Category Archives: Nikon

Close up lens selection for larger insects

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Roseate Skimmer Dragonfly, Orthemis ferruginea (m)-
Nikkor AF 200 mm F 4.0 Micro Nikkor lens. Fill flash.

 

Last week I was preparing to visit one of my favorite hunting grounds for insects and other critters. The nearby Hill Country Water Gardens is an amazing emporium catering to those who build and maintain ponds. Additionally, they are a very complete nursery with a wide variety of plants. The best thing for me is that they have many tanks and ponds with live water lilies and lotuses. These water features attract many varieties of aquatic insects, including dragonflies and damselflies.

As I was gathering equipment I was selecting the optics appropriate for the day. I knew that I needed more reach than standard macro lenses like my Nikon AF 60mm F 2.8 Macro Nikkor or my Nikon AF 105 mm F2.8 Macro Nikkor. These two lenses are great, but the magnification just is not enough. My longer, Nikon AF 200mm F 4.0 has more reach, but as a fixed lens, there is no angle of view versatility and it will not accept a teleconverter.

So, the tried-and-true solution is a mid-range telephoto lens, with the addition of a teleconverter and for close-focusing ability the addition of a short extension tube. Frequently, a prime lens like a 300 mm lens with a 1.4x or 1.5x teleconverter and a 10 to 25 mm extension tube works well. The arrangement allows a full frame sensor to produce a field of view of about 4 inches and will focus to about 2 feet. That’s perfect, but that arrangement still has no angle of view flexibility.

The answer lies with a zoom telephoto lens, a teleconverter, and if required, an extension tube. With a teleconverter and extension tube robbing the optics of light, a fast lens is most desirable. The solution is a Nikon AF 70-200 mm F 2.8 VR Nikkor lens. To it we add a TC-17EII AF-S teleconverter. This produces a focal length range from 119 to 340 mm and at 200 mm, a field of view of 3.5 inches wide on a full frame sensor. The good thing about this arrangement is that it will focus down to 3.6 feet (measured from the sensor- about 2.5 feet from the front of the lens), plenty close for dragonflies and similar insects.

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Four-spotted Pennant Dragonfly Brachymesia gravida (m)
Nikon AF 200mm F2.8 Nikkor lens with TC- 17 EII 1.7x teleconverter. Fill flash.

 

Canon makes the same arrangement with a 1.4x and a 1.5x teleconverter as well as a 2.0x. Their 70-200 F 2.8 lens will focus to 3.94 feet with a similar set up.

Both Nikon and Canon produce F4.0 versions of these two great lenses at a considerable difference in price.

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Robber Fly, Efferia albibarbis (m)
Nikon AF 200mm F2.8 Nikkor lens with TC- 17 EII 1.7x teleconverter. Fill flash.

 

As these minimum focusing distances are perfectly ideal for butterflies, dragonflies, damselflies, and other insects and creatures, there is no need for an extension tube. A 12 mm extension tube will produce a 3.0-inch field of view but will further reduce the effective aperture by an additional stop. In some cases, you need all the light you can get for best auto-focusing and low light situations.

Another benefit of not using the extension tube is the lens combination can focus to infinity. This is a great benefit for that surprise bird or other subject at greater distances.

As in all outdoor photography, a flash used as a fill flash about 1.0 EV below the ambient exposure helps produce images with lower contrast, higher dynamic range and with more motion stopping capability. All the images in this article, except the lilies,  were produced with a Nikon SB-910 Speedlight at minus 1.0 EV.

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White water lilies in water garden-
Nikon AF 200mm F2.8 Nikkor lens with TC- 17 EII 1.7x teleconverter.

Copyright © 2018 Brian Loflin All rights reserved.

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New tool simplifies focus stacking

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Many times when producing images of small subjects we find that there is insufficient Depth of Field (or depth of Focus) to render the entire subject sharply from front to back. Insufficient Depth of Field (DoF) is cause by three factors:

First, we understand that, in addition to exposure,  aperture controls DoF. As we increase the F number we add DoF. However we may not be able to make a good exposure with a big F number like F22.

Another factor is that as we increase the focal length of our lens, the DoF becomes smaller. We could select a shorter lens, but that changes perspective and ability to focus close in the case of a macro lens.

The final consideration is that when the lens is moved closer, the DoF also becomes smaller. Thus we are our best enemy and must deal with self-imposed photographic criteria.

Therefore we have learned to use focus stacking to solve this problem. This requires a series of often many images, each made at a different point of focus from front-to-back. The images are blended into on in the computer using specialized software. The image of the bee (below) is an example of a stacked composite of 50 blended images.

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The several images are captured using different points of focus. Some lenses change magnification as the focus is changes, creating alignment problems. The better approach requires moving the camera a measured increment between shots. A geared focusing rail (below) or an automated programmed focusing rail are specialized tools for changing the focal point without compromising image size.

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Another system uses a rail incorporated into a bellows system to change focus but not scale, as pictured below. There are several choices from several manufacturers to accomplish this movement process.

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Now comes the new tool on the market- The Helicon FB Tube. This new idea comes from the producers of Helicon Focus, the industry leader in image stacking software. Essentially it is an extension tube with integrated electronic micro-controller designed to enable automated focus bracketing in single or continuous shooting modes. The measured tube length is 13mm and adds somewhat to the magnification of the lens dependent upon the focal length. Mounted on the camera in the same way as a usual macro extension tube, Helicon FB Tube automatically shifts the focus by one step with each shot thus producing a stack of images of unlimited length that can be rendered into a fully-focused image.

Helicon FB Tube needs no additional hardware apart from conventional cameras and lenses. Helicon FB Tube has no optics and does not affect image quality. Helicon FB Tube settings are configured through an additional application for Android or iOS. The set contains: Helicon FB Tube with IR Receiver and LED Indicator; Front and Rear Caps; IR Transmitter – connects audio port of a smartphone and Extension cable for smartphone and IR Transmitter.

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The unit has been tested and found compatible with a wide number of camera models and lens. Helicon FB Tube is available with mounts for Nikon and Canon cameras and AF lenses with built-in motor.

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I tested the image focusing ability of the FB Tube making 15 focus step images of the acorns below using a step factor of 70. The camera was a Nikon D800 with the FB Tube and 105mm F2.8 Micro Nikkor. Selected aperture was F5.6. Electronic flash in TTL Mode within a softbox provided consistent light.

To set up the FB Tube a couple of simple settings are made on the smartphone device, including lens focal length, crop factor, aperture and step size. this was relatively straight-forward on my iPhone using the available ap:

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IMG_3537  IMG_3539

The phone then transmitted the data to the FB Tube via an IR emitter plugged into the phone audio jack and aimed at the tubes receiver. as shown below.

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To get started, the first focal point was focused manually at 3.0 CM on the rule. The rest of the images in the series were focused automatically by the FB Tube. Three of those images are shown below -the first, middle, and last- of the 15 image sequence.

Acorn Stack-01FP Acorn Stack-07FP Acorn Stack-15FP

The fifteen images were selected in the computer and rendered in Helicon Focus
Method B (depth map) in a normal manner, rendering sharp focus from front to back. Final adjustments for tone, color and sharpening was completed in Photoshop CC.

Acorn Stack Complete

There are several procedures to make images for stacking. Moving the camera is simple and inexpensive. A manual rail is a bit of an expense, Fully automated, servo motor driven rails and associated accessories are often more than $600. In comparison, the Helicon FB Tube costs $200.

Copyright © Brian Loflin 2017. All rights reserved.

Central Texas Endangered Aquatics

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Texas Blind Salamander (Eurycea rathbuni) lives underwater caves within the Edwards Aquifer only in the San Marcos, Texas area. They retain their external gills and have only vestigial eye spots. Nikon D800, 105 mm F 2.8 Micro Nikkor lens, SB 910 Speedlight in softbox.

In late September I had the opportunity to visit the US Fish & Wildlife Service San Marcos Aquatic Resources Center to photograph several of the endangered aquatic species from the nearby Central Texas waters.

Located near the Edwards Aquifer, a prolific artesian aquifer, the center is involved with scientific research, including equipment and technology development, captive propagation technique development, habitat restoration, native species life history studies, and invasive species life history and control studies. The Center currently serves as a refuge for several listed aquatic species associated with the Edwards Aquifer and other Texas spring systems.

The hatchery also works closely with the faculty at local universities to provide volunteer, work, and research opportunities to undergraduate and graduate students in biology.

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Artificial streams are the main aquaria for the center and use fresh water from wells drilled deep into the Edwards Aquifer. The water is filtered and chilled to temperatures suited for each species and circulated throughout the unit.

To facilitate the photography of these aquatic species, I used a macro tank photography technique with a small 2.5 gal. aquarium, an artificial habitat and background. To better confine the aquatic individuals, a second piece of glass in a vertical orientation was used to narrow the available space for the subject specimen.

Equipment included a Nikon D800 DSLR, 105mm F2.8 Micro Nikkor lens and a SB910 Speedlight in a Lastolite EXYbox softbox on a boom. A black cloth also on a boom with a opening slit for the lens was employed in front of the tank to prevent reflections on the front of the aquarium. The setup is illustrated below.

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Great care was given to the safety of every living specimen. Before introduction of any living subjects, the aquarium, any underwater props and gravel substrate was thoroughly washed and sterilized to prevent contamination of the endangered species. This procedure was also repeated between the introduction of each subsequent species. Water was that of the specimen’s home enclosure.

Over the course of a morning I had the pleasure to photograph the Texas Blind salamander (Eurycea rathbuni), San Marcos salamander (Eurycea nana), Fountain Darter (Etheostoma fonticola), all from the Edwards Aquifer near San Marcos, Texas, and the Devils River Minnow  (Dionda diaboli) from spring-fed streams in Kinney and Val Verde counties west of Uvalde, Texas.

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San Marcos Salamander

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Fountain Darter

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Devil’s River Minnow

Copyright © 2016 Brian Loflin. All rights reserved.

 

 

 

 

 

 

 

 

 

 

Which lens do you use?

 

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Nikon D800, Nikkor 105 mm F 2.8 lens.

We are told that the key to making a good composition is to pick the “right” lens and decide where to place it and the camera in relation to the subject.

It quite true that you can fill the frame with a portrait and make the head size the same dimension in the frame regardless of the lens focal length used. Even though this is true, there may be a better choice for selecting one focal length over another. Let’s evaluate a few images all made at the same spot:

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This image on the left is made with a 20mm Wide Angle lens. It is quite obvious the face is distorted by the wide angle. In addition, the lens was just over one foot from this lady’s nose- quite uncomfortable for the subject.

This image on the right is made with a “portrait” lens, a fast 60mm F2.8 prime. It still is a bit wide and the lens to subject distance is still quite uncomfortable. With these two lenses the background is more defined that desirable.

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The left image (above) is made with a fast 85 mm, F1.8 prime. It is beginning to look better. There is more comfort with the subject. Yet, the background is still somewhat more defined than desired.

The image on the right is a prime 105 mm F 2.8 lens. The working distance is very comfortable, the background becoming soft and there is little distortion of the subject’s face.

The next pair of images (below) are made with focal lengths in the telephoto range. They look much better than those above.

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Camera: Nikon D800. Nikkor lenses: 20mm F2.8, 60mm F2.8, 85mm F1.8, 135mm F2.8, and 70-200 F2.8 zoom.

The left image is a 135mm F2.8 prime and the right, a 200mm F2.8 zoom . Both of these lenses produced good frame-filling head shots with pleasing facial features and nicely softened backgrounds. All images are made on a full frame Nikon D800 digital SLR at an aperture of F3.5.

So, in my book you can’t beat the image quality and feeling with the two telephoto lenses. For years and years, the choice for portraits on full frame cameras has been the 105 mm lens, regardless of whether shooting on film or in digital. We can now understand why.

So, the concept of a “portrait” lens for digital is a little misleading. The 50mm F1.4 is and always has been a great choice for editorial portraiture. This is because of the ability to better manage the Depth of Field and to tell a story, not for its focal length. For many this lens is simply just too short to use for pleasing head shots.

However, with a full frame 50mm lens on a crop sensor camera, the 50mm acts much more like a 75mm in its angle of view and  because you may be a bit further back.

Still it’s hard to beat the longer lenses. The advantages are many. You may fill the frame further from the subject, reducing distortion and improving a soft bokeh and shallow Depth of Field in the background. The narrow angle of view allows a small  “slice of life” to be made, eliminating many background distractions. Additionally, if you are shooting with lights or lighting modifiers, you have more working room if further back.

Copyright © 2016 Brian Loflin. All rights reserved.

 

 

 

 

 

 

 

Manage the Background – Part three.

I previously discussed managing the background through Depth of Field and through contrasting tone values. This last discussion revolves around the third method of setting off the subject, using contrasting or complimentary colors.

To understand this color concept better, we need to review the theory revealed in the Color Chart. For purposes of discussion in digital photographic terms, we use the RGB (Red, Green, Blue) color chart (below), an additive color scheme.

RGB Secondary Color wheel

In the RGB color chart (above) we see the photographic Primary Colors of Red, Green and Blue labeled in white. You may notice they are spaced evenly in thirds, or 120 degrees, around the wheel. Across the wheel from each of the the primary colors we see the Secondary Colors of Magenta, Cyan and Yellow. These secondary colors are actually made up of equal parts of the two adjacent primary colors.

Colors that are opposite each other on the chart have maximum color contrast, and are called complimentary colors. Two colors commonly found in nature are blue and yellow, a maximum color contrast of two complimentary colors.

In this sunflower photo the yellow flower contrasts perfectly in color with the blue background. This is because the yellow is exactly opposite the blue on the color chart. That makes them complimentary colors and one of the most visible of color contrasts.

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_DSC6502-Sm Nikon D2Xs, 200mm F4.0 Micro Nikkor, daylight.

For this cone flower (above) we have the  secondary color of magenta petals against the primary green background. Based upon our understanding of the color wheel these colors are still complimentary, thus of maximum color contrast.

GalliardiaMoth-1533-SmNikon D2Xs, 200mm F4.0 Micro Nikkor, daylight.

However, in the Indian blanket flower photo (above) the reds and oranges are not complementary to the green background. This is because they are not opposite on the color wheel.They are in fact, analogous, meaning adjacent on the wheel. Analagous colors work well together and create a harmonious color scheme. Here, the yellow tips to the flower petals separate it from the background primarily by contrasting tones rather than color.

However , the Shinia moth near the flower  center, a symbiotic insect to the Indian blanket, does not contrast well with the flower. This is actually to the moth’s benefit- a color mimicry trait that protects this moth from predators.

So, what ever the method you can use to separate your subject from the background, it’s a good tool to help attract the viewer’s attention to the subject. If more than one technique can be used in a single image, that’s even better.

Good photographic composition begins with a visual preview of the scene. Do everything you can to find and use as many elements of good design to give your image as much impact as you can within the camera. That will make the task of post processing must easier and allow your images leave the viewer with a lasting impression.

Copyright © 2016 Brian Loflin. All rights reserved.

Manage the Background – Part two

I have often discussed the importance of assuring the subject stands out in the frame. To do this you must manage the background.

Previously, I discussed the first method in which you can separate the subject from the background by using a very small Depth of Field. Here I will talk about using contrasting tone values.

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Nikon D800, 105mm F2.8 Micro Nikkor lens, daylight.

In the image of the flowering seed head of Bushy bluestem grass, the highlight and mid-tone values of the plant structure contrast very well with the dark, mottled tones of the background. This allows even the finest detail to be visualized quite well. Remember, here I talk about tone values- not colors. This means changes in reflectance from dark to light. Even though monochromatic in characteristic, this subject is very well defined.

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Nikon D800, 200mm F4.0 Micro Nikkor, sun, SB-910 fill flash. Three frame HDR image.

A more colorful Passion flower really snaps out against the darkest of backgrounds. In this case some of the flower’s filamentous petals and the leaves themselves make up the background.

I am frequently asked how do you make the background dark. The answer is simple, don’t put light on it. In other words, find or make the background about two stops darker that the mid-tone exposure value. Find a Point of View that yields a nice underexposed background. Or conversely, shade the brighter background with your hand, body or a piece of cardboard or opaque reflector. If you make a shadow fall behind the subject, that’s it!

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Nikon D800, 105mm F2.8 Micro Nikkor. Two SB-910 Speedlight flashes.

The polar opposite of dark backgrounds is to make a high key, or very light background. In this case, the high key background is useful to better define the edges of medium-to-dark subjects as in the mating stink bugs above. Many times natural lighter surfaces or backgrounds may be found. When that is not possible, placing a light material or lighted surface behind the subject works well. In the case of the stink bugs, the subjects were placed on a sheet of opal acrylic plastic that was illuminated from behind with a flash (speedlight). An additional speedlight provided front illumination from above. With the capabilities found in today’s flashes, it is relatively simple to vary the TTL (Through the Lens) power ratio of each flash independently, producing the desired tone values of the subject and of the background separately.

Regardless of your choice-light or dark- be sure to manage the distractions to produce a subject that pops!

Copyright © 2016 Brian Loflin. All rights reserved.

 

 

 

 

 

 

 

Showoff your Subject- Manage the Background

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Northern Cardinal female, Nikon D800, Nikkor 80-200 F2.8 lens, 1.7x teleconverter.

 

To achieve the very best from every photographic composition it is very important to assure the subject stands out in the frame. To do this you must manage the background.

There are three basic ways to manage the background: Separate the subject from the background by using a very small Depth of Field; Use contrasting tone values; and Use complementary colors. The more of these effects that are used in a photograph, the more successful that composition becomes.

The first method is to set off or separate the subject from the background by muting all background distractions by using a minimum amount of Depth of Field  (or depth of focus).  To do this effectively first focus carefully on the subject and use a small F number aperture. The small F numbers provide a very small amount of the scene, both in front of and behind the point of focus that is in acceptable focus.

It is not reasonable to simply use the smallest F number provided by the lens. It is important to have enough DoF to cover the subject in its entirety. Larger subjects require a bit larger DoF.

Here is a comparison. The first image below is of the branch where the cardinal was perched. It was made with a lens at 340mm and at F29. The second image was made at F4.8. The comparison is quite evident. It is also important to remember that the DoF gets smaller as the lens focal length gets longer.

_BKL5594-1-SmDeep and distracting background above. Few distractions and smooth, pastel background below.

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In the next post we will review the second technique, use of contrasting tone values.

Copyright © 2016 Brian Loflin. All rights reserved.