Question about the 1/focal lenght as shutter speed

The general rule of thumb when shooting handheld, as everyone is told, is to set the shutter speed at 1/focal

length of the lens.

 

This rule must be as old as photography itself I imagine, so I kinda question how valid it is today.

Even strictly speaking with film, since that rule of thumb caught on, film has seem A LOT of improvements

especially when it comes to resolving resolution/grain size.

 

The reason I question this is because as DSLRs tend to get more pixels every generation, a point will come when

(as perceived by the pixel peepers) that the images will become blurry because of motion. Smaller photo-receptor

means the same motion that only affected one pixel in the previous gen of sensor is now an issue, since the same

motion will affect 2 pixels.

 

Anyone else thought about this?

Should the rule of thumb be revised to 1 / focal length * (some factor to account for pixel density)?

"Smaller photo-receptor means the same motion that only affected one pixel in the previous gen of sensor is now an issue, since the same motion will affect 2 pixels. "

 

How can you move only one pixel in the camera? The issue is that all of the pixels are in motion as the camera isn't steady as you take the picture, the blur comes from the movement of the camera during the exposure.

 

And 1/focal length is just a rough guideline, some people are more stable than others when using a camera. The camera being used also affects, i don't think i can hand hold my 4x5 monorail at any shutter speed.

This is definitely a YMMV situation. Some people with very steady hands have been able to get "good" photographs at substantially slower shutter speeds than the 1/focal-length "rule. Others, not so much...

 

There are a lot of assumptions about sharpness that are incorporated into the rule, and they may not be applicable to everybody's definition of "sharp" (very much the same way that "depth of field" tables rely on particular assumptions about enlargement and viewing distance).

 

Just FYI, remember the rule is really about a lens' field-of-view. The specific "1/f.l." formula is only applicable to 35mm full-frame cameras.

I remember reading it as a supposedly "true" anecdote when I was young. That version had violinist Jascha Heifitz being

hailed by a man on a New York street. The man asks Heifitz, "How do you get to Carnegie Hall?" And Heifitz replies,

always "without breaking stride," "Practice!" <br> <br>

 

This is what I would call a very crude but good guideline for a beginner that fades with experience. The more you shoot

the more you can push the limit of shooting at slower shutter speeds and with VR/IS you shoot even slower hand held. I

have shot images of 1/8 of a sec with a 70-200mm f/2.8 VR. it just takes practice. Here are some tips <a

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href="http://www.geocities.com/stalker+of+the+web/lowlight.html" target="_blank">ow light photography</a> with out a

tripod.

 

Realize this does not replace a tripod but gives you more options.<div></div>

I've never seen any reasonable testing that "proved" the 1/fl "rule." It's one of those things somebody invented and got repeated along the way. I'd ignore it and find out what works for you. If you can't shoot at the shutter speeds you like, do what Ralph suggest and practice.

It has to do with stead shots. Generally you need a faster shutter speed with a longer lens since any tiny movement is amplified. With digital if might be a good idea to go a little faster since the crop factor affects effective focal length.

 

But this is just for people with unsteady hands. Personally, i shoot much slower hand held than this "rule" suggests and my shots come out far from blurry.

"Should the rule of thumb be revised to 1 / focal length * (some factor to account for pixel density)?"

 

Depends how you interpret the rule - and Digital doesn't really have much to do with it. The "rule" is in fact only a guideline, it's not an absolute formula. If you were to make it a formula, it would depend on the capture format (35mm), the size of your print and, not least, your steadiness.

 

What could increase and decrease the 1/X factor (assuming similar "steadiness") is the print size (or magnification). If your print is larger, yes, smaller movements will become more noticeable, and the same would happen if you increase your senor megapixel count and observe at 100% on the screen.

 

But if you print at the same standard size (say, 10x8), the number of megapixels (assuming at least 6Mp) would not have any influence on the 1/X "rule". Even if you had more pixels that could capture smaller hand movements, you would not be able to see them in the print.

The rule of thumb, developed by 35mm photographers (the first who regularly used their cameras hand-held!) is based on

effective magnification as magnification amplifies camera shake. The rule is based on 35mm focal length-FoV

magnifications.

 

So, for instance, with a 35mm camera and a 100mm lens, 1/100 sec is considered a reasonable exposure time to obtain

an acceptably sharp photograph hand held. The same field of view/magnification with a Nikon DX format camera is

achieved with about a 65mm lens, so 1/100 sec would be an acceptable exposure time.

 

Note that it's only a "rule of thumb", a guideline, and there is a lot of fuzziness associated with how sharp a photo might

be vs your own personal capabilities of holding a camera steadily. When you want razor sharp photos, use a sturdy

tripod.

 

Godfrey

<i>The reason I question this is because as DSLRs tend to get more pixels every generation, a point will come when (as perceived by the pixel peepers) that the images will become blurry because of motion.</i>

<p>

They already are. That point is long past, as it was with film. If you want maximum sharpness, use a tripod. Guidelines like the once you cite are only about acceptable sharpness, and definitely exclude "pixel peepers."

Even a monopod increases the level of sharpness/ acceptability .... some of the 'experience' advocated I'm sure comes from learning how not to un-steady the camera when pressing the trigger :-) I remember Larry Bolch writing that he got better results at 1/5 than at 1/20 .. certain amount of scicology there I think :-)

When I closely examined Kodachrome slides from my Retina IIa (50mm lens) I found 1/100 was not consistently sharp and I needed to go to 1/250 if at all posible. Of course slides are subjected to large blow ups so prints are probably not as fussy.

"The general rule of thumb when shooting handheld ... is to set the shutter speed at 1/focal length of the lens. "

 

Not really. It's to use the fastest shutter speed you can get away with (versus not getting an image at all.)

 

A corollary with a fast DSLR is to burst multiple frames. Chances are that one of the exposures fire at the crest or nadir of body motion where the camera is effectively still.

It is meant as a starting point. Too many people have soft images and fail to realize that the lack of sharpness is due to motion blur. They will look at another photographer's images that are sharp and conclude that the other person has a "better" camera or lens when it is really just better technique.

 

Hand held sharpness is in part a function of the type of camera - big difference between a rangefinder and a DSLR with its mirror slap for example. I can hand hold a D3 at slower shutter speeds than a D300 as the extra mass of the camera serves to dampen the mirror slap. Same goes with larger lenses and their inertial mass. Super telephotos have problems from motion of the lens from wind and other factors in addition to the magnification which is why many experienced shooters will rest a hand on the lens at slower shutter speeds.

 

OS has reduced the shutter speeds needed by 2-4x but that applies only to camera motion. The slow f5.6 consumer lens have IS/VR to compensate but it only goes so far to alleviate the problems associated with slow glass.

The 1/fl "rule" was never worked for me. Even at fast shutter speeds my photos are noticably sharper (at a pixel

peepers level) when I use a tripod or turn IS on in my lens. I don't think there is a reliable rule of thumb, but mine has

always been stabilize your camera any way possible, if not on a tripod then with good technique and your

environment around you.