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j enea
3-Dec-2019, 11:21
Im new to 4x5, shooting MF for many years before. I have no issues with semi long exposures as some of my MF cameras allow for speeds up to 4 seconds, or worst case, I can use ap priority shooting and let the camera control the shutter.

for 4x5, all my lenses, and I assume most LF lenses, max out at 1 second. so suppose I meter the scene and decide that it needs 1.5 seconds, or 2 seconds, and say up to like 4 seconds. and I would prefer to keep the aperture the same, not opening up to allow a faster shutter speed. how do you take just longer than 1 second? I have taken 30 second exposure and used the T setting or B along with a stopwatch. at that length, being off by .1 second or so should not effect the exposure. but that difference could change the exposure of a 1.5 or 2 second exposure. you get what Im trying to say.

so how do you work in what I call the danger zone?

john

Two23
3-Dec-2019, 11:44
I shoot B&W and wet plate. I put shutter on B, open it, count the seconds, and close. I don't get very fancy.


Kent in SD

Arne Croell
3-Dec-2019, 11:48
Let me start with the following: the accepted error for f-stop, exposure time and film ISO is usually 1/3rd of a stop (for each). 0.1 or 0.2s at 1.5 s is significantly less than that. You might see it in slide film, otherwise it is probably not discernible. Also, unless you’re using Fuji Acros or T-Max 100, reciprocity failure will take you out of those times close to 1s very fast. I just use my wristwatch for timing 2s or more. In principle, if you have your shutter speeds calibrated, 1.5s could be done by adding 1s and 1/2s exposures.

Bob Salomon
3-Dec-2019, 11:49
You put the shutter on T press the shutter release and count 1 Mississippi, 2 Mississippi, 3 Mississippi and release the pressure on the cable release.
Or, I watch the second hand on my watch. Both are equally effective. Sometimes I just stamp my foot 3 times. A shutter speed is accurate if it is +/- 30% of the desired time. The longer your exposure is the greater the margin of error that 30% allows.

j enea
3-Dec-2019, 12:26
ok, sound like im thinking to hard about it. thanks!.

I like the idea of 2 exposures at 1 second and then 1/2 or another 1 second. never thought of that.

john

Doremus Scudder
3-Dec-2019, 12:40
You've got good responses so far, but I don't think they are addressing your real concern, which seems to be accuracy. So, indulge my rambling a bit:

First, just how accurate do you need to be? I think you are obsessing a bit about it. If you're shooting black-and-white or color negative film, you can safely overexpose up to a stop or more. So, say my meter says "f/22 at 1.4 seconds"? Heck, I'll just give it two seconds and be done with it. I can still make the best possible print from that negative compared to one made at 1.4 seconds.

Furthermore, the margin of acceptable error for shutters is 30% or so, as mentioned above. That's about a third of a stop. I find it easy to think in third-stop increments because that's what ISO numbers are in and how meter readouts are calibrated. Plus, most apertures are marked in third-stop increments. So...

At one second, that 30% margin of error is roughly 0.3 seconds or so one way or the other. A third of a second is not all that hard to estimate; musicians do it all the time. Triplets at 60 beats per minute (bpm) are really easy and exactly a third of a second each. I can accurately time to a third of a second just by counting triplets at a tempo of 60 bpm. Musicians are way more accurate, playing 32nd or 64th notes at the same tempo. I've got a built-in feeling for 60 bpm (one beat per second) since I'm a musician and I use a metronome for developing. You can easily develop that as well, or just get a metronome app for your smartphone and set it to 60 bpm. Then get triplets going in your mind (just think "blue-ber-ry, blue-ber-ry" at one berry per beat :) ). Need 1.66 seconds? Just start your exposure on the first "blue..." and end it on the second "-ry." EZPZ and really accurate; well within tolerances (probably closer than the shutter speeds!). You can use a similar technique for 2.5 seconds. Just get those seconds going and think "one-and-two-and..." The "and" is your half-second mark.

Alternately, you can stop down or open up a smidgen to get an even second number if you need to. Say my meter says f/22 at 1.6 seconds. I can just stop down a third of a stop more (most shutters have third-stop increments printed on them, so I'd set my pointer to the next little mark past f/22, which is f/25) and end up with a shutter speed of two seconds. That's an easy way to get a whole-stop shutter speed in your "danger zone" if you have difficulty counting thirds of a second. This is likely what you are already doing for intermediate shutter speeds between, say, 1/2 and 1 second.

For anything longer than about two seconds, you're going to be dealing with reciprocity failure and the inherent inaccuracy of determining the right compensation. Let's assume, however, that you have the perfect compensation table. For anything three seconds or longer, timing ceases to be an issue. If your meter gives you a reading longer than three seconds with a fraction of a second, you can just round up to the next whole second and be well within tolerances. So, for longer exposures, you'll be dealing with whole seconds, and there's no problem there, just watch your watch or count seconds or use the timer on your smartphone.

Just for fun, here's a list of slower shutter speeds in third-stop increments (whole stops are bold):

1 sec - 1.3 sec - 1.6 sec - 2 sec - 2.5 sec - 3.2 sec - 4 sec - 5 sec . 6.4 sec - 8 sec - 10 sec - 12.5" - 15 sec - 20 sec - 25 sec - 30 sec - 40 sec - 50 sec - 1 min. - 1' 15" - 1' 30" - 2 min. - 2' 30" - 3' 10" - 4 min. - 5 min. - 6' 20" - 8 min. - 10 min. - 12' 45" - 15 min. - 19 min. - 24 min. - 30 min. - 38 min. - 48 min. - 60 min.

Look familiar? Kind of like the ISO sequence? Yep.

Hope this helps,

Doremus

LabRat
3-Dec-2019, 12:55
You put the shutter on T press the shutter release and count 1 Mississippi, 2 Mississippi, 3 Mississippi and release the pressure on the cable release.
Or, I watch the second hand on my watch. Both are equally effective. Sometimes I just stamp my foot 3 times. A shutter speed is accurate if it is +/- 30% of the desired time. The longer your exposure is the greater the margin of error that 30% allows.

What Bob said,but I'll add that I will usually just open the shutter on T, take my old film box (that is lined with black felt, that I always carry in my kit) and is in front of the lens, wait for the camera to settle from vibrations for a few seconds, then move box out of the way and count out the time of exposure, then back and close shutter... Or use a black hat...

For timing, I count "one thousand and one, one thousand and two" etc to measure seconds... But another useful scale for shorter exposures (when using air bulb releases or Packard shutters) is by saying "half second" quickly takes a 1/2 second, saying "quarter" (note there are 2 syllables in the word) takes 1/4 of a second, and saying "eighth" takes 1/8 of a second, so you can use shorter open shutter exposures also...

Steve K

Bob Salomon
3-Dec-2019, 13:28
ok, sound like im thinking to hard about it. thanks!.

I like the idea of 2 exposures at 1 second and then 1/2 or another 1 second. never thought of that.

john

But to do that you have to touch and recock and fire the shutter each time, that is a great recipe for vibration.
Touch the camera and lens as infrequently as possible for an exposure.
Unless you are doing multiple pops in a studio with strobe.

Two23
3-Dec-2019, 13:39
But to do that you have to touch and recock and fire the shutter each time, that is a great recipe for vibration.
Touch the camera and lens as infrequently as possible for an exposure.
Unless you are doing multiple pops in a studio with strobe.

That's why I use B (bulb) and a cable release.


Kent in SD

Vaughn
3-Dec-2019, 14:55
ok, sound like im thinking to hard about it. thanks! I like the idea of 2 exposures at 1 second and then 1/2 or another 1 second. never thought of that. john
Most likely no more accurate than counting on "B". But you might consider closing down the lens another stop or two to increase the exposure time when the situation allows. Timing 5 seconds can easily be done accurately using your phone.

And Bob -- in the West, it is oneanseladams, twoanseladmas, threeanseladams...

I took a nap during this exposure:

goamules
4-Dec-2019, 06:06
I do 2-10 second exposures all the time with wetplate. I uncover and cover the barrel lens with a darkcloth, counting. No stop watch, not even a second hand wristwatch. But I can count seconds very accurately because of my former work as a signals analyst.

darr
4-Dec-2019, 07:19
I do as Bob suggests except I say “one and a two and a ...” to myself. Anyone that has studied a musical instrument can keep an accurate tempo. The metronome beat is embedded in my head. When I have to keep a lot of time, more than 10 secs, there is my wonderful phone with all kinds of photo apps installed. This is not hard and you’ll get use to it after a few good shots.

Nodda Duma
4-Dec-2019, 08:03
If my meter wants 1.5-3 seconds, it will often mean I’m not shooting wide open, and therefore not going for a narrow Depth of Field look. So... I will often stop down another stop so that the exposure time is longer, say 3+ seconds. I shoot bulb and count the seconds off. Lengthening the time reduces the counting error, making it a smaller percentage of total exposure with net result that exposure time is more accurate.

John Layton
4-Dec-2019, 11:20
I'll typically use the "B" setting for times between 1 and 15 seconds...and "T" for longer times. The trick with relatively short intervals (between 1 and 5 seconds) is to be decisive with the shutter control (cable release), and yet in a way which assures that no movement is transferred from the release to the camera. This is why I like using longish (20") cloth covered releases, further making sure that my release hand is close enough to the lens to avoid any sort of pulling of the release. I also try to take care that for longer exposures I can place the free end of the cable release in a way which does not allow for any kind of swinging movement during the exposure.

As for timing accuracy...I'll look at my watch for a few seconds prior to making an exposure, getting a good sense of cadence (of elapsed seconds) prior to making an exposure. If I'm doubting my capacity for accuracy...I may even do one or two "blank" exposures with the darkslide in place (also good for checking for cable-induced camera movement).

I also do exercises to help gauge timing accuracy - for the reason that I sometimes find myself ready for an exposure only to realize that I've forgotten my watch! So...when I find myself wide awake at 3am - I'll look across the room at my digital alarm clock...and start to count when the minute changes to see how close I can come to guessing an exact minute. Typically I'm within one second. I used to offer this exercise to students as a bonus question on exams - a given student sitting quietly across from me as I watched the seconds go by for a full minute. Two big mistakes...One - using the word "Mississippi" (or "alligator") - the result is (typically) too long! And two...starting a count with the number 1 - which entirely omits the interval between 0 and 1 second.

Yeah...I know - obsessive, right? And about those long mississippi's - they're actually useful in accommodating reciprocity failure...right? Perhaps, but the way I see it, the methodology for accommodating something like reciprocity failure, or depth of focus for that matter, should always be as precise as possible to help ensure meaningful, repeatable, and satisfactory results.

j enea
5-Dec-2019, 10:10
many thanks to all that replied. I think i have my game plan worked out. having been a pro drummer for years and recording in the studio with a click track, ill just get the 60 beats per minute thing going in my head and use that on bulb. no need to over think this.

thanks again

john

archphotofisher
5-Dec-2019, 10:11
I have a 30 sec face, stop watch, wind and go.

Drew Bedo
14-Dec-2019, 05:51
I shoot B&W and wet plate. I put shutter on B, open it, count the seconds, and close. I don't get very fancy.


Kent in SD

What he said . . .and I bracket some.

Tin Can
14-Dec-2019, 14:40
This Volute shutter runs perfectly at all speeds including 1,2 and 3 seconds.

https://www.largeformatphotography.info/forum/showthread.php?86525-Show-your-Beautiful-Volute-Shutters&p=1480411&viewfull=1#post1480411