Morning, over the years I have heard of or read of people doing a “ring around” I understand it to be some type of method for determining film speed I guess.
At any rate, I was hoping someone could enlighten me. What is the process and results?
Film testing I have done has been quite involved with charts, graphs and densitometers. Effective but time consuming.
my understanding of a ring around, is using paper, not film.
But this may be a regional thing.
Take a negative and print it on every filter grade with at least your most favorite developer.
It's also used with colour printing.
Take one negative and set the enlarger at a neutral filter setting. Then make a series of prints with changes to the filters. Pick the resulting print that looks best.
Or just do it so you can know what changes with the filters produce in the prints. In which case keep a labeled ring around next to the enlarger to compare to.
At least that's my understanding.
Ringarounds can be used for all sorts of tests, but as Ann suggests, they are often used for reference when printing. They provide a visual reference for variations in whatever process you're testing.
I first did one for color to see the effect of different types of color filtration. You can keep the ringaround posted or handy in your darkroom for reference. For color, for instance, if you want to know how far off your filtration is, you can compare the proof to the ringaround.
If you wanted to do one for film testing, you could shoot a series of exposures ranging from two or three stops on either side of what you think is the real speed of the film, and do this same series on five or six rolls of film, adjusting the development time below and above the predicted time for "normal" development. Make contact prints on your favorite paper using the same exposure and development time for all negs, and you'll have a good set of reference prints showing the relation between film development time and exposure, calibrated to that paper. If you wanted to factor in the effect of the enlarger, you could make small enlarged proof prints instead of contacts. If you use more than one paper or different grades, you could do it on each paper you use.
A "ring-around" in regard to b&w film testing is a series of (usually 9) combinations of exposure and development in predetermined increments. The usual scenario is to take 3 rolls of film and expose them all to the same subject. One roll is exposed at the manufacturer's ISO rating (e.g., ISO 400) and the other two rolls are exposed above and below that, by some ISO increment (in this example of plus or minus 1/3 stop you would use ISO 320 and ISO 500). The films are then cut into thirds and the pieces developed for different times.
Three pieces exposed at different ISO settings would get the manufacturer's recommended development, the next three would get reduced development (perhaps 25% less) and the last three would get extra development (perhaps 25% more). This results in a combination of 9 conditions which are contact printed and compared in order to determine the best combination for normal practice. (If you use a wider spread of the exposure and development variables, the effects of gross changes in exposure and development for "pushing" and "pulling" films can be illustrated.) You end up with pairings of either normal development and normal exposure (lets call that nD & nE), with under- and overexposure (uE,oE), and under- and overdevelopments (uD,oD).
The 9 combinations that result are usually displayed by contacting a frame from each condition in a "ring-around" the frame suggested by the manufacturer's settings. With development representing rows and exposure representing columns, in a clockwise rotation from the upper left corner you end up with: uD+uE; uD+nE; uD+oE; nD+oE; oD+oE; oD+nE; oD+uE; and nD+uE surrounding nD+nE.
You may need to fine-tune this through repetition but it is a way of determining the best ISO settings and development conditions for different situations. It (hopefully) gets you to the same point by visually representing the different combinations of exposure and development as if you were to do the Zone System tests using densitometers and H&D curves. The Zone System is probably quicker to fine-tune once you understand what goes on with the variables. OTOH, the ring-around is a lot easier where you can control the exposure variables, i.e., in studio situations.
Kodak's book on Professional Films has/had a section outlining the ring-around procedure. Another source is William Mortensen's "Mortensen On the Negative" which has an illustration of his ring-around test on the front paper cover.
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I have made ring arounds over the years and find them very helpful.
I make all new assistants do three different ring arounds now when they join our shop.
one for black and white film that is described by smiegltz
one for colour negative printing papers
and now a very complicated one for digital colour.
If done properly the information gained is of huge benifit to a novice and experienced printer. We use them all the time to verify colour correction for example and the chart is mounted in our colour correction area.
Thank you all! Joe, your explanation is what i was looking to hear. I guess that is precisely what they were talking about. I have in fact done similar tests without knowing it was a "ring around" when i didn't feel like going through the complexity of a full blown zone test.
Well it's always good to know what the heck folks are talking about and that i am not so far off track.
Would you mind giving an overview of the digital method? I'm curious why it's complicated. Do you print the results on silver based paper?
It`s just a simplified method of checking the accuracy of your light meter.
Originally Posted by shyguy
An even easier method is to make a one stop bracket each side of the meter reading in half stop steps, one of these should be right for you.
As for film development, just follow the manufacturers recommended time as a starting point and adjust the time if the negatives are a litttle too contrasty or too soft when printing onto your normal/standard paper grade.
It`s a method of light meter calibration for film exposure and developing by making a series of bracketed exposures. It is described in some of the Kodak publications.
Originally Posted by ann
You usually expose a minimum of three rolls and develop one for the recommended time, one for a bit less and one for a bit longer to fine tune film development so that you can find a negative that prints the best onto your regular paper. If the recommended ISO and developing time gives the best results, then that`s what you use in future, if one of the negatives exposed a little more generously and/or with a longer or shorter developing time works the best, then that becomes your personal exposure index and developing time for that film stock.