stability of 'sunny 16'
-
A
- Thread starter RalphLambrecht
- Start date
Recent Classifieds
-
For Sale Super Ikonta 530 - PreWar.
- Started by Alex Varas
-
For Sale Mamiya RB67 pro SD 120 back (6x7)
- Started by Guivd
-
For Sale Caltar II-E 210mm (Rodenstock Geronar) - Copal 1
- Started by Guivd
-
For Sale Gitzo GS3310GS geared column (systematic serie 2,3,4)
- Started by Guivd
-
For Sale FS: Nagaoka 4x5 Wooden Field Camera
- Started by B.S.Kumar
Forum statistics
markjwyatt said:
Correct. We are saying the same thing. I said" sunny 16" at ISO 100 = 15; "sunny 16" at ISO 400 = 17. I may have mis-interpreted @reddessert as saying it is necassary to state f-stop and shutter speed to establish sunny 16, but I guess he is saying you "can" state f-stop and shutter speed (at ISO). @reddessert is also correct in saying that eV=15 is always f16 at 1/125 s.
Last edited:
My point is that EV = exposure value, only tells you a shutter speed and f-stop combination. In order to measure an amount of light, one must additionally say what ISO the EV was read at.
EV 15 is always f/16 and 1/125 sec (or any equivalent such as f/11 and 1/250 sec). Sunny 16 is EV=15 at ISO 100. Sunny 16 is also EV=17 at ISO 400. Playing around with a meter that has dials showing EV and light reading, such as a Gossen Luna-Pro, will establish this.
EV 15 is always f/16 and 1/125 sec (or any equivalent such as f/11 and 1/250 sec). Sunny 16 is EV=15 at ISO 100. Sunny 16 is also EV=17 at ISO 400. Playing around with a meter that has dials showing EV and light reading, such as a Gossen Luna-Pro, will establish this.
OP
OP
^ EV changes with ISO value under the same light
Using a Minolta Spotmeter F, I am sitting in my family room with constant source of artificial light, targeting a 18% gray card...
- With ISO 250, 1/250 the EV measurement is 6.2
- With ISO 500, 1/500 the EV measurement is 7.2
- With ISO 2000, 1/200 the EV measurement is 9.2
- With ISO 250, 1/250 the EV measurement is 6.8
- With ISO 500, 1/500 the EV measurement is 7.8
- With ISO 2000, 1/2000 the EV measurement is 9.8
the aperture-shutterspeed combination(EV) required for a correct exposure changes with ISO; the illuminance or luminance does not.
Exactly the point that I was making that EV alone does not provide any information. EV requires the ISO as well, just as f/stop, shutter speed and ISO.
It would be interesting to see a scene without snow. White on white scenes need an incident meter and are very misleading when a reflectance meter is used.
That was incident reading. The photo was from different app just to show how the EVs looked like around.
Still I would like to see that same thing done with a scene without snow.
I welcome you here, I can loan snow sleigh shovel (if that is the correct word). There is about 40cm of snow everywhere.
That is the correct word. However I do not have a way to reproduce what you did the same way that you did it.
Also you could sent the snow here since we are in a many year drought.
It seems that all too frequently you hear about a giant snow storm, and the story reports that they don't what to do with all the snow that is being removed. My thought on that: "Melt it and pipe it to the western part of the country. Use wind-generated electricity to power the pumps to get it there."
One man's problem is another man's need. We are currently in the worst drought period in 1200 years, one would think we would afford a bit of time and effort to fix two problems with one solution,
What app gives you this type of image read out?
OP
OP
thi could be oneREASON TO GET A SMART PHONE; otherwise I'll stick to my dumb phone and a meter.
That would be absolute honor (I designed and wrote that app).
The exposure meter uses:
and modern nomenclature:
So for the exposure meter to arrive at an EV for the meter's calculator it uses the LS/K equation and you need an ISO. Most, if not all, exposure meters use a fixed ISO 100 for the EV and then use the exposure calculator to work out the f/stop and shutter speeds based on the user's ISO setting. Most exposure meter manuals state this. For example, Pentax Digital Spotmeter:
Sounds like ANSI PH2.7 Photographic Exposure Guide. Mine is from 1986.
According to the 1966 version, which is from a revised 1955 version, the guide was originally issued as Z38.2.2 - 1942 and subsequently reissued in the same form in 1949. "The data presented here resulted from extensive research, portions of which, have been described in publications."
Jones, Loyd A. and Condit, H.R., Sunlight and Skylight as Determinants of Photographic Exposure. I. Luminous Density as Determined by by Solar Altitude and Atmospheric Conditions, JOSA, Vol. 38, Number 1, February 1948.
Jones, Loyd A. and Condit, H.R., Sunlight and Skylight as Determinants of Photographic Exposure, II. Scene Structure, Directional Index, Photographic Efficiency of Daylight, Safety Factors, and Evaluation of Camera Exposures. JOSA, Vol 39, Number 2, February 1949.
Ralph, I don't know what project you are working on, but it might be interesting to compare the data you obtain to the results from the standard.
Last edited:
OP
OP
You apparently did a great job and know what is needed by users of the Zone System.
... this, from a 1906 photography handbook, worked well for alt printing under sun once a baseline exposer was determined.
-
- Alan Edward Klein
- Deleted
- Reason: Off topic
So, I bought ZoneView and have been giving it some casual "testing". I even paid full price! For me it won't replace a meter for actually exposing film but it is a good instructional tool as it gives visual and lighting data in a very easy to visualize manner. Well worth the $5...
So nice to hear - and thanks for supporting the development!
I’ve just downloaded it. I’ve a feeling it is going to be very educational and fun at the same time. Nice.
I surely hope it is. You described the experiences well that I've had with the app.
| Photrio.com contains affiliate links to products. We may receive a commission for purchases made through these links. To read our full affiliate disclosure statement please click Here. |
PHOTRIO PARTNERS EQUALLY FUNDING OUR COMMUNITY:  |