Sunny 16 calculation for ISO160 film

Graham_Martin · May 13, 2011

I would like a little clarification on calculating the proper exposure for ISO160 film when using the Sunny 16 rule.

Assuming a bright sunny day using 100 speed film at f/16 my exposure would be 1/125. I guess that technically the speed should be 1/100 sec. Using 200 speed my exposure would be 1/250.

If ISO160 is 60% faster than 100 speed then my theoretical shutter speed would be 1/200. Since the closest shutter speed on my RB67 lenses is only 1/250 do I not worry about the slight difference, or should I change my aperture by half a stop?

Thanks!

Sirius Glass · May 13, 2011

Graham_Martin said:
I would like a little clarification on calculating the proper exposure for ISO160 film when using the Sunny 16 rule.

Assuming a bright sunny day using 100 speed film at f/16 my exposure would be 1/125. I guess that technically the speed should be 1/100 sec. Using 200 speed my exposure would be 1/250.

If ISO160 is 60% faster than 100 speed then my theoretical shutter speed would be 1/200. Since the closest shutter speed on my RB67 lenses is only 1/250 do I not worry about the slight difference, or should I change my aperture by half a stop?

Thanks!

or should I change my aperture by half a stop? Yes

Steve

removed account4 · May 13, 2011

hi graham -

you might have film that is slightly underexposed ...
typically when i expose film sunny 16, i expose it sunny 11
because i don't think the sun is THAT intense that it would really be f16 ...
i also use the shutter speed BELOW the asa value ( so 125 for 160 film, and 60 for iso 125 film )
but i tend to like a beefy negative. if your working methods are working for you
with slight underexposure ... don't change a thing
thatsaid ... you could always fine tune your exposure method by bracketing a few shots
so you know the next time what works best with your camera, metering, and processing methods ...

have fun !
john

Rick A · May 13, 2011

Sirius Glass said:
or should I change my aperture by half a stop? Yes

Steve

+1

Tony Egan · May 13, 2011

It depends on what the film is. 160 ISO sounds like a colour negative or slide? My rule of thumb is to err on underexposure for slide film and overexposure for negatives, particularly B&W negative. I have invariably found the sunny 16 rule is too little exposure for B&W film. Closer to f11 or even f8 if you subscribe to the shadows on zone 4 approach. You can always run a test roll or at the end of a roll use the last 5 shots to do +/-1 and +/-2 stops around your sunny 16 baseline as suggested by John. Have fun.

Graham_Martin · May 13, 2011

Thanks for the responses. The film in question is color negative film.

moki · May 13, 2011

Sunny 16 might work for California in Summer or the african sun, but in most parts of northern America and Europe, Sunny 11 is the better rule. For 160ASA film, I'd go for about 1/125 and f/13 (1/125@f/11 for 100ASA and then half a stop less)
With negative film, you shouldn't worry too much. They do have very big tolerances, so half a stop more or less isn't going to change anything... even most slide films should be able to handle that. If you're guessing exposure, it's not that exact anyway.

Sirius Glass · May 13, 2011

moki said:
Sunny 16 might work for California in Summer or the african sun, but in most parts of northern America and Europe, Sunny 11 is the better rule. For 160ASA film, I'd go for about 1/125 and f/13 (1/125@f/11 for 100ASA and then half a stop less)
With negative film, you shouldn't worry too much. They do have very big tolerances, so half a stop more or less isn't going to change anything... even most slide films should be able to handle that. If you're guessing exposure, it's not that exact anyway.

Sunny 16 works even better it one meters the subject and not the sky. When I have worked with people who claim that Sunny 16 does not work, I usually find that they are metering a large part of the sky and not the subject.

If one is far North or South in the high number latitudes like 60º plus, then Sunny 11 would be better.

Steve

Graham_Martin · May 13, 2011

I live in Florida where the sun is very bright. When I use an exposure meter the readings indicate that Sunny 16 applies here.

pgomena · May 14, 2011

IS0 numbers are 1/3 stop apart. 100/125/160/200/250/320/400 etc. Strictly following sunny 16, you'd be at 1/160 second at f/16. I own no cameras or lenses with this particular shutter speed, so I would use 1/125 sec at f/16+1/3. Or, I'd open up a half stop if my lens did not have 1/3 stop increments available, as the others have said.

In Florida, I'll bet you can get sunny 16. I found it worked pretty well when I lived in southern California. Up here in Oregon, sunny 11 seems more like it.

Peter Gomena

Steve Smith · May 14, 2011

Sirius Glass said:
Sunny 16 works even better it one meters the subject and not the sky. When I have worked with people who claim that Sunny 16 does not work, I usually find that they are metering a large part of the sky and not the subject.

Sunny 16 is a method to determine exposure without a meter so how does this metering fit in with using sunny 16?

Or are you referring to comparing sunny 16 settings to actual meter readings?

Steve.

Diapositivo · May 14, 2011

The Sun shines basically equally all over the world given a certain angle above the horizon. When the sun is 30° above the horizon in Oslo, it shines like when it is 30° above the horizon in Tunis.

The catch in the "sunny 16" rule is that it applies only for clear cloudless sky when the sun is at least 20-25° above the horizon. When one lives at higher latitudes, the number of days, and of hours of day, in which the rule can be applied is smaller. And also cloudy days are more frequent. The light of a cloudy sky is very difficult to evaluate by mere sight.

When the sun is high and the sky is clear your incident lightmeter will probably give around 1/125@11 plus 1/3 or 2/3 of EV at ISO 100. That is pretty much consistent with the rule as in fact by using 1/125 instead of 1/100 (theoretically required by the rule) you are closing another little bit and getting closer to the theoretical 1/100@16, although not really there.

When using slides the sunny 16 rule applies but I would use a light meter for any quantity of clouds or diffused light. It's just so easy to block shadows or burn highlights with slides, even when using light meters.

When using negative film, I would also suggest the "sunny 11" rule, that means overexposing by almost 1 step but, with negatives, that means probably getting a more printable negative. Even "sunny 8" will work. You are in any case estimating exposure and a certain overexposure will prevent blocking shadows and act as a safe buffer.

markbarendt · May 14, 2011

The sunny 16 rule also gets simplified more than it should be. It has another major qualifier that is rarely talked about.

"For front lit subjects" 1/ISO at f/16

For side light subjects f/11 is better, for back lit subjects f/8 makes more sense.

Here in Colorado I find that the rule is seasonal. f/11 in the winter, f/16 the rest of the year.

For the rule to work all the qualifiers have to be applied.

benjiboy · May 14, 2011

I think guestimating exposures when good light meters are available so cheaply on the second hand market is ill-advised because any cost of buying a meter will soon be recouped by the increased percentage of accurate exposures, and to avoid the wast of time, effort and materials taking the pictures and processing them.

Jeff Kubach · May 14, 2011

benjiboy said:
I think guestimating exposures when good light meters are available so cheaply on the second hand market is ill-advised because any cost of buying a meter will soon be recouped by the increased percentage of accurate exposures, and to avoid the wast of time, effort and materials taking the pictures and processing them.

I agree!

Jeff

markbarendt · May 14, 2011

benjiboy said:
I think guestimating exposures when good light meters are available so cheaply on the second hand market is ill-advised because any cost of buying a meter will soon be recouped by the increased percentage of accurate exposures, and to avoid the wast of time, effort and materials taking the pictures and processing them.

The reason I know the numbers is because I use the meter.

Diapositivo · May 14, 2011

Yes, but things sometimes don't work, stuff happens. It's a bit like knowing how to change gear when the clutch doesn't work. You don't do it normally but, if it happens, you don't remain by the road side. I use light meters but I do want to know how to make an emergency exposure in an emergency case. And it's refreshing to understand exposure like a basically simple thing. Sometimes people worry too much about exposure and that doesn't help results. For "street shooting" sunny f/whatever is possibly the best thing (or just checking the light with your light meter from time to time, and stop worrying too much about light).

markbarendt · May 14, 2011

Here's a tool tool http://www.fredparker.com/ultexp1.htm

It work but it takes some practice to understand how to see the situations well. Good thing is that you can just print it and keep it with you and practice by seeing what the chart tells you anytime you please. Kinda fun actually.

Practice is one key; many pros, like busy wedding shooters, get so much practice in their normal shooting situations that they can get a very specific result almost every time even without a meter. The other thing about wedding work and most other types of specialized photography is that each has a normal rythym where the shots fall. There are say maybe a dozen (+/-) "setups" that are almost always the same.

It isn't too tough to remember how to set the camera for a dozen setups.

hpulley · May 14, 2011

The meter can fool you worse than the sunny 16. You need to use your mind and experience no matter what you're doing. Blindly following the meter or using full auto-exposure without thinking (not locking exposure and/or making exposure adjustments based upon your experience) will give you terrible under and overexposure if you don't know what you're doing.

If I have time I'll meter but often there is no time and the choice between me choosing the right exposure or hoping that rapid AE will work properly is a toss up really.

Sirius Glass · May 14, 2011

Steve Smith said:
Sunny 16 is a method to determine exposure without a meter so how does this metering fit in with using sunny 16?

Or are you referring to comparing sunny 16 settings to actual meter readings?

Steve.

Or are you referring to comparing sunny 16 settings to actual meter readings? Bingo, you got it. Usually it would start that they were derating the ISO by a factor of two because they were aiming the light meter to mostly cover the sky.

Sirius Glass · May 14, 2011

Graham_Martin said:
I live in Florida where the sun is very bright. When I use an exposure meter the readings indicate that Sunny 16 applies here.

It also works in Maryland, Virginia and New York.

steelneck · May 14, 2011

Both images below taken with the same camera, both at the same iso, same shutterspeed and aperture. The left in mars above the arctic circle in sweden, the right in august in the south west of Turkey. So, the sunny 16 do work in real bright sunny weather, no matter where on this globe. And to answer the initial qustion. I would err on the over-exp. side since you are using negative film. I usually rate color 160 film at 125.

markbarendt · May 14, 2011

hpulley said:
If I have time I'll meter but often there is no time and the choice between me choosing the right exposure or hoping that rapid AE will work properly is a toss up really.

I used to think that way.

It is truly rare for me to be caught flat footed on exposure anymore and part of that is because of sunny 16 and the ultimate exposure computer and just a lot of shooting.

removed account4 · May 14, 2011

GREAT LINK!

i never carry a meter around ..
except when i am shooting a job
still, i do the reading using sunny 11 for laughs,
and take my meter reading ... and they are the same
so i guess i am doing something right -

good luck graham!
john

markbarendt said:
Here's a tool tool http://www.fredparker.com/ultexp1.htm

It work but it takes some practice to understand how to see the situations well. Good thing is that you can just print it and keep it with you and practice by seeing what the chart tells you anytime you please. Kinda fun actually.

Practice is one key; many pros, like busy wedding shooters, get so much practice in their normal shooting situations that they can get a very specific result almost every time even without a meter. The other thing about wedding work and most other types of specialized photography is that each has a normal rythym where the shots fall. There are say maybe a dozen (+/-) "setups" that are almost always the same.

It isn't too tough to remember how to set the camera for a dozen setups.

2F/2F · May 14, 2011

With negative film, go ahead and use '125 at f/16 with 160 film.

The thing about sunny 16 is that the sky must truly be CLEAR. No haze, etc.

And the other thing is that you don't have to use f/16! I almost never do. I use an equivalent exposure at f/4 to f/8, usually, and with my few modern electronic cameras with super fast shutters, I can open up even more.

And of course, it must be solidly day time, not near sunrise or sunset.

Sunny 16 calculation for ISO160 film

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