The 'Sunny 16' Rule - break it down

[Brendo09]

After a good push from ameerat, I checked out the 'Sunny 16 rule.

Basically it's just saying that on a good day with good light, you can start your calculations from f16 - shutter speed (1/ISO) - ISO. That's your given in any exposure equation for that light condition? (I'm ignoring the super bright 22, the cloudy 11, the near total darkness 1.4)

It's not telling me that f16 is the ultimate great light aperture, is it?

So if you go up an f stop (from f16 to f11) then you need to increase the ISO a stop (100 up to 200), OR increase your shutter a stop (1/125 to 1/250) ... right?

[ameerat42]

Good on yer for researching.

Firstly, no. f/16 was just a convenient starting point, probably so they could make it into "Sunny 16". Ie, "what to use for a sunny day"

Yes for the rest of your findings. There's this Library article on the Exposure Triangle, and it contains a
list of f/stops and their relationships.

Basically - it never hurts to expound these betimes - it means for...

f-stops: Each "full" f-stop represents double or half (depending whether ascending or descending) the amount of light admitted by the aperture of the camera.
BUT - the full f/stops change by 1.4 (square root of 2). Your further research will tell you why.
(At this point, dissociate any idea of "equality" between "f-stop" and "aperture". The relationship is that the f-stop is a PARAmeter - not even a measure - of
the aperture.) Again, your research will tell you why.

The only thing that EQUAL f-stops (eg, f/8) will give between ANY lenses at all is the INTENSITY of the incident light. (Even this is theoretical because of other
transmission factors between lenses.)

Exposure time (coll. "shutter speed"): each full shutter speed step is a doubling or halving (again, direction) of the adjacent value. Each full "shutter speed" value is
equivalent to a full f-stop.

ISO: (a vexed measure, somewhat equivalent to "sensitivity" of the film or sensor). Each full ISO setting represents (again, direction) a doubling or halving of the
adjacent value. So, each full ISO step is equiv. to one full f-stop which is equiv. to one full shutter speed setting.

You may divine that the foregoing values have a rather "reciprocal" relationship between them. However, this tends not to hold when going to extremes of any
of the settings. For film photography, the breakdown of the reciprocity was referred to as "reciprocity failure/effect" (you look up), and for digital photography
extreme settings can lead to lots of signal noise (esp. for high ISO) or reduced saturation.

Anyway, that'll give you something to look up

[Brendo09]

You may have missed the 'break it down's part of the title ;-)

Thanks ameerat. I've got some more reading to do now before I put it into practice on the weekend.

[ameerat42]

Hmm! It does sound a bit vague, I suppose. My answer "no" was to
"It's not telling me that f16 is the ultimate great light aperture, is it?"

But now that I look at your next line, in this part
"So if you go up an f stop (from f16 to f11) then you need to increase the ISO a stop (100 up to 200)..."
you've got to go 200 to 100 ISO.

[Brendo09]

Good point. See, using one of the automatic modes you don't really have to get your head around the terminology to much.

[Cage]

It is my understanding that the increments for the SS16 Rule are as follows:

ISO: 100/200/400/800/1600 etc

'f' stop: f1-f2-f4-f8-f16-f32

Shutter: 1/100-1/200-1/400-1/800-1/1600

Most modern cameras have part incremental adjustments.

The Sunny Sixteen rule basically advocates that a subject in open sunlight will be close to well exposed at ISO100, f16 at 1/100sec and I'm assuming here, with the basic 50mm f1.8 lens.

To maintain the equilibrium, if one adjustment to the basic equation is made, a compensating adjustment must be made to one (or both) of the other settings.

Rough example 1: You are photographing the kids in the park, sunny day, kids facing sun and using ISO100 - f16 - 1/100sec and a bloody big cloud comes over. According to the SS16 rule you will now be underexposing so you change the 'f' stop to f11, 1/2 stop more light, so that should bring the exposure equation back to where you need it. OK, only the light changed so only one adjustment needed.

Rough Example 2: Same kids, same place, sun out, kids being kids, and are moving around, so you need to increase your shutter speed to stop their motion. You increase your shutter speed to say 1/400sec, that's two (2) full levels of adjustment, so you need to make a compensating adjustment to one or both of the other parameters to maintain the exposure equilibrium. You can do this by increasing your ISO from 100 to 400, two full increments, or open your aperture from f16 to f4, also two full increments, or a bit of each with the aperture at f8 and the ISO at 200.

Which way you decide to go about this will be influenced by the DOF (Depth of Field) you desire. Obviously f4 is going to give you a much narrower DOF than f8 and so one must have a working knowledge of the DOF for the lens you have attached.

Confused yet? Sheesh, I am just typing this.

I remember when I got my first DSLR, a Pentax K20D, I looked at the manual, hundreds of confusing pages, and lots of pre-sets that I couldn't see myself ever using, and thought to myself that it was just a SLR camera with a sensor instead of film. From the first day I treated it as a SLR without the need to drop my film at the local chemist or camera shop, only to pay and find out days later that I'd stuffed something up.

Brendo, I believe this is worth persevering with and will be a huge assist in your understanding of photography.

[ameerat42]

Kev. A couple of correc tifica tions...

'f' stop: f1-f2-f4-f8-f16-f32

Should be:
f/ 1; 1.4; 2; 2.8; 4; 5.6; 8; 11; 16; 22....

...Rough example 1: You are photographing the kids in the park, sunny day, kids facing sun and using ISO100 - f16 - 1/100sec and a bloody big cloud comes over. According to the SS16 rule you will now be underexposing so you change the 'f' stop to f11, 1/2 stop more light...

Should be "1 (full) stop more light".

Rough Example 2: Same kids, same place, sun out, kids being kids, and are moving around, so you need to increase your shutter speed to stop their motion. You increase your shutter speed to say 1/400sec, that's two (2) full levels of adjustment, so you need to make a compensating adjustment to one or both of the other parameters to maintain the exposure equilibrium. You can do this by increasing your ISO from 100 to 400, two full increments, or open your aperture from f16 to f4, also two full increments, or a bit of each with the aperture at f8 and the ISO at 200.

f/16 to f/4 is four (4) full increments. (Two would go from f/16 to f/8.)

[Brendo09]

I don't doubt that at all. It's just taking the time to get it to all make sense.

[Brendo09]

See! You guys know what you're on about and even you can't agree! What hope is there?

[Cage]

See! You guys know what you're on about and even you can't agree! What hope is there?

Nope, Am is spot on with his assumptions.

I need more tumeric in my geriatric diet.

- - - Updated - - -

Kev. A couple of correc tifica tions...


Should be:
f/ 1; 1.4; 2; 2.8; 4; 5.6; 8; 11; 16; 22....



Should be "1 (full) stop more light".


f/16 to f/4 is four (4) full increments. (Two would go from f/16 to f/8.)

And thanks Am for sorting out my brain fade. No wonder I'm having problems getting my head around this astro stuff.

[Mark L]

I like taking photos of birds. No way would I use f/16 or iso 100. Sunny 16 is a starting point for exposure that was formulated way before digital and PPing on your computer was ever imagined.
Use aperture priority at f/8. Many like to use auto ISO and let that and the shutter speed look after themselves. I'd much rather choice the ISO given the conditions and simply let the camera choose the shutter speed only.
And yes in the end the parameters look a bit like Sunny 16, but I want to over expose using high ISO with a dark BG and reduce exposure in PP to get less noise. and, and, ...

[EmzDad]

and, and, .... my head hurts ... I am going fishing. Whiting are on in the river at the moment .

But this is something I need to spend more time learning and practising... the basics... Not fishing that is... got that down pat.. the Triangle thing needs work...


Will be back to read more later this arvo after fishing.

Thanks
Shane

[Bennymiata]

Or buy yourself a light meter and play with it.

Muck around with it, and you can soon learn the relationships.
You'll see how adjusting one parameter effects all the others.

There are reasons for using certain apertures, or ISO's or shutter speeds for different effects.
For example, if you want a blurry background to your subject, you'll use a wide aperture (small number). If you want to include the background and have it as sharp as possible, you'll need a small aperture (large number).
If you make the lens opening smaller to get the effect you want, then you have basically 2 choices, do you increase the shutter speed so the sensor is exposed to the light for more time, or do I wind up the sensitivity of the sensor (ISO)?
There are pros and cons for either choice, and experience will tell you which you choose, or even a combination of the 2.

If you're taking shots of fast moving objects, then you will need a short shutter speed (faster shutter speed) to get sharp pictures, but in order to get a fast shutter speed, you'll need to open the lens up and/or wind up the ISO.

There is not always a definite right and wrong to exposure settings, but instead of trying to go from full auto to full manual, use the Tv and Av detents on the knob (they are semi-auto), and learn to control one parameter first and get to know it, then switch to the other. Make sure you look at what the camera is telling you about the exposure and learn to read your histogram. It's very important and a real boon to photographers, yet is a very underutilised feature.

[arthurking83]

Or buy yourself a light meter and play with it.

.....

NUP! .. (they)dunneedit .. only because they(or any other person interested in the topic) already has one in their camera.
Money wasted on stuff that doesn't help is an inefficient way to learn about that stuff.

But .. along the lines of what Bm has mentioned there .. use the laypersons guide to photography, in the simple display available on the review LCD.
** So for the purpose of this reply LCD will mean the image review LCD(not the top info LCD, which may or may not have been broken, and thus leaving .. for those models that have it)

On a Nikon, you simply press the i found on the back of modern DSLRs.
You can also see the changes being made through the viewfinder's LCD display area, but it's nice and easy to see the changes made on the larger LCD.

So using the S16 rule, set camera to [A](aperture priority mode) and then set f/16 with the twirly dial.
Important point is to set camera's metering to matrix here too.
Camera should also be set to manual ISO(fixed at say ISO100 for now).
Best to place camera on a stable non movable platform of some type so that it's looking at the same thing every time you change some thing too.
Point it at anything that is lit up by the sun on this fine sunny day.
Now you're set to 'understand' the exposure triangle .. but first you'll learn the exposure line(just working with two variables .. f-stop and shutter speed only(ISO changes will be made later for the more circular exposure triangle test).

ISO100, f/16 .. what shutter speed do you get? Depending on the thing that the camera is pointed at, it may sometimes vary by a small amount, and this is normal.
It's important to understand why and what causes this too .. the cameras meter does this .. and for good reason. The colour and tone changes of a subject is how the meter tells the camera to expose!!!
So keep the 'subject' as constant as you possibly can. Point it at a wall, or barn or shed or car, and on a bright cloudless day the meter will read stable.
If you handhold the camera, just a slight variation will cause the meter to read differently(due to that subtle change in the exact way you pointed it .. stable platform(tripod/table/rock/fencepost/etc)

Now in [A] mode all you can really change is Aperture, so as Cage suggested, go from f/16 to a wider f/11 and notice the change in the shutter speed.
eg. if at f/16 is showed 1/80s, then at f/11 it will(or should) show 1/160s .. ie. every full aperture stop is equal to half/double the shutter speed.
So by the time you get to f/4 in the same situation .. shutter speed will have quadrupled from 1/80s to 1640s (ie. 1/80s -> 1/160 -> 1/320 -> 1/640).

It's very simple. Reason why is that an 'aperture' on a lens is a circle. Because of our mate Pythagoras, who invented the term pi or π a specific ratio amount of increase(or decrease) in the size of a round area is doubled(or halved) in a certain way. The Aperture value you see or deal with is simply an area of opening that lets through the light. The specific value of the important ratio that causes the doubling/halving of area is 1.4.
This is why we have full stop aperture values of 1, 1.4, 2, 2.8 ...

** it's important to note that a f-stop isn't an actual size(say in mm) .. it's a ratio. This is why I introduced the complex idea into what should be a simple reply.
(I have a theory that ... ) what seems to confuse folks is that the fstop goes from a seemingly random value(say f/16) to another seemingly random value(eg. f/11) and it's described as halved or doubled!!
The reality is that this is true, and the reason is that the ratio value of 1.4 is the reason .. so all you have to do is remember those aperture stops.

11x1.4 = 15.7(ie. 16!!) so 1.4 is the ratio needed to halve/double the circular area, so this translates into 2x for the less complex shutter speed(and ISO values) .. which don't have to deal with our mate .. π!

if you look at the full aperture stop values from 1.0 and up .. they are all multiples of this 1.4x ratio(with a small amount of rounding to simplicity's sake).
Hopefully all that gobbeldygook helps to make it clear as to why it's all set the way it is.

So from f/16, to f/11 to f/8 to f/5.6 .. etc, gives you double the shutter speed while it gives you double the aperture (area!!) to let light through. And ovbviously the reverse is true when you halve every thing ..

All that blathering on only uses the linear scale of shutter vs aperture. Traditionally, in the film days, you loaded a roll of film and ISO was set until that film was used!

The triangular [A] - [S] - ISO relationship is circular becasue you now have more variables to tamper with. Affect one, and the others are affected to maintain the same(roughly) exposure.
So double the aperture from f/16 to f/11, and you could use a quarter the ISO + a quarter the shutter speed variables to adjust or just the half ISO adjustment or half the [S] adjustment alone.
As long as you keep the overall differences in changes so that they all balance out to keep the exposure constant .. it makes no difference.

Many folks use the 1/3rds variable steps in camera .. so that Aperture, Shutter and ISO all change in 1/3 steps.

So using the 1/3 step settings, the two different ways you could change the camera settings from f/16 to f/11

f/16 @ (1/80s + ISO100) = f/11 @ (1/100s + ISO160) this uses 1/3x shutter only and 2/3x ISO increases!
or
f/16 @ (1/80s + ISO100) = f/11 @ (1/125s + ISO125) this uses 2/3x shutter only and 1/3x ISO increases!

or .. remembering the half-half system ...
f/16 @ (1/80s + ISO100) = f/11 @ (1/120s + ISO150) this uses 1/2x shutter only and 1/2x ISO increases!

changing only one of the other (ISO or [S] variables gives you
f/16 @ (1/80s + ISO100) = f/11 @ (1/160s @ ISO100) this uses 2x shutter only and ISO same!
or
f/16 @ (1/80s + ISO100) = f/11 @ (1/80s + ISO200) this uses no shutter change and a 2x ISO increase!

The problem is that not all cameras allow you those true half value increases anyhow .. and are probably only approximations.
But you should have a camera setting option that allows you to use 1x(full stop) increment changes, 1/2 stop changes or (I think the better) 1/3stop increments.

Now given all that, my recommendation is to completely forget the sunny 16 rule. In the film days it was bunk, and it's even more bunk in the digital era!
Now, I understand that it's a rule(not a law, or a given) and to be used as a guide .. but it can be so grossly ineffective due to camera, film/sensor and lens variances .. and how you actually want something exposed too.
Whilst with digital it's easy to correct exposure in PP ... it's best to try to get into good habits if you want to achieve the best for your own sake.

Hope that makes some sense.

[ameerat42]

Brendo.
Instead of "Break it Down" you could as well have used "Come off the Grass"

It "seemed to be" common knowledge in film days that a light reading off "green grass" was
pretty close to the same off an 18% grey card. (I remember using this method 1x or 2x.)

[arthurking83]

....

It "seemed to be" common knowledge in film days that a light reading off "green grass" was
pretty close to the same off an 18% grey card. (I remember using this method 1x or 2x.)

That's what I do.
Wished I had've known about this back in the film days too tho. Probably wouldn't have lost so many pics due to exposure.

I'm usually out in some paddock(when I get a chance too get out) and set the camera to -0.3Ev to -0.7Ev to get some colour in the grass, use spot metering to keep the exposure consistent.
Manual ISO, Aperture priority .. and fire the shutter via a remote.

[Brendo09]

So the general consensus is... learn the Sunny 16 rule. You may or may not use it, or you may let the camera work it out.

I'm loving this stuff.

[ameerat42]

So the general consensus is... learn the Sunny 16 rule. You may or may not use it, or you may let the camera work it out.

I'm loving this stuff.

Yes to all the above

[Mark L]

Make sure you are taking you photos using RAW. Gives the photos your taking using the Sunny 16 rule much more latitude in PPing.
But I like to ETTR

[Brendo09]

Forgive my ignorance... But ettr?