Copal 0 shutter accuracy

[Alan Klein]

I just bought a Schneider APO 150mm Symmar from Japan, supposedly "top mint" from Japan for $520. I just checked the shutter accuracy.

1 sec thru 1/30 is 1/3 of a stop slow (1/4 is between 1/3 and 1/2 stop slow)

1/60 is about 1/6 of a stop slow, 1/125 looks OK. I can't determine 1/250 and 1/500 exactly with my test equipment. But they do operate.

So my questions are: Is this normal for Copal 0 from 1996 in Schneider lenses or not.

If I keep it what do you suggest in how to use?

[Bob Salomon]

I just bought a Schneider APO 150mm Symmar from Japan, supposedly "top mint" from Japan for $520. I just checked the shutter accuracy.

1 sec thru 1/30 is 1/3 of a stop slow (1/4 is between 1/3 and 1/2 stop slow)

1/60 is about 1/6 of a stop slow, 1/125 looks OK. I can't determine 1/250 and 1/500 exactly with my test equipment. But they do operate.

So my questions are: Is this normal for Copal 0 from 1996 in Schneider lenses or not.

If I keep it what do you suggest in how to use?

Industry speck is +- 30% of the marked speed except for the highest speed which was an engineers dream

[Leszek Vogt]

I've talked with Carol that the higher speeds tend to under-perform, she assured me that this is a norm even if the shutter was totally redone. I've had over 1/2 dozen shutters CLA'd (at once) and all the higher speeds were slower....while the speeds below1/100 were either on the money or really close.

If you know the "delay" (1/6th of a stop can't be much of an issue) you can work with it, otherwise send it in for CLA - there is no guarantee that the times will be perfect. Anyhoo, that's what I've discovered in the process.

Les

[Alan Klein]

So first, did I get screwed on the "mint" sale or is this really to be expected?

Who CLA's these things? How much does it cost?

So how do you handle shoots, Do you adjust your light meter to match the shutter errors or do something else?

[Bernice Loui]

Some thoughts on shutter speed accuracy.

~Back in the day when color transparencies were the most common means of producing color images for mass printing, high quality strobe lighting was absolutely preferred over shutter timed exposure. High quality studio strobe units can be held to 1/10 f-stop with ease and consistency and color temperature can be controlled and CC filtered as needed to achieve neutral color balance with color transparency film.

~Shutter speed is not a significant factor when strobe light is used in a controlled studio setting. Shutter speed accuracy and consistency comes into play if "synco-sun" or mixed outdoor lighting with strobe is used for images to be produced.

~This is NOT easy to do or even close to achievable with sun light which it's color temperature changes depending on the time of day, location and much more. Add to this, errors-tolerances in shutter speeds make absolute consistent exposures to 1/10 f-stop quite difficult to impossible.

~Fact is ALL mechanical shutters have variations in their shutter speed cycle to cycle, over time, over aging, over temperature, over condition of the shutter. This is how electronic shutters came to be as this was an effort to reduce shutter speed variations and improve shutter accuracy, consistency and related shutter requirements.

~Using a single reliable-accurate mechanical shutter can help reduce variations in accuracy, shutter speed, and all that by the fact a single shutter is used for each lens chosen to make a given image. This is one of the reasons why using a know good Sinar shutter with barrel or Sinar DB lenses can reduce shutter speed errors.

~The most accurate shutter ever used was the Sinar Digital, highest speed is 1/500 and it is accurate at 1/500 second, will time down to many seconds with equal accuracy and reliability. It is also HUGE, heavy, $$$$, not really portable at all.

~Fact is, for the majority of outdoor photography that 30% error is not that significant. There is sufficient differences in actual film speed, light at the moment of shutter release, light transmission of a given lens and a long list of many other variables that puts that 30% tolerance of shutter speed into perspective.

~While color transparency film is the least tolerant to exposure errors, B&W film is significantly more tolerant to exposure errors. Do consider variations in processing, developers and more to print making. This is why gaining control over the entire print making process often makes the greatest difference in the finished print.

~Focusing on a single parameter like shutter accuracy, camera, film and... can produce neglect of all the other factors that will affect the finished print.


Suggest not worrying about this variation in shutter speed and focus far more on image making and image content.


Berince

[BrianShaw]

How did you test the shutter speed, and how do you know the test was accurate?

... and who/what isn’t a bit slower after 24 years???? Ha ha ha.

You’ll be fine; the shutter is fine.

[Alan Klein]

Thanks Bernice, I understand. But I have to start somewhere. Large format photography is all knew to me I'm planning on shooting Tmax 100 BW and Velvia 50 chromes. When I shoot these in medium format, I meter for box speed and bracket +1 and -1 on my landscapes. (A pro lab processes). Now with LF 4x5, I'm not going to bracket like that, at least I didn't plan on it.

So what do you and others feel I should start with for these film and lens "in-accuracy" situation? SHould I just dial in 1/3 more on the meter's ISO setting from box speed? Ignore the errors?

[Alan Klein]

How did you test the shutter speed, and how do you know the test was accurate?

... and who/what isn’t a bit slower after 24 years???? Ha ha ha.

You’ll be fine; the shutter is fine.

I recorded the sound of the shutter and then analyzed in with an app. I'm pretty confident in my measurements because I did this before with electronic control 35mm camera and the accuracy was pretty much right on. When you get to higher speeds, the results are hard to analyze. But it's pretty easy to check at the lower speeds. Here's an example.

This is at 1/8 second which should be .125 seconds. It's actually at .103 second (see number at bottom of picture). That's about -1/3 stop shorter 1/10 instead of 1/8 of a second.

[dfort]

With those emulsions you’ll need stopwatch to time your exposures unless you’re shooting at wide apertures in full sunlight. Don’t worry about a slightly slow top speed.

I used to shoot Polaroids to check my exposure but I take it we don’t have that technology these days.


Sent from my iPhone using Tapatalk

[BrianShaw]

Ignore the errors... first make a picture and see if it matters.

[Bernice Loui]

What is the actual "speed" of the film being used? B&W film's actual "speed" or sensitivity to light will vary depending on a give batch-lot of film, developer used, needs of the print making process and more. Color transparency film is often very close to the speed noted on the box.

If you're just beginning LF, there are many other things and needs to be concerned about like loading film, setting up the camera, making sure the lens is stopped down to the needed aperture before exposure, setting the shutter speed, metering the scene to be imaged and ....

It takes LOTs of experience and wasted sheets of film before gaining the ability to get the image in mind in one sheet of film.

~Use the same techniques learned-gained from roll film and apply them in a more controlled fashion (avoid bracketing exposures) for LF and you should be OK.~

~Expect to waste LOTs of film initially. This IS part of the learning curve that is difficult to escape in the beginning.~

Being overly concerned about shutter speed accuracy (IMO, this Copal shutter is not a problem at all), lens performance and all that is not going to help one to progress up the learning curve. As with most learning, errors will be made, most important learning from the errors made is what matters most.


Bernice



Thanks Bernice, I understand. But I have to start somewhere. Large format photography is all knew to me I'm planning on shooting Tmax 100 BW and Velvia 50 chromes. When I shoot these in medium format, I meter for box speed and bracket +1 and -1 on my landscapes. (A pro lab processes). Now with LF 4x5, I'm not going to bracket like that, at least I didn't plan on it.

So what do you and others feel I should start with for these film and lens "in-accuracy" situation? SHould I just dial in 1/3 more on the meter's ISO setting from box speed? Ignore the errors?

[LabRat]

So you tested the shutter by sound? That's probably the problem...

A leaf shutter is like an opening and closing iris... It takes some time to the point where it is fully open, then the dwell time opened and some fraction of the time to close... This is called shutter efficiency... Shutters are calibrated for the time fully open, but some extra time happens between that open and shut...

For color professional work on chrome film, speeds can be critical but for color or B/W neg, not as critical, as these films have more latitude... (A 1/3 stop is not too much for general subjects...)

Film tests are in order, and hopefully your next shutter is in the same ballpark... A professional test is more precise...

Steve K

[Paul Ron]

So you tested the shutter by sound? That's probably the problem...

A leaf shutter is like an opening and closing iris... It takes some time to the point where it is fully open, then the dwell time opened and some fraction of the time to close... This is called shutter efficiency... Shutters are calibrated for the time fully open, but some extra time happens between that open and shut...

For color professional work on chrome film, speeds can be critical but for color or B/W neg, not as critical, as these films have more latitude... (A 1/3 stop is not too much for general subjects...)

Film tests are in order, and hopefully your next shutter is in the same ballpark... A professional test is more precise...

Steve K

+1

sound is not a measure of light entering the camera.

if you are using a diy gizmo that uses a microphone, just substitute a photo transistor in its place.

best is get a shutter tester. calumet had a nice one you can still find on ebay cheap.

[BrianShaw]

Industry speck is +- 30% of the marked speed except for the highest speed which was an engineers dream

... marketing persons dream.

... engineers requirement and design goal.

:)

[Alan Klein]

With those emulsions you’ll need stopwatch to time your exposures unless you’re shooting at wide apertures in full sunlight. Don’t worry about a slightly slow top speed.

I used to shoot Polaroids to check my exposure but I take it we don’t have that technology these days.


Sent from my iPhone using Tapatalk

With my medium format equipment, I often shot at 1/2 or 1 second. But I shoot mirror up on a heavy tripod and haven't noticed any shake. Hopefully, I'll have the same experience with 4x5.

[Alan Klein]

Ignore the errors... first make a picture and see if it matters.

Still waiting for the camera. FedEx has in in Tennessee. I'll probably bracket at first at least to get a feel with what's going on.

[dfort]

I'll probably bracket at first at least to get a feel with what's going on.

Bracketing is an advanced technique used by professional photographers working on assignments where it is critical to deliver a properly exposed shot and the client is paying the expenses.

Believe me--in school I had to learn the zone system, got my shutters and light meter checked for accuracy and ran countless tests with fellow students holding grey cards. I learned how to nail the exposure but once I was in the position where my reputation depended on it, I bracketed.

When shooting chromes (slide film, transparencies, etc.) and for whatever reason I couldn't bracket (fashion, portraits, action) I would have the lab develop a "test shot" and then push or pull the rest of the film. By the way, we also did this with 35mm and medium format by running a clip test, that's basically snipping off a piece of the roll and running it through the processor.

Back on topic, I had my shutter speeds checked by the legendary Marty Forscher of Professional Camera Repair and he gave me a list of the marked and actual shutter speeds. There was no way to get these mechanical devices running 100% accurate. So I had a friend who was handy with electronics build me a shutter speed checker and I made lists with the marked and actual shutter speeds for each lens. Now that we're in the age of the smartphone -- someone made an app for that. Check out THE PHOTOPLUG (https://www.filmomat.eu/photoplug).

And just for fun: Test Your Camera's Shutter Speed - Mr. Wizard's Challenge (https://youtu.be/hUGMTl-PJM0)

[Exploring Large Format]

Some thoughts on shutter speed accuracy.

~Back in the day when color transparencies were the most common means of producing color images for mass printing, high quality strobe lighting was absolutely preferred over shutter timed exposure. High quality studio strobe units can be held to 1/10 f-stop with ease and consistency and color temperature can be controlled and CC filtered as needed to achieve neutral color balance with color transparency film.

~Shutter speed is not a significant factor when strobe light is used in a controlled studio setting. Shutter speed accuracy and consistency comes into play if "synco-sun" or mixed outdoor lighting with strobe is used for images to be produced.

~This is NOT easy to do or even close to achievable with sun light which it's color temperature changes depending on the time of day, location and much more. Add to this, errors-tolerances in shutter speeds make absolute consistent exposures to 1/10 f-stop quite difficult to impossible.

~Fact is ALL mechanical shutters have variations in their shutter speed cycle to cycle, over time, over aging, over temperature, over condition of the shutter. This is how electronic shutters came to be as this was an effort to reduce shutter speed variations and improve shutter accuracy, consistency and related shutter requirements.

~Using a single reliable-accurate mechanical shutter can help reduce variations in accuracy, shutter speed, and all that by the fact a single shutter is used for each lens chosen to make a given image. This is one of the reasons why using a know good Sinar shutter with barrel or Sinar DB lenses can reduce shutter speed errors.

~The most accurate shutter ever used was the Sinar Digital, highest speed is 1/500 and it is accurate at 1/500 second, will time down to many seconds with equal accuracy and reliability. It is also HUGE, heavy, $$$$, not really portable at all.

~Fact is, for the majority of outdoor photography that 30% error is not that significant. There is sufficient differences in actual film speed, light at the moment of shutter release, light transmission of a given lens and a long list of many other variables that puts that 30% tolerance of shutter speed into perspective.

~While color transparency film is the least tolerant to exposure errors, B&W film is significantly more tolerant to exposure errors. Do consider variations in processing, developers and more to print making. This is why gaining control over the entire print making process often makes the greatest difference in the finished print.

~Focusing on a single parameter like shutter accuracy, camera, film and... can produce neglect of all the other factors that will affect the finished print.


Suggest not worrying about this variation in shutter speed and focus far more on image making and image content.


BerinceBernice, it is replies like this one that I just learn so much from. I too am just beginning ("wasting" sheets), and I have learned a great deal already from you experienced LF photographers. Really appreciate the patience with which so many of you explain, re-explain the basics. Also learning from fellow newbie questions. Thanks to all for such a generous community! Honestly can say that I'd not have taken the plunge into LF without this forum.

Sent from my SM-G955U using Tapatalk

[Sal Santamaura]

Every Copal shutter I have, from size 0 through 3, gets tested using a Calumet* shutter speed tester. This is repeated every few years to detect changes as the shutters age. Most of my lenses were purchased brand new, and all exhibited the kind of inaccuracies described by the OP. Newer ones are more precise (i.e. repeatable), but not more accurate.

I attach a small printed table to the lensboard of each lens indicating how much exposure compensation is needed at every speed where that shutter is not within 1/6 stop of accurate. For example:


1/500 -- close 2/3 stop
1/250 -- close 1/2 stop
1/125 -- close 1/4 stop
1/60 -- close 1/3 stop
1/2 -- open 1/3 stop

This is generated using MS Word in 8-point Arial Narrow bold, printed on a laser printer, cut out and affixed to the lens board using Scotch 810 Magic Tape. That particular tape can be removed without damaging lensboards when subsequent shutter recalibration requires replacing the table with a new one. After metering a scene and establishing a combination of aperture and shutter speed, simply adjust aperture by whatever amount the table indicates.

In my experience, this is the optimum way to deal with shutter speed inaccuracy. Attempting to adjust light meters every time a different shutter speed is used will inevitably lead to errors; it's too much to keep track of. With an extremely narrow latitude emulsion like Velvia 50, depending on subject brightness range, even 1/6-stop shutter speed errors might need exposure correction. If that proves to be the case, expanding the tables to include those speeds would be wise.




* The Calumet tester is long out of production. If one were in the market for such a device today, this one


https://www.phochronxa.com/

might be worth investigating. I have no experience with it.

[Doremus Scudder]

Alan,

Test your shutter speeds again, firing the shutter multiple times on each setting. If they are consistent (i.e., really close to the same every time), your shutter is just fine mechanically. No clockwork shutter is going to be 100% precise. the 30% margin of error for new shutters should tell you this.

Now, if the error for a given setting approaches a 1/3-stop difference, do what I do: Make a label with the actual speeds rounded to the nearest 1/3-stop and stick it to the lensboard. I mark my shutter speeds with a "+" and a "-" sign to indicate 1/3-stop faster and slower respectively, e.g., "1/15-" equals 1/3-stop slower than 1/15 (or 1/10 if you prefer). If you have a setting that's off by more, say your 1/125 is really just 1/3-stop faster than 1/60, then mark it "1/60+". Use these speeds to set your aperture against. Note that most meters and lenses have 1/3-stop increments marked; hence the use of 1/3-stop as a unit. Now you've got "accuracy" to 1/3 stop give or take a bit; well within exposure tolerances even for transparency films.

Best,

Doremus

[Drew Wiley]

I test all my shutters in advance with a Calumet electronic tester. This involves multiple readings for sake of predictability at any given speed, which is more important than nominal speed accuracy. Any slight deviation from the norm can be put on a lensboard label for sake of fussy applications like color chrome film. Every one of my Copal shutters of any size or vintage has been well within a third stop at every typically used speed, and generally even more accurate than that. But not a single one of those shutters, even brand new, was even remotely close to accurate at the very highest speed (typically 1/500th). I once had a Compur 3 which was spot on over the entire range, but disliked it for other reasons. Studio photographers were more concerned with flash speed synch, while people like me don't give a damn about the top speeds anyway, at least for view camera use.

[Alan Klein]

I test all my shutters in advance with a Calumet electronic tester. This involves multiple readings for sake of predictability at any given speed, which is more important than nominal speed accuracy. Any slight deviation from the norm can be put on a lensboard label for sake of fussy applications like color chrome film. Every one of my Copal shutters of any size or vintage has been well within a third stop at every typically used speed, and generally even more accurate than that. But not a single one of those shutters, even brand new, was even remotely close to accurate at the very highest speed (typically 1/500th). I once had a Compur 3 which was spot on over the entire range, but disliked it for other reasons. Studio photographers were more concerned with flash speed synch, while people like me don't give a damn about the top speeds anyway, at least for view camera use.

Drew, Who do you send them to to calibrate? Cost?

[Drew Wiley]

I bought my own testing machine, Alan. Perhaps there are still shutter testers around for sale used; but the instructions for different kinds of shutters must be carefully followed. Otherwise, a lens service like S.K.Grimes could no doubt do it.

[Doremus Scudder]

Drew makes a point that I neglected: The fastest speeds on clockwork shutters are never close, but it makes very little difference in practice since the fastest speeds are rarely, if ever, used. I don't think I've ever made a large-format photograph with natural light at a speed higher than 1/60th second. It's the slower speeds that need to be reasonably accurate.

Another consideration: when shutter speeds vary much from what they are marked, they are usually slower. That bit of extra exposure on negative film makes absolutely no difference in practice. You only really need to worry about being really precise when using transparency film. For that, testing actual speeds and making a label does the job superbly.

Best,

Doremus

[Bernice Loui]

Cannot remember needing or using the shutter speed of 1/120 second for the many, many thousands of 5x7 & 13x18cm & 4x5 & 6x9-6x7cm film images ever.

IMO, shutter speeds above 1/60 second for sheet film and larger format tool film is not an issue. The slower speeds below one second is more important.
If there is too much light to achieve the needed film exposure, add neutral density filter., which has also been as rare as needing shutter speeds of 1/120 second or higher.

For 35mm or Digital, 1/4000 or 1/8000 at times is not fast enough.


Bernice

[Chauncey Walden]

I suppose one more question would be just what to you plan to do with LF transparencies (other than look at it once and say "oh, neat") that wouldn't better be done with negative film?

[BrianShaw]

I suppose one more question would be just what to you plan to do with LF transparencies (other than look at it once and say "oh, neat") that wouldn't better be done with negative film?

That’s about it...

[Tin Can]

Same as any picture!

[Alan Klein]

Drew makes a point that I neglected: The fastest speeds on clockwork shutters are never close, but it makes very little difference in practice since the fastest speeds are rarely, if ever, used. I don't think I've ever made a large-format photograph with natural light at a speed higher than 1/60th second. It's the slower speeds that need to be reasonably accurate.

Another consideration: when shutter speeds vary much from what they are marked, they are usually slower. That bit of extra exposure on negative film makes absolutely no difference in practice. You only really need to worry about being really precise when using transparency film. For that, testing actual speeds and making a label does the job superbly.

Best,

Doremus

The shutter speeds up to 1/30th I checked were about 1/3 stop fast. For example, 1/8th setting was actually around 1/10th or -1/3 stop. So when I shoot Velvia 50 chromes, I may find that I'm underexposing. Many people already shoot chromes at 1/3 stop quicker so they don't blow the highlights. So it seems my lens shutter might be great for chromes. I'll bracket from box speed at least in the beginning, let's say +1/3 and -1/3, maybe +2/3 and -2/3. Then I can adjust for future shots.

With BW I may have to slow it down, which is what people do anyway. I'll bracket at +1 and -1 stops from box speed to see what I get.

[Alan Klein]

I suppose one more question would be just what to you plan to do with LF transparencies (other than look at it once and say "oh, neat") that wouldn't better be done with negative film?

I scan my photos and I like transparencies better than negatives. I know exactly what I got exposure wise by looking at the film, especially if I bracketed. Plus I've found Velvia chromes easier to scan than Ektar negative color and color correct in post processing. In any case, whichever I use, I plan to use digital printing which I believe comes from a scan. I'm not going to do chemical printing. Also, once scanned, I can make slide shows for UHDTV, and use on the web, in FLickr, and even here in the forums.

But I'm open to change.

[Bob Salomon]

Cannot remember needing or using the shutter speed of 1/120 second for the many, many thousands of 5x7 & 13x18cm & 4x5 & 6x9-6x7cm film images ever.

IMO, shutter speeds above 1/60 second for sheet film and larger format tool film is not an issue. The slower speeds below one second is more important.
If there is too much light to achieve the needed film exposure, add neutral density filter., which has also been as rare as needing shutter speeds of 1/120 second or higher.

For 35mm or Digital, 1/4000 or 1/8000 at times is not fast enough.


Bernice

Some photographers need higher shutter speeds to ratio ambient to flash or hot light to control how bright or dark the background is in relation to the foreground lighting. For example, portrait and event photography, architecture interiors, macro shooting. Or just to control motion in landscapes, water falls, tree movement in wind, etc.

[Bernice Loui]

Very much spot on Bob.

High shutter speeds are required to control the amount of ambient light relative to strobe for a given image. This is why leaf shutter Hasselblad and similar were FAR more popular with working wedding photographers and similar back in the day. It is also why the focal plane shutter Hasselblad were a lot less popular with these same working photographers.

Identical can be applied to a view camera, but not done as often. Another example of knowing the tools, their abilities, limitations then applying the tools and techniques as needed.


Bernice



Some photographers need higher shutter speeds to ratio ambient to flash or hot light to control how bright or dark the background is in relation to the foreground lighting. For example, portrait and event photography, architecture interiors, macro shooting. Or just to control motion in landscapes, water falls, tree movement in wind, etc.

[LabRat]

The high speed on faster leaf shutters is just a setting where the speed dial allows another heavy spring to additionally push the cocking mechanism to give it a boost to the normal mechanism, but crude to the rest of the system... No way to adjust it exactly...

Bob & Bernice are right, the best thing about a leaf shutter is X sync at all speeds... If you are shooting strobes and there is ambient from sun, room lights, modeling lights etc, you can measure and check the ambient light levels, and move up f stop/shutter speeds high enough to get strobe only exposure (hopefully), without ambient color casts or ghost images from the longer shutter exposure...

Steve K