stability of 'sunny 16'

[Curt]

14.91

 

[1L6E6VHF]

I've always have been suspicious of "sunny f/16" because of my own experiences. I had a LOT of underexposed slides using it. I also would be surprised when my metered camera would indicate f/8 on a sunny day - and that would actually give me a good slide (I grew up in a neighborhood of dark brick houses and 100' trees with dark green leaves)

However, even in open areas, I found that "sunny f/14" gave better exposure than f/16 on my Realist - despite the fact that my shutter tested a little slow. (BTW, in Michigan, 42°N at home, 46°N on vacation).

Need to get back to the "10:00 am - 2:00 pm" comment. Of course, that would vary with season and latitude. More importantly, that would also assume everyone is using solar time -that is, the sun being highest at 12:00 noon. Through Daylight Savings Time (aka Summer Time or War Time), that is rarely the case. Michigan, for example, is effectively on Daylight time in the late fall to mid-winter, and on DOUBLE Daylight Savings time from late winter to mid-fall, so 10 am-2 pm becomes 11:35 am - 3:35 pm in the summer in Detroit and Noon - 4 pm at Houghton. In the most extreme cases, there are people on quintuple Daylight Savings Time - making the "window" from 3:00 pm to 7:00 pm!

 

[markbarendt]

I've always have been suspicious of "sunny f/16" because of my own experiences. I had a LOT of underexposed slides using it.

Yes, one must remember that it is appropriate for front-lit-subjects. For back-lit subject sunny f/5.6 is a better choice, cross lit sunny f/11.

 

[pentaxuser]

. In the most extreme cases, there are people on quintuple Daylight Savings Time - making the "window" from 3:00 pm to 7:00 pm!

Just out of curiosity where are these areas, when do theses DSTs apply and if they revert to GMT is this done in stages?

Thanks

pentaxuser

 

[E. von Hoegh]

Just out of curiosity where are these areas, when do theses DSTs apply and if they revert to GMT is this done in stages?

Thanks

pentaxuser

Since "noon" is defined as the time the sun reaches it's zenith, simply find your longitude and calculate thusly - 15 degrees east of Greenwich means you are one hour ahead of GMT, 15 degrees west means you are one hour behind. I am at about 74 degrees west, so local noon here is 4hrs 56min behind GMT - meaning 13:56 local daylight saving time.

 

[removed account4]

hi ralph

just now ri 12:30
i waited for the sun to come out of a cloud
EV 15

 

[RalphLambrecht]

hi ralph

just now ri 12:30
i waited for the sun to come out of a cloud
EV 15

looks like your sun is perfectly calibrated at themoment.

 

[RalphLambrecht]

thank you all.the experiment is over!conclusionur sun is still working wiyhin specified parametersand we are looking forward to 4.5 billion more yearsTHANKS AGAIN FOR ALL OF YOU PROVIDING VALUABLE DATA FOR THIS TEST.

 

[removed account4]

looks like your sun is perfectly calibrated at themoment.

using the meter for this exercise was the first time i have used a light meter and not sunny 16 in about 7 years
i hate being bogged down with a meter !

 

[RalphLambrecht]

using the meter for this exercise was the first time i have used a light meter and not sunny 16 in about 7 years
i hate being bogged down with a meter !

you and me both

 

[E. von Hoegh]

thank you all.the experiment is over!conclusionur sun is still working wiyhin specified parametersand we are looking forward to 4.5 billion more yearsTHANKS AGAIN FOR ALL OF YOU PROVIDING VALUABLE DATA FOR THIS TEST.

Of course, there are occasional glitches.
http://arstechnica.com/science/2012/05/1859s-great-auroral-stormthe-week-the-sun-touched-the-earth/

One more argument for film.

 

[markbarendt]

using the meter for this exercise was the first time i have used a light meter and not sunny 16 in about 7 years
i hate being bogged down with a meter !

I understand that, one of the reasons I worked hard to "calibrate" myself and my various cameras to match incident meter readings.

There are times though that I kick myself for leaving the incident meter at home.

Last night I was out working at about midnight and wanted to take a shot of the scene lit by my headlights, it would have been much easier to set exposure with the incident meter.

 

[Chan Tran]

updated! I made the measurement yesterday at around 2:00 PM and pointing the dome directly at the sun gave me 15.0. Pointing it horizontally like making an incident reading for an object it read 14.7.

 

[Craig]

At 4 minutes past solar noon, incident meter pointing directly at the sun I get EV14. Latitude 51N, long 114W.

 

[Sirius Glass]

At 4 minutes past solar noon, incident meter pointing directly at the sun I get EV14. Latitude 51N, long 114W.

EV is also dependent on the ISO film setting and the design ISO. For example the Pentax Digital Spot Meter is designed assuming ISO as the basis and then the film ISO is set for the measurement. One takes the f/stop and shutter speed, then the EVs are adjusted fir filters on the camera, not the light meter. So without the design ISO and the film ISO setting, EV14 means nothing related to anything.

 

[SchwinnParamount]

8 year old post revived. Cool. Ralph is still around but is he still interested in this post?

 

[Craig]

8 year old post revived. Cool. Ralph is still around but is he still interested in this post?

Normally, I wouldn't "tomb raid" a thread from the dead, but it was referenced this morning in a different thread, so I thought I'd add another data point just for the heck of it.

 

[Sirius Glass]

 

[markjwyatt]

Chino Hills, CA (southern California, inland). Was cloudy yesterday, looks clear at this time.
34 N
1 PM, 2022JAN30

Luna Pro SBC 14.5
Luna Pro (my original ) 14 (EDIT: checked and zero set was good as was battery level).
Luna Pro (recent acquisition) 16* (EDIT- checked zero, it is off. Adjust, but no more working Wein cells...)

*I do not trust my recently acquired Luna Pro at this point... Need to see if I can adjust.

 

[awty]

Do I win?

I can get 17 if I spot new concrete.
From sunny f22 land.

 

[Deleted member 88956]

At best sun would have stable light power for maybe 2 hours and around its upper transit. It will change significantly with latitude AND time of year, and of course time of day. The hours after rise and hours before set its light is not only variable but has color cast.

The only stability is at the source not at earth’s end. These are reasons why sunny 16 works when it does and doesn’t when it doesn’t.

 

[wiltw]

I just stumbled across this old thread, and recalled that I took a series of readings on multiple 'Sunny 16' opportunities around Latitude 38
The readings show the INstability of Sunny 16!
https://www.photrio.com/forum/threa...g-color-print-film.184916/page-4#post-2442189

 

[markjwyatt]

Do I win?
View attachment 297119

I can get 17 if I spot new concrete.
From sunny f22 land.

Nope. This game is for incident readings. I got eV 16 in one case (but do not trust it...).

 

[Craig]

Luna Pro (recent acquisition) 16* (EDIT- checked zero, it is off. Adjust, but no more working Wein cells...)

Look on Ebay for a PX625or RC-53 battery. They are Russian made mercury cells and work perfectly in the older Gossen meters that need the1.35 voltage batteries. Work well in old Canon F-1's as well. Seller's name is Elkhartsix in St Petersburg, Russia.

 

[Deleted member 88956]

Look on Ebay for a PX625or RC-53 battery. They are Russian made mercury cells and work perfectly in the older Gossen meters that need the1.35 voltage batteries. Work well in old Canon F-1's as well. Seller's name is Elkhartsix in St Petersburg, Russia.

Why bother? Voltage reducing adapter is one time purchase, some 20 bucks, then off one goes to silver oxides.