Existing Light Exposure Metering

[denniskee]

Found a good web site explaining the title :thumbsup: , consisting of 7pages (scroll to bottom for the pointer)

http://daystarvisions.com/Docs/Tuts/Meter/pg1.html

Hope this can help newbies to understand this subject . Happy reading .

 

[Tachi]

Hi Dennis, thanks for the article. I have another useful article to share, its talking about Exposure Value (EV), to the old timers, its like bread & butter, but in the era of digital photography, I'm not sure though:

http://www.fredparker.com/ultexp1.htm

Regards
Tachi..

 

[student]

Hi Dennis, thanks for the article. I have another useful article to share, its talking about Exposure Value (EV), to the old timers, its like bread & butter, but in the era of <a style='text-decoration: none; border-bottom: 3px double;' href="http://www.serverlogic3.com/lm/rtl3.asp?si=22&k=digital%20photography" onmouseover="window.status='digital photography'; return true;" onmouseout="window.status=''; return true;">digital photography</a>, I'm not sure though:

http://www.fredparker.com/ultexp1.htm

Regards
Tachi..

I had read this article before, His assertion that lightmeter can "lie" is plainly nonsensical!

A meter is only calibrated to meter the amount of light falling on a subject or reflected from it.

If one uses a light meter, and the results are bad, it is not that the meter lied to you. It is because the user is too dumb to understand what the metering means.

Machine don't lie. Humans do. Such as this assertion written by Fred Parker.

 

[reachme2003]

it may mean that the user does not understand the meter's strengths or its shortcomings. a meter, being a calibrated instrument, does not 'lie' as it does not have the ability to 'lie'.

I had read this article before, His assertion that lightmeter can "lie" is plainly nonsensical!

A meter is only calibrated to meter the amount of light falling on a subject or reflected from it.

If one uses a light meter, and the results are bad, it is not that the meter lied to you. It is because the user is too dumb to understand what the metering means.

Machine don't lie. Humans do. Such as this assertion written by Fred Parker.

 

[denniskee]

I had read this article before, His assertion that lightmeter can "lie" is plainly nonsensical!

A meter is only calibrated to meter the amount of light falling on a subject or reflected from it.

If one uses a light meter, and the results are bad, it is not that the meter lied to you. It is because the user is too dumb to understand what the metering means.

Machine don't lie. Humans do. Such as this assertion written by Fred Parker.

yup, it the user alright, just look at how most photog hold the grey card while taking EV.

as with any eqpt, operating it without understanding it concept and function will lead to error. sad to say, most do not even read the user manual for their camera.

than again, it may be due to user's lousy english (like myself) that they dont read it. it is much easier for them to discuss with fellow photog to master their gear.

 

[denniskee]

Hi Dennis, thanks for the article. I have another useful article to share, its talking about Exposure Value (EV), to the old timers, its like bread & butter, but in the era of digital photography, I'm not sure though:

http://www.fredparker.com/ultexp1.htm

Regards
Tachi..

i knew this site through a fellow CSer last year. however, after using it, i find the ev for natural lighting are slightly off, my guess is it may be due to position of singapore and the auther's country.

the artificial lighting ev is quite similar though.

it quite a lengthy assay, but basically, for the benefit of those who might have difficulty in understanding, I will try to simplify it :

1) Exposure Value Chart,
the right column describe the type of lighting condition.
the left column is the exposure value of the respective lighting condition.

2) look @ the right column, select one that best describe your lighting condition.
eg, shooting in open area in the afternoon, hush lighting.
so you select "Subjects in bright or hazy sun (Sunny f/16 rule)."

3) look to the left (same row) for its exposure value.
in this case, it ev is 15.

4) Exposure Factor Relationship Chart B
column 2-9, row 2 states the sensitivity of the sensor medium (negative, positive, ccd, cmos) interm of ISO/ASA number. below the respective column states the EV value.
(notice EV1 for ISO50 is 1 row below the EV1 for ISO25 but 1 row above the EV1 for ISO100? try to figure out yourself.)

column 11-20, row 2 states the aperture value in step of 1stop increament. below them are the shutter speed, also in step of 1stop increament.

5.1) for the example i give, assuming I use a ISO100 medium, look at column 4, look down untill you see EV15 (row19).

5.2) look to the right, you have, stated in this chart, 10 possible combination of aperture & shutter speed.
if i want very shallow depth of view, i will use big aperture, say f2.8. ie column 13. go down untill you hit row19, i will shutter speed 1/4000sec.
if i want great depth, i will use f8, ie column 16, go down untill you hit row19, shutter speed of 1/500sec is to be use.

6.1) If i am using ISO50 medium, look at column 3, go down untill you find EV15 (row18).

6.2) look to the right, again, you have 10 possible combination of aperture & shutter speed.
if i use f4, look at column 14, go down untill you hit the row18, i am to use shutter speed 1/1000sec.
if i use f16, look at column 18, go down untill you hit row18, shutter speed to use is 1/60sec.

hope a/m can help those who dont want / cant understand the lengthy write up.