Category Archives: Film

Is a Kit Lens Better for Infrared Photography?

Okay, I have a digital camera converted to capture infrared light. I’m ready to go out and shoot pictures, right? My camera is ready–Is my lens?

Light is bent when it passes through transparent materials such as air, water, and glass. However, different colors (wavelengths of light) may not bend at the same degree so water droplets and prisms make rainbows by spreading out the mix of frequencies of light at different degrees. A lens bends this composite of colored light towards its focal plane, our camera sensor or film. It is shaped and coated with materials that eliminate the spreading out by different colors of light.

sample-hot-spot-dsc_0083
A premium Sigma 17mm-50mm f/2.8 lens at f16 produces a hot spot which I have exaggerated with a curves adjustment.
sample-kit-lens-no-hot-spot-dsc_0207
A Nikon 18mm-55mm f/3.5-5.6 kit lens at f/8 did not produce a hot spot. I have applied a similar curves adjustment which would have revealed an appreciable hot spot if it had been there.

My subject is in focus–what’s the big deal about infrared light? Camera lenses focus the visible spectrum. Some lenses also bring infrared to the same focus as visible light. Others don’t do as well and may produce a hot spot on the image.

Compared to pro lenses, a kit lens may not be able to produce as sharp an image in the visible spectrum, but may focus infrared frequencies more accurately. Look here to read a list of some lenses which have been tested for infrared photography.

Instant Photography, Ironically, Isn’t Instant

Yesterday, I put my old Polaroid SX-70 camera to use with a pack of Impossible Black and White instant film. The irony is that instant photography takes more time per capture than digital cameras do when I count shielding the film from light for a few minutes while it develops and the capacity of my digital camera to make bracketed shots with one click of the shutter realease button or bursts of several shots in sequence.

Original capture on Impossible Project B&W film
Original capture on Impossible Project B&W film
I feel differently working with analog media in photography. Shooting film feels more connected to mother earth. The tools are physical objects functioning in mechanical actions inside my camera: opening and closing shutters, advancing roll film, ejecting instant film. I have a wider selection of actions to perform as well: loading and unloading film, developing prints with chemistry (or waiting while instant film chemistry works its magic), pulling integral instant prints from a camera and shielding them from light, pulling, peeling, and waiting for Polaroid Land camera film to develop, etc.

 

Repeatedly, new inventions have provided quicker, less physically demanding tools and methods to get clean clothes, clean dishes, hot food, transportation for school, work, vacation, or family, and photographs! While it is easier to do more and more things, however, we’ve lost the down time that slower processes give us. In a way, every job is easier, but our lives are harder as we fit more and more tasks into our days.

 

Analog photography is one step back into the past that I can actually take. “You can’t turn back the clock,” the saying goes; but I can with my film cameras go back to a slower paced time, taking time to watch the seconds tick away while physical processes unfold into photographic images.

Inspiration by Association

I’ve learned not to think when I run out with my camera to take some pictures. I may have a feeling about a place, a time of day, a sense of perfection or ruin in mind, but I am looking in my camera for something that just feels right. When I began as a photographer I had to think until I mastered operating my camera controls, which were all manual. Unfortunately, that habit of thinking about every shot really inhibited my shooting; and I took forever to expose a roll of film.

 

2015startonthestreetI was over my hesitancy when my enthusiasm for photography was reignited in 2000 or so when I accepted warm invitations from Randi Laak, then an instructor at the Worcester Center for Crafts, to enroll in his Friday evening photography class. I freely experimented with exposures, films, darkroom chemistry and processes as I had not when I started out.

 

Together with the freedom in the darkroom (And now in Photoshop), the history of photography of which I had learned as a beginning photographer and witnessed in publications and exhibitions as time passed, and my love of many paintings, prints, sculptures, etc. at the Worcester Art Museum and elsewhere, I am endowed with feelings associated with these beautiful or provocative objects that are evoked, I believe, as I walk through the world. I think those feelings and associations are part of my feeling of “rightness” when something captures my eye.

 

The universe seems to notice that I take the time to stop and see things then  once in a while shouts at me to stop and look at this!

 

Here’s one example of a landscape photograph of a scene of light penetrating a shadowy wild place for which I felt similarly to when I look at an 18th century painting by Alessandro Magnasco:In painting and photograph the light seems to stab into a shadowy wild place.

 

Numbers, part three (Conclusion)

Sensitivity is defined by the International Organization for Standards (ISO) in its abstract thus:

“ISO 12232:2006 specifies the method for assigning and reporting ISO speed ratings, ISO speed latitude ratings, standard output sensitivity values, and recommended exposure index values, for digital still cameras. ISO 12232:2006 is applicable to both monochrome and colour digital still cameras.”

ISO 200 (low noise)
ISO 200 (low noise)

Long ago we used to call this the ASA, which was the similar method for determining film sensitivity from the American Standards Association.

The lower the ISO number is set the longer it takes to record an image; and the less noise appears in the image files; higher ISO’s make faster recordings of images with more noise. Camera image processors have improved noise reduction so I may select higher ISO settings with little noise in my image with recent digital camera models.

Click on images to view at full size for better comparison of noise levels in the two images.

ISO 16000 (high noise)
ISO 16000 (high noise)

Methods of noise reduction include blurring or smearing small artifacts, subtracting pixels based on another exposure, and so on. Perhaps some small details get lost in the process. Although, details may be recovered using the algorithms used in the camera image processor or post processing. Some pixels in the resulting image thus may be made by firmware or editing software rather than light.

In summary, I can apply three basic camera settings: aperture, time, and sensitivity to make creative choices such as sharpness, and blurred or frozen motion. I can compensate for the lighting; I can select high sensitivity for low light exposures, and low ISO settings for cleaner, more detailed images.

Making choices with these settings lets me capture how I see a thing and share it in a photograph.

Numbers, part two

Today, I want to talk about time. The duration of an exposure can be very short, very long or anywhere in-between. Cameras can be set for exposures of one thousandth of a second or less, or of many seconds or minutes.

OLYMPUS DIGITAL CAMERA
1/800 Second Exposure Freezes Motion

Time, how long the shutter is open, or how long the sensor is recording can be set for a capture that is shorter, which will freeze action, and is handy for sports and fast moving subjects like children and race cars.

I can choose a longer exposure to blur objects as they move across the frame for an impression of speed, or to smooth moving surfaces like river rapids in which the water is a smooth clear or milky flowing substance over rocks.

With very long exposure times, electronic noise can get recorded in my image file as the camera circuitry builds up heat, and, especially if it had been low at the start, the battery could run out of charge.

1/25 Second Exposure Blurs Motion
1/25 Second Exposure Blurs Motion

There may be technical consequences to very short and very long shutter speeds that I want to bear in mind. Higher sensitivity (which I’ll write about in my next post) may be required to capture an image completely when I wish or need to make a very fast exposure.

Numbers, part one.

Sometimes I understand the way one person says things better than others. So here in my words are a few comments about camera settings that may help us know our cameras better. Photo editing software may allow me to compensate for less than ideal exposures, but better results come with good initial captures.

Loosely defined, these settings are:

  1. Aperture: The size of the lens opening relative to the distance from the sensor.
  2. Time: How long the lens is open for light to pass, how long the sensor is recording.
  3. Sensitivity: How long it will take for the sensor to record enough data for an image.

Today, I’ll discuss number one, the aperture. Aperture, the diameter of the opening for light, is expressed as an f-stop. The higher the f-number is; the smaller the opening. The f-number is equal to the distance from the aperture opening to the sensor divided by the diameter of the opening. If I had a gigantic camera with a one mile diameter opening that was sixteen miles from my gigantic sensor, my aperture would be f/16. Sixteen miles distance divided by one mile diameter is f/16. Fortunately, my camera is smaller, but because f-stops are ratios they work at any scale.

f/64
f/64
f56-P6090436
f/5.6

One impact of my choice of aperture is how much of my photo is sharply in focus. The smaller the aperture (higher f-stop), the greater percentage of the distance in my capture from foreground to background is sharply in focus. The larger the light opening (lower f-stop), the less depth of field is in focus. High f-stops are ideal for lots of sharp detail in my image, maybe for a landscape or architectural shot. Low f-stops allow for selective focus, so I can, for instance, take a portrait shot of someone where they are in focus, but the background is softly focussed.

Next time, I’ll take a look at time and sensitivity.

Instant Photography

Bankruptcy and the ceasing of production of instant films by Polaroid could have left only Fujifilm as a producer of peal apart instant film for Land Cameras, but no integral instant films for classic Polaroid cameras. However, in 2008 The Impossible Project was conceived and funding was found to purchase the last Polaroid film manufacturing plant in the world.
Ten of the best former Polaroid employees were recruited to join in the effort to recreate film chemistry for SX-70, 600, and Spectra/Image cameras.By 2010 Impossible released its first black and white instant film, recreating instant film for Polaroid format cameras.
Polaroid SX-70 Black & White instant film
Scamper in the shadow of lace curtains. Polaroid SX-70 Black & White instant film.
Today, it produces black & white and color integral films, 8×10 black & white film, and the Instant Lab, which works with black & white or color SX-70 or 600 films to make instant prints from smartphones and tablets; and it refurbishes classic Polaroid SX-70, 600, and Spectra/Image cameras.
Polaroid SX-70 Black & White instant film
Pepper behind lace curtains. Polaroid SX-70 Black & White instant film.

Find out more about Impossible.

Film & Sensor Sizes

The naming scheme for digital camera sensors is derived from old television camera sizes expressed as the diameter of the tube through which light enters to strike the sensor at the end of the tube. The sensor’s diagonal measurement is about one third less than that of the tv camera tube so camera sensor diagonal measurements are smaller than you might expect from their names.
43-sensor010
Camera with a Four Thirds Sensor: Micro Four Thirds cameras are mirrorless.
Here are a few film and sensor dimensions, and their relative sizes compared to 35mm film and full frame digital sensors.
Type Format Dimensions (mm) Surface Ratio to 35mm
Width Height mm²
film 4×5 121 97 11737 1358%
film 645 56 42 2352 272%
Sensor 645 43.8 32.8 1436.6 166%
Sensor Full Frame 36 24 864 100%
Sensor APS-C 22.3 14.9 332.27 38%
Sensor four thirds sensor 17.3 13 224.9 26%
Sensor 2/3″ 8.8 6.6 58.08 7%
Sensor 1/1.6″ 8 6 48 6%
Sensor 1/1.8″ 7.2 5.3 38.16 4%
Sensor 1/2.7″ 5.3 4 21.2 2%