Rab-Eye Loc: Indiana

I just want to make sure I'm correct about the guideline to use a shutter speed at least as fast as your focal length for handholding. I would assume that if your body has a 1.5x crop factor, the guideline for a 300mm lens, just as an example, would shoot at 1/450 (or 1/500), not 1/300. Correct?

Thanks and have a great Thanksgiving!

russelray Loc: La Mesa CA

I never heard of the crop factor being a factor for handholding a lens. In my 51 years of photography, regardless of what kind of camera and lens, I use 1/focal length for my minimum shutter speed for sharp pictures. So a 300mm lens would require 1/300 shutter speed for me, any lens on any camera.

JPL

I do not see a reason to increase the shutter speed because of the crop factor of the sensor. Just like you would not increase the shutter speed of a full frame when shooting in crop mode using only part of the full frame sensor for the picture.

JohnFrim Loc: Somewhere in the Great White North.

I suspect you are correct, because the rule of thumb was created in the era of full frame 35 mm film cameras.

A simple check on your hypothesis is to push the limits to extremes and think of the result. If your sensor was only a few pixels or a few mm in dimension, then movement would be very noticeable, but if your sensor was VERY large then movement would only cause a small shift in the image. Another thought is that a crop sensor effectively increases the apparent focal length of the lens, so you have to treat it as a longer lens.

dsmeltz Loc: Philadelphia

I think your assumption is correct and useful. I am usually shooting faster than the rule anyway. The rule is a minimum and I usually shoot action. As a result, I shoot faster. Usually in the 1/600 and up range. Given the better ISO performance of today's cameras, I lean toward the freeze action side of shutter speed. First determine the minimum speed needed for the kind of photograph you are taking. If it is below the minimum, then you need a tripod.

GoofyNewfie Loc: Kansas City

Yes, you are correct, but it makes very little difference with an APS-C vs FF as it's only 1/2 a stop.
VR/IS, etc has been a game changer too, so it's kind of a throwback rule of thumb.
Let's look at Nikon's P900.
It has a 4.3-357mm lens, a 24-2000mm FF equivalent.
Can you successfully hand-hold a 2000 mm lens on a FF camera at...rounding up...1/500th sec (w/o using vr)?
I seriously doubt it!
That smaller sensor has to be magnified a lot more to get the same print size as a FF camera, magnifying any camera movement.
(Thank goodness for VR!)
For the same reason, you could get away with lower than 1/focal length with medium format cameras.
That 1/focal length is a rule of thumb for 35mm cameras and should be adjusted for other formats.

htbrown Loc: San Francisco Bay Area

Let's dissect this:

The easily verified idea is that a hand-held photo taken with a slow shutter speed will show some blur because you can't hold the camera perfectly still.

The truth is that any time you hand-hold a camera, no matter the shutter speed, there will be some camera motion. The notion behind the 1/focal length rule is that the amount of motion blur will be reduced to an acceptable level by following the rule.

What is acceptable? That depends on the photographer and the goal of the photo. What's acceptable in some times and places may not be acceptable in another. Also, some people are better at holding a camera steady than are others. Thus, a rule that may work for one, may not work for others.

Let us suppose the rule works (which it does, but I'm being pedantic). What does it mean in the photo? Because the camera moves, a sharp edge in the subject is blurred slightly. The amount of blur depends in part on how much of an angle the camera moves through, which is a function of how steady your hands are. But it is also a function of how big a portion of the photo that angle represents. On a short focal length lens, that angle and therefore the associated motion blur, will be a smaller fraction of the picture frame than it would be for a long lens. The blur will be much less noticeable.

The 1/focal length rule embodies the truth that blur will be more noticeable at longer focal lengths than at shorter, and you should compensate with shorter shutter speeds. It's easily remembered, and works well enough, but it's not a absolute. It does not mean that using a shorter shutter speed will result in tack-sharp photos and longer in hopelessly blurred ones.

So to the OP's question, using the 300 mm lens: All else being equal, the 1/450 exposure will yield the same amount of blur on a crop-sensor camera as 1/300 on a full-frame camera. But as it's not a sharp cut-off, it may not matter. Someone else posted they never compensate for sensor size, and still get good photos, which can be true because the rule is an approximation.

If you find yourself constantly shooting at the limits of your ability to hold a camera, you may want to invest in a tripod or up the ISO. I'm told modern cameras do well at higher ISOs, but I don't have one of those.

dsmeltz Loc: Philadelphia

I have decided the formula needs to be revised to 1/((length + AGE!) * crop factor) My hands are not as steady as they once were.

Peterff Loc: O'er The Hills and Far Away, in Themyscira.

OK. I'm not sure of this, but the logic would be as follows:

The reason for using a crop factor is about field of view, focal length remains constant, but the image is projected onto a smaller sensor, so the effect of any camera shake would be magnified, and enlarged when viewed to the same size as the image from a larger sensor.

In which case, the potential for camera shake problems with an APS-C sensor for say, a 300mm lens is similar to a 450mm or 480mm lens on a 35mm full frame camera.

So, the formula of 1/'focal length' would differ according to sensor size (which affects the image receptor size and thus alignment or movement blur).

So with full frame and a 300mm lens 1/300th might be the minimum guideline, but with an APS-C camera I would go with 1/500th.

Is that correct? I do not know, but it wouldn't seem to do any harm. Neither does a camera with better focusing technology and better low light ISO responsiveness.

I have noticed a difference even using old manual focus lenses.

speters Loc: Grangeville/Idaho

Absolutely, and a happy one back to you!

JohnFrim Loc: Somewhere in the Great White North.

I like your modified formula, assuming "length" refers to the lens. 👍😜

GoofyNewfie Loc: Kansas City

Ha!

Paulie Loc: NW IL

Hi, I came across an interesting take on this topic. Here is a link to the video. You might want to fast forward to 6:37, topic #3 "The Reciprocal Rule"

https://youtu.be/IsWGkUT5A_Y

Paulie Loc: NW IL

DaveO Loc: Northeast CT