The Sony A7 thread [Merged]

[kdriceman]

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Shutter Shock Example

 

 

 

 

Details here: The GetDPI Photography Forums - View Single Post - A7r - and why I'm keeping it ...

 

 

KH,

 

How much less noticeable is it at higher shutter speeds?

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[Doc Henry]

Hmmm.. As I said in this thread before, light cameras and long lenses are not a happy combination.But increasing shutter lag? That would be a solution that does not appeal to me.

 

I agree with you Jaap !

 

I'm trying to understand this. It would seem to me that perhaps the camera mount is more stable vertically than it is horizontally since the vibration and mass are the same and only the direction of vibration relative to the tripod has changed.

 

Yes Alan , it is very possible from a "physical" point of view (if a physicist is among us it would be nice to have an opinion)

 

Best

Henry

[k-hawinkler]

Hi kdriceman,

 

Well, I almost never use Portrait mode on a tripod with very long lenses. That's where the problem is.

For Landscape mode and handholding and shooting at 1/(3*focal length) for WA to moderate tele lenses there should be no shutter shake problem. Of course, only a few select Leica M lenses give great to acceptable results with the A7R. My 16-18-21/4 WATE is simply superb on the A7R, as is my 75 Cron, 90 Elmarit, and 135/4 TE. I also have great results with the Vario 28-90/2.8-4.5.

 

Also, please note the purpose of my test was to try to find the useful limits of the system by making it fail. Now that I have found some limits I can focus on avoiding those and concentrate on finding ways to improve its use.

[naturephoto1]

Let me get my RRS L Bracket which is still listed as Pre-order (RRS indicated yesterday that the Machine shops are closed during the holidays. It looks like I may not see the bracket till the middle of January ). I will run some tests particularly in the Portrait orientation. I think that I have a way to lessen the vibration affect with much less weight than is suggested. But, I need to run the tests for confirmation. I will be testing with my A7r and my tripod mounted R 280mm f4 Apo Telyt lens. I will try to lock down the camera from the bottom of the L bracket below the camera (along the long axis of the L to try to minimize any motion moving from the bottom of the camera toward the hot shoe).

 

Rich

[AlanG]

Yes Alan , it is very possible from a "physical" point of view (if a physicist is among us it would be nice to have an opinion)

 

Best

Henry

 

So are you saying that when the camera is in a vertical position it has a greater amount of vibration than when it is in the horizontal position... everything else being equal? Is there something about gravity that is affecting this? Or does the shutter somehow change into a different mode when it senses that it is in the vertical position? How and why would it do that? This would be pretty easy to measure with a vibration meter if the camera is on a lens that is attached to the tripod via a rotating mount.

[Doc Henry]

So are you saying that when the camera is in a vertical position it has a greater amount of vibration than when it is in the horizontal position... everything else being equal? Is there something about gravity that is affecting this? Or does the shutter somehow change into a different mode when it senses that it is in the vertical position? How and why would it do that? This would be pretty easy to measure with a vibration meter if the camera is on a lens that is attached to the tripod via a rotating mount.

I'm not a physicist.... but a physician

I think the difference is minimal and partially gravity (vertical or horizontal) also occurs through

the diffusion of noise impact , the conception of the shutter also plays

...to Sony to tell us more

 

But Karl will tell us about his experience because he did installation to take pictures...... sorry

to say you more

Best

henry

[mmradman]

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I'm not a physicist.... but a physician

I think the difference is minimal and partially gravity (vertical or horizontal) also occurs through

the diffusion of noise impact , the conception of the shutter also plays

...to Sony to tell us more

 

But Karl will tell us about his experience because he did installation to take pictures...... sorry

to say you more

Best

henry

 

Time for Engineer to chip in, shutter curtain travelling horizontally with camera in portrait orientation will cause momentum [mass x speed] to be directed in vertical axis vibration is caused as transversal momentum hits solid anchor and bounces back. This effect will be less pronounced where same camera is in landscape orientation as travelling vector will encounter less resistance and hence less bounce.

 

I have similar real life/work technical problem with extra high voltage circuit breakers that are fitted with breaking elements in either horizontal or vertical orientation, it all depends on vintage, manufacturer, type etc. As with A7/R EHV CB with vertical break exert much higher forces on the foundations - similar in value to thrust from Concorde engines at take-off but for less than 0.1seconds. If anyone is curious suggest google/images 400kV circuit breaker.

[mmradman]

Time for Engineer to chip in, shutter curtain travelling horizontally with camera in portrait orientation will cause momentum [mass x speed] to be directed in vertical axis vibration is caused as transversal momentum hits solid anchor and bounces back. This effect will be less pronounced where same camera is in landscape orientation as travelling vector will encounter less resistance and hence less bounce.

 

I have similar real life/work technical problem with extra high voltage circuit breakers that are fitted with breaking elements in either horizontal or vertical orientation, it all depends on vintage, manufacturer, type etc. As with A7/R EHV CB with vertical break exert much higher forces on the foundations - similar in value to thrust from Concorde engines at take-off but for less than 0.1seconds. If anyone is curious suggest google/images 400kV circuit breaker.

 

And talking of momentum never underestimate damaging effect of lightweight objects travelling at high speed - think bullet fired from fire arm. Only few grammes of metal travelling at several hundred meters per second are capable of killing adult human or big animal.

[k-hawinkler]

Time for Engineer to chip in, shutter curtain travelling horizontally with camera in portrait orientation will cause momentum [mass x speed] to be directed in vertical axis vibration is caused as transversal momentum hits solid anchor and bounces back. This effect will be less pronounced where same camera is in landscape orientation as travelling vector will encounter less resistance and hence less bounce.

 

I have similar real life/work technical problem with extra high voltage circuit breakers that are fitted with breaking elements in either horizontal or vertical orientation, it all depends on vintage, manufacturer, type etc. As with A7/R EHV CB with vertical break exert much higher forces on the foundations - similar in value to thrust from Concorde engines at take-off but for less than 0.1seconds. If anyone is curious suggest google/images 400kV circuit breaker.

 

Thanks. I agree.

Even the Sony NEX-5N and NEX-7 seem to show just a tad of vibration with my setup.

 

The GetDPI Photography Forums - View Single Post - A7r - and why I'm keeping it ...

[k-hawinkler]

So you are saying it is the way the camera is anchored (e.g. attached to a tripod) not anything about the camera itself that changes.

 

What changes is the orientation of the shutter movement with respect to anchoring and gravitational direction.

[AlanG]

What changes is the orientation of the shutter movement with respect to anchoring and gravitational direction.

 

Yes I deleted my post after you clipped it. I understand that the anchoring is a factor and even said that back a ways. But it seems some think there is more too it than that. I really can't say. The software I recommended graphs the vibration from three axis so it should be easy to check what is going on.

[naturephoto1]

So are you saying that when the camera is in a vertical position it has a greater amount of vibration than when it is in the horizontal position... everything else being equal? Is there something about gravity that is affecting this? Or does the shutter somehow change into a different mode when it senses that it is in the vertical position? How and why would it do that? This would be pretty easy to measure with a vibration meter if the camera is on a lens that is attached to the tripod via a rotating mount.

 

Alan,

 

I think that has to do with a vertical focal plane shutter. We have the ability to better control the vibration and locking the camera (with weight or to a rail, etc.) when in the landscape orientation than when the camera is in the portrait orientation. The vibration in the portrait orientation is now left to right rather than up and down when the camera is in landscape orientation. I think it is more difficult to lock this motion, but as I mentioned above, I think that I may have a way to lessen some of this motion.

 

Rich

[AlanG]

Alan,

 

I think that has to do with a vertical focal plane shutter. We have the ability to better control the vibration and locking the camera (with weight or to a rail, etc.) when in the landscape orientation than when the camera is in the portrait orientation. The vibration in the portrait orientation is now left to right rather than up and down when the camera is in landscape orientation. I think it is more difficult to lock this motion, but as I mentioned above, I think that I may have a way to lessen some of this motion.

 

Rich

 

I think that is what I pointed out a while ago too. "I'm trying to understand this. It would seem to me that perhaps the camera mount is more stable vertically than it is horizontally since the vibration and mass are the same and only the direction of vibration relative to the tripod has changed."

[jankap]

In the landscape mode the movement is up and down. Just like, if you nod "yes" with your head.

In the portrait mode the camera rotates, like saying "no" with your head.

What does brake these movements?

In the "yes" case the tripod legs brake the movement by bending. In the other - the "no" case - the legs must brake the movement like springs. Also bending, but in another way.

 

In both cases the length of the legs play a role. A table tripod perhaps.

In film Leicas the shutter moved in the other direction. Another possible try?

Jan

[JimKasson]

What changes is the orientation of the shutter movement with respect to anchoring and gravitational direction.

 

Anchoring is the long pole in the tent. Gravity, for coupled harmonic motion, which is what we're talking about here, creates a static force that affects location of the equilibrium point, but contributes nothing to damping, being perfectly non-dissipative. In a practical sense, where the constraining forces of the mounting system are far in excess of the gravitational forces (at least on Earth), the resonant frequencies are also unaffected.

 

Pick up a guitar. Lay it in your lap, face up. Don't fret it. Pluck the low E string in the usual direction, parallel to the plane of the fretboard, and note the note and how fast it decays. Twist it into the normal playing position, press it against your tummy to simulate the damping of your knees in the first part of the experiment. Pluck the string again. Does the note change? Does the sustain change?

 

I'm working on a more comprehensive explanation, and I'll post it on my blog when I get there, but I want to start some pushback to this gravity is important theory before it becomes conventional wisdom. Even Lloyd Chambers, who's a software engineer and should know better, is promoting this gravity business.

 

Jim

[AlanG]

Former Secretary of Energy and Nobel physicist Steven Chu used to live across the street from me. Too bad he moved or I would have asked him to do some research on this.

[k-hawinkler]

Anchoring is the long pole in the tent. Gravity, for coupled harmonic motion, which is what we're talking about here, creates a static force that affects location of the equilibrium point, but contributes nothing to damping, being perfectly non-dissipative. In a practical sense, where the constraining forces of the mounting system are far in excess of the gravitational forces (at least on Earth), the resonant frequencies are also unaffected.

 

Pick up a guitar. Lay it in your lap, face up. Don't fret it. Pluck the low E string in the usual direction, parallel to the plane of the fretboard, and note the note and how fast it decays. Twist it into the normal playing position, press it against your tummy to simulate the damping of your knees in the first part of the experiment. Pluck the string again. Does the note change? Does the sustain change?

 

I'm working on a more comprehensive explanation, and I'll post it on my blog when I get there, but I want to start some pushback to this gravity is important theory before it becomes conventional wisdom. Even Lloyd Chambers, who's a software engineer and should know better, is promoting this gravity business.

 

Jim

 

 

Jim, please, parse my sentence correctly.

You seem to read a lot into my sentence that isn't objectively there!

I answered a simple question correctly.

[JimKasson]

Jim, please, parse my sentence correctly.

You seem to read a lot into my sentence that isn't objectively there!

I answered a simple question correctly.

 

If I read something into your answer that wasn't there, I apologize. I think you're doing great things to help track this thing down.

 

Jim

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Hallo,

Look here: Interesting Leica gear

[steveclem]

I don't know if this has been posted before but here you are anyway....

 

Sony A7R vibration comparison with Nikon D3 and Sony NEX-7

 

Play nicely now.

[woorob]

I wonder if someone more proficient with the a7R could help me with some of the basic camera functions as the instruction manual is so poor.

 

1. Am I correct that holding down the shutter button half-way locks the focus zone, so I can reframe the shot without losing focus on that area?

 

2. Similarly, does holding down the shutter button half-way also lock auto exposure at that EV, so I can reframe the shot while maintaining that exposure? If not, how do I do this? By pressing and holding the small button associated with the AF/MF switch located just to the top right of the LCD?

 

3. Can the three-image exposure bracketing "drive mode" setting be used at the same time as the self-timer, or are they mutually exclusive? When shooting HDR pictures with my M I always use a tripod and the self-timer, but apparently you can't do that with the a7R. Am I missing something here?

 

My actual pictures with this camera and the 35mm FE lens have been somewhat disappointing, so I'm trying to ensure I am operating it correctly. It seems to pick a higher than average ISO automatically which results in more noise than I've experienced with my M at higher ISO levels, the auto focus fails completely when taking pictures while it is snowing heavily, the menu settings are absurd and many of the exposures are off when using A or P. On the other hand, I really like the grip on the front of the body, the SD card slot is in a much better location than on the M and the weight and size are great.

 

Any help would be appreciated. Thanks!