M240 live view-induced shutter vibration

[JimKasson]

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There has been discussion here and elsewhere on the web of vibrations caused by the closing and then opening of the shutter with a tripod-mounted M240 and long lenses. I've done some testing, and have concluded that it's not a problem with focal lengths of 135mm or less and M-mount lenses on a sturdy tripod.

 

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However, with really long lenses like the Nikon 400 f/2.8 tested here, you should turn live view off before tripping the shutter.

 

The M240 live view vibrations are nowhere near as bad as SLR mirror slap.

 

Jim

[jaapv]

A bit difficult turning it off. How are you going to focus/frame?

[JimKasson]

A bit difficult turning it off. How are you going to focus/frame?

 

I'm assuming the camera is on a tripod. so:

 

 

1. Make sure you're using classic metering
   
2. Set the shutter release mode to self-timer.
   
3. Focus and frame
   
4. Hit the LV button once if you're using the LCD on the camera back, twice if you're using the EVF. Now LV is off.
   
5. Press the shutter release and immediately take your hand off the camera.
   
6. After the shutter has cycled, press the LV button to turn LV on, and press the button on the back of the EVF if you want to use it.
   

 

Jim

[jaapv]

Assuming that the subject is static - which normally not. These lenses as a rule are used for wildlife and sport. Actually a tripod is often more of a hindrance than a help. I prefer a beanbag (which absorbs such vibrations), a chest pod or a monopod.

For a tripod you need terra firma (it is a nightmare using a long lens from a vehicle because it is unstable on its springs) and on foot it is a bit unwieldy, so it would be from a hide or the sidelines of the sports field -and your subjects are moving around. I agree that for leisurely static shots it might be a consideration. I seek my salvation in short shutter times and higher ISO, which works fine on the M.

[farnz]

... immediately take your hand off the camera. ...

If you're doing a vibration test you should not be touching the camera at all and should be using a remote release or at least the 12-second timer to let the vibrations attenuate sufficiently to be negligible otherwise you're at risk of defeating the purpose of the test.

 

Pete.

[JimKasson]

If you're doing a vibration test you should not be touching the camera at all and should be using a remote release or at least the 12-second timer to let the vibrations attenuate sufficiently to be negligible otherwise you're at risk of defeating the purpose of the test.

 

Pete.

 

The operative words are "at risk".

 

What you say is true if you don't have a way to measure how fast the vibrations from your hand damp out and you want to be safe. Since I do have a way to measure how fast the vibrations damp out, I can say with the M240 and both the APO-Telyt and the Nikon 400mm f/2.8, that 2 seconds is enough. I tried it both ways.

 

If I had a cable release that fit the M240 I would be using it.

 

Jim

[JimKasson]

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...let the vibrations attenuate sufficiently to be negligible.

 

Pete, you're absolutely right when you say that some vibrations take many seconds to die away. Take a look at what happens with mirror slap on the D4 and the 400mm f/2.8 (work completed this afternoon). The time constant of the decay exponential is at least two seconds, which means that it takes about six seconds for the vibrations to decay to one pixel peak-to-peak. And that's with big D4 pixels!

 

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Jim

[A Sfeir]

It would seem to me that the point at which the camera is attached to the tripod should make a big difference in the results.

Indeed, if the camera itself is attached to the tripod, the inertia force due to the shutter (or mirror) motion, would be transmitted to the tripod directly, and much of it neutralized.

In the case where the lens is attached to the tripod, the camera body mass is hanging away from the tripod mount, and the inertia jerk will induce an oscillation of the camera-lens around the point fixed to the tripod.

Does this make sense?

[JimKasson]

It would seem to me that the point at which the camera is attached to the tripod should make a big difference in the results.

Indeed, if the camera itself is attached to the tripod, the inertia force due to the shutter (or mirror) motion, would be transmitted to the tripod directly, and much of it neutralized.

In the case where the lens is attached to the tripod, the camera body mass is hanging away from the tripod mount, and the inertia jerk will induce an oscillation of the camera-lens around the point fixed to the tripod.

Does this make sense?

 

Absolutely! Unfortunately, you don't usually get a choice where to attach a long, heavy lens -- you need to use the collar on the lens itself. This is partially to make the combination not so front-heavy that you can't control it, but also -- and in my mind, primarily -- to keep from destroying the camera lens mount alignment.

 

Jim

[jaapv]

That is why the old Telyt 800 had two tripod mounting points, one to the rear more or less and one at the front. It needed two tripods.

The littérature on the use of long lenses recommends draping a beanbag over the front of the lens to dampen vibration.

[algrove]

Do agree anything that can help reduce shutter vibrations is welcomed. It's just expedient.

 

I often use a long tripod support made by RRS. But this is for static subjects. I always use a cable release with any lens on a tripod and do wait for vibrations I cause to hopefully subside.