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Author Topic: Focal Length Reciprocal Rule + mirrorless body  (Read 1044 times)

JohanCruyff

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Focal Length Reciprocal Rule + mirrorless body
« on: July 28, 2013, 07:53:44 AM »
Basic rule (FF): without IS, shutter speed should be 1/focal length.

APS-C rule: without IS, shutter speed should be 1/(1.6 * focal length).

What about (APS-C) mirrorless bodies rule, fellow friends from Canonrumors?
I suspect that the shutter spead should be much faster, because the camera body, without viewfinder-eye contact, is less stable than the DSLR's one.

Is there a basic empirical rule/suggestion for mirrorless, for example 1/(3 * focal length)?







Thank you in advance.
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Focal Length Reciprocal Rule + mirrorless body
« on: July 28, 2013, 07:53:44 AM »

neuroanatomist

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Re: Focal Length Reciprocal Rule + mirrorless body
« Reply #1 on: July 28, 2013, 08:03:27 AM »
I believe that Canon still applies 1/(1.6 FL) when selecting shutter speed in Av.  But you're correct that holding a camera for live view is less stable. Also, if you're judging 'in focus' by viewing at 100% on a monitor, higher pixel densities mean you need higher shutter speeds.
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JohanCruyff

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Re: Focal Length Reciprocal Rule + mirrorless body
« Reply #2 on: July 28, 2013, 06:11:34 PM »
Thanks.  :)




I'd like to share what I found on Canon Camera Museum: they seem to suggest that using hands and strap increases stability. Increases up to a DSLR level or not?




http://www.canon.com/camera-museum/design/frontline/product/eos_m/page3.html
Italian amateur. Gear: i) 5d Classic, 17-40 F/4 L, 24-105mm F/4 IS L, 100mm F/2.8 IS L, 70-200 F/4 IS L. & EOS M, 22 F/2, 18-55 + Mount Adapter, 55-250 F/4-5.6 IS STM
ii) Wife: Canon G12
iii) First Daughter: Canon 1100D, 18-55 IS iv) Son: Canon A1000IS v) Second Daughter: Nikon L21

Marsu42

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Re: Focal Length Reciprocal Rule + mirrorless body
« Reply #3 on: July 28, 2013, 07:19:28 PM »
I suspect that the shutter spead should be much faster, because the camera body, without viewfinder-eye contact, is less stable than the DSLR's one.

Absolutely, that's why newer cameras (6d, 5d3) allow you to set a min shutter speed in the firmware. You can get the same effect by using Magic Lantern's "ML Auto ISO" which lets you do the same and more, Canon's old school formula from the previous century most of the time results of in either too fast (wide angle, static scene) or much too slow (moving subject, shaky camera) shutter speeds.

dilbert

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Re: Focal Length Reciprocal Rule + mirrorless body
« Reply #4 on: July 28, 2013, 08:20:21 PM »
1/(focal length) is for 35mm film.

For cameras such as the 5D2, you probably want 1/(1.6*focal length) too.

The "algorithm" (as such) is based on the size of film grain and the amount of motion that the camera (and thus front of the lens) could sustain before a line of light would blur.

For this reason, the higher the MP count on a FF sensor, the higher the multiplier.

For a 5D2 or 5D3, you should also be applying 1/(1.6*FC). For those that own the D800, they're looking at 1/(2*FC). This is an operational cost of having high pixel density sensors.

And is why lens stabilisation is important.

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Re: Focal Length Reciprocal Rule + mirrorless body
« Reply #4 on: July 28, 2013, 08:20:21 PM »