Wednesday, June 01, 2016

Flower Power

Focus Stacking

For the photographers among my readers. 

Others might enjoy the images but have no interest in the methods. This first part is a bit of a loose tutorial on Focus Stacking, just from a hands-on, empirical direction. I thought about putting it in the tech blog instead but there's a very popular article there on exporting images from Lightroom, especially for print, that I don't want to push down. If you're at all confused about cropping or sizing images for print, read this article: www.faczentech.blogspot.com.

Often I like to work on new techniques, or at least techniques that I don't use frequently so that I can improve my skills. A good example is focus stacking. I spent some time on it the other day and at the same time, figured out how to get my camera down to ground level with my 3 Legged Thing tripod. Let's start there.

It's pretty simple, actually. Remove the tall centre column and replace it with the short one they provide. I even left off the collar under the ball head to get an inch or so lower, so I had the camera about 6" (15cm) off the ground. I could have had it even lower, in fact right ON the ground, by inserting the column upside down and hanging the camera underneath (image would be upside down) but that was overkill for what I was shooting. It's good to think about and practice this stuff for when I need it in the future.


This tripod (3LeggedThing "Brian") allows me to put the legs flat on the ground so the minimum height is governed by the height of the centre column and ball head. The camera is  Nikon D800 and lens is a Nikkor 105mm f/2.8 macro. I used a cable shutter release and to help see the LCD, a Hoodman Loupe which you see at lower left. I find shooting multiple shots using LiveView to be cumbersome so mostly I just used the viewfinder.

Focus Stacking is used to control depth of field. I could have used a small aperture to get the whole flower in focus but the background wouldn't have looked the same.


Besides, a small aperture means less light so shutter speed and/or ISO would have to be adjusted. This shot was 1/60 sec at f/18, ISO 100. Note this was after the sequence below and I had spritzed water drops on the flowers.
With a large aperture, depth of field is minimal and when you're shooting macro, often not enough:


1/2000 second at f/3.3 (as wide as this lens will go when you're shooting this close), ISO 100. Note that only part of the back flower is in focus. Click any image to blow it up if you want to see it more clearly.

So I took 7 exposures, each one focused a little closer to the camera than the previous one. I looked through the viewfinder and just moved the focus ring slightly between shots, using the cable release so as to not move the camera. Then I opened all seven as layers in Photoshop, auto-aligned them and then auto-blended them. Photoshop looks for the sharpest focus in each image and masks out the rest. You could do it manually but that would be tedious.


Here's the resulting image. I cropped it before exporting it here, as well as doing some sharpening and toning... notice the great-looking background as compared with the small aperture shot up above!

* You may have wondered why I didn't say "the Bokeh" of the background. Because that would be inaccurate. Bokeh refers to the shape and tonality of out-of-focus highlights, not the background as a whole. 

Faithful readers know me by now... I can't leave well enough alone! Here's my finished image after I applied some Topaz Impression, using the Impasto-1 preset as a basis.


These wild strawberry flowers are about the size of my thumbnail, by the way. When I did the frame for display here (an action I wrote in Photoshop), I took a colour from the image to use as a background. This image itself is ready for printing!

When you focus stack, you have to be careful to get all the slices in focus. Not that easy to do! Sometimes you need to work at smaller apertures than the minimum (deeper depth of field) or use more images in the stack. For the following image, I merged 20 exposures and on close examination, even that wasn't enough (the closer you are, the shallower the depth of field).


This is also a finished image. I added a bit of Topaz Glow and again, Topaz Impression for the painterly effect. 1/1000 second at f/4, ISO 100. 

I shot a couple of others, some worked out, some didn't: here's another focus stacked image:


Look at the delicious Bokeh in this image! I thought of cropping tighter but I thought the yellow corners – especially the flower at lower right – added a depth and balance to the shot. This has the look of a medium- or large-format image from the old film days! It's why I love my D800. This is comprised of 8 stacked images shot at 1/1000 sec at f/3.3, ISO 100.

You can click on any image to blow it up and view it larger onscreen. Pretty sure I'm going to print this one, probably on canvas.



Gales of November news



This was the banner atop the blog until today, when I replaced it with the Sandhill Cranes picture. 

Two more people have signed up for the October 27th workshop so we're slowly running out of room! If you've been sitting on the fence, time to hop off! The closer we come to it, the more excited I am about the experience we're going to have! 

Go to www.photography.to/gales for details and to sign up.



Flower Power

Carden Plain isn't just for the birds! There's interesting flora there as well. Among the many varieties there are two in particular that I photographed third week of May, the "Prairie Smoke" and the "Indian Paintbrush". I can't say that either are unique to the area but the word 'ubiquitous' comes to mind. Large bands of both plants give the Alvar a spectacular colour and texture in the Spring.


Bands of Prairie Smoke (and of course dandelions. Where AREN'T there dandelions!)


The buds of the Prairie Smoke are beautiful in their own right. Here I did a multiple-image focus stack while lying on my stomach in the grass. "They" are right when they say you have to get down on your subject's level! 


When the flower ripens, this is what you get. The tendrils give it a smoke-like appearance.  


That's more obvious when you get a whole bunch of them together. This was another focus-stack. 


A patch of Prairie Smoke. Now you can see where the name comes from!

Indian Paintbrush is a brilliant, photogenic Orangy-red and it also grows in bands across the open grassland. The bird in the distance is a Sandhill Crane! 


Here's a bunch of them. You can figure out where the name came from. This plant is more indigenous to the Pacific Northwest.  


I chose to do an artistic, painterly rendering using Topaz Impression. Many of the presets yielded interesting images, it was hard to choose just one! 


What I love about this shot is how the colours of the two flower species' work together on the green and yellow background to produce a coordinated palette of colour. Looks like this will make a fine abstract print on canvas. 

Next on tap is the trillium. Several species of these abound in Ontario for a short time in the Spring. One variety I haven't seen this year is the "Painted Trillium", but it ain't over 'till it's over!

Last week I posted some trillium shots that I painstakingly lit and stacked and crawled on the ground to capture. Then again...


I shot this one hanging out the car window with my long lens! We were driving on a dirt road just North of Carden when we saw these. The white trilliums turn pink as they fade and die. 


This specimen was so beautiful I had to give it special treatment. Another one I shot from the comfort of my car seat!



Birds...

Yeah, well! I'm definitely not an experienced birder but I'm an enthusiastic one. I don't know what I'm looking at, it's hard for my eyes to pick them out, but it's a challenge. And I don't have the best optics, just adequate. It's good to know some really qualified birders such as Dan Busby and Bill Bunn, and some people with phenomenal eyes like Kathy McKelvey-Brown and Linda Cresswell to shoot with.

I just went through the list at the back of my Peterson's Field Guide and I came up with 84 species that I've seen (I may have seen others but haven't recorded them). I don't necessarily have photos of all of them. I look forward to seeing more!


Grey Catbird, seen behind the Cultural Centre in Minden. There were lots of birds there, I'm looking forward to
going back. 


Brown Thrasher at Carden Plain 


If Dan hadn't told me what this was, I'd never have guessed! But now that I look at it, I realize, well, it's obvious! This is an American Robin fledgling just out of the nest, wisps of down still on its head. Shot right behind my house! 

I have some spectacular bird pictures for you for next time, so stay tuned. To get an email note that a new Blog entry has been posted, please click the newsletter button at top right.

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