Density vs. Contrast

Transcription

1 Density vs. Contrast

2 In your negatives, density is controlled by the number of exposed crystals in your film which have been converted to hardened silver during processing. A dense negative (over exposed) will produce a light positive; a thin negative (under exposed) will produce a dark positive. over exposed negative under exposed negative

3 In your negatives, density is controlled by the number of exposed crystals in your film which have been converted to hardened silver during processing. A dense negative (over exposed) will produce a light positive; a thin negative (under exposed) will produce a dark positive. print from over exposed negative print from under exposed negative

4 In your print, density refers again to the number of exposed silver crystals, but this time it refers to the number of exposed silver in your paper emulsion. This means that print density is the overall brightness or darkness of a print & it s determined by exposure the amount of light that reaches the printing paper. shorter exposure created a print with low density (under exposed). longer exposure created a print with high density (over exposed).

5 Too much exposure produces a print that is too dense (dark); too little exposure produces a print that is not dense enough (light). A dense print is dark all over in both the highlight and shadow areas; a light print lacks density in both highlights and shadows. Too dense (dark) 24 seconds at f/11 Too light 8 seconds at f/11 Just right 16 seconds at f/11

6 The main ways to control print density are by varying the exposure time (the length of the light) and/or the aperture on the enlarger s lens (the intensity of the light) to change the amount of light that strikes the paper. This relationship is the same as that between the aperture and shutter speed on your camera. print exposure timer = length of light aperture = intensity of light film exposure shutter speed = length of light aperture = intensity of light

7 We always print for the correct density by starting with a test strip, and looking at the density of the highlights to be sure that they are not blown out & the darkest shadows to be sure they ve achieved true black. 20 seconds 16 seconds 12 seconds 8 seconds 4 seconds 12 seconds

8 There are several factors that determine how much exposure is needed to make a print with the proper density but the main two are: the density of the negative (dense negatives need more exposure than thin negatives); & the brightness of the enlarger bulb (some bulbs are newer/brighter or older than others). light bulb condenser lenses Condenser enlarger negative

9 Contrast is the difference in darkness between the highlights and the shadows of your print. The shadows include all dark areas (not simply literal shadows). Contrast is your print s tonal range.

10 A successful print from a correctly exposed negative will have normal contrast: this means that the shadows will not be too dark (information or texture will be visible) and non-spectral highlights will contain tone (not paper white). A print with good contrast will have a full range of grey tones plus true black and bright white.

11 Print contrast is adjusted with the use of multi-contrast filters which work with different spectrums of light to either decrease or increase the level of contrast in your prints.

12 They are numbered from 0-5, where 0 & 1 (yellow filters) produce low contrast/ flat images with information in highlights and mid-tones, 2 & 3 (magenta) produce medium contrast images with information in the shadows, and 4 &5 (magenta) produce high contrast images with depth in the shadows. filters 0, 1 = lowers your print contrast filters 2, 3 = used for medium contrast filters 4, 5 = increases your print contrast

13 Number 2 filter is considered to be normal contrast, meaning that it should be similar to your correctly exposed negative...which is why we start with a #2 filter and work from there. #0 filter #2 filter

14 #0 filter #1 filter #2 filter #3 filter #4 filter #5 filter

15 #1 filter #2 filter

16 #3 filter #4 filter

17 #1 filter #2 filter

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19 tonal range master: Ansel Adams

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