Minimum Shutter Speed with teleconverters and cropped sensors

Discussion in 'Canon EOS' started by cleeo_wright, Feb 7, 2013.

  1. The old adage goes that, when hand holding, you should keep your shutter speed faster than the reciprocal of the focal length of the lens. That is pretty simple and easy to remember. My question is how is the affected by the following.
    1. Teleconverters - If I am using a 1.4X converter do I need to adjust the shutter speed accordingly? (eg. 200mm + 1.4x = 280mm -> min shutter speed 1/280?)
    2. What about cropped sensor cameras - Does the restricted view have the same affect? (eg. 200mm on 1.6 crop factor camera -> min shutter speed of 1/320?)
    The attached photo has the following specs
    Canon 50D
    ISO: 1600
    f/ 5.6
    300mm (actual focal length)
    1/200 sec
    Thanks for your help.
  2. 1. yes
    2. yes
    Of course this is only a rule of thumb. The pickier you are about motion blur, the faster the shutter speed you will want. The better your hold, the less speed you can tolerate. With enough caffeine or fatigue, all bets are off. I usually apply an additional "me" factor when estimating what shutter speed I want. My hold is quite firm, so I usually go with the reciprocal of the effective focal length / 2 without image stabilization. If I need to shoot with a slower speed, I then take more shots by that factor. So if I have to shoot at 4x my comfortable speed, I take quadruple the shots and find that one will usually come out pretty good.
  3. Following the "old rule"
    1. yes.... as your 200mm becomes a 280mm
    2. NO, NO, NO and NO!

    A 200mm D.O.E.S. N.O.T. become a 320mm on a cropped sensor.
    it is simply a 200mm from which you are only using a portion of the "potential" image. Therefor if you follow that rule a non IS 200mm should be used at 1/200th on a FF or a Cropped sensor!

    If the answer was yes, then should you shoot at 1/400s if you plan to cropped the final photo in half with that same 200mm lens? no
  4. Sarah is right.

    On No. 2., of course the focal length does not change with a crop camera. But the "rule" (which is actually a starting point--people differ in the steadiness of their hands) is based on angle of view, because shaking is usually manifested as angular movement.
    Denis, try shooting hand-held at 1/70 sec with a point and shoot whose maximum focal length is 70 mm, but whose focal length equivalent is 600mm. Turn stabilization off. The focal length is still 70mm, but the shaking will ruin the image.
    If the answer was yes, then should you shoot at 1/400s if you plan to cropped the final photo in half with that same 200mm lens? no​
    Ahem . . . the answer is actually yes. If you're planning to crop, and thus enlarge a small portion of the image, you should raise the shutter speed unless you want to see too much movement.

    But again, people differ in the shakiness of their hands. And the same person will differ depending on the amount of coffee imbibed, the time that a heavy camera has been hand-held, etc. There are some fine photographers whose hands are not steady. Each person has to determine their own capability.
  5. Yes and Yes.
    You have to compensate for format if you intend to enlarge the image to a given size. Since cropped sensor images have to be enlarged more, they have to be sharper to start with, hence require a faster shutter speed to minimize blue due to camera movement.
  6. What Sarah, Hector and Bob said.
  7. zml


    The "reciprocal of the focal length" myth is a main reason for unsharp photos. Unless you are after a special effect, such as panning or milk flowing off a milkfall :), use the shortest possible shutter speed especially with moving subjects. Sometimes one needs to compromise between the quality and technique and that's OK as long as you are aware that 1/30s will most likely deliver an image inferior in terms of sharpness to an image obtained at, say, 1/250s. IS or not...
    I often shoot with a stabilized 400/2.8 + 1.4x TC on a FF or a 1.3 crop and keep my shutter speed at 1/1250s or faster: significantly slower speeds deliver often uneven results, unwanted motion blur, etc.
    The "rule" you are talking about is a stubborn holdover from the time when most people used roll film cameras (4.5x6 cm, 6x6, 6x9...) or 24x36 mm cameras with 40-70 mm lens and a typical print size was 6x9 or 6x12 cm ("postcard.") These prints were either "contact" type (1:1 enlargement) or enlarged only slightly (2-3x.) With such small enlargements almost everything looks sharp just like a "web-size" digital image looks great regardless of its sharpness.
  8. Agree with Michael. 1/280th for a 280mm (without IS) is a recipe for unsharp pics. You need at least 2X the reciprocal of the focal length to be sharp, and higher is even better.
  9. It's remarkable a bunch of photographers can't agree on a simple principle like this!
    Therefore, out of Wikipedia, the ultimate source for all information:
    The rule of thumb to determine the slowest shutter speed possible for hand-holding without noticeable blur due to camera shake is to take the reciprocal of the 35mm equivalent focal length of the lens.​
    But again, it's a very personal thing. The better your technique, the slower you can shoot.
    And this all should be with respect to stationary objects. Moving objects can require faster shutter speeds, often remarkably faster. You can also apply a few stops correction to the slower side if you have IS, but again, the IS doesn't help with action photography.
    It's all about knowing your own capabilities and those of your gear; however, the reciprocal rule helps you to extrapolate between focal lengths when shooting stationary objects. So let's say you have Parkinson's and have just snorted cocaine after your 6 cups of morning coffee. If you require a minimum shutter speed of 1/2000 sec at 50mm, you're going to need 1/4000 sec for similar results at 100mm.
  10. zml


    Yes, Sarah, believing in Wikipedia is your prerogative, but applying a 70-80 year old "rule" (it was never really a real rule, just something to note) from the era of post-stamp size enlargements, crappy and unsharp films, and often cheap optics in a very narrow range of focal lengths, to hi-res digital photography is just plain silly. It is sad that otherwise reasonable poeple (evan Canon...) repeat this nonsense in a very authoritative way which leads to really silly conversations. ("May I use my 8 mm lens aat 1/8s handheld..." and such.)
    Again, when the adage in question was conceived, most people shoot with roll films, enlargements were 2-3x times (or 1:1 contact prints), there was no mirror slap, no shutter pull (no mirrors and no FP shutters...), the films were crappy and the standards much lower. Want a proof? Look at the pics of your grandparents or even parents. Yeah, there was a lot of technically exquisite photography back then...done by the people who would never use such as a silly "rule" :)
    I have no vested interest in the sharpness (in technical sense) of your photography but running repeatable and honest sharpness test using the "rule" and way faster shutter speeds for comparisons in a variety of photographic situations, might be very educational. (Even though, judging from the tenor of your posts, you have already made up your mind and if the evidence doesn't agree with your convictions, too bad for the evidence...)
  11. William Michael

    William Michael Moderator Staff Member

    Regarding the application of the “Rule of Thumb”
    What Sarah, Hector, Bob and Robin said.
    But also, I agree with the comment to use as fast a shutter speed as possible, lest one gets camera shake.
    I believe that I am pretty good at hand holding at slow shutter speeds: I practice a lot...
    BUT this test is one of many I have made and the results are very interesting – and are typical results I get, most of the time when an heavier and longer lens is used (in this example the 70 t0 200/2.8L).
    There is an explanation in the text below first shot.
    These were taken on an APS-C camera, so you might be interested in investigating the images and also the original thread which I reference below the first image “The Scene”.
    On another matter - the side issue raised here:
    "The "rule" you are talking about is a stubborn holdover from the time when most people used roll film cameras (4.5x6 cm, 6x6, 6x9...) or 24x36 mm cameras with 40-70 mm lens and a typical print size was 6x9 or 6x12 cm ("postcard.") These prints were either "contact" type (1:1 enlargement) or enlarged only slightly (2-3x.) With such small enlargements almost everything looks sharp just like a "web-size" digital image looks great regardless of its sharpness. . . . a 70-80 year old "rule" (it was never really a real rule, just something to note) from the era of post-stamp size enlargements"​
    I happen to have a particular passion for the History of Photography and in that regard only, I would be very interested in any reference you have for backing up those particular comments – i.e. that the “One over the Focal Length Rule for Hand Holding”, has ANY relationship to either:
    "roll film cameras (4.5x6 cm, 6x6, 6x9...)" OR
    "prints were either "contact" type (1:1 enlargement) or enlarged only slightly (2-3x.)" OR
    "a 70-80 year old "rule" (it was never really a real rule, just something to note) from the era of post-stamp size enlargements
    The earliest reference I have been able to find about this particular ‘Rule of Thumb’ was in Popular Photography - 1972: and in the article header it referenced specifically the commentary was applicable to the 135 format SLR interchangeable cameras
    “[Header refers to 35mm SLR cameras]
    A rule that will help you determine the slowest hand-held shutter speed to use is: place the number one over the focal length of the lens (in millimetres).
    For example, with a 100mm lens, one over 100 is 1/100, (1/125 would be the closest speed to set); with a 250-mm lens, the rule gives 1/250 sec. Use this rule as a guide. You may be able to hold for somewhat slower speeds if you're steady and your camera holding technique is good.
    If you're shaky, you may have to shoot at a faster speed than the rule indicates. Experience will tell this. If in doubt, use a tripod or other firm support and a cable release, when possible.”
    Popular Photography Volume 71 – 1972 p 85
    I have many other examples from first source documents and all are from the 1970s period and all directly reference or imply that the 'Rule of Thumb' is applicable only to the 135 Format and usually also specifically reference SLR Cameras (i.e. NOT Rangefinder Cameras).
    I am not particularly keen on Wikipedia generally unless it can footnote and quote first source documents - which can then be interrogated
    Also a small technical note: I roughly calculated that a 135 negative enlarged to a 3½” x 5½” postcard, is closer to about x4 ‘enlargement’ – I could be wrong - it is late over here . . . but I am not interested in correcting your maths - just interested in any references you might have, as I mentioned above.
  12. zml


    All this is older than 1972... I was told that in mid 1960s :)
    (Granted, not in the US...)

    Leica w Polsce ("Leica in Poland") magazine from 1937 makes a similar statement while talking about a 75mm lens (that 1/60s is a good slow shutter speed to use it: a Leica from that era, Leica III, had a 1/30, 1/40, 1/60, 1/100s, etc. progression.)
    In any event, that "rule" is silly and following it blindly guarantees unsharp pictures. It might be useful as a rough guidance if you state that "1/focal length shutter speed might produce bearably, "good enough", sharp pictures..."
    I'm speaking for myself only so YMMV, of course.
  13. Those are great rules of thumb, but today's Image Stabilization is amazing. Here's a hand held shot with 700mm hand held at 1/30-sec.:
    There's blur from subject movement and shallow DOF, but the image is useful to document wild turkey behaviour. Not ideal, but useful.
  14. YMMV​
    Mileage can vary a lot. I'm like you and several others here, I don't have a very steady hand, so I need to be very conservative with this rule. But take a look at the work of William Albert Allard, for example. He works often in low light with very slow shutter speeds. His photos capture motion blur, but that's what he's after, a sense of motion, and there is always some part of the image that's in focus, showing that he's got a steady hand.
  15. Wikipedia, the ultimate source for all information​
    Surprisingly, and contrary to all common sense, Wikipedia is actually a pretty reliable source. Frankly, in areas where I am an expert, it often outshines traditional encyclopedias in getting it more nearly "right".
    The obvious exceptions occur in the areas where there are "strong interests" in falsifying the information to protect some ideological or commercial interest. Even there, Wikipedia usually handles these better than the traditional printed sources did.
    As any optics text will reveal, what diameter a "circle of confusion"* is depends on the degree of enlargement of the image, not the focal length of the optics.
    *I think this was the name of an early camera/photo club somewhere, wasn't it?
  16. William Michael

    William Michael Moderator Staff Member

    “All this is older than 1972... I was told that in mid 1960s :) . . . etc.”​
    Yes, thank you for that second source reference to the Leica Magazine: your observation adds weight to the other historical evidence that this 'Rule of Thumb' refers to and / or was derived from the use of 135 Format Cameras, exclusively.
    I have other ‘manufacturer specific’ documentation, preceding 1972, which gives similar guides to shutter speeds with hand holding with telephoto lenses and although the ‘reciprocal of the FL’ or ‘1 over the FL’ is never mentioned as such, the shutter speeds quoted revolve around those figures. Such documentation appears in some early Minolta manuals, as one example.
    However that Leica reference is special in so far as it is the first that I have which incorporates a rangefinder camera.
    And also thank you for your personal recollection of being "told" about this Rule of Thumb in the mid 1960's.
    I am not located in he USA.
    So, for my cause, I still have early 1970 as the earliest documented “reciprocal” or “one over the Focal Length” as the formation of this rule though – as these things develop, the formation into a ‘rule of thumb’ would have preceded the formal writing of it: it seems I might need to dig more into old Leica Documents – thanks for that lead.
    I am not and was never debating the absolute worth of this Rule of Thumb: by definition a "Rule of Thumb" is only a guide, and should never be followed ‘blindly’.
    In fact I don’t believe that any of the preceding commentaries were ever advocating a blind following . . . so if that is an ‘argument’ I don’t think you have much opposition to it . . .
    And of course personal mileage varies and it varies for each of us from day to day.
  17. the films were crappy and the standards much lower. Want a proof? Look at the pics of your grandparents or even parents.​
    Actually my grandfather and mom were both excellent photographers, and their tool of choice was the venerable Leica IIIf. (They each had one.) Although my grandfather liked to shoot color, which wasn't really all that good back then, my mom shot slower B&W films like Panatomic X. Now THAT was an awesome film. I shot it too. Resolution was never an issue.
    This roll film camera notion makes no sense to me, as roll film cameras typically did not have interchangeable lenses. Therefore why have a rule of reciprocal focal length if you're not going to change a lens anyway? Instead, why not just have a rule like "don't shoot below 1/50 handheld with this camera?" Heavens, some of my old roll cameras wouldn't even have a high enough shutter speed to be handheld by this reciprocal focal length rule. As has been discussed, this is a 135 format rule of thumb.
  18. Thanks everyone...
    As stated in the OP the question was really about the impact of teleconverters and cropped sensors on the rule of thumb. I think I have my answer there. I rarely do anything hand held. I work slowly and don't do a lot with moving subjects but with the advent of image stabilization and variable sensitivities on digital sensors I'm temped to try a little handheld work and thus my curiosity about the rule of thumb.
    Thanks again...
  19. William Michael

    William Michael Moderator Staff Member

    Cleeo . . . yes, apologies if there is any ‘high-jacking’ here, on my behalf: but I AM really interested in the History and couldn't miss the opportunity to garner some more information, whilst the fire was still hot . . .
    Yes, I noted exactly what your question was and also I expected you did indeed have an answer to it – hence (perhaps a tad rudely) I took my opportunity . . .
  20. No worries William. Lots of good information.
  21. Interesting discussion about the origin of the old rule of thumb. As a student of history, I appreciate the effort to dig out actual sources.
    As far as photography goes, though, I'm amazed that anyone is arguing about exactly how much the "rule" needs to be modified in the digital age.
    This is a rule of thumb -- a rough approximation.
    With digital equipment, it would take far less time to try it out -- and thus establish your own rough rule, based on your own standards -- than to read even a fraction of what's been written on the web about the "rule."
    My own rule of thumb, based on experimentation, is two-fold:
    For small prints, something around 1/(3*focal length) is probably a reliable minimum for hand holding my crop camera if I'm careful. (Miracles do occur with stabilization -- sometimes -- and so you can get away once in a while with very unlikely long exposures. But that's once in a while.)
    If I care about image quality, I use a tripod, monopod, beanbag or other bracing.

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