Accurate Timing of Long Exposures

[richard_weber]

When shooting in low light conditions with slow film at small apertures, exposure times can easily exceed one second in many cases. Does anyone know of an effective method for accurately timing exposures that exceed one second? I am using Copal #0 and #1 shutters with a cable release. I have tried counting "one-thousand and one, one thousand and two..., etc) in my head while the shutter was open, which is not a very consistant methodology, as an error of 1/4 second on a two second exposure is significant. I've also tried cocking and firing the shutter twice at one second exposures each, but that introduces the possibility of moving the camera between exposures. Any ideas?

[david_munson]

I just time my long exposures with my wristwatch, a Timex of the

digital variety. With shorter exposures, I'll just watch the seconds

count off until the proper exposure has been reached and hit the

shutter release a 2nd time (shutter speed set on T). For <i>long</i>

exposures, generally anything exceeding 30 seconds or so, I'll just

use the stopwatch function on my watch so I don't have to remember

when I started counting. In low light when it's hard to see the face

of the watch, just hit the little Indiglo button. I'm sure there are

other ways of timing long exposures, but this has worked well for me

as long as I've been doing photography.

[ken_burns1]

Richard, you might try counting elephants. "One elephant, two

elephants, three elephants," etc. If you are shooting neg film and

are worried about inconsistencies, just make sure your error is on

the overexposure side. A 1/4 second error on the overexposure side

of 2 secs is negligible. Like has already been mentioned, a wrist

watch is a good tool to use especially if yours has a timer that

beeps. Some meters have a timing device function. My Sekonic 518

does. If exposures get really long, exposure accuracies become less

important. If an exposure is, say, several minutes long, a 15 second

error won't be all that bad. When I am working in the studio, I

often have to make exposures of 15 to 30 minutes. I always bracket

by making two exposures, one is twice the time of the other. With

exposures that long, it can be difficult to tell the difference

between the 15 minute neg and the 30 min neg.

[david_goldfarb]

Try using a metronome (an electronic one that doesn't have to rest on

a level surface). Set it to 120 and subdivide each beat into two or

four. Figure out how many half seconds the exposure should be, and

once you've got the rhythm, press the release. Musicians do this all

the time and manage to be quite precise (on the order of thousandths

of a second).

[sean_yates]

When I shooting chromes in the last studio I worked for, exposures

run 30 seconds plus on a regular basis. We used quartz digital and

mechanical stop watches purchased at the local hardware store, etc.

[richard_weber]

I suppose I should have also mentioned in my original posting that I

am shooting large format landscapes, so metronomes and the like are a

little impractical. The timing issue is generally most critical with

exposures between 2-5 seconds, where the "human factor" of inaccuracy

is most significant. I suppose without having some widget that would

depress the cable release for a pre-set time (yippee! another widget

to drag along with me!), the "human factor" will be unavoidable.

[geoffrey_chen]

Richard,

 

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Prontor makes an interesting gizzmo which has a timer (2-32 sec)

attached to a cable release. Linhof sells it for about $625, but you

can find a used one for about $25. It should help you with your long

timing exposure. Cheers,

[david_clark4]

Hi Richard, if you are shooting B&W I don't think it has to be all

that accurate. In the past shooting at night and at dusk or dawn, If I

metered a couple of secs, I'd think, OK somewhere between 2 and 4 sec,

maybe shoot one around 2 1/2 to 3 1/2. It might be more critical the

amount you cut back on your development so you don't block out

details. Seems in the 2-5 bracket half sec more or less didn't seem to

me to make much difference, but then again maybe I'm wrong. I don't

think I'd opt for the two exposure method, I'd be worried about

something moving. Best, David

[steve_baggett]

Radio shack makes a small (2in x 2in) countdown timer for about $15

that is very accurate (quartz timer). I use one and set it to 2-??

seconds and hit the start at the same time I open the shutter. It

beeps when it hits zero and I close the shutter immediately. If it

is light enough to see the face of the LCD, I can be "prepared" when

zero is near. If it is so dark that I can't see the LCD, the

expopsure times are usually >30 seconds and it doesn't matter if I'm

a 1/2 second slow on the close, anyway. It has a little clamp that

allows me to clamp it to my shirt or jacket. Especially useful for

long (>10 second) exposures but still useful for 2-10 second ones.

[david_goldfarb]

I shoot large format landscapes and don't find a metronome

impractical. Have you seen a modern quartz metronome lately? They

are quite small and compact. Not one of those big Seth Thomas

spring-wound metronomes (the kind Ansel used in the darkroom to time

dodging and burning exposures, incidentally) with the baton waving

back and forth or the old Franz electric with the faceted light on top

that you need to plug in. You can find an accurate, sufficiently

loud, battery operated metronome that weighs about an ounce or two and

fits in your shirt pocket for less than $30.

[wayne__]

Sheesh, it aint rocket science, its amazing how complicated some

people can make it. Just do what Steve there sez, get an el cheapo

timer and wing it. I use a stopwatch that I stole from my psychotic

high school football coach after he tackled me and a friend from

behind in the hallway because we were making fun of him.

 

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Ooops, guess that cats out of the bag 23 years later. But its taken a

lickin and keeps on tickin.

[philip_y._graham]

With a Calumet electronic shutter tester I find that all my large

format shutters are rarely closer than 1/6 stop to the indicated

shutter speed (and these are all on new and well looked after lenses).

 

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According to Calumet this means that at an indicated speed of 1

second the actual shutter speed can range from 0.89-1.12 seconds.

This is about a 12% error.

 

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I�ve also tested how accurate the shutter speed is on the B setting

using my wristwatch second hand as the timer at 2, 4 and 8 seconds. I

found that there was always less than a 10% error. I was never even

close to a 1/4 second error on a 2 second exposure timed with my

wristwatch. I doubt if there�s any point in being more accurate.

[george_nedleman]

The electronic metronome is a great idea. The one I use in the

darkroom for test strips,dodging/burning is a little larger than a

watch and costs about 20 $US. It makes a very distinct beep.

George

[jnorman1]

i like the old eugene smith exposure method - you lick your finger

and hold it up in the air to see which way the exposure is coming

from, and then you expose the film untils it feels right. i have

always been paranoid about reciprocity failure (after being reminded

of it 50,000 times by my mentor long ago), and have consequently

always given wildly too long exposures in compensation. i have never

managed to overexpose a negative that way. i shoot lots of interiors

of old unlit warehouses and commercial bldgs, inside hwy tunnels,

powerhouses, etc. if my meter says 4 secs, i will do one at 8secs

and one at 16 secs - i can usually hardly tell the difference between

the negs, and either neg will be quite printabble. when my meter

says 1 minute, i just open the shutter and wander around for a

while. my experience has shown that this method works flawlessly.

obviously there is a lot of latitude in exposures of this length.

[armin_seeholzer]

Hi Richard

 

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I learned in the swiss army ( the only thing I learned ) count seconds

like thies: Twenty-one,twenty-two,twenty-tree etc. You can drill it

with a watch in the beginning to get the feeling how fast to count!

Otherwise I`m thinking much similar to jnorman`s posting!

[larry_huppert7]

I'll also cast my vote for the metronome. About a year ago I tested

myself with the calumet shutter timer, and compared the metronome vs.

a stopwatch. I was more accurate and consistent with the metronome.

I expect you anticipate better because you get a rhythm going before

you trip the shutter. Besides it's fun to play with! A number of

the portable electronic units have an earphone jack in case you want

your timing to be private. For longer exposures I'll set mine at 30

beats/minute so you get a bleep every two seconds which makes

counting easier. Of course for exposures over 10 seconds the error

difference between the two isn't that significant.

[david_goldfarb]

"...I tested myself with the calumet shutter timer..."

 

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I wouldn't say that too loudly. We look strange enough as it is

hauling around these big cameras standing under the darkcloth and all.

[brian_ellis3]

I too use a metronome but set it so that it beeps once per second.

The kind of metronome I'm using (and I suspect others also are using)

is not the traditional old large woode thing that you used to see

sitting atop pianos. The one I use is digital, about a half inch or

less wide, and smaller than a pack of cigarettes. It easily fits in

your shirt pocket, can't weight more than a few ounces, and cost

about $10 at a music instrument store. I don't like to wear my watch

when photographing in many areas because of the theft problems - I

figure they might get my camera gear but at least they won't get my

watch if I leave it at home.

[robert_a._zeichner1]

Take a small lead fishing sinker, paint it white (for visibility) and

tie a string to it. At a distance of one meter from the sinker, mark

the string with some tape or dye. Tie the string around any available

tree branch leaving one meter between the sinker and the cinch point

and give it a swing. Start your count from the top of the swing and

note each time the sinker reaches that exact point in it's arc. Voila!

You've made a second timer that will fit in your camera bag or pocket

and needs no batteries, AND is ACCURATE!

[scott_walton1]

If your in doubt why not just shoot several sheets?!... or shooting at

less of an apeture so you can get the second exposure...

[richard_ross]

I too shoot landscapes in the wilderness. For most of my low light

shots I am dealing with tens of seconds to minutes. My digital wrist

watch is as accurate as needs be (plus the alarm is crucial to wake me

up in my tent at 4:30am!). The hard part is correcting the final

exposure time on the fly when the light is increasing at a stop per

minute. Fortunately, plus or minus ten seconds makes no practical

difference.

 

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For shorter exposures, 2-5 secs say, an analog watch with sweep second

hand is indispensible. I can usually avoid this touchy range, however,

by stopping down or opening up an extra stop.

[rob_tucher]

YEARS ago Popular Photography had an article on how to make a tiny

electronic metronome. It is a list of parts put together in a certain

configuration inside a tiny parts box that Radio Shack sells

(1/2"x3"x1-1/2") with an earplug plugged in. I made one. I put the

device in my shirt pocket or elsewhere, the plug in my ear, and turn

it on. It clicks every 1 second. I started and stopped exposures on

the count and it was very accurate. Unfortunately it got smashed and

I don't have the article anymore. But something like this might be

available, or you might find the article in an archive.

[chris_jordan3]

i've been doing exclusively night photography for years, frequently

exposing in the 2-3 hour range, and never shorter than about 4

minutes. i had my view camera for something like 3 years before i

finally used one of the shutter speeds on my shutter! unfortuantely i

frequently forget to bring a watch with me, and consequently end up

making wild guesses on exposures. once i had an exposure that required

18 minutes (including reciprocity failure) and i had forgotten my

watch so i just stood there and counted "one thousand one, one

thousand two..." for 18 minutes. just to be sure, i bracketed one at

40 minutes, which i didn't count-- just hung out for about 40 minutes

and clicked the shutter closed. and i gotback two transparencies,

both spot-on, that look like they're exposed about 1/4 of a stop

apart!

~cj

[sean_yates]

Anybody know how fast the sun moves? I'm assuming there's someway to

gigure out how much time has passed by the change in shadows, but of

course that'd be a function of time of year, lattitude, etc. and of

course you couldn't do it on a cloudy day or in Greenland in

winter,etc.............

[yong_ran_zhu]

I have bought a Prontor cable release made in Germany (Schneider

Optics) from Jeff at Badger Graphics (Tel. 920-766-9332). It is a

great tool for precise long exposure. It is expensive. However, if you

will use long exposure a lot for your photography, you will be very

happy to have it.