Impact of leaf / focal plane shutters

[martin_wouterlood1]

<p>A couple of years ago I needed to sell off my medium format gear but kept a few Hasselblad, Contax 645 and Mamiya RZ lenses. After a brief want affair with the d800 (we didn't really get along - too complex) I am again looking at mf options for mostly flowers, close and far nature scenes and some portraits.<br>

Ok...I'm on a tripod (solid Gitzo 5 cf...well done, thou good and faithful servant of these past 12 yrs), mirror up and cable release in hand...<br>

The theory says that using the best technique, with lenses of approximately equal (and high) performance, sharper results can be obtained using the leaf shutters of the Hasselblad and RZ lenses than with a focal plane shutter, due to the leaf shutter's inherently better controlled vibrations, and that this difference is likely to be greater with increase in focal length (greater magnification of micro-movements).<br>

Anyone done the prac? Has anyone worked this out to their own satisfaction and said, yep, I can see a significant difference on my big monitor / print...or, nope, can't really see any difference - use whatever system floats your boat the most.<br>

I should just add that I am planning on getting into a 20-30 mp ish digital back, so the format difference is essentially negated. I am comfortable with any of these systems and have worked out most of their other different issues as they apply for my uses, but wonder if this shutter issue is now more significant with digital's increasing demands for system accuracy. <br>

Many thanks for helpful replies.<br>

Martin </p>

[martin_wouterlood1]

<p>Sorry, but at what focal length did this become a deal breaker for you, if at all? If lenses under about 200mm seemed ok that would be good enough for me not to have any concerns. </p>

[mukul_dube]

<p>A tripod that keeps the camera immovable should reduce the difference to nothing.</p>

[martin_wouterlood1]

<p>Yes, I kop that, Mukul (see op), but how big and heavy is your portable tripod to make it micro "immovable"? Even if I had a studio setup I am unlikely to construct Ansel Adams' ideal of "a big lump of concrete with a quarter inch bolt". My limit of compromise, and I have no idea how far this is from the ideal, is about 4.5kg...3 for my 1548 + 1.5 for my B1G or Foba 3-way (thank you Edward). </p>

[mukul_dube]

<p>Since you reject the perfection of concrete, you must find out for yourself which compromise in our imperfect world gives you what you want. At some point you should come upon a solution which is good enough.</p>

[martin_wouterlood1]

<p>You are right...I suppose I should get both a 500 and a C645 body with lens adaptor to shoot them both with my 180 cfi lens...that ought to prove it to my satisfaction but at some expense. Hence the question was posed.</p>

[donbright]

<p>I agree that if the tripod is sturdy enough, and the head is equal to the task, and will overwhelm shakes, and vibrations, the differences between leaf, and focal plane shutters are mute. I use a Gitzo Studex with an Arca Swiss monoball head that keeps a Pentax 67II inline, and also handles a Nikkor 400mm 3.5, with F3, and MD-4 attached. I have also done the experiments with Hasslelblads, and leaf lenses compared, and I see no difference. In the mix is a Pentax SMC 165mm Leaf, and even then switching from Leaf to shutter, no difference.</p>

[martin_wouterlood1]

<p>Thanks Don, this is good to hear, albeit Pentax-specific...a couple more similar experiences will let me open up my options as I feel confident that I can overcome it with my tripod setup.</p>

[q.g._de_bakker]

The tripod will be able to help a bit, but not that much.<br><br>The vibrations caused by shutters originate inside the camera. For the tripod to be able to do something about that, the vibrations have to travel to the tripod first. So the camera shakes no matter the tripod which may or may not be underneath it, and no matter what sort of tripod it is.<br><br>The important bit as far as the tripod is concerned is what it can do about those vibrations once they have reached the head. And what it should do is absorb them. A completely rigid setup, with a comparatively large mass beneath the camera will reflect those vibrations back into the camera. Not what we want. Hence the advice you get here and there to help dampen the vibrations by pushing your flubby hands on top of the camera. They will absorb at least some of the energy.<br>Handholding too would prevent refections, but since our hands then introduce more shake than they take away, not an option.<br>The very sound advice (better than putting your hands on top a tripod mounted camera) is to use a tripod head that will absorb vibrations: a fluid head. That fluid head however must be allowed to do it's thing, i.e. it must not be locked down too tight.<br>Not many of us will have a good fluid head, but that last bit of advice transfers to normal heads too: do not (!) lock every movement as tight as possible. Tighten screws tight enough not to have gravity do its thing. But leave room for some micromovements. The vibrations caused by camera and lens will then have some place to go, instead of being reflected back into the camera.<br>Though you then counter movement by allowing movement, which sounds silly, it works. The result will be smaller amplitude shake that dies away much sooner.<br><br><br>Back to leaf vs focal plane: it does make a difference, yes. (And you can't remove much of that by using a heavy tripod.) Whether it will be big enough that you would notice depends on the make of the focal plane camera. Some are worse than others. Comparing a 500-series Hasselblad to a 2000-series Hasselblad, the difference isn;t big enough to notice, so to all intents and purposes no there (only audible). A Contax 645 would also be a well designed and well made camera, and may be good too. You will have to try.

[Ed_Ingold]

<p>If you have a body with a focal plane shutter and a lens with a leaf shutter, you usually have a choice which shutter to use (e.g., with a CF lens). A focal plane shutter causes more vibrations, which may be critical in the exposure range of 1 second to 1/15 second (or higher). A leaf shutter introduces practically zero vibration, because it's motion is nearly symmetrical about the lens axis, whereas a focal plane shutter is from one edge to the other.</p>

<p>As a rule of thumb, I use the lens shutter unless the speed is 1/60 or faster. I can see doubling in the image at 1/15 second with a digital back, so impose a two stop safety factor. That means I give up automatic exposure, but I can live with that (and a good light meter).</p>

<p>It's also important to pre-fire the mirror and use a cable release (or self-timer), and the heaviest tripod you are willing to carry. Adding weight helps if you are on a soft surface (e.g., grass), but doesn't really add reaction mass unless it were bolted to the tripod. For closeups, you are at the mercy of the wind.</p>

[q.g._de_bakker]

<i>"If you have a body with a focal plane shutter and a lens with a leaf shutter, you usually have a choice which shutter to use"</i> to time the exposure, yet the focal plane shutter (covering the film) will always have to open in a hurry and stop suddenly.<br>Whatever vibrations it produces it still produces even though the actual exposure is timed by the leaf shutter. The difference (besides having another shutter with its moving parts as well) is that the focal plane shutter starts and stops before the leaf shutter opens, i.e. there is a very short period in which vibrations caused by the focal plane shutter can die down a bit.

[dan_fromm2]

<p>Interesting idea, QG. My little 2x3 Speed Graphic doesn't agree with you.</p>

<p>When focusing a Speed Graphic on the ground glass, the usual procedure is: open focal plane shutter, open leaf shutter, focus and compose, close leaf shutter, set aperture, cock leaf shutter, insert film holder, withdraw dark slide, shoot, insert dark slide.</p>

<p>When using the range finder to focus a Speed Graphic, the usual procedure is: open focal plane shutter, make sure leaf shutter is closed, set aperture, cock leaf shutter, focus, compose, shoot. I don't mention the film holder or dark slide because the film holder (sheet or roll film) can be inserted anywhere in the process and the camera can be carried the dark slide partially withdrawn.</p>

<p>You folks who use modern cameras that do most of the work for you are spoiled.</p>

<p>I can't address focal plane shutters in general, but with Speed Graphics the large shock (and loud noise) from the focal plane shutter are generated when the shutter stops, not when it starts. And the shutter closes before it stops so the large shock has no effect on the image. With Graflex SLRs there's a shock and bang when the mirror goes up, also a lag between the time the mirror is fully up and the shutter is released. There are 2x3 Graflex SLRs, I have a very unsatisfactory one.</p>

[q.g._de_bakker]

You're right Dan: we're spoiled using these newfangled little cameras. :-)<br>Or wait a minute: you get more control over what happens, so ...<br><br>Re stop vs start: the first curtain of the focal plane shutter stops before the second curtain, i.e. while the shutter is still open (!) and film is still exposed. So any vibration it produces will be recorded. Whatever the second curtain does is of no concern, because it (and only it) indeed stops after having covered the film completely.<br><br>Using a leaf shutter lens on a focal plane shutter Hasselblad, the shock of the first curtain coming to a sudden stop is still resonating when the leaf shutter opens and exposes the film.<br>But the vibration it causes really is nothing to worry about. And we have to remember that when using a leaf shutter lens on a leaf shutter reflex camera there still is a film cover (the two-baffle auxillary shutter in the Hasselblad) that has to get out of the way in a hurry and does the same thing as a focal plane shutter: come to a sudden stop, needing a way to get rid of all that kinetic energy.<br>All in all, i wouldn't worry much about focal plane shutters. That is: not in those newfangled little cameras. Using a Graflex however...

[dan_fromm2]

<p>QG, modern (!) Speed Graphics and Graflex SLRs have roller blind shutters with only one curtain. There's no first curtain, so no possibility of shock when the first curtain stops.</p>

<p>You raise an interesting point. Why is the OP is less worried about mirror slap than about vibration a focal plane shutter might make?</p>

[Ed_Ingold]

<p>I have a 205TCC. When you pre-release the mirror in "C" mode, the mirror raises and the focal plane shutter opens. The lens shutter closes, and remains closed until you press the shutter release. In "C" mode, the focal plane shutter serves the same role as the auxilliary shutter in a 500 body.</p>

<p>If you pre-release the mirror in "F" mode, the lens shutter remains open, but stopped down. The focal plane shutter remains closes until the shutter release is pressed. The focal plane shutter in an Hasselblad has two separate curtains. The opening, which "scans" the film, is determined by timing the release of the second curtain. It takes about 1/90 second for either curtain to traverse the film plane. That means the shutter is 100% open at speeds of 1/90 or slower. The mirror creates most of the vibration in operation. However, the focal plane shutter creates enough to disturb the sharpness at slow speeds. Each curtain creates a little vibration when it is released and when it stops. Of course, when the second curtain stops it has no effect, since the shutter is completely closed at that instant.</p>

<p>In a Speed Graphic, you crank the focal plane shutter to an open position when you want to use the lens shutter. The focal plane shutter remains in that position indefinitely. The shutter curtain has fixed openings, which you select, along with the travel speed, to achieve various exposure settings. You have to be sure the dark slide is inserted before winding the focal plane shutter with the lens open.</p>

<p> </p>

[q.g._de_bakker]

Mirror slap, Dan, can be countered by prereleasing the mirror. But even when you do, the curtain of the focal plain shutter (or the blades of the leaf shutter) will have to do what it has to do.<br><br>I don't know, Dan, how does a focal plane shutter with only one curtain work? It opens from one side, and then what? From what Edward writes i gather it isn't a shutter that can be used to time exposures. Just a film 'cap'.<br><br>In C mode the focal plane shutter does indeed work like the rear baffle shutter. So if you prerelease the focal plane Hasselblad, allow some time to allow all vibrations (including those caused by the focal plane shutter) to die away, there is no problem. If you don't prerelease, the focal plane shutter opens a tad earlier then it would if it were used to time the exposure. And then vibrations the shutter curtain causes can be a problem just as those caused by the mirror.<br><br>But again (and that was the OP'S question) how big a problem is it really? Not a big one, if you'd ask me.

[dan_fromm2]

<p>QG, a roller blind shutter is a strip of cloth with one or more slits in it and a pair of rollers, one on each side of the camera's gate. If the shutter curtain has more than one slit, the slits' widths vary. The shutter curtain travels from one roller to other. A roller blind shutter is cocked by rolling it up. When it is fired, the curtain moves from one roller to the other and a slit traverses the camera's gate.</p>

<p>The focal plane shutters you're thinking of have two curtains and obtain variable width slits by changing the time interval between the time the first and second curtains begin to move. Roller blind shutters obtain variable width slits by choosing a slit. That's why Graflex shutters have two speed controls. One to select the slit, the other to select spring tension (= the speed at which the curtain moves).</p>

<p>Mr. Ingold pointed out correctly that on Speed Graphics and Graflex slrs the film has to be protected from light when the shutter curtain is wound up (= the shutter is cocked). With Graphics, the dark slide has to be in or the leaf shutter has to be closed. With Graflex SLRs the dark slide has to be in or the mirror has to be down. Graflex SLRs have an interlock that doesn't allow the shutter to be wound up while the mirror is up.</p>

<p>I thought you'd have been familiar with Mentor cameras, which use roller blind shutters.</p>

<p>I agree with you that mirror slap and vibration generated by focal plane shutters can be managed.</p>

[donbright]

<p>It's quite clear we know camera shutters cause blur issues within an image, and how to correct this goes on, and on, but can we just say the word, ' Tripod,' without discussing, which tripod? Also, what to do when camera attached to the tripod, QG makes a good point, and my solution is to use the camera bag weight with strap draped over the camera to absorb vibrations. It works. If not on the camera, around the neck of the tripod head. The dead weight acts as a transfer, or damper.</p>

[steve_rasmussen]

<p>"Sorry, but at what focal length did this become a deal breaker for you, if at all? If lenses under about 200mm seemed ok that would be good enough for me not to have any concerns."<br /> One of the most notorious focal plane cameras (P67) for shutter induced vib can shoot its 35mm to 200mm lenses at any speed without fear of degraded images. It is only when one tries to shoot the longer lenses (300 Takumar, 600 Takumar) at speeds in the 1/4 to 1/30 second range that problems arise. Each focal plane camera system will have different characteristics when it comes to the amount of vib generated but I thought I'd give an example of one of the extremes in the Pentax 67. For the work you describe that you shoot, a focal plane system could easily work.</p>

[martin_wouterlood1]

<p>Thank you all for an enlightening string of comments, which has given rise to some further thoughts of my own.<br>

To my thinking, increasing the mass of a thing and subjecting it to a given force, ie leaf shutter opening/closing = x whatevers, focal plane = say, 3x whatevers, the energy instilled is constant for each, and since it cannot be created or destroyed, only changed in form (Newton?), the frequency of the vibration is increased with a corresponding lowering amplitude of vibration, which is what we all want, right?...same thing with hi fi turntables...hence the mass dampening thing. The other influencing factor that comes to mind is rigidity...there's no good in welding a 10 kg steel reo rod to your rig if it is 5m long, is there?...hence the influence of carbon fibre - currently the stiffest thing for the weight one is willing to schlep around.<br>

My Gitzo 5 series cf I mentioned has been about the stiffest 3kg set of legs I have tried, but I may have an interest in the new RRS series 4, as one of their marketeering guys told me it quells vibes 3 times faster than the competition (probably the cheapo copies).<br>

I have used favourably a fluid head as Q.G. suggested and may look into this again. I also had with it the video double tube legs. These are rated for much higher payloads than the Gitzo style and in carbon, appear to be stiffer in design, but with some practicality lost, namely proximity to the ground and ease of handling.</p>

<p>A number of years ago now, Kornelius Fleischer/Mueller from Zeiss posted an article (here, or it may also have been in a Zeiss news periodical) of a guide to sharper photos which he no doubt used to get his great lpm results for the (now named V) lenses he was promoting, and there was probably 5-6 grand's worth of support under his camera.<br>

A little off my op in places but still relevant in many instances, here's what I retained of it:<br>

USING CAREFUL AND DELIBERATE TECHNIQUES FOR BETTER QUALITY PICTURES<br>

High performance optic<br>

Strong camera, all metal housing, large sturdy bottom plate, tripod thread under centre of gravity, remove removable winder for better rigidity<br>

Double check for correct back focal flange distance, and for SLR, perfect alignment of mirror and focusing screen to film plane<br>

Rigid attachment to very stiff tripod and head<br>

High performance films such as Fujichrome Velvia (50)transparency, Kodak Technical Pan (25) or TMax (100) black and white with resolutions > 150 lppm adequately processed<br>

Acute Matte D split field indicator to focus lenses up to f/5.6 is best tool used and recommended by Zeiss, standard screen not best choice for resolution >100 lppm<br>

Focus with aperture wide open, use X 5 magnification<br>

Use f/5.6 (diffraction limit = 280 lppm) to f/8 (200) stop down further (f/11=140) and diffraction will drop resolution, open up and effects from thermal expansion, film curvature from moisture and temperature, mechanical tolerances from wear, rough handling and residual warpage of the focusing screen may limit resolution<br>

Pre release / lock up mirror<br>

Central shutters have inherent lower vibration levels<br>

Wrap hands around body of focal plane cameras, perhaps omitting cable release<br>

Write notes of all lens and camera parameters and settings, focusing details, etc<br>

Use a lab that is very quality conscious and uses high performance optics in printers and enlargers, nothing less than Rodenstock Apo Rodagon N lenses<br>

Use of a properly adjusted compendium shade will reduce flare and stray light in contre jour, sidelight reaching the lens and overcast sky and improve contrast<br>

(From Kornelius Fleischer, Zeiss lens applications manager, who prefers Sachtler ‘HD – ENG’ CF legs with ‘Video 18+’ head as even more stable support than wooden legs)<br>

</p>

 

[martin_wouterlood1]

<p>And posting before I read your last post, Steve, thanks for being so specific.</p>

[q.g._de_bakker]

Don't forget, Dan, that i'm one for whom those newfangled thingies were made.<br>I think i might have know about those primitive shutters, somewhere in the back of my mind, perhaps. But blame it on dementia, or what you will (a lack of Graflex camera - always wanted to get one, but never did), i learned a bit just now. Thanks.<br><br>Martin, tripods must have enormous amounts of mass not to be impressed, or even shaken, by whatever the world throws at them. So they are certainly not impressed, or shaken, by whatever the camera wants them to absorb, so it (the camera) can stop shaking sooner.<br>Rigidity is not our friend here. We need the energy to dissipate somewhere. And if the tripod is rigid, it will not help in any way, but leave the camera to deal with it alone.<br>So carbon fiber tripods are the worst of the wordt: no mass, and "the stiffest thing for the weight one is willing to schlep around". Giving that they also cost lots more than sensible tripods, it's amazing how many of these are sold.<br>The best tripod is a heavy one. Lots of mass. That is the working part. As far as not being easily shaken by whatever outside influence is concerned.<br>As far as helping to minimize the effect of any movement that has reached the camera anyway (perhaps because the camera itself is the source of it), it must not be rigid, unflexible, not 'highly strung'. Or else it does what a highly strung string, attached firmly to a two ton marble slab, will do: ring forever and ever.<br>The idea of leaving some room for movement by not tightening everything as fast as you can, by having some 'slop' and 'flop' in the joints and the things that are joined, is a good one. Just like a string, that makes a short an dull sound when attached loosely, running over a bridge and nut that are not the hardest material imaginable, the vibrations caused by the camera will die soonest when the energy can be used up setting something else besides the camera in motion too.<br>So a big NO to "Rigid attachment to very stiff tripod and head". A fluid head, by all means, because it has that sloppiness already built-in. On purpose.<br><br>Using long lenses, it would be a good idea to find a lens support, i.e. support not only the camera but also the lens.<br>The usual way to mount a camera, using one small diameter screw in a single point, often also does anything but help. What that screw must do is (besides prevent the camera falling off) is pull the bottom of the camera into contact with the tripod head, over as wide an area as possible. So use a head with a large plate. And increase the support by adding a lens support (there are purpose built ones. I use Manfrotto 'magic arms' when needed. Nice things, those).

[dan_fromm2]

<p>QG, I agree with you about mass' importance, don't agree at all about slop's usefulness. This after struggling to use a long lens on a Manfrotto hex plate that was a loose fit in the quick release. On a windy day the point of aim was, um, poorly defined. One of the consequences of locking everything down tight is that the mass to be moved by the shock is maximized. When, for example, the camera/lens assembly is slightly loose on the head it is decoupled from the rest of the assembly and the shock has to move only its mass.</p>

<p>I think you're mistaken about fluid heads. They're used with cine cameras to allow smooth pans and tilts. When the camera isn't going to be panned or tilted the head is locked down tight. I've had no vibration problems with a Manfrotto fluid head under my S8 Beaulieus (these have reciprocating shutter that doesn't make the camera bounce up and down) with lenses up to 300 mm.</p>

<p>I'm surprised you didn't advocate wooden tripods, which are widely believed to damp vibration better than metal or carbon fiber ones.</p>

<p>I agree completely about the usefulness of magic arms for reducing movement in the camera/lens/tripod assembly, stole the idea from Robert Polidori. See <a href="http://www.cnngo.com/hong-kong/play/robert-polidori-257129">http://www.cnngo.com/hong-kong/play/robert-polidori-257129</a>, you can read about my application at <a href="http://www.galerie-photo.com/baby-bertha-6x9-en.html">http://www.galerie-photo.com/baby-bertha-6x9-en.html</a> . In my setup one of the sources of motion that the magic arm tames is movement of the center post in the tripod's top. The only short bearing surface in a Berlebach tripod is between the center post and the platform; it can cause problems with a long lens that isn't mounted directly above the center post.</p>

[sterling_bjorndahl]

<p>The Pentax 6x7 family is famous for not only a lot of mirror slap but also significant shutter shock. There's an article at Luminous Landscape, <a href="http://www.luminous-landscape.com/reviews/cameras/pentax67ii.shtml">http://www.luminous-landscape.com/reviews/cameras/pentax67ii.shtml</a>, where the bottom line is that the tripod+head should weigh TWICE as much as the camera+lens.<br>

Another trick I've read about is to attach a bungee cord to the tripod's neck and use one's foot to stretch it to the ground. I haven't tried that myself.<br>

I think if one is using a focal plane shutter one must take more precautions than with a leaf shutter, all other things being equal. I still love my Pentax 67, though. It's just a loveable, old bear of a camera. </p>

 

[q.g._de_bakker]

Dan, the thing is that even though we don't want to nor perhaps expect it, when something hits the long lens on your camera, it will start moving no matter how tight the thing is locked down. The choice we have in all this is pretty much as i described it: will we allow that vibration to stay in there and let it ring like a string under high tension, or do we allow that vibration to 'leak' away?<br>I do the latter.<br><br>Yes, fluid heads were invented to make smooth pans possible. But their usefulness doesn't stop there. They really are good too for still photographers, for the reason mentioned. And for that you do not want the fluid head locked down tight. A bit surprising indeed that their usefulness still is something of a "Geheimtipp", a bit of insider knowledge. But there it is. Abovementioned Fleischer/Mueller knew.<br><br>I don't advocate wooden tripods, because i don't know them to be better. Yes, there is lore that will have us believe they are. But are they? Not to my (of course limited) knowledge.<br>And they have one huge drawback: they lack mass. Mass is the most important bit in isolating a camera on top of the tripod from the world around it. (And very unhelpful when the source of the vibration is the camera itself, since it (mass) still does a wonderfull job isolating the vibrating thing from the rest of the world. We really need somewhere for that vibration to go if we want to minimize the effect it will have on image quality).<br><br>Good thingies, aren't they, those magic arms?<br>The annoying bit about magic arms, i find, is that a single magic arm, though providing a useful extra strut, will need another magic arm as a strut to hold and keep the strut still. And the assembly really becomes stable when you add a third arm, so... ;-)