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A Off-day or not good fitting Camera?


PasMichiel

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That question sounds maybe strange, but I'll try to explain:

 

I think I have a theory about flash-synchronization-time and the minimum time you can take a picture without a flash: "Half flash-synchronization-time is the minimum!"

 

As that been told you get this: The R4 and R5 (I have those, so I can tell) have a flash-synchronization-time of 125, so a 60 is still good in the greatest aperture.

 

The R8 (the worst R I have, I think) has a flash-synchronization-time of 250, and I can only take pictures at a minimum of 125. (nice for outsite photography only I think).

 

The M4-2 and M6 (I have those, so I can tell) have a flash-synchronization-time of 50, and I take pictures a a minimum between 15 and 30 without any trouble.

 

 

Is there a connection??

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Not sure I understand you. If the flash sync speed on a focal plane shutter camera is say 1/125th, you can shoot with flash at any speed below that.

 

With a leaf shutter you can shoot at any speed full stop - that's one of the reasons I used a Bronica ETRS for weddings, because of the ability to use fill in flash at any shutter speed.

 

The M7 with dedicated flash has some feature that allows fast speeds with flash sync, I think by firing a very quick series of flashes.

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James, I think what the op is saying is that the slowest speed you can shoot handheld (without flash) is twice the flash sync speed. So if the flash sync is 1\60th the slowest speed you can shoot handheld at 1\30th. As pointed out this doesn't make sense.

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Flash sync speed is related to shutter technology (the picture frame must be ENTIRELY exposed when light flashes).

Minimum speed one can work handeld is related to factors like camera shake when shutter fires (and, in SLR, mirror moves), lens' focal, photographer stability, way to handle the camera (at eye is different than, for instance, with a TLR).

Anyway... unrelated issues.

There was an old dumb rule that, for SLR, min. handeld speed is around 1/focal length... 50mm=1/60 28mm=1/30 200mm=1/250...

RF cameras are notoriously more stable for absence of shake induced by mirror movement... many people say that a Leica M with traditional cloth shutter can work fine, for instance, at 1/8 with a 35 mm lens... of course, depending on the photog, the sbject distance etc... ;)

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Shake factors:

 

Nicotine - don't smoke

Alcohol - don't drink

Drugs - avoid

Stress - keep calm

Exertion - rest before taking a photo

Physiological - seek medical help

 

I remember years ago a photo magazine - PP I think - doing a piece on this; nicotine came out as a top factor in causing the shakes, more so than a glass of wine or a brisk walk up a steep hill.

 

Regards,

 

Bill

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Shake factors:

 

[...]

Alcohol - don't drink

[...]

 

 

Here is a contradiction: persons who have Essential Tremor, AKA Familial Tremor, very often benefit from a couple ounces of alcohol because it temporarily stops or lessens the tremor. You can check it out in authoritative medical literature.

 

I am not recommending the practice, but it usually works.

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Back in the '70s there was a Canadian snooker professional, Bill Werbenuik (sp?) who had a benign tremor kept in check by lager; he drank pints of the stuff at each tournament.

 

Regards,

 

Bill

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Then I find it strange that with a 50mm on a R I need a faster time as with a M.

 

That's easily explained. In an R you have a vertical-travel metal focal plane shutter and a mirror in an M it is a horizontal-travel cloth focal plane shutter and no mirror. The M is easier to hold at lower speeds because there is less crash-bang going on inside the body. :D

 

The other factor may be direct vision - the fact that you continue to see the subject with an M, whereas with an R there is a blackout when the shutter fires; this can be disorientating.

 

Regards,

 

Bill

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Back in the '70s there was a Canadian snooker professional, Bill Werbenuik (sp?) who had a benign tremor kept in check by lager; he drank pints of the stuff at each tournament

 

He was also allowed to claim it against tax. Something we non-snooker playing mortals can only dream about.

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Well, there may be an indirect link to sync speed and hand-holdability with focal-plane shutters (not a leaf-shutter Rollei). The faster the X sync, the faster the shutter blades/curtains have to be moving to allow the whole frame to be uncovered all at once, which means the first curtain slams to a stop harder.

 

E.G. in a vertical-blade shutter, the blades have to be 1" apart at sync speed for the whole frame to be uncovered at the moment of the flash. If the sync speed is 1/90th sec, the blades have to be traveling 1" in 1/90th sec. (~8 kph), and if the sync speed is 1/250th, they have to be traveling 1" in 1/250th sec (~22.5 kph). In a film M, the horizontal shutter travels 1.5 inches in 1/50th sec. or 1" in 1/75th sec. (~7 kph).

 

F(orce)=m(ass)*a(cceleration), so the faster the shutter has to decelerate, the more force (shake) it will apply to the camera.

 

In addition, in a curtain shutter the braking force is rotary, as the curtain winds onto a spindle, so it may torque the camera about the centerline of the spindle but the linear left-right movements cancel out - whereas in a blade shutter the braking force or shock is linear and all in one direction.

 

But such factors as RF vs. SLR, or lens focal length are also significant, as noted in posts 9 and 16.

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