ECOR 1100 Lecture 2: Understanding depth of field


instant-university_ECOR1100-lecture-2-understanding-depth-of-field-iconTHE FOLLOW-UPinstant-university_yellow-border

Since last lecture, you have known an important element in Photography: the Exposure Triangle. You learn that the aperture value controls depth of field. In fact, there are
2 more critical factors affecting depth of field.


FACTOR 1: THE FOCUS DISTANCEinstant-university_yellow-border


Focus distance is a calculation from the subject to lens. By changing the focus distance, you will get different depth of field of an image. If you are closer to the subject you are focusing on, you will have an image with shallower depth of field, and vice versa.


FACTOR 2: THE FOCAL LENGTHinstant-university_yellow-border


Focal length (usually measured in mm) is a calculation of an optical distance from the convergence point in the lens to the sensor or film inside the camera, but IS NOT the actual length of a lens. Basically, the longer the focal length, the narrower the angle of view and the more magnifying effect in your picture with shallower the depth of field, and vice versa.

**Shallower lens (e.g. 200mm) → longer focal length→ shallower view captured + shallower depth of field → telephoto effect
**Wider lens (e.g. 28mm) → shorter focal length → wider view captured + deeper depth of field

CC 1420 Lecture 3: Air traveling with instant films and cameras





Many Instant Photographers may have the same X-ray concern about carrying undeveloped films when traveling. In this chapter, you will learn what to do and what NOT to do when traveling, without X-ray damaging to your instant films and cameras.




instant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#3Before departure



instant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#5Unprocessed film is sensitive to light just as they are waiting to be exposed. Although Impossible Project film has a rather low ISO of 160 for SX-70, and ISO 640 for 600 cameras, X-ray of checked baggage screener may still penetrate and expose the film. Whereas carry-on baggage screener has a much milder X-ray – films under ISO800 such as Fujifilm instax mini film and instax wide film are usually not affected.

So never pack unprocessed film in baggage that will be checked. Or you can politely insist on hand-inspection of the film whenever possible.


instant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#7After arrival


instant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#8Extreme cold guideinstant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#8

When you want to take photos in a freezing cold place (e.g. -10°C to -15°C / 14°F to 5°F and below), you should put the camera inside your bag or  your coat pocket and keep it near your body prior to shooting. Using your body temperature is a good way to ensure that your camera will work well.

Instant film is highly sensitive to temperature. After the camera ejects picture, immediately place it in your pocket or directly onto heat pads. A moderate room temperature of around 25°C / 77°F is optimal for developing camera pictures. Warm the photo with your body temperature is the easiest way. Low temperature will overexpose a photo. It may look bluish, lightened and less contrasted.

instant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#9Extreme hot guideinstant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#9

Travelling in a place with hot weather (e.g. 35°C to 40°C / 95°F to 104°F and above) is a different situation. Keeping the developing image under shade and keep it cool will help correcting the white balance and prevent reddish and yellowish to a large extent. DO NOT leave the exposing photo under direct sunlight.

Hot temperature has a greater effect on B&W film than color. If you wish to get a better result with Polaroid cameras, snap with Impossible Color Film!

Impossible Project film can deliver good results when used within a temperature range of 13°C to 28°C / 55°F to 82°F, while 5°C to 40°C / 41°F to 104°F for Fujifilm instant film.


instant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#7After arrival


Even with Color Protection Film, it is possible to be overexposed under strong sunlight. The first few seconds are extremely crucial for image development. Always shield the film from light when it is ejected.

Can I use a black card, to cover the film with a hand or quickly turn the photo upside down?

To put a black card at picture exit slot is economical and may help, but it will not work as perfect as the Frog Tongue from Impossible Project.


instant-university_CC1420-lecture-3-air-traveling-with-instant-films-and-cameras-#7After arrival



Some Polaroid cameras such as SX-70 Sonar, use sonar to auto focus. When you are on a coach or railway cabin, visiting in museum or aquarium, as long as there is glass between you and the object, the sonar auto focus will not work because sonar will bounce back when it hits the glass. In order to shoot through glass, simply switch to manual focus and you are good to go!