[GUB]

Yes, but I'm wondering to what degree (no pun intended) is it the haze which normally would reduce 1 EV vs. the latitude?

Sunny 16 is not a function of latitude but rather a function of what is between your subject and the sun ie haze or clouds.

[stevebrot]

Yes, but I'm wondering to what degree (no pun intended) is it the haze which normally would reduce 1 EV vs. the latitude?

Hard to say. That is not to say that we have no gonzo meterless photographers here, only that they are not using straight sunny 16.


Steve

[stevebrot]

Sunny 16 is not a function of latitude but rather a function of what is between your subject and the sun ie haze or clouds.

Sun angle is important in the same sense that when it is low, we get dusk, and if every day, winter. The amount of light is less and the spectral composition is different as well. If I remember, I can attempt to repeat the experiment at high (low?) noon for the winter solstice; assuming, of course, that we get clear weather.

Speaking of which, what is your latitude? Are you able to meter an honest gray card EV 15 for ISO 100 in NZ. You are a lot closer to the equator in Wanguanui (39°56′S), but it might be fun to see what you get.


Steve

[GUB]

Sun angle is important in the same sense that when it is low, we get dusk, and if every day, winter. The amount of light is less and the spectral composition is different as well. If I remember, I can attempt to repeat the experiment at high (low?) noon for the winter solstice; assuming, of course, that we get clear weather.

Yes but only because there is more atmosphere (haze) between the sun and the subject. For all practical purposes the sun remains the same distance from the subject. Plenty of haze between the sun and here at the mo - steady drizzle and EV10 !!

[Dartmoor Dave]

The amount of haze, combined with the height of the sun in the sky, determines whether I'll use straight Sunny 16 or more usually Sunny 11 around here. But for beach or snow shots, where the ground bounces back a lot of light, I usually go for the full Sunny 16. And of course I adjust for different densities of cloud, as has been described earlier in the thread. In the golden hour I tend to work off f/8, but really it's about using experience to judge the particular conditions by eye.

Around here there's usually some cloud, and I prefer to expose so that the brightest parts of any cloud will be just below clipping (assuming that the sun isn't directly in the frame). That quite often means that there's some shadow recovery needed on the ground, but that's easy with digital.

For people who want to get into Sunny 16, I'd suggest doing a series of test shots on a sunlit day, with some clouds with bright highlights but not with the sun directly in the frame. Find the exposure that captures the brightest parts of the clouds at just below clipping, and from now on you can use that as your standard "Sunny 16". My normal Dartmoor exposure is f/11 at 1/125 at ISO100. Switching to f/16 at 1/125 at ISO100 in sunlit snow, and of course opening up as needed when there's cloud. It's not strictly Sunny 16, but it works for me.


Edit: The height of the sun in the sky is relevant based on the time of day, not time of year. I use the same exposure in direct noon sunlight on 21st December as I do on 21st June. But at any time of the year, as the sun drops towards the horizon and the colour of the light visibly changes, you need to adjust exposure. In the summer there are more hours where you can go full Sunny 16, and the winter there are more hours of the day where you need to open the lens up a bit. The colour of the light is the best guide.

[Kerrowdown]

Sunny 16 Rule:

Something we've never had to worry about in Scotland...

Ours would be if we had one... F16 and for exposure time, go and have lunch.

[photoptimist]

To summarize, we have:

• Sunny f-16 rule
• Hazy f-11 rule
• Moony f-8 rule
  
• and then there's the Rainy f-the-weather rule

Note: f = "forget" in the case of Pentax, which can take a bit 'o inclemency!

[Ian Stuart Forsyth]

Yes but only because there is more atmosphere (haze) between the sun and the subject. For all practical purposes the sun remains the same distance from the subject. Plenty of haze between the sun and here at the mo - steady drizzle and EV10 !!

While the difference in the distance between the sun and the subject has not really changed the density of the light striking the surface will vary with the angle of the subject it is striking , tilt the surface of the target further away from 90 degrees to that light source and the density of the light striking the surface will decreases thus less light is being reflected by that surface (for photography) or absorbed by that surface (increasing the temperature).

In photography if you are trying not to blowout a white surface it is best to meter off of the white surface that is nearest to 90 degrees to your light source.

There is also the problem with white balancing if your target is 90 degrees to your light source like the sun as you white target surface tilts away from that right angle to the sun a secondary light source can produce a white balance shift to another color. On a sunny day this could be the blue sky shifting that white surface to a bluer tint as the density of light coming from the main light source the sun has decreased and your second light source the blue sky is shifted to the more dominate light source.

[GUB]

While the difference in the distance between the sun and the subject has not really changed the density of the light striking the surface will vary with the angle of the subject it is striking , tilt the surface of the target further away from 90 degrees to that light source and the density of the light striking the surface will decreases thus less light is being reflected by that surface (for photography) or absorbed by that surface (increasing the temperature).

In photography if you are trying not to blowout a white surface it is best to meter off of the white surface that is nearest to 90 degrees to your light source.

There is also the problem with white balancing if your target is 90 degrees to your light source like the sun as you white target surface tilts away from that right angle to the sun a secondary light source can produce a white balance shift to another color. On a sunny day this could be the blue sky shifting that white surface to a bluer tint as the density of light coming from the main light source the sun has decreased and your second light source the blue sky is shifted to the more dominate light source.

Yes these are all totally valid variables.
And that is why I am a bit pedantic about pointing out that the solar output itself is an actual constant. It varies by about 0.3 percent in the 11 year cycle.
You as a photographer have to spot the variable.

[Ian Stuart Forsyth]

And that is why I am a bit pedantic about pointing out that the solar output itself is an actual constant. It varies by about 0.3 percent in the 11 year cycle.
You as a photography have to spot the variable.

While there is a variation in output from the sun and also the atmosphere haze these most of the time are rather small when compared to change the angle of the rays that reach a surface if we go beyond 45 degree angle to the light source this can vary greater than 1 stop that's half the density of light illuminating a subject and much more than what the atmosphere is filtering out.

[GUB]

So a beautiful blue sky morning here in NZ . 9.30 am less than a week after the shortest day. My observation as I headed out the door was the sunlight was a bit "watery" if you know what I mean. So I guessed f4 iso100 1/1000. That is a bit over exposing for EV 14 or just over half a stop under sunny 16.
One shot is the old white painted clothes line pole.
The grey card on the clothes line is close to perpendicular to the sunny. (But it maybe guilty of reflecting extra light.)
The grey card on the ground is obliquely lit.
And the blue sky is with my back to the sun.
No surprises here. And it is probably about my choice of working exposure. (slightly underexposed at base iso.)
The point is the sunny 16 is the starting point for your guess. Unless an unusual environment magnifies the light output, the exposure will not be more than the EV15 of the sun.

[stevebrot]

So I guessed f4 iso100 1/1000. That is a bit over exposing for EV 14 or just over half a stop under sunny 16.

What did the camera meter for the gray card?


Steve

[GUB]

What did the camera meter for the gray card?


Steve

It never occurred to me to meter anything.
I wasn't thinking of this as a test of metering.
It would be reasonable to presume the meter would have tried to place the greycard on the centre of the histogram in both situations wouldn't it? (spotmeter).

[Dartmoor Dave]

It's 9.45am here and the sun rose at about 5am, so almost five hours after sunrise with patchy cloud but little haze. Metering in direct sunlight, my Sekonic L308S gives f/16 at 1/125 at ISO 100. The Samsung GX-10 version of the K10D with an 18-55mmWR, metering off a calibrated grey card, gives f/16 at 1/180 at ISO100, which seems to confirm my suspicion that the camera's meter is calibrated to underexpose slightly.

With that lens on that camera, I'd usually shoot at f/16 at 1/125 at ISO100 in this light without bothering to meter, as I know the brightest parts of the patchy clouds will be just below clipping in the raw file.

[GUB]

as I know the brightest parts of the patchy clouds will be just below clipping in the raw file.

Yeah the clouds play by their own rules don't they!
Here again today out for a walk about 1.30. The day is now moderate to heavy cloud, but to catch this scene with a margin in the clouds I went f4 1/4000 Iso 100 (EV16 and a bit).

It left me with about half a stop spare in the clouds and this unchanged image reflects pretty well what i was looking at.
A portrait in that environment would have required 3 or 4 more stops.