auto ISO sucks with X cameras

Started May 3, 2014 | Discussions thread
John Carson Veteran Member • Posts: 4,253
Re: auto ISO sucks with X cameras

Jim in Hudson wrote:

John Carson wrote:

Jim in Hudson wrote:

MartinEA wrote:

As a wedding photographer and like Jim the auto ISO works perfectly for me. Photographing moving objects means I have to freeze people and that means a higher shutter speed.

Having the auto ISO working to a focal length wouldn't work for me.

If your photographing something not moving how easy is it just to move the shutter speed dial.

Fair question but one both of us should answer, not just me!

IMHO, the primary burden is on the photographer to adjust for subject motion/blur instead of having to adjust for camera-induced blur. Why? Because the camera can reasonably calculate the minimum shutter speed needed to compensate for camera blur given the effective lens focal length and whether OIS is active. By contrast, there is no algorithm to compensate for subject motion/blur because the camera can't (realistaclly) know the speed of the subject.

So what does this mean? If you're first concern is subject blur, you should be shooting in S mode where you pick the shutter speed needed for the subject. Only you know what speed is needed for a race car versus a boat to eliminate subject blur. This would leave the camera to calculate minimum shutter speed needed for all of the rest of us who want to shoot in A or P and who's first concern is camera-induced blur. Just my two cents.

Clearly, the only satisfactory solution is to allow both an absolute minimum shutter speed and a focal-length-related minimum shutter speed.

The problem with setting the shutter speed manually is that in bright conditions you might want the camera to choose a much faster speed than the minimum. I prefer to reserve manually setting the shutter speed for those emergency situations where you know the camera will choose too low a speed for some unanticipated fast moving subject.

I understand but you can't possibly know in advance the needed minimum shutter speed required to eliminate subject motion blur. There's absolutely no relationship between motion blur of someone's face and a race car. It's going to be different for every combination of relative subject speed and focal length. This is why no other camera maker (to my knowledge) has bothered to provide such a setting... they know it's a waste of time. Instead, everyone else has focused on the one thing that can be known and controlled via calculation... camera shake. For some unknown reason, Fujifilm has all of a sudden shifted gears from solving a solvable problem to solving an unsolvable problem.

It is not a problem that can be solved with 100% success, but it can be solved with a success rate in the 90%s. Usually people have  a pretty good idea if they will be photographing people or race cars and change their settings in advance to reflect that fact. Likewise, if you are going to photograph people who are stationary and talking, then you have one setting. If you are photographing people who are walking, you have a different one.

As an aside, it is not so much focal length as the number of pixels traversed with a given movement of the subject. Thus with a fixed focal length, you get more blur with a subject that is close to the camera than one that is far away. If the subject is a constant size in terms of the photo frame, then focal length is largely irrelevant. Those using a zoom lens will frequently seek to maintain a constant sized subject.

Pick a shutter speed that works when the subject is at its largest. That will also work for smaller subjects.

This requires experience and experimentation. I recently spent some time photographing walking subjects in order to get a feel for what shutter speeds were required.

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john carson

 John Carson's gear list:John Carson's gear list
Fujifilm X-E2 Fujifilm XF 18-55mm F2.8-4 R LM OIS Fujifilm XF 55-200mm F3.5-4.8 R LM OIS
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