Originally Posted by
Bernice Loui
Some thoughts on shutter speed accuracy.
~Back in the day when color transparencies were the most common means of producing color images for mass printing, high quality strobe lighting was absolutely preferred over shutter timed exposure. High quality studio strobe units can be held to 1/10 f-stop with ease and consistency and color temperature can be controlled and CC filtered as needed to achieve neutral color balance with color transparency film.
~Shutter speed is not a significant factor when strobe light is used in a controlled studio setting. Shutter speed accuracy and consistency comes into play if "synco-sun" or mixed outdoor lighting with strobe is used for images to be produced.
~This is NOT easy to do or even close to achievable with sun light which it's color temperature changes depending on the time of day, location and much more. Add to this, errors-tolerances in shutter speeds make absolute consistent exposures to 1/10 f-stop quite difficult to impossible.
~Fact is ALL mechanical shutters have variations in their shutter speed cycle to cycle, over time, over aging, over temperature, over condition of the shutter. This is how electronic shutters came to be as this was an effort to reduce shutter speed variations and improve shutter accuracy, consistency and related shutter requirements.
~Using a single reliable-accurate mechanical shutter can help reduce variations in accuracy, shutter speed, and all that by the fact a single shutter is used for each lens chosen to make a given image. This is one of the reasons why using a know good Sinar shutter with barrel or Sinar DB lenses can reduce shutter speed errors.
~The most accurate shutter ever used was the Sinar Digital, highest speed is 1/500 and it is accurate at 1/500 second, will time down to many seconds with equal accuracy and reliability. It is also HUGE, heavy, $$$$, not really portable at all.
~Fact is, for the majority of outdoor photography that 30% error is not that significant. There is sufficient differences in actual film speed, light at the moment of shutter release, light transmission of a given lens and a long list of many other variables that puts that 30% tolerance of shutter speed into perspective.
~While color transparency film is the least tolerant to exposure errors, B&W film is significantly more tolerant to exposure errors. Do consider variations in processing, developers and more to print making. This is why gaining control over the entire print making process often makes the greatest difference in the finished print.
~Focusing on a single parameter like shutter accuracy, camera, film and... can produce neglect of all the other factors that will affect the finished print.
Suggest not worrying about this variation in shutter speed and focus far more on image making and image content.
Berince
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