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How to read the camera back EV table of the Rolleiflex 3.5E
hi,
the talbe is below, 1 2 3 4 5 6 7 8 ------------------------------------ f/22 250 125 60 30 15 8 4 2 f/16 125 60 30 15 8 4 2 1 f/11 60 30 15 8 4 2 1 f/8 30 15 8 4 2 1 f/5.6 15 8 4 2 1 f/4 8 4 2 1 f/3.5 6 3 1.5 f/2.8 4 2 1 i've not managed to find a way to read the table, it looks so confusing to me. - woody |
#2
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How to read the camera back EV table of the Rolleiflex 3.5E
Steven Woody wrote:
hi, the talbe is below, 1 2 3 4 5 6 7 8 ------------------------------------ f/22 250 125 60 30 15 8 4 2 f/16 125 60 30 15 8 4 2 1 f/11 60 30 15 8 4 2 1 f/8 30 15 8 4 2 1 f/5.6 15 8 4 2 1 f/4 8 4 2 1 f/3.5 6 3 1.5 f/2.8 4 2 1 i've not managed to find a way to read the table, it looks so confusing to me. What's so confusing? The top row lists EV values, the column under each gives the shutter/f-stop combinations for that EV value. -- dadiOH ____________________________ dadiOH's dandies v3.06... ....a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at http://mysite.verizon.net/xico |
#3
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How to read the camera back EV table of the Rolleiflex 3.5E
dadiOH wrote: Steven Woody wrote: hi, the talbe is below, 1 2 3 4 5 6 7 8 ------------------------------------ f/22 250 125 60 30 15 8 4 2 f/16 125 60 30 15 8 4 2 1 f/11 60 30 15 8 4 2 1 f/8 30 15 8 4 2 1 f/5.6 15 8 4 2 1 f/4 8 4 2 1 f/3.5 6 3 1.5 f/2.8 4 2 1 i've not managed to find a way to read the table, it looks so confusing to me. What's so confusing? The top row lists EV values, the column under each gives the shutter/f-stop combinations for that EV value. that's just what make me confusing: i think every combinations in each column should have same EV, but it's not. for example, in column one (EV=1), ( f/22, 1/250s ) differs with ( f/16, 1/125s ) in the term of expusure value. |
#4
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How to read the camera back EV table of the Rolleiflex 3.5E
Steven Woody wrote:
that's just what make me confusing: i think every combinations in each column should have same EV, but it's not. for example, in column one (EV=1), ( f/22, 1/250s ) differs with ( f/16, 1/125s ) in the term of expusure value. The table on the back of the camera is for exposure times of one second or longer for exposure values 1 to 8. Exposure value 1 is 250 seconds at f/22 or 125 seconds at f/16 or a mere 8 seconds at f/4. Peter. -- |
#5
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How to read the camera back EV table of the Rolleiflex 3.5E
Peter Irwin wrote: Steven Woody wrote: that's just what make me confusing: i think every combinations in each column should have same EV, but it's not. for example, in column one (EV=1), ( f/22, 1/250s ) differs with ( f/16, 1/125s ) in the term of expusure value. The table on the back of the camera is for exposure times of one second or longer for exposure values 1 to 8. Exposure value 1 is 250 seconds at f/22 or 125 seconds at f/16 or a mere 8 seconds at f/4. Peter. -- oh! i understand, thank you. one more question: what's the Rollei's formula for EV calculation? i heard, (1s, f/1) = 1(EV), and, in the case, f/22 is 9 stop smaller compared to f/1, but 250s is 8 stop longer compared to 1s. there is one stop difference. any idea? |
#6
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How to read the camera back EV table of the Rolleiflex 3.5E
Steven Woody wrote:
oh! i understand, thank you. one more question: what's the Rollei's formula for EV calculation? i heard, (1s, f/1) = 1(EV), and, in the case, f/22 is 9 stop smaller compared to f/1, but 250s is 8 stop longer compared to 1s. there is one stop difference. any idea? 1 second at f/1 is EV0. The easiest way to figure EV is to think of it as being the sum of the aperture value (AV) and the time value (TV). Value Aperture Time ----- -------- ---- 0 f/1 1s 1 f/1.4 1/2s 2 f/2 1/4s 3 f/2.8 1/8s 4 f/4 1/15s 5 f/5.6 1/30s 6 f/8 1/60s 7 f/11 1/125s 8 f/16 1/250s 9 f/22 1/500s 10 f/32 1/1000s EV = AV + TV so: 1/125s at f/16 is 7+8 or EV15 1/1000s at f/5.6 is 10+5 also EV15 You could try googling: http://www.google.ca/search?hl=en&q=apex+system+exposure Peter. -- |
#7
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How to read the camera back EV table of the Rolleiflex 3.5E
Peter Irwin wrote:
Steven Woody wrote: that's just what make me confusing: i think every combinations in each column should have same EV, but it's not. for example, in column one (EV=1), ( f/22, 1/250s ) differs with ( f/16, 1/125s ) in the term of expusure value. The table on the back of the camera is for exposure times of one second or longer for exposure values 1 to 8. Exposure value 1 is 250 seconds at f/22 or 125 seconds at f/16 or a mere 8 seconds at f/4. Good luck in photography. -- dadiOH ____________________________ dadiOH's dandies v3.06... ....a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at http://mysite.verizon.net/xico |
#8
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How to read the camera back EV table of the Rolleiflex 3.5E
Steven Woody wrote:
dadiOH wrote: Steven Woody wrote: hi, the talbe is below, 1 2 3 4 5 6 7 8 ------------------------------------ f/22 250 125 60 30 15 8 4 2 f/16 125 60 30 15 8 4 2 1 f/11 60 30 15 8 4 2 1 f/8 30 15 8 4 2 1 f/5.6 15 8 4 2 1 f/4 8 4 2 1 f/3.5 6 3 1.5 f/2.8 4 2 1 i've not managed to find a way to read the table, it looks so confusing to me. What's so confusing? The top row lists EV values, the column under each gives the shutter/f-stop combinations for that EV value. that's just what make me confusing: i think every combinations in each column should have same EV, but it's not. for example, in column one (EV=1), ( f/22, 1/250s ) differs with ( f/16, 1/125s ) in the term of expusure value. I see what you are saying...been a long time since I used my Rolleis and they don't have that table anyway. Peter Irwin's second post gives you the straight scoop but the practicality of the system boggles my mind I assume you have the EV numbers on the shutter or aperture setting knobs and that they will lock so they synchronize. If so, I'd totally ignore the table and just set the shutter/aperture combo I wanted and then lock the knobs so that a change in one will change the other. Alternatively, if you have a meter that reads in EV values, set the aperture/shutter knobs to reflect the value, lock and then turn either knob to get the shutter speed or aperture you want. -- dadiOH ____________________________ dadiOH's dandies v3.06... ....a help file of info about MP3s, recording from LP/cassette and tips & tricks on this and that. Get it at http://mysite.verizon.net/xico |
#9
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How to read the camera back EV table of the Rolleiflex 3.5E
Steven Woody asked:
oh! i understand, thank you. one more question: what's the Rollei's formula for EV calculation? i heard, (1s, f/1) = 1(EV), and, in the case, f/22 is 9 stop smaller compared to f/1, but 250s is 8 stop longer compared to 1s. there is one stop difference. any idea? EV = log ( (f-number ^ 2) / shutterspeed) / log(2) "shutterspeed" is the actual duration of the exposure, i.e. 0.008 s for 1/125 s, etc. So for instance, 250 seconds, at f/22: EV = log( (22 ^ 2) / 250) / log(2) = log(484 / 250) / log(2) = 0.95 Why not 1? Because of nominal vs real issues. The true shutterspeed range consists of values that change by factor 2 each step. 250 seconds isn't part of that range. 256 seconds is. And the true f-number range consists of values that change by a factor sqr(2) each step. f/22 isn't part of that range. f/22.63 is. Use those real values, and the result is the one expected: "1". That is: it is very close, because 22.63 is a rounded value. 22.627417 is the correct one. ;-) Same, of course, with speeds shorter than 1 second. 1/125 in reality is 1/128 = 0.0078125 sec. So 1/250 sec at f/22: = 1/256 = 0.00390625 sec. at f/22.627417 EV = log( (22.627417 ^ 2) / 0.00390625) / log(2) = 17 |
#10
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How to read the camera back EV table of the Rolleiflex 3.5E
thanks for all your helps!
Q.G. de Bakker wrote: Steven Woody asked: oh! i understand, thank you. one more question: what's the Rollei's formula for EV calculation? i heard, (1s, f/1) = 1(EV), and, in the case, f/22 is 9 stop smaller compared to f/1, but 250s is 8 stop longer compared to 1s. there is one stop difference. any idea? EV = log ( (f-number ^ 2) / shutterspeed) / log(2) "shutterspeed" is the actual duration of the exposure, i.e. 0.008 s for 1/125 s, etc. So for instance, 250 seconds, at f/22: EV = log( (22 ^ 2) / 250) / log(2) = log(484 / 250) / log(2) = 0.95 Why not 1? Because of nominal vs real issues. The true shutterspeed range consists of values that change by factor 2 each step. 250 seconds isn't part of that range. 256 seconds is. And the true f-number range consists of values that change by a factor sqr(2) each step. f/22 isn't part of that range. f/22.63 is. Use those real values, and the result is the one expected: "1". That is: it is very close, because 22.63 is a rounded value. 22.627417 is the correct one. ;-) Same, of course, with speeds shorter than 1 second. 1/125 in reality is 1/128 = 0.0078125 sec. So 1/250 sec at f/22: = 1/256 = 0.00390625 sec. at f/22.627417 EV = log( (22.627417 ^ 2) / 0.00390625) / log(2) = 17 |
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