E-M5 micromanages shutter speed in A mode

Started Aug 19, 2012 | Discussions thread
Veteran MemberPosts: 5,298
Re: E-M5 micromanages shutter speed in A mode
In reply to Allan Brown, Aug 20, 2012

Allan Brown wrote:

gollywop wrote:

Allan Brown wrote:

klauspauk wrote:

Where do you hide all these marvelous photos you took after you took this clever test ?

gollywop wrote:

Allan Brown wrote:

gollywop wrote:

Allan Brown wrote:

gollywop wrote:

In the 3rd UniWB/AutoWB discussion thread, Detail Man raised the issue, apparently initiated by Andy Westlake, that some (many) cameras select finer than 1/3 EV shutter-speed divisions when setting exposure in Aperture Priority mode. Some of the cameras that do this apparently report the actual (finer) divisions in the Exif data, while others simply report a figure comporting to the standard 1/3 EV divisions. Since the E-M5 only reports 1/3 EV divisions, it is not clear whether it is among the cameras that use finer speeds or not.

How does this differ from the "continuously variable shutter speeds" that was a feature of many electronically controlled cameras since at least the 70s?

Well, Allan, I'm not exactly sure, but if it does differ, it doesn't appear to differ much. And I'm not sure just what they mean when they talk about "continuously variable." But the gradations do appear to be fine grained.

Well, I remember seeing a graph of the shutter speed vs exposure for A mode. I believe it was for the Yashica Electro GT.

Anyway, it was step-less - continuously variable within the limitations of the mechanical shutter. It was definitely not by EV steps.

Allow me to risk belaboring the point, but nothing digital is continuous. An exposure calculation is made to determine the shutter speed. It is made in integer arithmetic and the number is stored in some number of bits. I have no idea how many bits that might be, and it could vary from camera to camera, but 8 is a likely possibility. That would imply 256 steps. Maybe it's twice that, or four times -- but they are steps. And the steps could indeed be in equal fractions of an EV.

And, so what?

Have you even considered the possibility that the digital resolution may be greater that that of the mechanical shutter and, therefore, essentially it is step-less?

That statement makes no sense. Please desist.

makes no sense?

Oh, ye of little understanding.

More time wasted on my part. Having intelligent discussions with people on this forum is, well, a scunner.


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