Nikon 1988 Instruction Manual - Page 13

Without TTL metering At close ranges (reproduction ratios greater than 1:10), the amount of light reaching the film decreases as the lens-to-film distance increases. When non-TTL measurement is used in these cases, photographs will be underexposed unless you have compensated for this decrease. (When the Micro-Nikkor 105mm f/2.8 lens is used with the Nikon/Nikkormat or Photomic TTL meter, compensation is not necessary since the meter will give accurate readings of the amount of light reaching the film.) The tables at the right give the exposure factors (compensation values) with exposure increases in f/stops for non-TTL exposure measurement at reproduction ratios greater than 1:10. If you don't want to increase aperture compensation more than one full f/stop, use slower shutter speeds. For example, for a 1:1 reproduction ratio, use 2steps slower shutter speed and then open the lens by 2/3 stop, or use 3-steps slower shutter speed and then stop the lens down by 1/3 stop. Lens only Reproduction ratio 1/10 1/8 1/6 1/4 1/2 With PN-11 ring Reproduction ratio 1/2 1/1.8 1/1.6 1/1.4 1/1.2 1/1 1/0.88 Exposure factor 1.1 1.2 1.2 1.4 1.9 Exposure factor 3.4 3.4 3.4 3.5 3.9 4.7 5.1 Exposure increase in f/stops approx. 1/4 approx. 1/4 approx. 1/3 approx. 1/2 approx.1 Exposure increase in f/stops approx. 1-3/4 approx. 1-3/4 approx. 1-3/4 approx. 1-3/4 approx. 2 approx. 2-1/4 approx. 2-1/3 13