A question about this P67 vibration thing

dpurdy · Apr 11, 2008

Following the discussion of the nature of the P67 vibration in a previous thread I did some playing around with mine last night trying to get a sense of this shutter kick versus the Mirror slap. I put the shutter on B and held the camera in my hand in various ways.

My observtaion is that just locking the mirror up, I feel it but it doesn't seem like a powerful kick. I hear it more than feel it. And just opening the shutter in B, so that it doesn't close, it is quieter than the mirror but I feel it more, due to the direction of it. The mirror slaps up, which doesn't cause much sensation in my hand, whereas the shutter causes the camera to move sideways a little bit as the shutter travels sideways. But even so it doesn't feel like a poweful kick. It seems, as I let the mirror back down and let go of the shutter so it can close, that the kick is far greater than when I opened it. But at that point of course the kick would cause no optical harm. I also noticed if I held up the mirror lock button while I held the shutter open in B that the shutter wouldn't close until I let go of the mirror lock up button. Not sure if that is a malfunction or not.

My question is .. does the vibration of the opening shutter cause any internal motion? Or if I put the camera on a very solid tripod with solid head connection so the camera itself can't move will that stop all the motion? Same question regarding the mirror slap. Does just stopping the motion in the whole camera eliminate all the motion or is there still some internal motion in the film or lens?
I guess I could spend the day running tests.
Dennis

JRJacobs · Apr 11, 2008

Dennis -

In my experience, there is no "internal motion" in the film or lens caused by the shutter - the P67 is a tight and solidly built camera if it is anything, and the film-pressure system holds the film tight and flat - a virtue it is well known for. You need a good enough tripod to eliminate any shake during slow exposures and you should be fine. I use a Manfrotto tilt head and tripod, but the model name escapes me. I used to use a Tiltall and it was more than adequate. I have found that carbon fiber tripods are not generally a good choice for the P67 as they are not heavy enough, but YMMV.

dpurdy · Apr 11, 2008

Well I shot a test on some still life stuff this morning and put the camera on a Bogen tripod I use for 8x10 with a heavy duty tripod head and I hung the camera bag (heavy with lenses) by the strap on the prism and shot with and without mirror lock up at 1/4 1/2 and 1 second exposures with my 165 (the longest Pentax lens I have) so I will see how my personal mileage varies. I do love this camera though am usually either too lazy to use it and prefer the lighter Rollei or more ambitious and use a view camera. the p67 suffers from middle child syndrome.
dennis

Doug Webb · Apr 11, 2008

I can't answer your question completely because I never use my 67 without mlu unless I am handholding it (usually for portraits), I never enlarge hand held images very much, and I never use a lens longer than 165mm when handholding, but, even with the mirror locked up, and particularly if you use lenses of 300mm or more, and you try to enlarge the image to say 16x20, you will, at least sometimes, see evidence of image degradation, unless you use a sturdy tripod, read heavy as well as rigid, a good head, and a good quick release or other mounting system. Every link in the chain is important and I did not eliminate vibration to my satisfaction until I obtained a professionally manufactured quick release for my Bogen head that has the additional metal pin that inserts into the 67 body next to the tripod threads. I also often hang my camera backpack from the tripod to add weight. This additional weight may be overkill, but just the tripod, weight, and good head alone were not quite enough until I bought the Kirk or was it, Really Right Stuff?, quick release. I don't know that all of the vibration in any camera can ever be stopped, but at least for my purposes, I think I have found a way to successfully minimize vibration with the 67.
Doug Webb

JRJacobs · Apr 11, 2008

Dennis -

Another point worth mentioning is that it really depends on the shutter speeds being used. Like Doug, the longest I use is a 165. My personal handholding limit is around 125th shutter speed. I have successfully done 1/60th as well, but I don't count on my skills to be able to repeat it at critical times.

When I bought my most recent tripod/head combo, I brought the camera in to the camera shops to test before buying. I was amazed at the differences between tripod/head combos. Biggest and most expensive was not always the best, and tripods with the same weight rating did not have the same dampening characteristics at all. Heads that do not have a "quick release" plate were much better. Another test I did was just to rap on the top of the camera while mounted on the tripods - it gives you a good idea of dampening of each tripod.

I would suggest if you are worried about shake, do a set of tests with your current equipment. If you need to buy a tripod, take your camera in to the shop with you.

max_ebb · Apr 11, 2008

Here's a link to an interesting thread on this subject (I hope I'm not breaking any rules by posting a link to a thread on another forum).

http://photo.net/bboard/q-and-a-fetch-msg?msg_id=00OSFd

max_ebb · Apr 11, 2008

Doug Webb said:
I can't answer your question completely because I never use my 67 without mlu unless I am handholding it (usually for portraits), I never enlarge hand held images very much, and I never use a lens longer than 165mm when handholding, but, even with the mirror locked up, and particularly if you use lenses of 300mm or more, and you try to enlarge the image to say 16x20, you will, at least sometimes, see evidence of image degradation, unless you use a sturdy tripod, read heavy as well as rigid, a good head, and a good quick release or other mounting system. Every link in the chain is important and I did not eliminate vibration to my satisfaction until I obtained a professionally manufactured quick release for my Bogen head that has the additional metal pin that inserts into the 67 body next to the tripod threads. I also often hang my camera backpack from the tripod to add weight. This additional weight may be overkill, but just the tripod, weight, and good head alone were not quite enough until I bought the Kirk or was it, Really Right Stuff?, quick release. I don't know that all of the vibration in any camera can ever be stopped, but at least for my purposes, I think I have found a way to successfully minimize vibration with the 67.
Doug Webb

When I related a very similar experience, I got flamed and harassed, and accused of "slamming anything other than Mamiya".

dpurdy · Apr 15, 2008

Since I started this thread with a question and then said I was going to test it I will "report" my test result in case someone looks at this with a search. Putting the camera on a heavy tripod intended for 8x10 with a heavy duty bogen head and putting the camera strap over the prism to weight the camera down and shooting mirror locked up and mirror not locked up at 1/4th second I could see absolutely no difference and every image on the roll is sharp. Which leads me to conclude that there is no internal vibration and a good solid tripod with a tight head eliminates the vibration problems with or without the camera bag drapped on the camera as I tried it both ways. So if you are willing to carry a heavy tripod out on a hike, the Pentax 67 is an excellent camera.
dennis

eumenius · Apr 16, 2008

Okay, I became interested in this thread and made a small test with P67 on my work. I put a switched-on laser pointer on the camera with a tight rubber band, put the system on a tripod in a long room, and fixed a sheet of paper on opposite wall (5 meters away, approx.) where the red dot is projected on this screen. I was standing near the dot, and released the camera by 5m long air release. Lo and behold! The vibration IS there, and it's especially high in sideway direction - as it should be with that huge FP shutter. The dot made about 2 centimeter travel here and there, and did not return in its exact original position. I was using a VERY heavy Manfrotto tripod with central column (positioned down), well locked, and a very massive Manfrotto Ball head - the tripod I use with my LF systems. That's the purely scientifical test, so you be the judge.

Zhenya

weasel · Apr 16, 2008

I would only wonder when in the cycle the vibration is happening. Physicist I am not, but i would think the bulk of the movement would occur when the shutter is at he end of its run, after having built up momentum, and rapidly stopping.
If that is true, the only part that would matter would be the first curtain, as by the time the second curtain closes the exposure is done.
All this makes you wonder how any body gets a sharp photo from one of these beasts.
I need to dig out Edge of Darkness again. Didn't Thornton take pictures of a pin point light source under various conditions to test for shake?

Krockmitaine · Apr 16, 2008

weasel said:
I need to dig out Edge of Darkness again. Didn't Thornton take pictures of a pin point light source under various conditions to test for shake?

Yup, in Edge of Darkness

AlanC · Apr 18, 2008

I had a Pentax67 with a 150mm lens, and could get a sharp pictures out of it when I used fast shutter speeds, but with the lens stopped down and shutter speeds of around 1 second I just couldn't get a sharp picture, even with mirror locked up, and a very sturdy ,weighted tripod.
I found out why when I took the head off, placed a sherry glass of water on the ground glass screen and fired the shuter for 1 second. The shutter curtain opened with such a thump that water rippled in the glass for the whole of the exposure.

Alan Clark

dpurdy · Apr 18, 2008

AlanC said:
I had a Pentax67 with a 150mm lens, and could get a sharp pictures out of it when I used fast shutter speeds, but with the lens stopped down and shutter speeds of around 1 second I just couldn't get a sharp picture, even with mirror locked up, and a very sturdy ,weighted tripod.
I found out why when I took the head off, placed a sherry glass of water on the ground glass screen and fired the shuter for 1 second. The shutter curtain opened with such a thump that water rippled in the glass for the whole of the exposure.

Alan Clark

I just tried your test myself Alan and clearly there is a stability problem in your system that doesn't exist in mine. After putting the sherry glass of water on my screen and locking up the mirror then firing off the shutter in B. I didn't get even the slightest ripple. No motion at all. So I tried it in B without locking the mirror up and opening the shutter with mirror flop again caused absolutely no ripple or motion at all. However when I let the mirror and shutter go back closed I got a tiny bit of motion though not enough to cause a ripple, just enough to see.

My Pentax 67 is one of the last made before the 67II and hasn't really had much use.. perhaps 150 rolls. My Tripod is a large bogen with a heavy duty bogen head and a 4 inch hex plate. It fits very tightly and when the camera is in place and I try to wiggle it, it won't wiggle, it is quite solid.

So there must be some variation in the device of stablility in different people's systems or some variation in the stability of the camera itself to account for the different results. I can only look at my results and worry about my problems.

But thanks for the great idea to check for motion. I have used that idea myself in checking the floor of buildings to see if the building was moving. Old wooden buildings never sit still especially above the ground floor so you can't do long exposures, darkroom work or holography in those kinds of buildings.
Dennis

Krockmitaine · Apr 18, 2008

dpurdy said:
I just tried your test myself Alan and clearly there is a stability problem in your system that doesn't exist in mine. After putting the sherry glass of water on my screen and locking up the mirror then firing off the shutter in B. I didn't get even the slightest ripple. No motion at all. So I tried it in B without locking the mirror up and opening the shutter with mirror flop again caused absolutely no ripple or motion at all. However when I let the mirror and shutter go back closed I got a tiny bit of motion though not enough to cause a ripple, just enough to see.

My Pentax 67 is one of the last made before the 67II and hasn't really had much use.. perhaps 150 rolls. My Tripod is a large bogen with a heavy duty bogen head and a 4 inch hex plate. It fits very tightly and when the camera is in place and I try to wiggle it, it won't wiggle, it is quite solid.

So there must be some variation in the device of stablility in different people's systems or some variation in the stability of the camera itself to account for the different results. I can only look at my results and worry about my problems.

But thanks for the great idea to check for motion. I have used that idea myself in checking the floor of buildings to see if the building was moving. Old wooden buildings never sit still especially above the ground floor so you can't do long exposures, darkroom work or holography in those kinds of buildings.
Dennis

Just did the test and it failed miserably (I'm not surprised though). I don't think it's the tripod, a Berleback in this case, but the tripod head, a Manfroto 141RC that I bought new for a steal mainly (salesman's error). In hindsight, this model is really not meant to be used with a P67II and I never really liked it.

Kent10D · Apr 18, 2008

I think the evidence is in 30+ years of very fine photographs taken all over the world with this system, from the 6x7 through the 67 to the current 67II. They're out there, they're sharp, and there are lots of them.

usagisakana · Apr 19, 2008

I havent noticed any problems with my 67 so far, however this has me a bit worried... I always use MLU, and try to set the tripod up so it is as stable as possible. When doing long exposures at night, i cover the lens, trip the shutter, uncover, expose the film, then re-cover the lens, then release the shutter. I think the problem for me would be between 125 and B, where I can't use the technique I just described.

craigclu · Apr 19, 2008

eumenius said:
Okay, I became interested in this thread and made a small test with P67 on my work. I put a switched-on laser pointer on the camera with a tight rubber band, put the system on a tripod in a long room, and fixed a sheet of paper on opposite wall (5 meters away, approx.) where the red dot is projected on this screen. I was standing near the dot, and released the camera by 5m long air release. Lo and behold! The vibration IS there, and it's especially high in sideway direction - as it should be with that huge FP shutter. The dot made about 2 centimeter travel here and there, and did not return in its exact original position. I was using a VERY heavy Manfrotto tripod with central column (positioned down), well locked, and a very massive Manfrotto Ball head - the tripod I use with my LF systems. That's the purely scientifical test, so you be the judge.

Zhenya

I did something similar some years ago while comparing tripods for the P67. I burned some old freezer-aged rolls of odds and ends and inspected the on-film patterns. I found much less vibration recorded on the film than what seemed apparent from watching the dot. I learned of the widely varying behavior of the tripods and heads in combination with the P67 and concluded at the time that certain combinations dealt better with the specific frequencies present. Some heavy rigs fared less well than certain middle-weights.

It even seemed that something as simple as the softness of the head to camera material changed the results. A Bogen head with a cork surface plate was better than the rubber version plate, for instance.

max_ebb · Apr 20, 2008

It seems that some people are comparing apples to oranges at this point. In my experience (and the experience of many others, judging from reports I have read), the main problem with the shutter vibration is when shooting extreme macro (my own experience), and with long telephoto lenses (reported experiences that I have read), AND using slow shutter speeds (not just slow shutter speed shutter speed by itself). I have taken a lot of tack sharp landscape photos with a 105mm and 165mm lenses at slow shutter speeds without any problems. IMO (and in my experience) the argument that 'a lot of sharp images have been made with the p67 over the years' is completely beside the point if one is comparing apples to oranges.

dpurdy said:
Since I started this thread with a question and then said I was going to test it I will "report" my test result in case someone looks at this with a search. Putting the camera on a heavy tripod intended for 8x10 with a heavy duty bogen head and putting the camera strap over the prism to weight the camera down and shooting mirror locked up and mirror not locked up at 1/4th second I could see absolutely no difference and every image on the roll is sharp. Which leads me to conclude that there is no internal vibration and a good solid tripod with a tight head eliminates the vibration problems with or without the camera bag drapped on the camera as I tried it both ways. So if you are willing to carry a heavy tripod out on a hike, the Pentax 67 is an excellent camera.
dennis

What type of photos were you taking in your tests? Were any of them macro at 1:1 or more magnification? Did you use a long telephoto lens for any of the test images? When you say that every image on the roll is sharp, how large did you print them? Did you print them 16x20 or larger? If you didn't do any macro or telephoto shots, and/or you didn't print them to 16x20 or larger, then I would opine that the evidence you are providing is anecdotal at best.

Kent10D said:
I think the evidence is in 30+ years of very fine photographs taken all over the world with this system, from the 6x7 through the 67 to the current 67II. They're out there, they're sharp, and there are lots of them.

Unless you are talking specifically about photos that are 1:1 or greater macro, or were taken with a long telephoto lens AND were taken at slow shutter speed AND were printed to 16x20 or larger, the point is completely moot IMO.

dpurdy · Apr 20, 2008

Well of course my test was anecdotal. I am a guy with a camera and a tripod just shooting stuff and looking at in my enlarger or with a loupe. I just wanted to see if there was any difference with or without mirror lock up if I made the camera as stable as I can. Trying to see for myself if I could detect any internal motion. My lens was a 165 and I shot closest focus possible. I actually printed a neg from the test and it looks absolutely sharp. I still have the camera set up on that tripod and several times I have laid my hand on the prism and fired off the shutter with and without mirror lock up and I can only feel it when it closes. However I can hear it very well.

To me and for myself it means that when using the camera at slow speeds, if I can find a way to completely lock the camera down stable, the mirror flapping open won't cause internal vibrations.

but that is just anecdotal of course.
Dennis

dynachrome · Apr 20, 2008

Pentax 67 Vibration

My two 6X7 cameras are Bronica GS-1s. I find the GS-1 with a Speed Grip and eye level prism finder to be easier to use hand held than any of the Pentax 6X7 models. They are both heavy but I just like the feel of GS-1 better. The GS-1 has no shutter, It just has a mirror box. Each Zenzanon lens for the GS-1 has its own leaf shutter. There is mirror slap to contend with when it comes to the GS-1 too but there is very little vibration or noise from the shutter of each lens. Medium format SLR cameras with focal plane shutters have both the mirror slap and the extra shutter noise/vibration. Try running your test with a leaf shutter lens on the Pentax and see if that makes a difference. I find with my Bronica cameras that their extra weight cancels out some of the vibration at soeeds where I can hand hold.

max_ebb · Apr 20, 2008

dpurdy said:
To me and for myself it means that when using the camera at slow speeds, if I can find a way to completely lock the camera down stable, the mirror flapping open won't cause internal vibrations.

but that is just anecdotal of course.
Dennis

My point was that I haven't seen or heard very many reports of problems with shutter vibration at slow shutter speeds with 'normal' photography, using 165mm or smaller lens. In my experience, it doesn't take a great tripod to get good results with those conditions/circumstances, just a decent tripod.

When you add long telephoto lenses or 1:1 macro to the equation, what worked fine for normal photography might not work fine anymore. IMO (and in my experience), it's an apples to oranges comparison. Also, if you print to 16x20 or 20x24 (or crop to print the same enlargement factor), it's possible to see softness that you might not see looking at smaller prints or looking at the film with a loupe.

max_ebb · Apr 20, 2008

dynachrome said:
I find with my Bronica cameras that their extra weight cancels out some of the vibration at soeeds where I can hand hold.

Inertial confinement. More mass is able to absorb more shock energy and keep it from converting to vibration. More mass = more inertia.

Kent10D · Apr 20, 2008

max_ebb said:
Unless you are talking specifically about photos that are 1:1 or greater macro, or were taken with a long telephoto lens AND were taken at slow shutter speed AND were printed to 16x20 or larger, the point is completely moot IMO.

That's pretty specific, Max, and I don't believe that's what the thread was about. My point is that if the image looks sharp, then it is sharp. This is a very old, very long-running camera that has produced a large number of spectacular images (spectacularly sharp, too), so getting hunkered down with laser pointers and what-not at this point seems to be a little out of sync. If the goal is scientific photography of some sort, then maybe, but that is a very limited discussion.

My point is that for general photography the ultimate test is the final image.

A question about this P67 vibration thing

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