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What You Need to Know About the F/16 Rule - Printable Version

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What You Need to Know About the F/16 Rule - Jeffbridge - Jan 22, 2016

The f/16 rule has a lot of applicability today and could mean the difference between getting a good exposure and one that’s over or underexposed.

https://www.photographytalk.com/photography-articles/6185-what-you-need-to-know-about-the-f-16-rule


RE: What You Need to Know About the F/16 Rule - MrB - Jan 22, 2016

The article quotes -
f/16 at ISO 200 and a shutter speed of 1/200 seconds is good for a sunny day
on our overcast day at f/11 and ISO 200, increase the shutter speed from 1/200 seconds to 1/400 seconds
On a really cloudy day, an aperture of f/8 would be needed, so at ISO 200, a shutter speed of 1/800 would be necessary

End quotes

Unless I'm not thinking straight, surely that info is incorrect?

f/16 & 1/200s, f/11 & 1/400s, and f/8 & 1/800s, are all equivalent exposures at constant ISO. Therefore, as there is less incident light available when there is cloud cover, any one of these pairs of values is going to under-expose the image on the duller days.

In my opinion, the histogram in a good digital camera, used thoughtfully, is the best guide to a good exposure.

Cheers.
Philip


RE: What You Need to Know About the F/16 Rule - EdMak - Jan 22, 2016

Dead right, also, it's a peculiar page that I get, lot of scrolling, to get little. Ed.


RE: What You Need to Know About the F/16 Rule - JohnF - Jan 25, 2016

(Jan 22, 2016, 01:29)Jeffbridge Wrote:  The f/16 rule has a lot of applicability today and could mean the difference between getting a good exposure and one that’s over or underexposed.

https://www.photographytalk.com/photography-articles/6185-what-you-need-to-know-about-the-f-16-rule

The article assumes that by opening the aperture more light is let in so the shutter must be increased. The fallacy here is that the incident light is reduced. Sunny has higher light intensity than cloudy and the reduced Fstop is to account for that. Of course, cloudy is a variable term in that the clouds can be thin/wispy to thick/socked-in.


RE: What You Need to Know About the F/16 Rule - GrahamS - Jan 25, 2016

The article also says that "the f16 rule measures incident light"!!!
It doesn't measure anything. It's just a rule of thumb. I think the author should stick to his/her day job..


RE: What You Need to Know About the F/16 Rule - JohnF - Feb 6, 2016

(Jan 25, 2016, 16:26)GrahamS Wrote:  The article also says that "the f16 rule measures incident light"!!!
It doesn't measure anything. It's just a rule of thumb. I think the author should stick to his/her day job..

The F16 rule and its equivalents at other lightings is BASED on incident light. When they say F16 Sunny they mean clear sky out of shade and sun at noon (standard time) or 1 PM (daylight savings time). Latitude makes a difference, also.


RE: What You Need to Know About the F/16 Rule - GrahamS - Feb 6, 2016

Measures = based on? Huh?


RE: What You Need to Know About the F/16 Rule - JohnF - Feb 6, 2016

(Feb 6, 2016, 11:09)GrahamS Wrote:  Measures = based on? Huh?

If you set a light meter set to incident illumination mode in a sunny illuminated scene the rule says at F16 the shutter will be 1/ASA. Of course, this is just approximate but owing to the lattitude of film a certain amount of over or under misexposure is tolerable. To the extent that a digital sensor has exposure lattitude the F16 rule may fail or be tolerable. I actually put my old Sekonic out when this thread started to see if incident confirmed the rule. It did but not precisely.


RE: What You Need to Know About the F/16 Rule - MrB - Feb 6, 2016

A camera is no longer just a black box with a lump of glass over a hole at one end and a light sensitive material at the other. Most people have paid good money for the amazing technology built into their modern cameras - for goodness sake, use it. Taking photos is now almost cost free, so practise taking lots of shots - to gain understanding of the camera's electronic metering system and to learn how to interpret the displayed histogram for each image. Those are the best guides to good exposure.

Cheers.
Philip