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7218/5218 Pull or over-expose


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#1 Stephen Whitehead

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Posted 15 September 2005 - 09:56 PM

Hey I am just curious, quite often when people talk about the stock 7218/5218 (Or many other stocks for that matter) they say they rate it at 400 ISO, or in some cases 320 ISO. Does this mean they simply over-expose the stock then print it down for a thicker neg, or do they pull process the film at that rating? What would be the result of both of these? Does pull processing also create a denser neg, just with less contrast? If someone could explain that to me, I'd very much appreciate that.

Cheers,

Steve
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#2 Dominic Case

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Posted 15 September 2005 - 10:05 PM

7218 is rated at 500EI by the manufacturer. If someone exposes it at 400EI or 320 EI, it simply means they are overexposing by 1/3rd or 2/3rds of a stop. That makes for a denser negative, which would make a lighter print at normal printing lights: so the lab would have to "print down" to get the image back to normal. Printing down means using higher printer lights - if it's normally around 28 28 28, then a neg exposed at 320EI would print at around 33 33 33. (7 lights per stop).

Pull processing means reducing the development time (as a way of partly comensating for more exposure caused by downrating the stock). SO by itself it results in a thinner negative: the contrast may be slightly reduced, but modern colour negative emulsions are pretty resistant to processing variation, so the density change would be more noticeable than the contrast change.
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#3 Stephen Whitehead

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Posted 15 September 2005 - 10:19 PM

7218 is rated at 500EI by the manufacturer. If someone exposes it at 400EI or 320 EI, it simply means they are overexposing by 1/3rd or 2/3rds of a stop. That makes for a denser negative, which would make a lighter print at normal printing lights: so the lab would have to "print down" to get the image back to normal.  Printing down means using higher printer lights - if it's normally around 28 28 28, then a neg exposed at 320EI would print at around 33 33 33. (7 lights per stop).

Pull processing means reducing the development time (as a way of partly comensating for more exposure caused by downrating the stock). SO by itself it results in a thinner negative: the contrast may be slightly reduced, but modern colour negative emulsions are pretty resistant to processing variation, so the density change would be more noticeable than the contrast change.

<{POST_SNAPBACK}>


Visually how are these techniques going to effect the negative. My guess is that the over-exposure would cause less grain, but greater contrast. While the Pull process would still have the same amount of grain but be slightly less contrasty.
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#4 John Pytlak RIP

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Posted 16 September 2005 - 09:14 AM

Visually how are these techniques going to effect the negative. My guess is that the over-exposure would cause less grain, but greater contrast. While the Pull process would still have the same amount of grain but be slightly less contrasty.

<{POST_SNAPBACK}>


Yes, slight overexposure and normal processing can be used to reduce graininess and get a bit more saturation, shadow detail, shadow contrast, and 'richer" blacks. The lab simply prints at a slightly higher printer lights, as determined in the color timing (grading) process.

If you "pull-1 process", there will be a slight decrease in contrast and some softening of the grain and color contrast, and the overexposed negative will print/transfer more like a "normal" negative.

Caution not to "pull" too much in process by simply speeding up the processing machine, as you do need to maintain adequate bleach, fix, and wash times.
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