Working with older shutter speeds shooting E6

[rjbrine]

I am thinking of buying a second hand lens with the older shutter speeds as they are so much cheaper. I shoot mostly on Provia 100F and wondered if I am being unrealistic to think that I can achieve the necessary accurate exposure required for E6 when the light meter is displaying modern speeds.

Any advice / experiences on this matter would be gratefully received.

Thanks.

[Gordon Moat]

I have been doing this with some very old cameras. My first suggestion is to try some colour negative film, and then inspect the film to see if you are way off, or sort of close. Usually the fastest speeds are more off than the slower speeds, though sometimes 1 second can be quite a bit slower than that.

Another thing is to use your computer mic to record the shutter sound into audio software. Then view the wave shape for each shutter click, and you can measure the actual passage of time at each shutter speed. You should find at least a few of the speed settings within less than 1/3 stop off optimum marked speed. As long as you can be within 1/3 stop, then you are fine with E6 films, but then you need to stick to those few accurate shutter speed settings. If it is off more than that, then you need to remark your shutter to avoid mistakes, or ideally have it serviced.

Ciao!

Gordon Moat Photography (http://www.gordonmoat.com)

[Dan Fromm]

rj, are you worried that your new old lens' shutter is off speed or that you don't know how to reason from, say, f/16 at 1/30 to f/? at 1/25?

Gordon addressed the former. If you're going to test, use color reversal film. It is much more sensitive to exposure errors than the negative film that Gordon suggested. And if you want certainty, buy the shutter a CLA (for clean, lube, and adjust). There's a law of nature to the effect that all old shutters are off.

About the latter, think a little. At, say, 1/30, the shutter is effectively open for 33 ms. At 1/25, 40 ms. At 1/15, 66 ms. 40/33 = 1.21, so if the meter says f/30 @ 1/16 is it, then at 1/25, very roughly you want an aperture that's 20% smaller than f/16. That's around mid-way between f/16 and f/22.

If you find thinking hard, get a dead Weston Master V and use its calculator dial.

[Gordon Moat]

I think Dan might have meant transparency film. You could do a test with that, especially if you have a rollfilm holder (to keep costs down and simplify the test). Basically assume the aperture is precise, then devise an evenly lit test that you then repeat for each shutter speed, just changing the aperture to compensate for (assumed) proper exposure.

However, the reason I did not suggest that is due to the higher per frame cost of 4x5 transparency film. It would be an expensive test to figure out the accuracy of an old shutter, while with negative film you could at least see if it was close enough to be useful. Far cheaper is the sound test, for which Dan has nicely provided some numbers.

Ciao!

Gordon Moat Photography (http://www.gordonmoat.com)

[BrianShaw]

My experience has been that the difference between, say, f/16 at 1/30 to f/16 at 1/25 is negligable... even when shooting color transparency film.

[rjbrine]

Thank you all for your advice.

I think working with older speeds will be fine after a little experimentation. Very inventive suggestion to record the sounds. Following the advice I will do some test sheets for comparison in the region I normally work (1/8th - 1/30th) for piece of mind. My gut feeling is that there will not be a huge amount of difference between 1/8 and 1/10 for example but I don't want any disasters on a commercial shoot. In theory if I am careful with my metering then it should be a slight push or pull in the lab.

If I can find myself a bargain on Ebay it is probably worth learning how to work with both sets of shutter speeds. I now wish I hadn't given away my Weston V thinking I would never use it....

Thanks again for your contributions.

[C. D. Keth]

I subscribe to the nudge method. Since 1/25 is slightly more light than 1/30th, I stop down a nudge.

Photography is not an exact science. Hell, it isn't a science at all.

[BrianShaw]

Photography is not an exact science. Heck, it isn't a science at all.

Oh thank goodness! I almost asked "how much is a nudge" and "what unit of measurement is that in"?

[C. D. Keth]

Oh thank goodness! I almost asked "how much is a nudge" and "what unit of measurement is that in"?

It's more than a smidge and less than a tidbit.

[AFSmithphoto]

Are we talking METRIC nudges and smidges or US Standard? I prefer skoshes, they are standardized across all measuring systems.

[Ivan J. Eberle]

Can't vouch for using an actual microphone to time my shutter, but after reading numerous web how-to's on making an shutter tester using a phototransistor connected to the the microphone port of a computer sound card (then recording & reading out shutter speeds with a freeware sound editor like Audacity), I spent all of an afternoon and less than $20 to build one.

The difference of the old-increment shutter speeds versus new is a mere squidget compared to the nearly a whole stop sluggishness I was seeing at speeds longer than 1/25, until I gave the old Rapax shutter several Ronsonol soaks and a re-lube. At the speeds care about, it's now within 1/6 of a stop, consistently.

Easily earned back the cost of the tester in 4x5 film savings with the first round of testing.

[Ivan J. Eberle]

Might also mention that the increments on old shutters actually make more sense if shooting modern transparency film. Most films these days come in ISOs that are divisible by 50, not 30. (Exceptions would be what--Ektachrome 64T? They still making that?)

"Sunny 16" rule states that the reciprocal of the film speed at f/16 in typical bright sun will yield the correct exposure... e.g. 1/50 @f/16 for Velvia 50. But shooting 1/60 would be a 1/5 stop underexposure with Velvia rated at a straight 50. Back in the day when it first came out, original Velvia 50 was most often recommended to be rated at an ISO of 40 (not pulled but processed normally), so 1/60 at a f/16 would really represent a 1/2 stop underexposure from that, which proves significant.

(And here's where slightly slow shutter might be an advantage.)

Of course, this is just an example; we all know by now that Velvia 50 sucks at high noon but Sunny 16 +1 stop is Thin Clouds 16 +1 stop is P. Cloudy 16-- you get the idea.

[Jeff Dyck]

Keep in mind that you can set the aperture of a large format lens to anything you want. There is nothing stopping you from adjusting your aperture by a fraction of a stop to compensate for the difference between a shutter's discrete speeds and those given by your meter.

My bigger concern with an old shutter would be the accuracy of the shutter speeds themselves (i.e. when the dial says 1/10sec is that really how long the shutter is staying open?). I purchased a relatively inexpensive shutter testing unit from Calumet some years ago and have never once regretted that purchase. These testers pop-up for sale regularly or you can do like Ivan and build your own (if you google "shutter tester" there are instructions available online). I am often amazed at the inaccuracy of modern shutters. I've tested all my shutters and taped a strip with the measured shutter speeds to the lens boards of some of the worst offenders - I make adjustments to the aperture as required based on these actual speeds when I am setting up for a shot.

[Jim Graves]

The photo-transistor shutter tester is also sold by a guy on ebay in the $40 range. I bought one and tested it on two shutters that I had just had professionally timed. The slower shutter speeds (up to about 1/100) tested very accurately. Above 1/125, the homebuilt got increasingly divergent from the professional times ... at 1/500 it was way off. So, I trust it only on the lower speeds ... I still test the higher speeds with it and kind of interpolate (i.e. guess) considering the variance of the slower speeds from their original number.

The tester just plugs into your mike jack on the sound card. It comes with instructions and the program on a CD (you can download it for free from the web also.) Turn on the computer program, turn on a light, hold the shutter up to the light, hold the tester behind the shutter and click. Works very easy.

One thing invaluable that I learned using it is how much the shutter speed increases after 10-15 dry fires. Now when I go into the field, I run off about 10 clicks before shooting my first shot of the session.

[Ole Tjugen]

My lighting conditions are rarely exactly on the EI point zero. So it doesn't matter what kind of shutter I use, with a little adjustment of the aperture i can always make it match (especially if I know the real shutter speeds as opposed to thenominal speeds.

One of my folding plate cameras has a three-speed shutter (1/10, 1/25, 1/75). even with that it's easy to get correct exposures!

[Steve M Hostetter]

Are we talking METRIC nudges and smidges or US Standard? I prefer skoshes, they are standardized across all measuring systems.

Well, us folks in the construction business use terms that transend any internation measuring standard but the women folk here might be a bit offended:eek:

[john borrelli]

How about using Velvia 50 and a higher fstop.

Most of the time (with the 50's reciprocity issues) you will be using the bulb setting and counting out the seconds on your own(assuming your shutter has a working bulb setting).

[Emmanuel BIGLER]

I have placed on the link below a bar-chart showing the correspondence between old-compur-style speeds and modern speeds, rounded to one-third of f-stop.

http://farm1.static.flickr.com/128/412475261_57e8f77071_b_d.jpg

The difference between an old engraving and the nearest modern standard value never exceeds 1/3 f-stop.