Sequence viewing > black & white film - processing Index - Resource - © Lloyd Godman

What affect does the speed of a film have on image quality?


Low Speed Film - (up to 100 ASA) Low speed film has the following characteristics:

*fine or small grain structure

* good accutance

*excellent resolution

*more contrast

This film is better for big enlargements where maximum detail is required, but will require a longer exposure and perhaps need the use of a tripod to avoid camera shake.

I used a low speed (25 ISO) film to assist with giving a long shutter speed for this image from the  Last Rivers Song Project. It also gave very fine grain.

 

High Speed Film - (400 ASA up) High speed film on the other hand displays the opposite characteristics:

* larger grain

* less accutance

* less resolution

* less contrast

High speed film is better for low light and fast action photography as it is less likely to require a tripod.

It may however need to be loaded in low light levels because of its extended sensitivity.

By contrast, I used a high speed (400 ISO pushed to 1800 ISO) film to giving a fast shutter speed for this image from the  Last Rivers Song Project. It also gave  large grain size 

 

 

Medium speed film (200 ASA approx.), is often a compromise between the two.

 

 

 

Want to learn more? - do a workshop or one on one with Lloyd Godman