Jump to content

Mirror slap an issue?


eric_m4

Recommended Posts

Hi guys,

 

I've heard/read several people say that vibration from mirror slaps on old, robust bulldozer cameras like Bronica S2's and Kowa 6 are so brutal that they can negatively affect the result of image as far as lack of sharpness/motion blur is concerned. I know the mirror slap is loud but is the powerful vibration an exaggeration or is it really a problem? Would this still be an issue if used on a good tripod?

Link to comment
Share on other sites

It will only be an issue when used on a good tripod. Handholding has a far greater effect than mirror slap.

 

Mirror slap is often mentioned, and i suppose that there is some truth to it. But even though demonstrable under test conditions, the question really is how big an issue it is. It has not lessened people's satisfaction with the cameras they use, going by the long periods these were produced and sold without adressing the issue. Insignificant enough not to worry about at all, i'd say.

But having said that, when possible, it doesn't hurt to prerelease the mirror.

Link to comment
Share on other sites

That mechanical clatter is post-exposure. The old mechanical beasts like Pentax 6x7s and focal plane shutter Bronicas never gave me grief. That their mirrors sounded like an old screen door slamming didn't, as q.g. observed, affect their function.
Link to comment
Share on other sites

There were a series of tests in the old enthusiasts' magazines. While I can't lay my hands on any scans of them right now, my recollection was that q.g. has the right of it

.

Here is a column from the incomparable Burt Keppler about the broader problems of camera vibration:

234764609_Keppler-vibration-misc-1985-01-MP-vibration.thumb.jpg.68afca6a0ef0cbc88d28319dd1abf7ac.jpg

Modern Photography 1985-01

  • Obviously, it's about small format, but the general lessons are as much or more true for larger formats. On the other hand, the fact that less enlargement is needed for a larger negative, helps the other way.

Link to comment
Share on other sites

Hasselblad mirror slap is definitely an issue when used on a tripod. With film, it might cause a noticeable blurring, but with a digital back you usually see doubling at the pixel level. I make it a practice to raise the mirror whenever possible, e.g., for landscapes. Even a focal plane shutter can show vibration in the image, which is why I seldom use it for fussy work.
  • Like 1
Link to comment
Share on other sites

That mechanical clatter is post-exposure. The old mechanical beasts like Pentax 6x7s and focal plane shutter Bronicas never gave me grief. That their mirrors sounded like an old screen door slamming didn't, as q.g. observed, affect their function.

No, it's when the mirror swings up and comes to a sudden stop immediately before the exposure. Not post-exposure.

 

The amount of blur also depends, not only on the magnitude, but on shutterspeed, i.e. the duration of the vibration relative to the duration of the exposure. At long shutterspeeds, it wil not be noticable at all.

Another factor is the relative mass and speed of the moving part, compared to the mass of the camera it should set in motion.

And how well dampened the mirror is.

 

But it is indeed not something to worry about.

Link to comment
Share on other sites

No, it's when the mirror swings up and comes to a sudden stop immediately before the exposure. Not post-exposure.

 

The amount of blur also depends, not only on the magnitude, but on shutterspeed, i.e. the duration of the vibration relative to the duration of the exposure. At long shutterspeeds, it wil not be noticable at all.

Another factor is the relative mass and speed of the moving part, compared to the mass of the camera it should set in motion.

And how well dampened the mirror is.

 

But it is indeed not something to worry about.

 

What vibration the camera "feels" and you hear as mirror clatter aren't necessarily the same. Massive, all-metal cameras like the old Bronicas and Pentax 6x7(no experience with Hasselblad) did, as Keppler noted, dampened vibration rather well. Neither camera ever produced any blurring I could attribute to mirror slap. Any blown shots were my fault alone.

Link to comment
Share on other sites

I have been using SLRs and DSLRs for 50 years and change. Just last week, got a pair of quite a decent images at 1/5 and 1/6 hand held. There is no doubt in my mind that at some arcane, far borders of photography the issue may impact outcomes, but I have never encountered it. Just call me "Slap Happy".
Link to comment
Share on other sites

When shooting close ups (on a tripod) like minimum focus on the 80mm on my 500c or when using an extension tube, the vibration is real and although the average viewer may not see it, you don't have to be critical to see its impact - especially with digital. I have made a habit of pre-releasing the mirror for this reason.
  • Like 1
Link to comment
Share on other sites

I have been using SLRs and DSLRs for 50 years and change. Just last week, got a pair of quite a decent images at 1/5 and 1/6 hand held. There is no doubt in my mind that at some arcane, far borders of photography the issue may impact outcomes, but I have never encountered it. Just call me "Slap Happy".

Yup, and Natty Bumppo could shoot the eye of a grasshopper at 50 yards. (Of course, Mark Twain remarked in his scathing review of James Fenimore Cooper, "If you can't see it, you can't shoot it.")

 

Not all photos need maximum resolution, including those situations where 1/5 second is all you can get. I have achieve surprisingly good results at 1/15 with a 300 mm lens, with the aid of in-body image stabilization and a convent door frame for support.

 

Digital imaging is a whole other ball game for medium format. The acuity is high enough, even in my 16 MP sensor, to detect the camera shake of the flapping mirror in an Hasselblad. Even with the advantage of electronic shutters and solid tripods, getting pixel-sharp results at 40-60 MP takes extra care.

  • Like 1
Link to comment
Share on other sites

So those SLR manufacturers that fit an MU (Mirror-Up) facility were just wasting their time designing it? And everyone using MU is wasting their time using it?

 

I don't think so.

 

Fit a really long lens on a less than rock-steady tripod (i.e. any tripod you can easily carry more than 500 yards) and watch the image dance at the slightest touch of a tripod leg. Then tell me mirror-slap will make no difference?

  • Like 2
Link to comment
Share on other sites

So those SLR manufacturers that fit an MU (Mirror-Up) facility were just wasting their time designing it? And everyone using MU is wasting their time using it?

 

I don't think so.

 

Fit a really long lens on a less than rock-steady tripod (i.e. any tripod you can easily carry more than 500 yards) and watch the image dance at the slightest touch of a tripod leg. Then tell me mirror-slap will make no difference?

 

But when most shoot 80-150mm lenses? Not so much. As Herb Keppler noted, it's shutter speed dependent.

Link to comment
Share on other sites

But when most shoot 80-150mm lenses? Not so much. As Herb Keppler noted, it's shutter speed dependent.

One tends to expect more from medium format than from a cell phone, or even a small format camera. Use of a 500 mm lens was simply an example which makes visible how easily even a solid tripod can be disturbed. The effect of mirror vibration on a "normal" MF lens (60-110) is easily visible in a digital image. For landscapes, I would not only raise the mirror, but use a soft release. My favorite Hasselblad was an ELD555, which has an electronic cable release (and uses a CFV digital back without a sync cable).

 

The 1/F rule for acceptably sharp handheld photos is actually closer to 1/3F before camera shake is nearly invisible. In practice, that limits you to 1/250 or faster, which is not always easy to achieve with slow MF lenses.

Link to comment
Share on other sites

The 1/F rule for acceptably sharp handheld photos is actually closer to 1/3F before camera shake is nearly invisible. In practice, that limits you to 1/250 or faster, which is not always easy to achieve with slow MF lenses.

 

And that's why God created tripods...Enough tedium already.

Link to comment
Share on other sites

The 1/F rule for acceptably sharp handheld photos is actually closer to 1/3F before camera shake is nearly invisible. In practice, that limits you to 1/250 or faster, which is not always easy to achieve with slow MF lenses.

 

And that's why God created tripods...Enough tedium already.

 

... and gave us enough sense to recognise that mounting a heavy rig out of balance on a too flimsy tripod is not the thing to do.

 

I will join the mood and change my initial reply to "it is an issue when it is an issue".

Link to comment
Share on other sites

It's odd, but I used a Rollei for twenty years, starting while I worked at a local newspaper, and only bothered with a tripod 5 or 6 times. Tension on a neck strap and elbows planted on my sides was good enough. On the other hand, I only used my Hasselblad by hand once between 2001 to 2015, and the rest of the time on a tripod. If you spend that much money and time for medium format quality, hand-held is simply not worthwhile. Those old Rollei negatives weren't sharp by modern standards, but good enough for newsprint.
Link to comment
Share on other sites

I believe that the camera's state of repair has something to do with it. A properly functioning camera with a recent CLA will have less of an issue with mirror slap than one that hasn't been serviced in 20 or 30 years.

Not necessarily Bronicas in particular are really noisy with mirror slap. Yet the Mamiya RB 67 is REALLY WELL damped

Link to comment
Share on other sites

[ATTACH=full]1384300[/ATTACH]

 

When mirror shock is an issue.

 

(It's a Carl Zeiss tripod, so it must be good...)

 

 

I think the NEXT shot after firing off on that rig is the one you have to worry most about vibration (unless you wait fifteen minutes between exposures) :)

  • Like 1
Link to comment
Share on other sites

So those SLR manufacturers that fit an MU (Mirror-Up) facility were just wasting their time designing it? And everyone using MU is wasting their time using it?

 

I don't think so.

 

Fit a really long lens on a less than rock-steady tripod (i.e. any tripod you can easily carry more than 500 yards) and watch the image dance at the slightest touch of a tripod leg. Then tell me mirror-slap will make no difference?

I agree that if it's possible to eliminate mirror-induced vibration from the imaging equation it's prudent to do so. Whether it will actually be germane to sharpness of the images involved is another point. But given the choice between living with or managing, a source of vibration, or eliminating it—I'll nearly always choose the latter. Granted—lifting the mirror might not help. But maybe it would, and it can do no harm—so, if the feature is available—why not use it?

 

That said, (as far as 35mm SLRs are concerned, at least) most manufacturers did not include a mirror lock up to help reduce vibration—at least not primarily. The function was usually included to facilitate the use of one or more non-retrofocus wide angle lenses, the fitting of which to the camera without first locking the mirror up would damage same. That the MLU would also be of particular benefit with long lenses or great degrees of subject magnification was surely of secondary importance.

 

Getting back to medium format SLRs, historically, relatively few models have actually been fitted with a genuine mirror lock up. Eg the 500C, C/M and their derivatives are oft-said to have MLU, but in fact, this isn't the case. A pre-release button permits the reflex mirror and rear shutter to be pre-fired before using their lens shutters. But on winding the film to the next frame, it is impossible to stop the mirror from descending. "Mirror lock up", as the words "lock up" suggest, means exactly that—the reflex mirror is mechanically locked in the retracted position. and until it's unlocked by the photographer—it stays locked.

 

There have been certain MF SLRs manufactured with true MLU capability. Some focal plane shutter Hasselblads Eg. their 2000FC and FC/M have various mirror operating modes apart from mirror instantly returning after exposure; one of these is mirror remains up after exposure and wind on. The 500EL & EL/M may have had a similar option—can't recall offhand.

 

Purely as far as vibration reduction is concerned, of course, a pre-release confers all of the benefits of MLU to a camera fitted with the function.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...