Ranchu
Veteran
charjohncarter
Veteran
I never thought about that but it makes sense. Like you say 1 stop at 1/500th. That is a lot.
Chriscrawfordphoto
Real Men Shoot Film.
True. I've been burned by that issue a couple times when shooting transparency film.
Ansel Adams's book The Camera has a discussion about the effects on the image of focal plane or lens shutters, and it goes into some detail about the efficiency of different shutter types, particularly the lens shutter, at different speeds and apertures. It's worth a look as it sums up the issues involved accurately including some graphs and photographs, without being excessively technical. See Chapter 6.
On the one hand, the efficiency of a lens shutter due to the effects of the opening and closing sequences of the blades will decrease as the shutter speed increases and this will be exacerbated by small apertures. A focal plane shutter does not have this problem. On the other hand, a FP shutter is able to synchonise electronic flash at a more limited range of slower shutter speeds than most lens shutters, and may, in situations involving moving subjects, cause some distortion of the image on film (or digital sensor for that matter).
Depending on the type of photography being done, the sort of shutter used by a camera may be of no significance whatsoever (usually, in the case of general photography), or might be critical in certain scenarios. In any case it's good to be aware of the strengths and limitations of either type of shutter, in the event it's germane to what you want to photograph, and how you plan to do it.
Cheers,
Brett
On the one hand, the efficiency of a lens shutter due to the effects of the opening and closing sequences of the blades will decrease as the shutter speed increases and this will be exacerbated by small apertures. A focal plane shutter does not have this problem. On the other hand, a FP shutter is able to synchonise electronic flash at a more limited range of slower shutter speeds than most lens shutters, and may, in situations involving moving subjects, cause some distortion of the image on film (or digital sensor for that matter).
Depending on the type of photography being done, the sort of shutter used by a camera may be of no significance whatsoever (usually, in the case of general photography), or might be critical in certain scenarios. In any case it's good to be aware of the strengths and limitations of either type of shutter, in the event it's germane to what you want to photograph, and how you plan to do it.
Cheers,
Brett
Ranchu
Veteran
I seem to spend a fair amount of time at 250-500 with 400 in the camera- lmao edit: got confused. The last thing I want is a stop slopping around I don't know about!
Ranchu
Veteran
Also, I read somewhere "compur shutters generally run a stop slow on the highest speeds unless the lubrication is replaced with modern synthetic lubrication". So I don't know if that's two stops now, or the person made an error, and attributed the shutter efficiency loss to the lubrication. Leaning toward error.
Without actually getting the manual out as I recall, Deckel's own tolerance for the top speed was 20% anyway, and, I believe, less (10-15%?) for the slower speeds when new. These shutters are all well over forty years of age by now, some considerably older, so it's quite normal nowadays for one to benefit from cleaning and lubrication. Given this it doesn't necessarily mean they will achieve their rated top speeds plus or minus a few percentage points in light of the 20% allowance when new, but if a particular example is in need of servicing, this is obviously not going to improve its chances of being in the ballpark.
I think it's good not to overstate the importance of perfect speed times. These are quite old shutters, now. If one is running a bit slow, but is consistent, it's simply a matter of adjusting the aperture in use, if it's important enough to warrant (and often, if a negative film is being shot it won't be, in my experience). That said: if accuracy within a decimal place or so at high shutter speeds across a range of aperture settings is crucial to someone's imaging process, using a 50-odd year old mechanical shutter of any configuration is doing it the hard way, surely? A late model body with electronic shutter control is probably a better solution, if precise exposure times are really that critical, yes?
Cheers,
Brett
FujiLove
Well-known
Very interesting info. I'm wondering whether this affects all cameras with leaf shutters, or are some (more modern?) ones able to compensate by transmitting aperture information to the shutter? I'm thinking about Mamiya 7 etc. with auto exposure electronics.
Ranchu
Veteran
Absolute exposure accuracy would be fine with me. Failing that, the ability to expect a stop of inaccuracy instead of being surprised by it seems better to me.
Ranchu
Veteran
They'd be smart to do that. I was thinking about things like the Konica C35 where it's a programmed, closed sysyem. The manufacturer would be able to compensate for the inaccuracy because there's no manual mode..
Yes it's better to know, definitely. But in terms of absolute accuracy the problem, of course, it that it doesn't really exist, so what it really boils down to is how much accuracy manufacturers and consumers are prepared to pay for.
I really don't know much about the Mamiyas, but various cameras over the years have actually exploited the variable efficiency of lens shutters based on aperture selection, on the basis that a set of shutter blades can traverse a smaller aperture opening more rapidly than the time it takes them to expose a lens at full aperture, as long as they don't have to open fully.
For example, Minolta's interesting little V2 leaf shutter rangefinder offered a blistering top shutter speed of 1/2000 in about 1958, but only at apertures smaller than f/8, and could achieve 1/1000 at f/4 or smaller. All apertures from f/2 to f/22 could be used from 1/500 and longer times. It achieved this by not cycling the shutter blades from fully closed to fully open and back again at those two top speeds. Very clever, and just quietly I wouldn't mind a V2 one day.
If I'm not mistaken, didn't some digital Fuji models feature certain high shutter speeds only in combination with smaller lens openings not too many years ago?
Cheers,
Brett
retinax
Well-known
Very interesting! On digital cameras with electronic leaf shutters like the x100 or GR, this certainly appears to be compensated for, otherwise one could see a difference in exposure in aperture/shutter bracketing series. or are they physically too small for this this to matter much?
So if this effect is a thing, then the part of the exposure happening with half-open shutter must also have a effect on the look of the image when using a leaf shutter with wide apertures and short speeds. I'd expect there to be less blur, essentially the image is partly made with a smaller aperture. Has anyone noticed this, compared images from lenses available with lens shutter and for cameras with focal plane shutter, like the lenses for Hasselblad?
So if this effect is a thing, then the part of the exposure happening with half-open shutter must also have a effect on the look of the image when using a leaf shutter with wide apertures and short speeds. I'd expect there to be less blur, essentially the image is partly made with a smaller aperture. Has anyone noticed this, compared images from lenses available with lens shutter and for cameras with focal plane shutter, like the lenses for Hasselblad?
Rob-F
Likes Leicas
Funny, I have never noticed this with my Hasselblad lenses, even with Velvia. I usually shoot at 1/250 or or 1/125. I generally shoot between f/8 to f/16.
Maybe the Hasselblad shutters are compensated for this effect.
Maybe the Hasselblad shutters are compensated for this effect.
FujiLove
Well-known
Same here. I've recently shot a load of slide film with my Hasselblad 503CX with it's 80mm CF lens, and a Mamiya 6 with 75mm lens in fairly bright conditions using a handheld incident meter. All the images look perfectly exposed, with nothing obviously blown out.
BUT I shot one roll of slide film with my Rolleicord Vb last year while away on holiday, and a couple of the photos do look a touch overexposed. Both of them were taken in very bright conditions. I wonder if the relatively modern Hasselblad and Mamiya are compensating while the old Rollei isn't?
charjohncarter
Veteran
I had my Mamiya Super 23 101mm f3.5 serviced, and she said the 1/500 was really 1/400. I have been using this 1/400 number, but who knows is there is a difference as metering can change so much.
rumbliegeos
Well-known
Tables for shutter speed compensation for small apertures were provided in old Kodak shooting guides. There was a lot of good information in those guides.
Pioneer
Veteran
You're right. There is a huge amount of information in those old Kodak publications. They were put together and published for advanced amateurs who were moving up from the Brownie images.
Still quite valuable.
Dwig
Well-known
And it should be noted that this table applies to the more modern leaf shutters that have a 1/500th top speed.
On older and larger shutters that have lower top shutter speeds the table would be somewhat different. There, the speed "error" kicks in at lower speeds. As a rule of thumb, there's around a 1 stop "error" at any leaf shutter's highest speed when using apertures 4-5 stops smaller than the lens' maximum aperture.
Robert Lai
Well-known
This makes me feel better about my Kodak Medalist II's shutter. When it was overhauled by Ken Ruth, he provided a list of actual shutter speed timings done with the lens wide open. I was always dismayed that the top 1/400 speed was only a bit faster than 1/200, even though I can feel the booster spring when I set the 1/400 speed.
I realize now that the clever engineers at Kodak reasoned that if you need 1/400 speed, you're probably in bright enough conditions that you'll be stopping the lens down. So, my effective exposure shutter speed truly would be 1/400!
Kodak was great in those days. The Medalist (converted to 120 film) is truly a butt kicking camera. Scans from the 6x9cm format on the Nikon Coolscan 9000 reach 500MB in size.
I realize now that the clever engineers at Kodak reasoned that if you need 1/400 speed, you're probably in bright enough conditions that you'll be stopping the lens down. So, my effective exposure shutter speed truly would be 1/400!
Kodak was great in those days. The Medalist (converted to 120 film) is truly a butt kicking camera. Scans from the 6x9cm format on the Nikon Coolscan 9000 reach 500MB in size.
retinax
Well-known
Robert, unfortunately it's the other way around, the effective shutter speed at smaller apertures will get longer.
But the numbers you were given really should be taken with a grain of salt if we don't know how the shutter speeds were measured: if it was the duration starting from a small opening, it's not quite so dramatic, if the time the shutter was fully open, or the effective exposure was measured, then your shutter is really slow.
But the numbers you were given really should be taken with a grain of salt if we don't know how the shutter speeds were measured: if it was the duration starting from a small opening, it's not quite so dramatic, if the time the shutter was fully open, or the effective exposure was measured, then your shutter is really slow.
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