How Heavy a Tripod is "Stable Enough" ?

[Steaphany]

I've heard the guide line that to hand hold a camera, you need to have the shutter at a minimum of 1 / Focal Length, and obviously if the composition allows for a faster shutter speed, the better.

Today I was reading a product review article in the January 2012 issue of Rangefinder for the Phase One IQ180 Digital Back by Stan Sholik where Stan writes:

The first thing I learned was that hand holding it ( the IQ180 Digital Back ) on a Phase One camera, even with a 55mm lens ( equivalent to a ~35mm Wide Angle on an 35mm Full Frame ) and a high shutter speed, defeats the purpose of all that resolution.

Stan continues:

The system requires a solid tripod or studio stand to deliver the sharpness of which it is capable.

Huh

First off, I wondered how much resolution was he talking about ? Granted, the Phase One IQ180 is classed as Medium Format with a 53.7 x 40.4 mm CCD with a 5.2 um photosite pitch. Well, this is not quite a medium format frame size which are typically 60 x 60 mm, 60 x 45 mm, but frame size and photosite counts don't measure resolution. As I started with and still shoot film, I always fall back to the measure of Line Pair / mm, which amounts to the number of alternating light and dark line pairs that can be resolved per millimeter. With digital technology, the limiting factor for the minimum line is the photosite pitch. Anything less will result in aliasing artifacts from sub-photosite sampling or blending a dark and bright line pair into a mid tone grey.

For the Phase One IQ180, you need 10.4 um to resolve a minimum Line Pair, or calculating 1 / 0.0104 mm for 96.15 LP / mm.

Now I'm even more confused

OK, the Phase One IQ180 at 96.15 LP / mm beats my Sigma SD14 with only 64.10 LP / mm, but you can still buy Pharmacy/Chemist cheap crappy film with a resolution of 100 LP / mm ! If you really look around, you can find professional films that boast 160 LP / mm.

My first question that I'm seeking help with, Why would a professional photographer like Stan Sholik make a claim that a high shutter speed and wide angle lens can not be hand held for a resolution of only 96.15 LP / mm ?

Now, for my photography, Focus and resolution are paramount. This is why I still shoot film. When I calculate lens Hyperfocal distances, I use a circle of confusion matching the photosite pitch or film line width derived from the LP / mm. If a tripod is mandatory for only 96.15 LP / mm, What weight rating and stability is necessary for higher, film, resolutions ?

As it is I have a low cost Velbon DF-50 rated to 5.44 kg and my peak loading only amounts to 1.6 kg, not even reaching 30% of the tripod's weight limit, but based on the above information Do I need a heavier tripod or has Stan Sholik gotten a bit off track ?

[Colin Southern]

I tend to ask the question "what shutter speeds are you planning"? - if you're doing shots that are several minutes, then you may well benefit from something VERY solid - but if it's just you're "average" "fraction of a second" then I wouldn't be going overboard.

[Glenn NK]

I'm surely not going to recommend a tripod to anyone - but the question isn't unlike asking "how high is up"? There isn't an easy answer. If there was, I wouldn't be on my fourth in five years.

I've only found one article on vibrations concerning photography, you can look at it or DL it from here:

http://www.box.com/s/q1yj0jxecmudpd9i4vbc

I will point out a few things that I know based on my knowledge of materials (as a structural engineer I deal with these on a daily basis):

Strength and Stiffness are not the same thing. Consider a heavy rubber band and a piece of light sewing thread; when you stretch both gently, the rubber band stretches easily, the thread does not - the thread is stiffer. When you pull harder, the thread will break much easier than will the rubber band - the rubber band is stronger. Obviously rubber would be a poor material choice for a tripod.

To prevent vibrations, whether it be a building frame, a floor system or any other physical system, stiffness is the critical factor. Stiffness is the attribute that limits deflection and vibration.

A tripod will rarely collapse under the weight of a camera, so strength is not often the primary attribute for a camera tripod. If the camera is a large heavy view camera, then strength could be the important attribute.

One of the higher end tripod manufacturers in the world is Gitzo. They make tripods of aluminum and carbon fibre. Most pro or advanced amateur photogs use carbon fibre, and I think one reason is that they are lighter to carry around. For a given weight, carbon fibre is both stronger and stiffer than aluminum.

I've looked at many manufacturers websites; not one rates the tripods for stiffness - they are all rated for weight. Weight capacity tells me how strong the tripod is, but doesn't really tell me how stiff it is or how resistant it is to vibration.

And of course, the other reason I mention vibration is that the pdf I linked to primarily is considering how to limit vibrations.

Obviously I haven't provided any answers, and perhaps not any useful information. Other than the pdf file, I haven't found anything that really address the primary problem - vibration.

Glenn

[Colin Southern]

PS: THis is an oldie but a goodie ... Best Tripod and head for stability and I've STILL yet to see anyone emulate my Gitzo test!!! (post #13)

[Black Pearl]

The bloke is right. Unless you have any camera on a solid tripod, use the mirror lock-up and a cable release you will never get the full resolving power of all of your pixels. I am the first to scream at pixel peepers but in this instance I'll keep calm and just say go try some test shots with and without factors like a Tripod/MLU/Remote Release - then view them at 100%


A couple of points:

Your Velbon DF-50 is rated to 3k but that is just the maximum weight it can hold without the head slipping. It is a mostly plastic tripod and one of the least stable ones I know of. Yes it is better than nothing - any tripod is better than nothing - but it is far, far from being decent so any slow shutter shots are going to still show serious amounts of sharpness loss due to the camera moving.

So yes you need a better, more sturdy tripod if you want sharper pictures.

You say resolution is critical in your photography but other than your 28mm (assuming its a good one) none of your lenses have a decent resolving power so whether you're shooting with your film or digital body you are not getting what they can output. Even at their optimum aperture I'd be highly surprised if they go beyond the sensor/films capabilities.

Stick a good prime on the front an do some tests.

[Colin Southern]

Stick a good prime on the front an do some tests.

An EF600 in a stiff breeze will do nicely

[Steaphany]

If photographic tripods have no specification for vibration dampening and stiffness, Look else where. I know the fields of laser optics have severe specifications on stability and vibration. A deviation of a few nm would be sufficient to ruin a holographic exposure.

I've looked at optical antivibration tables which aren't the most portable, but in the field of precision surveying equipment, the tripods do list their vibration dampening characteristics.

What your opinion on something like a Leica GST40 applied to photography ?

[JonathanC]

I wonder what type of camera he was using? If it was something like an RB67 with the two pound mirror flapping about (I know its not quite that big) he would see problems. Shooting a shotgun from the hip comes to mind as an analogy here.
Here's something I found relating to a Pentax 67 (Dear Santa....) http://www.luminous-landscape.com/re...ntax67ii.shtml
This article points out that even shutter vibration in a big shutter camera like the P67 causes camera shake. As newton pointed out, when a big shutter mechanism goes one way, the camera is very likely to want to go the other way.
I suppose the way forward is to get away from SLR type cameras and go to leaf shutter folders of something like a Mamiya 6 or 7 rangefinder. The tripod ought to have a lot less to cope with as there's so much less mass whizzing about when you take the picture.
Just out of interest (nosiness) Steaphany, what MF camera do you use?

[Glenn NK]

More ramblings - ignore as you wish.

Had a look through the thread that Colin linked to. I've seen other photos of people hanging from their tripods - which pretty much proves that the weight capacity of a tripod isn't much of a guide as to how it will perform in the wind.

http://www.manfrotto.ca/product_list...0.0/055_Series

The Manfrotto 055 Series are quite common - 7 or 8 kg capacity (15.4 to 17.6 lb). I had one - it was tripod number two.

Colin's demo would seem to indicate that the ratings of the tripods are very conservative - and yet many of these tripods will vibrate in the wind. So much for weight ratings.

The reduction of internal vibrations (mirror, shutter) can be minimized by using ML (mirror lockup), but external (wind) vibrations are another matter. It's my feeling that if it's really windy, one is better off hand-holding with a high shutter speed. The advantage of this is that the mass of one's body doesn't usually vibrate in the wind. Although I may wave back and forth in the wind, I don't usually vibrate.

I don't think there is a perfect tripod - but my philosophy says there is no perfect anything.

Glenn

PS My latest version is a Gitzo CF tripod.

[rpcrowe]

A quick and totally unscientific answer...

I usually recommend that a photographer select as his/her tripod/head combination; one that is rated for at least twice the weight of the heaviest unit you expect it to support. This may be overkill but, I think that manufacturers are very liberal when they list the capacity of their tripod.

Additionally, I tend not to use the center column to elevate my camera when shooting tripod mounted.

Finally, the type quick release setup you use will influence the capability of a tripod/head to support a camera/lens. This is especially true when using the camera in the portrait position.

When shooting in the portrait position with the camera attached directly to the tripod head or when using a standard quick release such as the Manfrotto RC2 sytem; the camera hangs cantilevered over the the side and therefore is not as stable as when the camera is placed directly over the head and apex of the tripod.

However, when shooting with an Arca Compatible quick release system and a L-plate such as produced by Really Right Stuff; the camera is situated directly over the apex of the ripod, not hanging off to the side. You can get away with a lighter tripod/head when using an L-plate...

http://reallyrightstuff.com/WebsiteInfo.aspx?fc=80

I use a Giottos carbon Fiber MT8180 Tipod with a Giottos MH1300 head and Arca Compatible quick release system. This is a very sturdy tripod which articulates and can securely lock into place at virtually any angle.

However at about eight pounds, it is a decent load to carry when I am boonie tromping and contraindicated when I am flying because of the limited baggage weight allowance of some airlines. It is however a great tripod for long lenses and for long exposures.

I modified a lightweight SLIK Pro 330D tripod by substituting an optional shorter center column and by switching from its heavy stock pan-tilt head to a lightweight Adorama Flashpoint F-1 ball head which has an Artca Compatible quick release which can take advantage of my Artca Compatible plates including L-plates.

I have used this outfit with my 1.6x cameras and 70-200mm f/4L IS lens in some pretty stiff winds in Utah and it works fine. It would not be my selection for "only tripod" but, serves its uses for travel and boonie tromping.

My modified Slick next to my Giottos full-size tripod...


The SLIK/Flashpoint setup with my camera and lens...


The one problem with the SLIK is that it is fairly short. However, I am willing to bend over a bit and/or use a right angle finder to have a tripod/head combination that is reasonably sturdy and weighs right at about 2.2 pounds or 1-kilo.

Sometimes, if you can make do with a shorter tripod you can get a lighter and/or less expensive tripod to suit your needs.

BTW: I used wood tripods for motion picture photohraphy and they were stable as a rock. They were also very heavy and fairly difficult with which to work since they did not articulate to place your camera where you wanted...

[Steaphany]

Just out of interest (nosiness) Steaphany, what MF camera do you use?

Right now my only MF camera is an 1930's era Voigtländer Bessa and I want to augment this with a 1950's or 1960's era Hasselblad. ( I also want a 4x5 LF View camera, fixed body cameras compromise too much )

[rpcrowe]

You know Stephany, in the days of film, I used a Hasselblad as well as a 4x5" Graphic view camera. The teipod I used in those days was a Tiltall. It was not as sophisticated as today's tripods but, it seemed to do the job quite well. It almost seems appropriate to use a retro tripod with a retro camera.

http://www.google.com/products/catal...d=0CFIQ8gIwAA#

It didn't articulate and it certainly wasn't fancy. It was not the lightest tripod but, it was quite solid.

I don't know who makes the Tiltall now or if it is still a good unit. The Tiltall that I used was made by Leitz...

[Colin Southern]

Colin's demo would seem to indicate that the ratings of the tripods are very conservative - and yet many of these tripods will vibrate in the wind. So much for weight ratings.

Hi Glenn,

Just a couple of things to keep in mind ...

1. I've always assumed that the weight rating of a tripod includes worst-case-scenario positioning - in the case of the Gitzo, you may well end up with it setup like this ...



(Obviously I wouldn't be able to support my weight on it in this configuration, but it would still withstand it's rated load).

2. Although there's probably no direct relationship between max weight capability and tortional rigidity, there's probably none-the-less an indirect relationship. My Gitzo 1548 is so darn solid I can shoot shots like this in what was probably close to 35km/hr winds with no problems at all (the movement in this shot are trees being whipped around) ...



But as with almost anything in life, it's nearly always a trade-off. On one hand, the Gitzo 1548 & RRS 55mm ball head is solid - rigid - damn near bullet proof (after many years of abuse including frequent immersions in salt water) - but on the other hand, I think I paid something like about NZD $2500 (inc freight) - and it's heavy / PITA to lug any serious distance. For me - because I often do exposures lasting many minutes - in a breeze - it's just one of those tools that have served me well.

[Glenn NK]

Colin:

To the original question, "How Heavy a Tripod is Stable Enough", I don't think there is an answer - it depends on how and where it's being used. A tripod adequate for indoors won't cut it outdoors in a strong wind.

Heaviness or weight isn't what makes a tripod stable - stiffness is what makes it stable. With the advent of carbon fibre, the relationship between weight and stiffness has been further weakened, as has the relationship between weight and strength.

One method of decreasing vibrations is to hang a load off the centre column - there are tripods that come with a "stone bag", but my gear bag is heavier than a bunch of stones.

Glenn

[Colin Southern]

Colin:

To the original question, "How Heavy a Tripod is Stable Enough", I don't think there is an answer - it depends on how and where it's being used. A tripod adequate for indoors won't cut it outdoors in a strong wind.

Heaviness or weight isn't what makes a tripod stable - stiffness is what makes it stable. With the advent of carbon fibre, the relationship between weight and stiffness has been further weakened, as has the relationship between weight and strength.

One method of decreasing vibrations is to hang a load off the centre column - there are tripods that come with a "stone bag", but my gear bag is heavier than a bunch of stones.

Glenn

Hi Glenn,

I don't disagree

There are even more variables - like mass damping where a tripod can aid in keeping a camera stable even with vibrations (from traffic etc) shaking the tripod.

Personally, once I open the shutter for a long exposure I move away from the tripod - or for shorter durations, I'm sure to keep very still.

Although "heaviness or weight" may not make a tripod stable, there's probably a pretty good co-relation between a heavy/solid tripod and one that is stable (or more stable than a cheap/nasty).

Also probably a good assumption that an expensive one will have more of these variable optimised for performance as opped to a cheaper one that would probably be more "optimised for a low price".

Either way, I'm sticking with my Gitzo (I've even used it as a crane to lift camera bags over a fence at night -- and that was just 1 leg!)

[Steaphany]

As my original question

Why would a professional photographer like Stan Sholik make a claim that a high shutter speed and wide angle lens can not be hand held for a resolution of only 96.15 LP / mm ?

was never addressed, I conclude that no camera should ever risk being hand held. ( Good thing I never wasted any money on image stabilizing lenses, IS needs to be turned off when on a tripod. )

After some research, I found something which may work for me:

Berlebach 3032

Rated for 12 kg, 26 lb, and being wood, they at least specify the vibration damping at being very good ( what ever that means )

[Glenn NK]

Good thing I never wasted any money on image stabilizing lenses, IS needs to be turned off when on a tripod.

This is only partly true. The first generation of Canon lenses had to have the IS turned off when on a tripod.

Later (newer) models sense that the camera is stable and on a tripod, and don't activate. I have two lenses for which this is true: EFS 17-55 and EF 24-105. Basically I never turn the IS off - ever.

Actually this makes sense. Suppose a photographer was able to hold the camera/lens as motionless as a tripod - should the IS activate? Would it have to?

It's reasonable that IS only activates when it senses that the camera is not absolutely still.

There is much debate about the cost/benefit of IS/VR/OS on many forums (and the same old tired arguments keep coming up). I refuse to be part of it.

Glenn

[Colin Southern]

Later (newer) models sense that the camera is stable and on a tripod, and don't activate.

Hi Glenn,

I had an interesting exchange of eMails with Canon's tech guru Chuck Westfall about the IS unit in the 70-200 F4.0 IS USM - he draws the distinction between a tripod mounted lens with IS enabled essentially going into standby mode (where it shifts the image down slightly after 1/2 second or so) -v- having it switched off altogether (where it's caged). He felt that having it switched off was "better practice", although I must admit that I leave mine on if there's any wind.

Not sure if this appies to many other IS units, although the one referenced above is a 3rd generation / 4 stop unit, which I believe is still the current technology. I have witnessed first hand a slight unsharpness introduced by the older EF70-200 F2.8L IS USM with IS on whilst tripod mounted (which in theory being a generation 2 unit should also have been "tripod aware") (in the end we pretty much eliminated the degradation with more agressive capture sharpening.

[JonathanC]

As my original question



was never addressed, I conclude that no camera should ever risk being hand held.

I thought I had alluded to what might cause the issue earlier, however:-
Well let’s do some sums to work this out then.
He is using a 55mm lens and blur would be seen as movement of one half a sensor pitch of the image, or so I’m going to assume.

To turn that into something that we can think about, let’s use a tree at a range of 55 metres, so that would be 1000 times the lens focal length from the camera.
The pixel pitch is 5.2um, so the tree detail would be 5.2mm per sensor pitch, which would be quite a small twig. If the camera were to move enough that the twig appeared to move more than half that distance, or 2.6mm, we might begin to detect blur.

Going to the amount of movement of the camera required to cause this blur brings on the dreaded trigonometry. The sine of the angle that the camera would move would be movement divided by subject distance i.e. 2.6/55000 (in mm) = 4.73E-5
Turning this into an angle sin-1(4.47E-5) gives an angle of 0.0027 degrees of movement.

At a shutter speed of, lets pick 1/125 as being “comfortably fast enough for hand holding”, then the camera has to be turning at a rate of 0.0027 X 125 = 0.34 degrees per second, or 20 degrees per minute. Eighteen minutes for a full turn, that doesn’t seem to be what you might call fast, more like imperceptible as its only three times as fast as the minute hand on a clock.

I think that what he is seeing here is the springiness of the stuff on his fingers, the skin, flesh, muscle and other bouncy stuff. If, as I suspect, he’s using a large medium format SLR, it will have some mirror recoil. Now most SLR mirrors work on a hinge, so the rotation of the mirror will cause the camera body to try to rotate in the opposite direction. If that recoil is not prevented, the camera will move. If the camera restraint is springy, like the guys fingers, then the camera will move.

Now we can ask the guy what the modulus of elasticity of his fingers is and things like that, but I bet its pointless. He should use film and a good MF camera like a Bessa with a leaf shutter and all his problems will go away.
HTH

[Glenn NK]

Interesting and illuminating post Jonathon. Thanks for going through the calculations (I checked them; you nailed it).

I use a tripod for virtually every image I take with the exception of informal family pictures (last night was my nine year old granddaughter's birthday). At these occasions a tripod is too awkward. For everything else I use a tripod because what you are saying is correct. I might suggest that in addition to the factors you point out, small imperceptible hand tremors are more common than is realized/noticed and add to the problem with hand-holding.

Related to this issue, there is an ongoing thread on POTN wherein the OP was shooting images of his dog, and is not happy with the focusing of his camera. One reply pointed out that in one image, the catch light in the dog's eye was a vertical splash of light (the eyeball surface is roughly spherical, so the catch light should not be a vertical line). The image was taken at 1/500 second and the vertical blur is obvious (the dog was running and its head was bobbing up and down). It was suggested that 1/500 wasn't fast enough - based on the evidence, I would concur.

As an aside, I find that one of the major advantages of live view is that by zooming in 10X, the amount of movement the camera and/or the object is undergoing becomes quite obvious. My first body didn't have LV, and I would wait for flowers to stop moving; with my newer LV equipped camera, it became obvious that there was more movement than I could detect with the naked eye and no magnification.

To me, the tripod is as essential as the camera.

Glenn

PS: In case not everyone understands the numbers with E-5 behind them, it means that the decimal point is moved to the left five times (for E-5).