Tag Archives: 24-70

Sensor Size and Depth of Field

It is commonly said that crop sensor cameras make images having both a narrower field of view and a greater depth of field. Well, that's partly right. (Bill Ferris)

It is commonly said that crop sensor cameras make images having both a narrower field of view and a greater depth of field. Well, that’s partly right. (Bill Ferris)

It is well-known that a lens of a given focal length will deliver different angles of view when used with cameras having different sized sensors. For example, the above image was made with a Nikon D90 and a Nikkor 200-500mm f/5.6E telephoto zoom lens at 500mm. The D90 is a DX format camera having a 1.5x crop factor. In other words, the DX sensor crops the outer portion of the image formed by the lens. As a result, photographs made with this camera will display an angle of view equivalent to that produced by a lens with 1.5x the actual focal length used. In the above image, the 200-500 is at 500mm but the angle of view matches that produced by a 750mm lens.

It is often said that a crop sensor camera will also produce an image having a greater depth of field. In other words, the same lens at the same focal length will produce, not just a wider angle of view when paired with a full frame camera, but also a shallower depth of field. The claim is that the DX sensor not only crops the angle of view but forces a significant increase in depth of field. That assertion is just plain wrong.

In the below test images, you’ll see side-by-side comparisons of photos made with Nikon FX (full frame) and DX (crop sensor) camera bodies. The cameras used were the full frame Nikon D610 and the DX format Nikon D90. These cameras were used with the following lenses:

  • Nikkor 200-500mm f/5.6E VR
  • Tamrom 70-200mm f/2.8 Di VC USD
  • Tamron 24-70mm f/2.8 Di VC USD

To isolate sensor size as the only variable, the comparison images were made with the lenses at the same focal length, focal ratio and at the same distance from a fixed position subject. The Nikkor 200-500mm f/5.6E and Tamron 70-200mm f/2.8 Di VC USD were mounted on a tripod in a fixed position. The Tamron 24-70mm f/2.8 Di VC USD has no tripod collar or foot. The cameras were mounted to the tripod with the tripod in the same position for each set of exposures.

To create a large enough set of images to suitably address the question, each lens was used at a multiple focal lengths:

  • Nikkor 200-500mm f/5.6E VR: 200mm, 300mm, 400mm and 500mm
  • Tamrom 70-200 f/2.8 Di VC USD: 70mm, 100mm, 135mm and 200mm
  • Tamron 24-70 f/2.8 Di VC USD: 50mm and 70mm

Each lens was used wide open at its smallest f-stop number. ISO and shutter speed were kept constant for exposures made at the same focal length with both cameras.

Why did I decide to test the notion that sensor size has a significant impact on depth of field? I performed this experiment to test my belief that that lens aperture and distance to subject are the two factors having the greatest impact on depth of field. In other words, if a lens is used at the same physical aperture and distance to make photographs of a fixed position subject with two cameras of different sensor size, the depth of field recorded in the two images should be identical or, at least, very nearly so.

If I’m correct in this belief, the images should confirm it. If I’m wrong and if crop factor needs to be applied to depth of field as well as to focal length, photos made under the above conditions should exhibit obviously different depths of field with the photo made using the full frame camera consistently displaying an obviously shallower depth of field than the photo made using the crop sensor body.

Keeping all this in mind, let’s go to the photos. Below, are ten composite images. The photo occupying the left half of each composite was made using the Nikon D610. The photo to the right of the divider was made using the Nikon D90. Since the same lens at the same focal length, f-stop and distance to subject was used to make each image in a composite, the image made with the crop sensor D90 (on the right) shows a narrower angle of view. In each composite, I’ve indicated similar sections of the two photos that, when compared, reveal both photos to have identical – or nearly so – depths of field. This conclusion is reached by comparing the relative size of the subject, a hula dancer toy, and the out of focus highlights and details in the background.

Comparison #1: Nikkor 200-500mm f/5.6E (200mm, f/5.6)

The photo to the left of the divider was made with the Nikon D610 and Nikkor 200-500mm f/5.6E at 200mm, f/5.6, ISO 400, 1/200-second. The photo on the right was made with the same lens at the same distance from subject also at 200mm, f/5.6, ISO 400, 1/200-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Nikkor 200-500mm f/5.6E at 200mm, f/5.6, ISO 400, 1/200-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 200mm, f/5.6, ISO 400, 1/200-second. (Bill Ferris)

Comparison #2: Nikkor 200-500mm f/5.6E (300mm, f/5.6)

The photo to the left of the divider was made with the Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/5.6, ISO 400, 1/200-second. The photo on the right was made with the same lens at the same distance from subject also at 300mm, f/5.6, ISO 400, 1/200-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Nikkor 200-500mm f/5.6E at 300mm, f/5.6, ISO 400, 1/200-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 300mm, f/5.6, ISO 400, 1/200-second. (Bill Ferris)

Comparison #3: Nikkor 200-500mm f/5.6E (400mm, f/5.6)

The photo to the left of the divider was made with the Nikon D610 and Nikkor 200-500mm f/5.6E at 400mm, f/5.6, ISO 400, 1/250-second. The photo on the right was made with the same lens at the same distance from subject also at 400mm, f/5.6, ISO 400, 1/250-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Nikkor 200-500mm f/5.6E at 400mm, f/5.6, ISO 400, 1/250-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 400mm, f/5.6, ISO 400, 1/250-second. (Bill Ferris)

Comparison #4: Nikkor 200-500mm f/5.6E (500mm, f/5.6)

The photo to the left of the divider was made with the Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/5.6, ISO 400, 1/250-second. The photo on the right was made with the same lens at the same distance from subject also at 500mm, f/5.6, ISO 400, 1/250-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Nikkor 200-500mm f/5.6E at 500mm, f/5.6, ISO 400, 1/250-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 500mm, f/5.6, ISO 400, 1/250-second. (Bill Ferris)

Comparison #5: Tamron 70-200 f/2.8 VC (70mm, f/2.8)

The photo to the left of the divider was made with the Nikon D610 and Tamron 70-200mm f/2.8 VC at 70mm, f/2.8, ISO 400, 1/400-second. The photo on the right was made with the same lens at the same distance from subject also at 70mm, f/2.8, ISO 400, 1/400-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Tamron 70-200mm f/2.8 VC at 70mm, f/2.8, ISO 400, 1/400-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 70mm, f/2.8, ISO 400, 1/400-second. (Bill Ferris)

Comparison #6: Tamron 70-200mm f/2.8 VC (100mm, f/2.8)

The photo to the left of the divider was made with the Nikon D610 and Tamron 70-200mm f/2.8 VC at 100mm, f/2.8, ISO 400, 1/400-second. The photo on the right was made with the same lens at the same distance from subject also at 100mm, f/2.8, ISO 400, 1/400-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Tamron 70-200mm f/2.8 VC at 100mm, f/2.8, ISO 400, 1/400-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 100mm, f/2.8, ISO 400, 1/400-second. (Bill Ferris)

Comparison #7: Tamron 70-200mm f/2.8 VC (135mm, f/2.8)

The photo to the left of the divider was made with the Nikon D610 and Tamron 70-200mm f/2.8 VC at 135mm, f/2.8, ISO 400, 1/400-second. The photo on the right was made with the same lens at the same distance from subject also at 135mm, f/2.8, ISO 400, 1/400-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Tamron 70-200mm f/2.8 VC at 135mm, f/2.8, ISO 400, 1/400-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 135mm, f/2.8, ISO 400, 1/400-second. (Bill Ferris)

Comparison #8: Tamron 70-200mm f/2.8 VC (200mm, f/2.8)

The photo to the left of the divider was made with the Nikon D610 and Tamron 70-200mm f/2.8 VC at 200mm, f/2.8, ISO 400, 1/400-second. The photo on the right was made with the same lens at the same distance from subject also at 200mm, f/2.8, ISO 400, 1/400-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Tamron 70-200mm f/2.8 VC at 200mm, f/2.8, ISO 400, 1/400-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 200mm, f/2.8, ISO 400, 1/400-second. (Bill Ferris)

Comparison #9: Tamron 24-70mm f/2.8 VC (50mm, f/2.8)

The photo to the left of the divider was made with the Nikon D610 and Tamron 24-70mm f/2.8 VC at 50mm, f/2.8, ISO 400, 1/640-second. The photo on the right was made with the same lens at the same distance from subject also at 50mm, f/2.8, ISO 400, 1/640-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Tamron 24-70mm f/2.8 VC at 50mm, f/2.8, ISO 400, 1/640-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 50mm, f/2.8, ISO 400, 1/640-second. (Bill Ferris)

Comparison #10: Tamron 24-70mm f/2.8 VC (70mm, f/2.8)

The photo to the left of the divider was made with the Nikon D610 and Tamron 24-70mm f/2.8 VC at 70mm, f/2.8, ISO 400, 1/640-second. The photo on the right was made with the same lens at the same distance from subject also at 70mm, f/2.8, ISO 400, 1/640-second. (Bill Ferris)

The photo to the left of the divider was made with the Nikon D610 and Tamron 24-70mm f/2.8 VC at 70mm, f/2.8, ISO 400, 1/640-second. The photo on the right was made with the Nikon D90, the same lens at the same distance from subject also at 70mm, f/2.8, ISO 400, 1/640-second. (Bill Ferris)

Comparing the above ten photo sets, it’s clear the photographs capture equivalent depths of field despite the fact that they’re made with full frame and crop sensor cameras. As expected, the crop sensor camera captures a more narrow angle of view. However, a comparison of the relative size of the hula dancer toy with the details of the out of focus background reveals that the DX format Nikon D90 captures the same depth of field as the FX format Nikon D610. This flies in the face of the common (but mistaken) belief that crop sensors significantly alter depth of field.

To understand the performance of each camera as illustrated in the above photos, one need only understand that photographic depth of field is largely determined by two factors: distance to subject and lens aperture. Each lens was kept at a constant position and distance from the subject for the photos made with the two camera bodies. By keeping focal length and f-stop constant in each photographic set, lens aperture was kept constant.

The f-stop number describes the ratio of lens focal length to aperture. In other words, a 200mm, f/5.6 lens has an aperture of about 36mm. This is true regardless of the size of the sensor in the camera to which the lens is attached. Here’s a listing of the focal lengths and apertures for each set of photos:

Nikkor 200-500mm f/5.6E VR

  • 36mm aperture (200mm, f/5.6)
  • 54mm aperture (300mm, f/5.6)
  • 71mm aperture (400mm, f/5.6)
  • 89mm aperture (500mm, f/5.6)

Tamron 70-200mm f/2.8 VC

  • 25mm aperture (  70mm, f/2.8)
  • 36mm aperture (100mm, f/2.8)
  • 48mm aperture (135mm, f/2.8)
  • 71mm aperture (200mm, f/2.8)

Tamron 24-70mm f/2.8 VC

  • 18mm aperture (50mm, f/2.8)
  • 25mm aperture (70mm, f/2.8)

As you review the above list, notice the constant f-stop results in increasing lens aperture as focal length increases. By keeping subject distance constant and increasing the physical aperture of the lens, depth of field becomes more shallow. By definition, the reverse is also true. With subject distance kept constant, decreasing lens aperture would result in a deeper or increased depth of field. And as illustrated by the above comparisons, keeping both subject distance and lens aperture constant produces constant depth of field. This holds true regardless of sensor size.

How is it, then, that so many photographers have come to accept the false assertion that crop sensor cameras make images having increased depth of field? The key to understanding this is the concept of equivalence. In simplest terms, equivalence describes two images made with different cameras and lens settings but having identical qualities. There are many factors that go into describing truly equivalent images. For the purposes of this discussion, we’ll focus on angle of the view and depth of field.

This set of images compares performance between crop sensor and full frame DSLR bodies. The images in the left column were made with a Nikon D90. Images in the right three columns were made with a Nikon D610. Both cameras used the same Tamron 70-200mm f/2.8 Di VC USD zoom lens, which was set up on a tripod to ensure it would not change position during the test. Both cameras used ISO 200, center point average metering and were operated in Aperture Priority. The subject in these photos is a scale model of the Lunar Excursion Module (LEM) from the Apollo program.

This set of images compares performance between crop sensor and full frame DSLR bodies. The images in the left column were made with a Nikon D90. Images in the right three columns were made with a Nikon D610. Both cameras used the same Tamron 70-200mm f/2.8 Di VC USD zoom lens, which was set up on a tripod to ensure it would not change position during the test. (Bill Ferris)

Let’s consider the above image set made with the Tamron 70-200mm f/2.8 VC. Due to its smaller sensor, a photograph made with the D90 captures a more narrow angle of view in comparison with an image made with the D610 at the same focal length. To capture an equivalent angle of view at the same distance from the subject, the D610 needs to use a greater focal length. At that increased focal length, the FX format camera will capture an angle of view equivalent to that recorded by the D90.

If both lenses are used at the same f-stop of f/2.8, their respective apertures will be about 46mm for the 130mm, f/2.8 lens on the D90 and 71mm for the 200mm, f/2.8 lens on the D610. Bear in mind, both cameras are at the same distance from the subject. Due to the larger physical aperture of the 200mm focal length lens, it records a shallower depth of field. To match the depth of field of the D90, the D610 is closed down from f/2.8 to f/4. This closes the aperture from 71mm to 50mm, which roughly matches the depth of field recorded by the D90 and its 46mm aperture.

Also, compare the quality of the out of focus background detail in the photos made with the DX format D90 (left most column) with the same detail in the second set of photos made with the FX format D610 (middle of three columns). Pay particular attention to the grouping of four bokeh balls to the left of the lunar lander model. In the D90 photos and in the equivalent D610 photos (right most column), that grouping is well defined with clear separation. In the middle column of D610 photos, that grouping is more diffuse, less well defined and not as clearly separated from the background.

This is what we would expect, considering that all the photos in that collection were made with the cameras and lenses at the same distance from the subject. The first and third column sets of images made with the D610 were made with the same lens aperture as the D90. The third column set of D610 images were made at an equivalent focal length to the D90 images. Both the angle of view and depth of field are equivalent. The first set (left column) of D610 images, while showing a wider angle of view, have equivalent depth of field as the D90 images. Again, this is exactly what one would expect given that the D90, and first and third set of D610 images were made at the same aperture, while the second set (middle column) of D610 photos were made at a larger aperture.

Another approach to producing equivalent depths of field, would have been to increase the lens aperture on the D90. The D90 would need a 130mm f/1.8 lens, which would have a 72mm aperture. That’s very nearly identical to the 71mm aperture of the 200mm, f/2.8 lens on the D610.

If equivalence is your objective, applying the crop factor to the f-stop allows you to calculate the aperture needed to make a photograph having an equivalent depth of field at a focal length delivering an equivalent angle of view. This adjustment can go either way. We can use a larger f-stop (multiply by the crop factor) to close down the aperture of the lens on the larger sensor camera or we can use a smaller f-stop (divide by the crop factor) to open the aperture of the lens on the smaller sensor camera. Either approach will produce equivalent apertures on the two cameras, which allows them to capture matching depths of field.

This is what has led so many photographers to mistakenly conclude that crop sensors significantly alter depth of field. What folks overlook is that the crop factor is applied to allow the lenses on the cameras to operate at the same physical aperture. Again, the key to understanding depth of field is recognizing that distance to subject and lens aperture are the critical factors. If you keep subject distance constant, keeping lens aperture constant will deliver equivalent depth of field. This holds true even if the lenses are used at focal length delivering non-equivalent angles of view.

Wildlife photographers often choose to shoot with crop sensor cameras to effectively bring the animals closer. They want the narrower angle of view delivered by the crop sensor. Shooting at 500mm f/4 with a DX camera will not only produce a larger image of the subject (in comparison with a photograph made using the same lens at the same distance on an FX camera), the DX camera will also record the same shallow depth of field and beautiful, buttery bokeh. That’s a huge advantage and a big reason why crop sensor cameras are so popular with sports and wildlife photographers. Of course, the smaller sensor also captures less total light with each exposure and this has implications for image noise. But that’s another blog entry.

In the meantime, armed with this new information and understanding of the role lens aperture plays in depth of field, let’s get out and shoot.

Bill Ferris | March 2016

Autofocus Fine Tune

Autofocus Fine Tune test shot for Tamron 70-200mm f/2.8 Di VC USD lens at 200mm, f/2.8, ISO 100, 1/200-second with flash and Nikon D610 AF Fine Tune set to OFF (Bill Ferris)

Autofocus fine-tune test shot for Tamron 70-200mm f/2.8 Di VC USD lens at 200mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune is turned off. (Bill Ferris)

Choosing the right autofocus (AF) mode can be a real challenge. You could leave the driving to the camera and go with Auto-servo AF (AF-A) mode. If you go that route, don’t expect that dumb box of a camera to make the right choices. It will make choices but they’ll probably not be the same choices you would make.

Being the risk-taker that you are, I’m sure you spend most of your time shooting in either Single-servo (AF-S) or Continuous-servo (AF-C) mode. These allow you greater control and, when good choices are made, a higher success rate making keeper images. Among those choices, is deciding which one or more AF points to use. Do you use one, nine, twenty-one or all the AF points on your camera’s sensor? If just one, do you go with the center point or an outer point? If you choose a group of points, which group? Do you allow the camera to have a say in which AF points are used? So many choices.

Let’s assume you’ve chosen an AF mode, and selected the number and location of the AF points that will be used. The next challenge is to successfully place at least one AF point over your subject and acquire focus. When it all comes together, it’s a beautiful moment. The shutter clicks open and the image swiftly, silently, gets encoded as a collection of 1’s and 0’s on an SD card.

Later, when you look at the photograph in Lightroom and realize it’s still not in focus, that moment of joy becomes frustration. What happened? Why is the eye just ever so slightly soft?

Of all the factors than have the potential to cause an out-of-focus image, arguably the most pernicious is a camera/lens combo that is ever so slightly miscalibrated. Despite your mastery of the camera’s AF system, your successful effort to track the subject and the presence of mind to make an exposure at the decisive moment, that slight miscalibration wreaks havoc. Focus is not set on the eye beneath the AF point. Instead, focus is slightly in front of or just behind the eye. The result is an out of focus image that ends up being deleted rather than marked as a keeper.

Autofocus fine-tune is a tool offered by many professional and high end consumer cameras. It allows you to adjust where focus is set to compensate for a miscalibrated lens. How does it work?

In the above images, the blue shaded portion of the semitransparent square overlay represents an out-of-focus area of the black and white image. The portion of the black and white photo visible within the blue shaded overlay represents the area of the face falling within the focus plane and appearing to be be in focus in the image. TOP: This illustrates a properly focused image. The eyes, brow and mouth fall within the focus plane and appear in-focus. MIDDLE: This represents a back-focused image. The ears an temples are within the focus plane and appear sharp. However, the eyes are above the focus plane and look soft. BOTTOM: This represents a front-focused image. The tip of the nose and chin fall within the focus plane and appear sharp. However, the eyes are behind the focus plane and look soft.

In the above images, the blue shaded portion of the semitransparent square overlay represents an out-of-focus area of the black and white image. The portion of the black and white photo visible within the blue shaded overlay represents the area of the face falling within the focus plane and appearing properly in-focus.
TOP: This illustrates a properly focused image. The eyes, brow and mouth fall within the focus plane and appear in-focus.
MIDDLE: This represents a back-focused image. The ears and temples are within the focus plane and appear sharp. However, the eyes are above the focus plane and look soft.
BOTTOM: This represents a front-focused image. The tip of the nose and chin fall within the focus plane and appear sharp. However, the eyes are behind the focus plane and look soft.

In the above illustration, the focus plane of the camera is represented by the semitransparent, blue square overlay. While all photographs have at least a minimal depth of field, for simplicity, I’m illustrating the focus plane as a two-dimensional, flat zone. With large aperture, small focal ratio lenses being popular for portraiture, the shallow depths of field produced by such lenses leave little margin for error when it comes to achieving accurate focus. If focus is not set on the eye or within a few millimeters of the eye, the resulting image will look “soft” and out-of-focus. There will be portions of the subject’s face that look sharp and in-focus, but if the eyes look soft, the overall impression will be that the photo is soft.

A miscalibrated camera/lens combo may give every indication of making a properly focused exposure. However, despite the fact that the focus point may be directly over the subject’s eye, the camera will set focus slightly in front of or behind the eye. If you are shooting with a fast f-stop, that slight miscalibration can result in unacceptably soft images. Autofocus fine-tune allows you to compensate for this problem.

In the Nikon D610 menu system, AF Fine Tune is found in the Setup Menu. (Bill Ferris)

In the Nikon D610 menu system, AF fine-tune is found in the Setup Menu. (Bill Ferris)

Entering the AF fine-tune menu, the first option is where you select, ON or OFF, for this control. The second setting is the Saved Value for the lens. (Bill Ferris)

Entering the AF fine-tune menu, the first setting allows you to select, ON or OFF. The second setting is the Saved Value for the lens. (Bill Ferris)

Entering the Saved Value setting, select a positive or negative number from +20 to -20. Positive numbers move the focus point farther from the focus plane to compensate for front-focused images. A negative setting moves the focus point closer to the camera focus plane to compensate for back-focused images. (Bill Ferris)

Entering the Saved Value setting, select a positive or negative number from +20 to -20. Positive numbers move the focus point away from the camera to compensate for front-focused images. A negative setting moves the focus point toward the camera to compensate for back-focused images. (Bill Ferris)

Nikon cameras recognize Nikkor lenses and many third party lenses, and are able store AF fine-tune settings for up to 12 different lenses. (Bill Ferris)

Nikon cameras recognize Nikkor lenses and many third party lenses, and are able store AF fine-tune settings for up to 12 different lenses. (Bill Ferris)

The above series of images illustrate how to use AF fine-tune to add an adjustment to compensate for a lens that consistently front-focuses or back-focuses when used with a specific camera body. AF fine-tune settings are not transferable. A setting on one camera may not be needed on a different but same model body. The setting is unique to that specific camera/lens combination.

Also, Nikon bodies do not allow you to define multiple settings for the same lens. For example, when working with a zoom lens, you are limited to one setting for that lens. If AF fine-tune is engaged, the adjustment will be applied regardless of the focal length used. I recommend you test a zoom lens at the focal length at which it will most likely be used.

The below series of images illustrate my approach to testing a lens to determine if an AF fine-tune adjustment is needed. Right click the below images to open a full-size JPEG in a new window.

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at OFF. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune turned off. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at +2. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at +2. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at +4. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at +4. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at +6. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at +6. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at +8. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at +8. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at +10. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at +10. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at -2. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at -2. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at -4. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at -4. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at -6. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at -6. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at -8. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at -8. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF Fine Tune at -10. (Bill Ferris)

Photo made with Nikon D610 and Tamron 24-70mm f/2.8 Di VC USD lens at 70mm, f/2.8, ISO 100, 1/200-second with flash. AF fine-tune at -10. (Bill Ferris)

The above series of images is a real world test under real world conditions. When shooting portraiture with the D610 and Tamron 24-70 f/2.8 Di VC USD, I typically shoot wide open with a mix of ambient light and flash at 1/200-second. If you’re going to test a lens to determine an appropriate AF fine-tune setting, test the lens under the same conditions in which it will most likely be used.

AF fine-tune is turned off for the first image in the series. The next ten images were taken with AF fine-tune turned on. A +2 adjustment is applied in the second image. Images three through six have adjustments of +4, +6, +8 and +10 applied, respectively. A -2 adjustment has been applied to image seven in the series. The next four images have adjustments of -4, -6, -8 and -10 applied, respectively. At each setting, I took five handheld exposures with vibration compensation (VC) engaged. The above series includes the second exposure in each five-exposure set.

Reviewing the exposures at 1:1 in Lightroom, all five exposures with AF fine-tune turned off were acceptably sharp at the focus point. Two of the five in that set were a bit shallow in focus, displaying minimal in-focus depth of field in front of the focus point. The set which most consistently produced sharp images with good depth of field both in front of and behind the focus point is the set with an adjustment of -6 applied.

Now, it gets complicated. Normally, I would choose the -6 setting for the Tamron 24-70mm f/2.8 VC and leave it at that. However, I also have a Tamron 70-200mm f/2.8 Di VC USD lens but the Nikon firmware does not distinguish between it and the 24-70mm f/2.8 VC. If I leave AF fine-tune turned on with a -6 setting for the 24-70mm f/2.8, the same adjustment will be applied when the 70-200mm f/2.8 is mounted on the D610. So, I’ve also tested the Tamron 70-200mm, using the same approach as with the shorter zoom.

The results of the testing with the Tamron 70-200mm f/2.8 VC were fairly straightforward. The best set of images was taken with AF fine-tune turned off. The set taken with an AF fine-tune adjustment of -6 were among the worst of the lot.

After testing both lenses, I’ve decided to store a -6 adjustment for the Tamron lenses but to leave AF fine-tune turned off. Both lenses make sharp, usable images without an AF fine-tune adjustment. If I remember to activate AF fine-tune when the 24-70 VC is mounted, so much the better.

Now, it’s time to get out and shoot.

Bill Ferris | November 2015

Shallow

A lone juniper tree clings to life on a stony outcrop overlooking Grand Canyon. (Lipan Point, South Rim) (Bill Ferris)

A lone juniper tree clings to life on a stony outcrop overlooking Grand Canyon. This photograph was made with a Nikon D610, Tamron 24-70 mm, f/2.8 VC lens at 60 mm, f/2.8, ISO 100, 1/800-second. (Lipan Point, South Rim) (Bill Ferris)

Depth of field is as important to photography as lighting and composition. Normally when doing landscape photography, I use focal ratios in the f/9 to f/16 range. Large focal ratios deliver images with great depth of field where objects in the fore-, mid- and background are all in focus. On a recent trip to the South Rim of Grand Canyon, I decided to experiment with using shallow depth of field and the above photograph is the result.

I was at Lipan Point, one of my favorite overlooks on the South Rim. From Lipan Point, you are treated to a fine view of Desert View and Palisades of the Desert to the east, and of Wotans Throne and Angels Gate to the west. I followed a social trail from the parking lot to a stone outcrop offering an unobstructed view of the canyon. Even on days when the light isn’t good for photography, the view from this little perch is still worth the 90-minute drive. In the truest sense of the phrase, the view from this vantage point is awe-inspiring.

The sun was low in the southwest sky and painted the surrounding landscape with a slightly warm hue. A small juniper tree clinging to its perch atop the Kaibab limestone was bathed in a wonderful rim light. As I set up my tripod and Nikon D610 to frame the shot, it occurred to me that this photograph should be a portrait of the tenacious tree.

In portraiture, wide open apertures and the associated small focal ratios produce shallow depths of field. This blurs everything not in the focal plane and helps to create separation between the subject, and anything in the foreground or background.

For the above portrait, I used the Tamron 24-70 mm, f/2.8 VC lens. I chose a composition that would include the distant South Rim, inner canyon temples and buttes, a short section of the Colorado River and the creamy late-day light streaming into Grand Canyon. This context clearly identifies the location of the portrait as being Grand Canyon. blurring the background allows the tiny juniper tree to be the subject of the photograph, the star of the show so to speak.

The tenacity of life in a desert environment is on full display, here. The tree clings to a rocky outcrop, a place where you might think a plant would have no chance of survival. But life is determined and defiant in such places. Water can pool in the small rough divots atop the limestone. And where water collects, life is almost always found.

The next time you head out with your camera, why not try something you don’t normally do? If you usually shoot with long focal lengths, try using a wide angle lens. If you often shoot with wide open apertures, make it a point to use a small aperture. Wherever your comfort zone may be, step outside it and try something new.

Now, get out there and shoot.

Bill Ferris | December 2014

Giving

Arizona fundraisers and non-profit organizations gathered at Prescott Resort to celebrate 2014 National Philanthropy Day.

Arizona fundraisers and non-profit organizations gathered at Prescott Resort to celebrate 2014 National Philanthropy Day. (Bill Ferris Photography)

I recently had the opportunity to photograph and document a 2014 National Philanthropy Day celebration at Prescott Resort. My wife, founding partner of GoalBusters Consulting and a long time fundraising professional, asked me to be the photographer for the event and I readily accepted. While my first love in photography is landscapes, I have been actively seeking opportunities to expand my horizons – and develop new skill sets – by doing portraiture, sports and event photography. Taking on this assignment would not only allow me to grow my event photography portfolio, it would be an opportunity to give back by volunteering my time and talent in support of people who make it their daily mission to improve the lives of others through the arts, charitable and other not-for-profit organizations.

My task list was fairly straightforward; make photographs of the following:

  • Award plaques
  • Speakers making remarks at the podium
  • Each honoree with their presenter
  • Group shots of the honorees and also of the honorees with their presenters
  • People attending the event

As you can see in the above photo, the conference room where the event was held features a panoramic wall of windows. With most clear skies on the day of the event, a wonderful, soft midday light filled the room. Seeing the award plaques displayed on a table at the front of the conference room, I started the morning by capturing a series of photos of the awards. I made at least one photo of each plaque, individually, and also of the awards as a group. After some introductory remarks by my wife and her business partner, the attendees settled in for a catered lunch.

I took advantage of this break to make some photos of the attendees relaxing and chatting with each other. I also scouted the outside terrace patio for a location to use for the group photos. The patio outside the conference room overlooks the town of Prescott, Arizona to the west-northwest. Arranging the honorees with their backs to the terrace wall would position the sun behind and to their right. This would put their faces mostly in shadow so, I made a trip to my vehicle to retrieve the speedlight kit, light stands, umbrellas and modifiers.

GoalBuster's Jim Anderson speaking at the podium during National Philanthropy Day at the Prescott Resort

GoalBuster’s Jim Anderson speaking at the podium during National Philanthropy Day at the Prescott Resort (Bill Ferris Photography)

The photo immediately above shows how the ambient outdoor light served as a beautifully soft light source when filtered through the window wall. I would have continued to shoot the event from this vantage point with my back to the windows, if not for two significant issues.

With most attendees seated directly in front of or to the left of the podium, speakers tended to look straight ahead or to their left to make eye contact with the audience. Rarely, would they look in my direction. As a result, there were few opportunities to see their eyes. The other and more significant issue was that honorees would approach the podium from the speaker’s left to receive their plaque. In hindsight, this is something I could have anticipated given that the awards were arranged on a table along the wall behind and to the left of the speaker.

When the first honoree approached the front of the room, she quite naturally stood to the left of the podium. This placed the podium between me, the honoree and her presenter, which made for an unflattering composition. I walked around the back of the room to the other side to get a better angle on the presentation. While standing with the podium to my left gave me an unobstructed view of the award presentations, it also meant that I was more or less facing the window wall. A proper exposure for the half of a person’s face illuminated by that gorgeous ambient light would leave the other half of the face darkened by shadow. A proper exposure for anything in shadow would leave the rest of the shot blown out.

Earlier after retrieving my speedlight kit from the car, I had made the above photograph of the attendees enjoying lunch in the conference room. Wanting both the view through the windows and the interior of the room to be properly exposed in a single shot, I had set up four speedlights to illuminate the room interior during the exposure. Two were Yongnuo YN-560 III’s, which have built-in radio receivers. The other two were Nikon SB-700’s, which were mounted on Vello FreeWave Fusion radio receivers. With a Yongnuo 603 NII radio transmitter attached to my Nikon D610 hot shoe and a Vello radio trigger mounted atop the 603 NII, I experimented with shutter speed and flash intensity until I was happy with the result.

Here, are the settings for the final exposure (Nikon D610, Tamron 24-70 f/2.8 VC):

  • 24mm
  • f/10
  • ISO 450
  • 1/160-second
  • Two speedlights at 1/2-power
  • Two speedlights at 1/4-power

While making my trek to the other side of the room to a vantage point with an unobstructed view of the honorees, I powered up and the speedlights (they were still set up and in position) and switched on the radio triggers on the D610. After a couple test shots to adjust settings, I was back in business.

An honoree (left) and her presenter at the National Philanthropy Day celebration at Prescott Resort

An honoree (left) and her presenter at the National Philanthropy Day celebration at Prescott Resort (Bill Ferris Photography)

The above photograph is one of many I shots I made using speedlights on radio triggers to illuminate the subjects. I bounced the flashes off the ceiling to create and even wash throughout the conference room. With four speedlights at between 1/4- and 1/2-power, the recycle time was kept to a minimum. When photographing the presenter speaking at the podium, I used the following settings (Nikon 610, Tamron 70-200 f/2.8 VC):

  • 200mm focal length
  • f/2.8
  • ISO 200
  • 1/200-second exposure

When the honoree came up to accept their award plaque, I made portraits using different settings (Nikon 610, Tamron 70-200 f/2.8 VC):

  • Variable focal length (95mm to 140mm)
  • f/5.6
  • ISO 640
  • 1/200-second exposure

My only concern with this set up was that the speedlights, when firing, would be something of a distraction for the attendees. However, I can safely say very few people even noticed I was using flash to illuminate the room. There was one gentleman who asked me about my lighting after the awards ceremony. Rather than finding it a distraction, he wanted to know more about the radio triggers and receivers.

While processing the RAW exposures, I noticed that the depth of field at f/5.6 was not quite enough to guarantee crisp focus on the eyes of both people. While the images are acceptable (in my opinion), I would probably shoot at f/7.1 or f/8 in the future to ensure sharp focus on both sets of eyes.

A group photo of the honorees and presenters at Prescott Resort for Arizona's National Philanthropy Day celebration

A group photo of the honorees and presenters at Prescott Resort for Arizona’s National Philanthropy Day celebration (Bill Ferris Photography)

After the ceremony, I went outside with the honorees and presenters to take the group photos. I made an exposure of the full group without using speedlights and, as expected, the faces were in shadow. After retrieving the Nikon SB-700’s, I recruited a couple of lighting assistants to hold the speedlights, one to the left and the other to the right of the group. I then made an exposure firing the SB-700’s at full power. This photo looked overexposed so, I reset the flash intensity to 1/2-power on each unit and retook the group photo. The resulting image is presented, above.

While the speedlights definitely help this photograph, I should have done a better job of arranging the group so nobody would be in shadow. Also, I had to do a fair bit of processing in Adobe Lightroom to recover highlights and reduce the overall exposure. Shooting in RAW compensates for a multitude of sins. I reduced the exposure by 1.10 stop without losing any detail in the final image.

So, what did I learn from this experience? First, it is critical to be equipped for any lighting situation. The speedlights gave me more shooting options. When the ambient, natural light was at my back, I could simply switch off the radio triggers. When shooting toward the window wall and into the light, I could switch on the triggers and use the speedlights to illuminate my subject. Second, using down time (I chose to forego lunch) to make the wide angle photo of the luncheon paid huge dividends. With the speedlights already set up, it only took me a minute to power them back on and adjust their intensity. As a result, I was able to very quickly adapt to a new shooting location and a different lighting environment. I only missed photographing one award presentation during the ceremony and was able to make that up as soon as the ceremony ended.

Finally, I should have taken the time to better arrange the group shot and do test exposures on the outdoor terrace. This would have taken only a few minutes, but would have resulted in better images and saved some worry on the drive home. Shooting in RAW allowed me to recover all the detail that was lost in the original, overexposed photographs. If I had taken the time to properly arrange the group photo and to adjust my exposure settings, those original RAW files would have been better exposed and nobody would have been in shadow.

A celebratory embrace during the National Philanthropy Day event at Prescott Resort

A celebratory embrace during the National Philanthropy Day event at Prescott Resort (Bill Ferris Photography)

I was also reminded of the joy of giving. As each presenter shared the story of their respective honoree, I was so impressed by the generosity and compassion of the human spirit. Each award recipient had generously given their time, talent or treasure in support of a non-profit organization or cause. Attending this event and hearing these stories, I was reminded that the simple act of giving often delivers the greatest personal rewards.

Now, get out there and shoot.

Bill Ferris | November 2014

 

Hit the Street

It's a busy Friday night at "The Sweet Shoppe" in historic downtown Flagstaff, Arizona. (Nikon D600, Tamron 24-70 at 70mm, f/2.8, ISO 6400, 1/250 sec.)

It’s a busy Friday night at “The Sweet Shoppe” in historic downtown Flagstaff, Arizona. (Nikon D600, Tamron 24-70 at 70mm, f/2.8, ISO 6400, 1/250 sec.) (Bill Ferris)

Street photography is all the rage. Candid images of unsuspecting people capture the personality of a community. On a recent Friday night, I roamed the streets of Flagstaff looking for scenes of real life to photograph. The above image of a friendly exchange between a customer and employee in a downtown Flagstaff business, captures a touch of the good feeling that filled the streets on this particular evening. It was the first Friday of the month. People were out and about having dinner, buying a dessert to share with a friend and enjoying out the diverse collection of art and artists on display. It was wonderful to be out and in the midst of such a positive vibe.

Often, street photographers seek out subjects that challenge our senses or sensibilities. There is nothing wrong with taking that approach unless it crosses a line and becomes exploitation. Homelessness is a real problem in America. At the very heart of this problem is a healthcare system that leaves far too many people without access to needed professional medical treatment for mental illness or addiction. Mental illness and addiction make it incredibly difficult for a person to function in society. As a result, far too many people suffering from these illnesses are out on the streets–homeless.

Homelessness is tragic. It is all around us and easily recognized. I suppose this explains, in part, why the anonymous homeless person is a favorite subject for some street photographers. What the photographer sees, is the person’s circumstance: homelessness. What is missed, is the person’s condition: illness. Personally, if I never see another black & white photograph of an elderly person in tattered clothes, blankly staring and oblivious to the passing world, it will be too soon. There is a good chance the person in that photograph is suffering some form of illness. And that, in my opinion, makes the act of photographing the person a form of exploitation.

It seems to me there is a misguided notion that photographing the homeless carries on a tradition begun during the Great Depression. What most people don’t understand is the fundamental quality that made homelessness during the Depression so different from today’s version. During the Depression, the underlying condition or cause of homelessness was not a physical or mental illness. The underlying condition was a global economic collapse that had destroyed the very foundation of society.

The catastrophic economic disaster which produced the Great Depression sent tens of millions of Americans out of their homes and onto the streets. By and large, these were not folks struggling with mental illness or addiction. They had been fully-functioning members of society–working, raising a family and being neighbors. But the physical institutions that served as the foundation for American society had been hit by an economic tidal wave. With entire industries destroyed, there literally was no societal framework within which a person could function. There was only chaos, a maelstrom engulfing millions who lost their jobs, their homes…everything.

The families and individuals featured in the most iconic of Depression-era photographs were just like you and me with one significant exception: They were homeless. An economic collapse was sweeping across the nation like a plague. Jobs had not been lost as casualties of a dreadful addiction or a debilitating mental disorder. The jobs had simply gone away. Not given to another person. Just…gone.

You could see the despair in people’s eyes in those photos. You could also see the determination and the dignity. These were people who had all the potential and ability in the world. In any other circumstance, they would have been the neighbors we met at the local super market, joined in worship on Sunday or socialized with at the next school open house. What made the Depression-era homeless so admirable, was that look in their eyes. They had been stripped of every physical element of dignity. But that circumstance did not touch their inner sense of dignity. They were survivors and they were determined to regain what they had lost.

In the 1930’s, homelessness was a random act of cruelty. Today, homelessness is more preventable and treatable. This makes the act of photographing a homeless person different. Depression-era photos are evidence that a person can lose every worldly good, and still retain their resolve and dignity. Photographing the mentally ill and addicted exposes people at their weakest, at a time when dignity and resolve are rare commodities. It is a means of objectifying a person in need of medical attention. It is exploitative. We may not be able to rescue every homeless person from the addiction or illness that has sent them to the curb. But we can, at the very least, treat that person as more than a compositional element in a photograph.

A patron sits lost in thought at a downtown Flagstaff cocktail lounge.

A patron sits lost in thought at a downtown Flagstaff cocktail lounge.in a different circumstance altogether. (Bill Ferris)

So, while out walking the streets of downtown Flagstaff the other night, I wasn’t looking for homeless people to photograph. Instead, I looked for every day people. People like you and me. People who share the same dreams, struggle with similar worries and who, on a Friday night, were seeking a brief respite from their work-a-day lives. I looked at the man in the above photograph and wondered, “What is he thinking?” I suppose he could have been contemplating some great world problem. Or maybe, he was thinking what I would have been thinking in that situation, “Should I go home or have another beer?”

When I got home that night, I did enjoy a cold beer. But I didn’t head home, right away. I had my camera, a fast lens and a downtown full of interesting people to photograph. People like you. People like me. Good street photography reveals the qualities that make a town a community. It celebrates the people, their dignity, their compassion for others and their ability to enjoy life’s simple pleasures. Like a bag of chocolates or a cold beer.

Get out and shoot!

Bill Ferris | November 2013