the focus through the subject a fraction at a time. I usually do this from front to rear and then rear to front. Make sure you rack through the entire range. You may want to turn on Live View, so you can track your progress on the rear LCD. It is easier to see the minute differences in focus on each photo when you're looking at the LCD.. Now, import the photos into Lightroom; make any adjustments you want to the first image; and synchronize those settings across all your photos. Consistency, remember?

Getting the photos into Photoshop, is easy. Highlight all your images in the series; right-click on them; and choose “Open as Layers in Photoshop.” It may take some time, depending on the file size and number of images, but you'll get one Photoshop file, with each of your images on a separate layer.

Highlight every layer and choose “Edit>Auto-Align Layers.” Even with the camera on a tripod, you may have had some movement. Next, (with all layers still selected) choose “Edit>Auto-Blend Layers>Stack Images.” Make sure you check the box that says “Seamless Tones and Colors.” Photoshop will create masks for each layer, revealing only the portions that are in sharp focus. Something like this.

Photoshop will create the complex masks.  You don't want to try this manually.

Photoshop will create the complex masks.  You don't want to try this manually.

From here, I flatten the image and make any touch-ups I want and save the image.  You don't have to flatten the image if you're a stickler for non-destructive editing, but your final file size is going to be ridiculously large. Voila! You have the entire subject in focus. I threw in a background color that I took from the image, so there was a little less white and cropped it.

Final image, composed of stacked layers.

Final image, composed of stacked layers.

Like the compositing I showed last week, this is not a very complex technique and can yield a photo that isn't possible with one photograph. Take your time and get all the different focus points before you move the camera. This one took 20 images and still isn't perfect when you zoom in to 300%. If this was more than just a demonstration, I would do another round. Have fun.

Yearly Review

By Roger (14 Nov 2013)

At the end of every year, I go through an annual (hopefully, contemplative) photo review. I look for photos I never got to in post-processing; trends in what I'm shooting; and things that need to be deleted. I'm actually catching up on my post-processing. I've blogged about culling photos from the database and hard drive, so I won't go down that road, again. This year, as I'm considering a new lens purchase, so I decided to look at trends in how I use my lenses.

Things were going pretty well. I already knew my most used lens is the 70-200mm; it accounted for almost exactly 50% of my photos. The 28-300mm came in next. It is my walk-around lens, so it gets a lot of use. It was artificially high, however, because I used it for the wedding in Poland when I broke my 70-200. Third place was the 400mm I've rented several times this year for my sesquicentennial project. And the other lenses were used quite a bit, until...my 105mm macro. I only used it about 2% of the time. Hmmm.

This is why I do these things – to find new insights to my work and point to some areas I may want to consider changing for the coming year. The fact is I knew I wasn't using this fine lens as much as the others; I just didn't know the stats would come out so lopsided.

It wasn't supposed to be this way. Mark loaned me his light tent early last year when I thought I wanted to try some macro work. It's still in its case somewhere in my library. (Obviously, he hasn't been shooting too many macro photos using his light tent, either.) The last time we blogged about anything macro was last December when Mark put up Christmas tree ornaments. I guess we should put up some macro blogs in 2014.

Macro lenses can fill your frame with chocolates.

Of course, the 105mm macro is not a single purpose lens. It is a great lens for portraits, with a maximum aperture of 2.8 and delivers the bokeh that so many people like in portraits. For many photographers, this lens and/or the 85mm are the go-to lens for portraits.  The low use here indicates I've been a little lazy in my portraits and have been relying on the 70-200 zoom, instead of zooming with my feet.

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I've happily used the 105 for photos of many other subjects, too. In fact, I've had a lens of this focal length almost as long as I've been making photographs. It just needs to find its way back onto my play list.

The 105mm macro lens is not limited to making photos of small objects.

The 105mm macro lens is not limited to making photos of small objects.

There are lots of good reasons to add a little analysis of your photography during the end of year review. You may want to look something else than the items on my list. Are your best photographs from the year landscapes? Maybe you should shoot more of those or put more efforts into something else. If you like street photography, but only tried it a couple times, you may decide to make a bigger effort on that next year. Heck, maybe you think this whole exercise is futile. The decision is always yours, but, for me, it is worth the time and helps influence some of what I plan for the next year.

Have Yourself a Slow and Macro Little Christmas

Merry Christmas to one and all.  The bright lights of the tree look so inviting, but are often difficult to photograph.  Flash makes the tree look washed out and hides the colors of the lights.  Hand holding your camera makes all the colors blur together.  So what is the secret to capturing good tree photos?  As with so much in photography, the answer is a good tripod, slow shutter speeds and a remote trigger.  Even with the very nice low light capabilities of the D800 and the 50mm 1.8 lens, putting the camera onto a stable platform makes all the difference.   From the LR histogram you can see that I pushed the ISO all the way up to 640, and it still took a 4.0 sec exposure.  By using a remote cable trigger, it removes the shaking caused by my ham-handed fingers, pressing the buttons. The other way to catch the warmth and depth of colors from the tree is to go in close.  A good macro lens can get more detail and usually needs less light.  We have quite a few lighted ornaments which offer their own set of challenges.  The bright inside lights can blow out the rest of the image, leaving the background too dark.  With a macro, you can be very precise in selecting your focal point.  I used the darkness of the tower clock, and then applied the LR development brush to reduce the exposure and highlights of the lights. 

Our house also maintains a fair and balanced approach between the forces of good and others for the holidays.    Well, we didn’t have much of a white Christmas; and that is ok with me.  I hope you got whatever you were wishing for.  The joy of spending time with friends and family is what makes this season special.  We hope that all our readers enjoy the holidays. 

Something Has Been Bugging Me—How Do I Pick the Best Images?

Now that the election stuff is all over we can get back to photography.  Roger wrote last week about purging his catalog.  Once you get past the obvious discards in your library, how do you get decide between those final few images to really determine which ones to keep? Luckily Lightroom has some helpful tools which can make the job a little easier.  Today I am just going to talk about the Survey panel in the Library module.

I walked out the front door a couple of weeks ago to see a giant monster sitting on my porch railing.  It was a praying mantis in its fall camouflage pattern.  I ran back inside and got my 105mm Macro lens and went out and shot a lot of images.  The 105 has such a shallow depth of field that the first culling of pictures was easy.  If the face wasn’t in focus, out they went.

Finally I got down to these seven images. There were basically 3 different poses, so I knew I wanted to just keep the best one.

Down at the bottom of the Library screen just above the filmstrip are the 4 choices for displaying your images.  Most of the time you work in the Grid (G) or the Loupe (E) views, but the other two Compare (C) and Survey (N) allow you to compare pictures side by side. 

Survey lets you pick multiple images and then remove them just by selecting the x in the corner. You can then add flags or ratings right from inside the window.  I’m just glad mantids are not the size of dogs—they are really scary hunters.