Is the "1/mm" rule universal?

[dem]

So a 4/3 for instance rule would be 1/(2*focal length) Obviously rubbish especially now cameras have IS of one sort or another...

Really though given IS the rule doesn't apply now at all.

You can still apply the 1/(eq. ff mm) rule to 4/3, 1", 2/3", 1/2.3" or whatever sensor and take the image stabilisation (IS) into account.

First, let's postulate that on any camera and any sensor format the 1/(eq. ff mm) shutter speed is the recommended minimum shutter speed at which an average shooter will on average get about 50% shots of acceptable sharpness WITHOUT IMAGE STABILISATION ON. If you are shooting at equivalent focal length of 600 mm without a tripod and any IS using either a super zoom P&S camera with a 1/2.3" sensor or a full frame DSLR with 4 kilos of glass attached to it (you'd be mad to go out without a tripod but bear with me), the safe shutter speed is about 1/600 s.

Now the image stabilisation or IS. Most manufactures are currently selling their top range lenses with 5-stop IS. This means that with IS ON, in theory, one can safely reduce the 1/(eq. ff mm) shutter speed by a factor of 32 = 2 power of 5. In the example above, shooting with 5-stop IS at 1/20 s should give the same percentage of sharp images as shooting at 1/600 s without IS. Even the cheapest cameras have IS of about 2-3 stops and the shutter speed can be reduced from 1/(eq. ff mm) by a factor of 4-8. Have to know your gear!

This is an example of hand-held shot I took with a Fuji X-S1 bridge camera at 624 mm ff eq, F/5.6, 1/125 s, ISO400.

I know that the IS is doing a good job up to about 2.5 stops (that's a factor of about 6) on this camera, so the slowest shutter speed I would go for at this focal length is 1/100 s (about 6 times slower than 1/624 s). Not the best shooting conditions as it was quite dark with the sun already half way below the horizon behind the heron. About 20-25 meters to the bird standing in the middle of the lake and no tree to lean on, just mud everywhere. Had it not been for IS, this shot would have been very blurry.

[george013]

You can still apply the 1/(eq. ff mm) rule to 4/3, 1", 2/3", 1/2.3" or whatever sensor and take the image stabilisation (IS) into account.

First, let's postulate that on any camera and any sensor format the 1/(eq. ff mm) shutter speed is the recommended minimum shutter speed at which an average shooter will on average get about 50% shots of acceptable sharpness WITHOUT IMAGE STABILISATION ON. If you are shooting at equivalent focal length of 600 mm without a tripod and any IS using either a super zoom P&S camera with a 1/2.3" sensor or a full frame DSLR with 4 kilos of glass attached to it (you'd be mad to go out without a tripod but bear with me), the safe shutter speed is about 1/600 s.

Now the image stabilisation or IS. Most manufactures are currently selling their top range lenses with 5-stop IS. This means that with IS ON, in theory, one can safely reduce the 1/(eq. ff mm) shutter speed by a factor of 32 = 2 power of 5. In the example above, shooting with 5-stop IS at 1/20 s should give the same percentage of sharp images as shooting at 1/600 s without IS. Even the cheapest cameras have IS of about 2-3 stops and the shutter speed can be reduced from 1/(eq. ff mm) by a factor of 4-8. Have to know your gear!

This is an example of hand-held shot I took with a Fuji X-S1 bridge camera at 624 mm ff eq, F/5.6, 1/125 s, ISO400.

I know that the IS is doing a good job up to about 2.5 stops (that's a factor of about 6) on this camera, so the slowest shutter speed I would go for at this focal length is 1/100 s (about 6 times slower than 1/624 s). Not the best shooting conditions as it was quite dark with the sun already half way below the horizon behind the heron. About 20-25 meters to the bird standing in the middle of the lake and no tree to lean on, just mud everywhere. Had it not been for IS, this shot would have been very blurry.

That's exactly what it means. If you choice a shutterspeed of s without IS/VR and you can reduce that shutterspeed by a factor 4, 2 stops, then you will have the same motion blur with a shutterspeed of s/4 with IS/VR on. The reduction of your shutterspeed is relative to the shutterspeed you would use without IS/VR.

George

[Glenn NK]

I've done a bit of thinking on this matter with regard to the "crop" factor. The crop factor has absolutely nothing to do with the 1/mm rule.

Consider two cameras using the same lens, both focused on the same object at the same distance; one is a FF and the other is a crop - both have the same pixel density.

The resulting images are different in size, but that's because the smaller sensor simply "wastes" the light coming in around the perimeter of the image. The light is absorbed by the black sensor box. The lens does not change its properties (focal length) with the smaller sensor - it simply does not collect as much light (image) around its perimeter.

So the "crop factor" has nothing to do at all with the sharpness or the required shutter speed for sharpness.

All that affects the blurriness or sharpness is how much movement takes place when the shutter is open.

It has been well covered, and concluded, on other forums that smaller pixels will more readily pick up the very small camera movements that occur during exposure.

It was pretty well documented with the advent of Nikon's high MP FF bodies. And it has been confirmed with Canon's high MP 7DII.

It is not rocket science.

Glenn.

[NorthernFocus]

...It is not rocket science....

So true. It's psychology. Those of us who participate in discussions like this get a higher resolution camera, shoot with painstaking technique, pixel peep, and are disappointed in the results. John Q gets a higher rez camera, shoots with the same old sloppy technique, and is thrilled at how much better his photos are. It is definitely not rocket science.

[george013]

So true. It's psychology. Those of us who participate in discussions like this get a higher resolution camera, shoot with painstaking technique, pixel peep, and are disappointed in the results. John Q gets a higher rez camera, shoots with the same old sloppy technique, and is thrilled at how much better his photos are. It is definitely not rocket science.

That you need a higher shutterspeed with a higher resoltion camera for the same motion blur is not psychology, just simple calculation.

The 1/x rule is nothing more as a start point. Practical I shoot A and only when the shutterspeed is much to low I will change something. What is depending on the situation.
People that shot at a low density camera and used to use rather fast shutterspeed will experience less trouble with a high res camera. People that are used to a rather low shutterspeed will experience more trouble with a high res camera. And will adjust what he/she thinks is the limit.
And everybody happy again.

George

[dem]

Consider two cameras using the same lens, both focused on the same object at the same distance; one is a FF and the other is a crop - both have the same pixel density.

The resulting images are different in size, but that's because the smaller sensor simply "wastes" the light coming in around the perimeter of the image. The light is absorbed by the black sensor box. The lens does not change its properties (focal length) with the smaller sensor - it simply does not collect as much light (image) around its perimeter.

So the "crop factor" has nothing to do at all with the sharpness or the required shutter speed for sharpness.

Glenn, if you always print your full frame photos on A4, your mFT photos on A5 and photos from your compact camera on passport photo sized paper, your thinking is absolutely right. They will have the same amount of visible camera shake when we compare shots taken at the same shutter speed and focal length.

If you print these photos on the same paper size, you might find that full frame produces better results. However, if we now compare shots taken at the same shutter speed and the same equivalent focal length, equal size prints will have the same camera shake blur across different formats.

Obviously, if I take an A4 print and cut out the middle part of it with a pair of scissors, this will not change the sharpness of the print. But I will end up with a smaller photograph.

It has been well covered, and concluded, on other forums that smaller pixels will more readily pick up the very small camera movements that occur during exposure.

It was pretty well documented with the advent of Nikon's high MP FF bodies. And it has been confirmed with Canon's high MP 7DII.

I agree entirely with the above. That is all true for viewing photos at 100% on computer screens and has nothing to do with the (1/mm) rule. If you like, there is sharpness per pixel and sharpness per image size. The 1/mm rule is for the latter.

[NorthernFocus]

...That is all true for viewing photos at 100% on computer screens and has nothing to do with the (1/mm) rule. If you like, there is sharpness per pixel and sharpness per image size. The 1/mm rule is for the latter.

Finally!

[Brev00]

I think the 1/mm rule is a beginner's guideline. If you look at the photography and questions from beginners, a typical issue is blur. Why are my pictures so blurry? I am using auto. What is wrong with my camera? The 1/mm rule immediately and quickly offers an easy to absorb numerical guideline that anyone can follow. All the shutter speeds may mean absolutely nothing to a beginner but this sort of gives a photographer really of any ability a reference point. Now, as anyone progresses with photography, I would think each person would develop their own understanding of the limits of both their gear and their hand holding ability which, I think, is less easily quantifiable. At least, I would be hard pressed to find a standard that applies equally to everyone.

[Simon Garrett]

I think the 1/mm rule is a beginner's guideline.

After 50 years as a photographer, I'm afraid I'm still a beginner.

No doubt that when I learn a bit more, I'll instinctively know when I might get camera shake without ever thinking of shutter speed or focal length. But at my early stage of learning, the relationship between shutter speed and focal length still gives me an indication of whether camera shake is likely to be an issue, also considering VR/IS, crop factor, and the likely use of the image (how big it will be enlarged, for example).

But the starting point for me is focal length and shutter speed.

[William W]

"1/Tripod Rule" has worked universally for me.

WW

[William W]

Is the "1/mm" rule universal?. . . or is it hangover from the glorious days of film, when "everybody" shot 35mm cameras with 100 ASA film and rules were needed because folks were perhaps less technical than today, what with the web and that?

Ted, et al,

I understand that the thrust of the conversation is about Digital and the relevance today of the 1/FL Rule, but none the less, this may be of interest to you . . .

*

I researched extensively, but not exhaustively, the history of the “1/FL Rule” for a paper I wrote in the early 1990’s.

A summary of main points of that paper, in no order of priority, are here:

1. > All relevant references to the ‘1/FL Rule for Hand Holding’ were to 135 Format Cameras, which were earlier referenced technically “Miniature Format” – as opposed to “Medium Format” and “Large Format”.

2. > The first source materials that mentioned or implied the "1/FL Rule", included both 135 Format Rangefinder and 135 Format SLR Cameras

3. > Sometimes the reference was specifically to 1/50th Second Shutter Speed, but elsewhere in the source it was stated implied or assumed that a 50mm lens was being used.

4. > The earliest first source reference (that I found) was in “Popular Photography", Dec 1946, in an article by Bill Cartwright where he discusses Wrestling Photography. Though not directly stating the rule as “1/FL” the article at one point moves away from discussing roll film and (probably) TLR cameras and there is an implication (by way of the article's location in the magazine with advertising and the text of the advertizing), for the use of (the newer) 135 Format Camera with a 50mm Lens.

Cartwright states:

‘However a good general rule to follow is: always use a shutter speed of 1/50 second if your lens film and light will permit’

There are many reasons why I concluded Cartwright was referencing or perhaps even inventing this ‘1/FL Rule’, because at that time there was much debate (heated at times it seems) between the Editor(s) and contributing writers to Popular Photography, remembering of course that in 1946 ‘Photography’ was a pastime mainly of the elite, educated and wealthy and many read (or thumbed) these magazines in awe of the expertise with which the writers, wrote.

5. > Cartwright's article seemingly was quickly rebuffed (*a) in the June 1946 Edition, by the Editor, in his Editorial discussing Candid Shots where he states:

‘Use a tripod wherever possible, especially when shooting with shutter speeds less than 1/100 second(*b). This avoids camera movement and insures sharper negatives.'

Note (*a) - "quickly rebuffed" I conclude - noting the prep time for print in those days could be a few months and also taking into account that readers' astonished responses would be by mail.

Note (*b) - As an aside, my paper also noted that speed “less than 1/100s” would be shutter speeds such as 1/125s . . . 1/1000s etc.

6. > This banter went on during numerous editions of Popular Photography and other Photography Magazines in USA and Great Britain. For Popular Photography it became quite heated with the “1/FL Rule” being presented by a few contributing writers and the standard “1/100s Rule” which, it appears, the Editors clung on to.

7. > Notably, in 1951, again in PP Editorial made this grim statement to the wayward ones who might follow this new “rule” which had developed for Miniature Format Cameras. The Editor warned:

‘There are countless amateurs who like to make pictures whenever an occasion presents itself, and you will usually find them carrying their cameras wherever they go. It’s an easy matter to slip a small camera in a coat pocket or sling a case strap over the shoulder on trips and hikes. But the problem of carrying a tripod is too often solved by leaving the valuable accessory at home. The result: unsharp pictures for many who shoot hand held at shutter speeds under 1/100s.'

8. > By the mid 1970’s and continuing on into the 80’s and 90’s the “Rule” was well established; and notably editorial and contributing authors alike were more inclined to reference the now well established 135 Format Camera directly when mentioning the rule. Especially more commentary was around 135 Format SLR cameras during this period.

9. > This example is also an extract from Popular Photography, July 1981, in which a contributing writer is extolling the virtues of the (then) new Mamiya ZE-X:

‘Mamiya has divided their assortment of lenses for the ZE into four groups according to focal length” 14-60, 61-140, 141-300 and 300-mm and longer. A slow-shutter-speed threshold has been assigned to each group: 1/30, 1/80, 1/200 and 1/500sec, respectively.

The purpose of assigning such shutter speeds was determined mostly from the well-proven rule that the reciprocal of the focal length is the slowest shutter speed that we can use when hand holding the camera to photograph stationary subjects.

The effort to automate this old rule of thumb seems at first thought, unnecessary. But many people don’t read the instruction manual packed with the camera more than once (if at all), so we see the merit of a camera that tries to help avoid the single error most responsible for unsatisfactory pictures, image motion.’

10. > And, indeed the Mamiya ZE-X User Manual cites the then well established “1/FL Rule”, even associating (and elevating) said rule to ‘professional' photographers.
Extract here:

‘• "Camera Shake" Prevention

It is the rule of thumb among professional photographers that the slowest shutter speed at which sharp pictures can be taken with a hand-held camera is the speed closest to the reciprocal of the focal length of the lens in use counted in seconds. Below this speed, "camera shake" is likely to occur blurring the photograph. The ZE-X is designed to operate within the following "camera shake" limits depending on the focal length of the lenses as follows.’

11. > Many Curriculum Texts during the 1980s, 1990, 2000’s cited the Rule and applied it directly to 135 Format Cameras: notably my paper cited numerous texts by M.J. Langford FIIP, FRSP.

***

My paper’s conclusions, in summary:

1. The “1/FL Rule” developed during the introduction of the 135 Format ‘miniature format’ camera and was a and continued to be a direct reference to the FL of the lens when using that particular ‘miniature format’ camera

2. The “rule” was often viewed as a radical breakaway and in conflict with the more temperate “always carry and use a tripod” school of thought

3. At first, the “rule” was hotly debated

4. The first reference found to the germinating ‘rule’ was in 1946

5. There are a few, but very tenuous assertions, to the history of the ‘1/FL Rule’ being born from the common use of a TLR and 80mm lens combined with the (then and previous) standard rule of thumb (for TLR and hand-held, Portable Bellows Cameras) "to use a tripod, for speeds slower than 1/100th second", but none of these assertions sustained even mild scrutiny

6. 135 Format Camera Manufacturers began to cite the "1/FL Rule" in their User Manuals, arguably giving more credence to the "rule"

***

Much of the research for my paper was done manually and during the late 1980's (as opposed to electronically i.e. via 'google it'). Though I have maintained an interest in the history of the history of the 1/FL Rule, (and many other aspects of the History of Photography), I haven't, with any dedication, added to my initial research of the 1/FL Rule.

But, in the absence of viable conflicting data, I believe that the above is a most reasonable account of about when (1946) and probably about where (Photography Magazines) the "1/FL Rule" began.

And certainly the conclusion that the "1/FL Rule" had an initial purpose and was directly and only applicable to 135 Format Cameras seems to me to be water-tight.

WW

[mikesan]

Bill,
Thanks for that very complete and literate post on the history of this rule.

And now for something completely different.

We are (most of us) now in the digital age and among the advantages of digital capture is the fact that every photo comes with exif data, including focal length and shutter speed. It seems beyond obvious to me that each of us could establish our own personal rule by just going through our work, find the images which suffer from camera motion, and note what parameters were used. I certainly can find a pattern in my work, but it likely isn't the same as what someone else may find in theirs.

A truly scientific approach however would require collecting some additional data. Hours of sleep last night. Alcohol and caffeine consumption during prior 4 hours. Photographing solo or with wife and small children in tow. So you see how hard it is to construct one hard and fast rule.

[William W]

Mike,

That’s clever.

That made me laugh: like all good humour, it made a very good point, too.

***

On another tack - what I like to do – is continuously practice my techniques and set games to play to find and improve my limits. So, if the time comes when an opportunity for a shot presents itself and the only gear is what I have to get the moment – then I am practiced up enough to have a reasonable chance of making the shot:

The conversation below the image is self explanatory.

In summary: FL 100mm; 135 Format Camera; SD about 9ft; Hand-held; Tv = ⅛th second.

WW

[george013]

Mike,

That’s clever.

That made me laugh: like all good humour, it made a very good point, too.

***

On another tack - what I like to do – is continuously practice my techniques and set games to play to find and improve my limits. So, if the time comes when an opportunity for a shot presents itself and the only gear is what I have to get the moment – then I am practiced up enough to have a reasonable chance of making the shot:

The conversation below the image is self explanatory.

In summary: FL 100mm; 135 Format Camera; SD about 9ft; Hand-held; Tv = ⅛th second.

WW

Shooting in a studio is different from shooting in the street. The rule, or any rule, isn't meant how slow you can go, but what is the safe speed in average circumstances. If you don't use that rule, then you probably use another one.
George

[William W]

George,

I don't quite understand why you quoted my comments to make a response to this thread.

But for clarity:

My Photograph of the young Athlete, was NOT a studio shot, it was indeed in the genre of 'street photography' and that is clearly spelled out in the conversation below the image.

WW

[george013]

George,

I don't quite understand why you quoted my comments to make a response to this thread.

But for clarity:

My Photograph of the young Athlete, was NOT a studio shot, it was indeed in the genre of 'street photography' and that is clearly spelled out in the conversation below the image.

WW

I did read that later. My excuse. But a rule of thumb is not a rule of finding the limits. It's a rule for daily use. That's what I wanted to say.
George

[Brev00]

After 50 years as a photographer, I'm afraid I'm still a beginner.

No doubt that when I learn a bit more, I'll instinctively know when I might get camera shake without ever thinking of shutter speed or focal length. But at my early stage of learning, the relationship between shutter speed and focal length still gives me an indication of whether camera shake is likely to be an issue, also considering VR/IS, crop factor, and the likely use of the image (how big it will be enlarged, for example).

But the starting point for me is focal length and shutter speed.

All very good (and nicely humble) but I did say the rule continues to have value for more advanced photographers as they used it as a reference point (different, perhaps, than finding it to be earthshaking new) and modified it more precisely with the additional field experience. I think it is fantastic that such a simple and easily remembered formula has such a positive impact for you me, and many, many others. So many discussions here and elsewhere go into minutiae I need further degrees or iq points to comprehend.

[dem]

In summary: FL 100mm; 135 Format Camera; SD about 9ft; Hand-held; Tv = ⅛th second.
WW

This macro lens has a 4 stop IS, which means that it allows you to reduce shutter speed by a factor of 16 from 1/100 s to about 1/7 s.

A perfect illustration of the 1/mm rule in action. Thank you for sharing.

EDIT: Sorry, a wrong lens, no IS.

[William W]

This macro lens has a 4 stop IS, which means that it allows you to reduce shutter speed by a factor of 16 from 1/100 s to about 1/7 s.

A perfect illustration of the 1/mm rule in action. Thank you for sharing.

No, it is not.

*

It appears that there may be confusion, misunderstanding and misinterpretation regarding Post #53.

For clarity:

1. The reason for Post #53 was to make comment that, whilst it might be good to know, appreciate and generally employ the 1/FL Rule, as a 'rule of thumb' or a 'guideline' - I also think that it is good to practice techniques, so that when I come across a shooting scenario where a Rule of Thumb or Guideline has to be broken, severely broken, I am then in a good position to have a reasonable chance of making the shot, simply because I had practiced techniques to establish limits of what I can and cannot control

2. The image in the link was an 'Opportunity Shot' - it is 'Street Genre Photography'. The Subject was not controlled in any manner and it was not in a Studio

3. Details about the shooting scenario are contained in the conversation below the image

4. To make that image, I used the: EF100 F/2.8 Macro USM, (Stated as 'EF100F/2.8Macro' in the link) - i.e. NOT the EF 100F/2.8 L IS Macro USM

WW

[george013]

No, it is not.

*

It appears that there may be confusion, misunderstanding and misinterpretation regarding Post #53.

For clarity:

1. The reason for Post #53 was to make comment that, whilst it might be good to know, appreciate and generally employ the 1/FL Rule, as a 'rule of thumb' or a 'guideline' - I also think that it is good to practice techniques, so that when I come across a shooting scenario where a Rule of Thumb or Guideline has to be broken, severely broken, I am then in a good position to have a reasonable chance of making the shot, simply because I had practiced techniques to establish limits of what I can and cannot control

2. The image in the link was an 'Opportunity Shot' - it is 'Street Genre Photography'. The Subject was not controlled in any manner and it was not in a Studio

3. Details about the shooting scenario are contained in the conversation below the image

4. To make that image, I used the: EF100 F/2.8 Macro USM, (Stated as 'EF100F/2.8Macro' in the link) - i.e. NOT the EF 100F/2.8 L IS Macro USM

WW

You used 2.8, the maximum, ISO 1600, rather high, your only variable was the shutterspeed. This has nothing to do with any rule of thumb or guideline. At that moment you're working within the circumstances available. And being lucky your subject didn't move.
It's a nice picture.
George