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Thread: Shutter lag? Fast Lens?

  1. #1

    Default Shutter lag? Fast Lens?

    Hi all,

    I'm using Canon Powershot A60, something which i realised is there is a significant lag between the moment i press my shutter and the time the picture was captured so here are my questions.

    1)Is this called shutter lag?
    2)Where can we find the shutter lags spects for cameras?(Can't find it on dpreview)
    3) Is this shutter lag thingy only significant in consumer cameras like mine?
    4) For DSLR cameras, is the shutter lags dependable on lens or the body itself?

    I read from many threads about the need to use 'fast lens' in sports photography. Here's another questions:

    5) Does fast lens means it is able to focus on the subject much faster than normal lens, thus we're able to capture the 'moments' we wanted in fast moving subjects'?
    6)Is the speed of focusing in a DSLR only dependable on the lens, is it dependable on the body as well?


    I know there are quite a few questions , please take your time to answer

  2. #2
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    1) Think its called shutter lag
    2) Dunno too.
    3) Should be, not really knowledgeable in this aspect.
    4) Think both.
    5) Fast lens = lens with large aperture, say f2.8 or Bigger. Big aperture means more light can enter, so can go for faster shutter speed to capture fast moving object or subject. Not really mean it can focus very fast. fast or slow focusing speed depends on lens as well as the camera and the light condition too.

    I believe the shutter lag not only happen in consumer digi cam, but also in some consumer film camera.

    Think SLR or DSLR don't have the problem, unless due to low light condition when the auto focus start to hunt, so have to wait till it is focus then the shutter will work. Of course some SLR/DSLR can set priority, can even shoot when the lens still not in focus.


    Hope that helps and anyone have anything to add? please correct me if I'm wrong, so I can learn too.

  3. #3
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    1) Yes. It is the tiime the shutter takes to actually open from the time you press the shutter release button

    2) Dunno.

    3) Think consumer digicams have greater shutter lags as compared to prosumer or DSLR.

    4) I think that shutter lag is a function of the body, not the lens. It's the camera that controls the shutter. But in some medium format systems, you can get the shutter being part of the lens instead of the body, so dunno about that case.

    5) Nope. Fast lenses are lenses with big maximum apertures, such as F2.8, F1.8 or even lower. They are called fast lenses because the larger maximum aperture allows you use to a higher shutter speed in the same shooting situation as compared to a 'slower' lens.

    6) Speed of focussing in DSLR can depend on both the body and the lens. If you are using the Nikon AF-S lenses or the Canon USM lenses or the Sigma HSM lenses, you are going to get significantly faster AF regardless of body. The AF module in the camera body also dictates how fast the lens achieved focus, and how sensitive is the AF. If you can, pick up the pro level SLRs and compared the speed of focus. The faster AF will blow you away.

    Note that all cameras have some shutter lag. It's up to the individual to decide if the lag is acceptable for the type of shooting they do.

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    Quote Originally Posted by ordinaryless
    1)Is this called shutter lag?
    Yes it is.

    2)Where can we find the shutter lags spects for cameras?(Can't find it on dpreview)

    Unfortunately it's up to manufacturers to state the camera's shutter lag, or alternatively sites like Imaging Resource (I think) which conduct their own shutter lag tests for the cameras they review.

    3) Is this shutter lag thingy only significant in consumer cameras like mine?

    Yes and no. Everything's relative. If you're taking tabletop still lifes, then it's not going to be significant in any camera. If you need split second timing, then yes, it will matter in consumer cameras and even between cheaper and more expensive DSLRs.

    That said, one of my most successful pure action pictures was taken with one of the slowest DSLRs on the market. So it makes a difference yes, but it doesn't stop you from being able to still produce useable pictures.

    4) For DSLR cameras, is the shutter lags dependable on lens or the body itself?

    Both to an extent. A body can only be so fast. Whether it can achieve that speed depends to an extent on the lens. If the lens struggles to achieve focus, the body's maximum potential can never be realised. But if you start with a "slow" body and attach a fast lens, it still isn't going to get any faster.

    5) Does fast lens means it is able to focus on the subject much faster than normal lens, thus we're able to capture the 'moments' we wanted in fast moving subjects'?

    Both. Although generally fast lenses in sport refers not to focus speed but maximum aperture, which in turn allows you to use faster shutter speeds in similar lighting conditions, which gives you more leeway in freezing action.

    6)Is the speed of focusing in a DSLR only dependable on the lens, is it dependable on the body as well?

    Again, both. In fact, the situation is very similar to the explanation I've given about to shutter lag. A DSLR has a hypothetical focusing speed. With a fast lens it will reach that, with a slow lens it won't. But if you stick a fast lens on a slow body, it won't focus any faster than that camera's hypothetical maximum. Although it will focus faster than a slow lens on the same camera.

  5. #5

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    Thank you all of you who have answered. All of your replies have been clear and useful and i appreciate them.

    From this thread, i learnt that smaller F number means larger aperture, hence, more light can go in and a much faster shutter speed is allowed.

    Here's another question
    If we're taking pictures in low light condition, Is it possible that a picture taken at F2.8 and faster shutter speed produce the same ambience lightings as a lens with bigger F number but slower shutter speed? So far i've been using slower shutter speed to capture the ambience lights during low light conditions, never tried using larger aperture before esp when i'm taking a picture of a large group of pple, hence i want even clarity throughout the picture.

    Don't have my camera with me now, can't experiment.

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    You're correct. In terms of exposure, they will be the same. Of course the image with the bigger aperture will have less DOF which will make the resulting image look different.

  7. #7

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    Quote Originally Posted by Jed
    You're correct. In terms of exposure, they will be the same. Of course the image with the bigger aperture will have less DOF which will make the resulting image look different.
    thanks!

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    Jed,

    I would like to clarify the use of the term "shutter lag" and its meaning to most photographers. Your explanations to ordinaryless questions started by addressing the speed of the shutter's response while towards the end, u focussed on focussing speed of the lens.

    My question is when we talk of shutter lag, what we are specifically referring to?

    Are we talking about how fast the camera's shutter responds to the depression of the shutter release, assuming a pre-focussed frame? Or do we include the focussing speed of the lens as well (from an unfocused state)?

    I think Image-Resource does it differently in that they measure the time taken for the camera to focus, then fire the shutter and capture the image from the time the shutter release is depressed without a pre-focussed image to the image capture.

    But then it begs the question, would Image Resource's method of measuring "shutter lag" be considered indicative of shutter lag? It brings in the element of focussing speed as well as indicated in by your explanations later in your post. You will find that for a SLR, that lag would differ with different types of lens (primes, internal motor, etc). Then would such a definition be meaningful? Surely shutter lag should be constant, since it is but a mechanical and/or electronic triggering of a mechnical device that prevents like from exposing film or the CCD? In that case, given the same ambient temperature, the time taken for the shutter to fire should be a constant (within appreciable limits) isn't it?

    My understanding is that shutter lag refers specifically to just that - how long the shutter lags before firing after the shutter release has been depressed. I have ever used an early generation Olympus digicam (like the C-750 form factor, but with four-digits in the model number, can't remember what now) and that had a hell of a shutter lag. I would pre-focus the camera (under low light with flash, f/5.6 @ 1/60 sec) and it took the shutter about 1/2 second to trigger after I have completely depressed the shutter release. As a result, my shots always looked as if I was a tad too slow to catch the action. In fact all that was hapening was just a speaker on stage giving an opening address and all the action taking place was the occasional bobbing of his head as he bent to look at his notes!

    Hence I usually divorce discussion of shutter lag from focussing speed. Reason is that focussing speed is dependent only on the quality and build of the lens and the quality of the sensor mechanisms on the body and is totally independent of the shutter. If the camera is already focussed, and the shutter takes its own sweet time to trigger, that would be considered shutter lag right? But if the same camera is not pre-focussed, and the shutter triggered, and some time elapses before the shutter fires, then that would be a combination of shutter lag + focussing speed?

    What do you think? Is my interpretation of shutter lag too narrow?

  9. #9

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    Quote Originally Posted by TME
    Jed,

    I would like to clarify the use of the term "shutter lag" and its meaning to most photographers. Your explanations to ordinaryless questions started by addressing the speed of the shutter's response while towards the end, u focussed on focussing speed of the lens.

    My question is when we talk of shutter lag, what we are specifically referring to?

    Are we talking about how fast the camera's shutter responds to the depression of the shutter release, assuming a pre-focussed frame? Or do we include the focussing speed of the lens as well (from an unfocused state)?

    I think Image-Resource does it differently in that they measure the time taken for the camera to focus, then fire the shutter and capture the image from the time the shutter release is depressed without a pre-focussed image to the image capture.

    But then it begs the question, would Image Resource's method of measuring "shutter lag" be considered indicative of shutter lag? It brings in the element of focussing speed as well as indicated in by your explanations later in your post. You will find that for a SLR, that lag would differ with different types of lens (primes, internal motor, etc). Then would such a definition be meaningful? Surely shutter lag should be constant, since it is but a mechanical and/or electronic triggering of a mechnical device that prevents like from exposing film or the CCD? In that case, given the same ambient temperature, the time taken for the shutter to fire should be a constant (within appreciable limits) isn't it?

    My understanding is that shutter lag refers specifically to just that - how long the shutter lags before firing after the shutter release has been depressed. I have ever used an early generation Olympus digicam (like the C-750 form factor, but with four-digits in the model number, can't remember what now) and that had a hell of a shutter lag. I would pre-focus the camera (under low light with flash, f/5.6 @ 1/60 sec) and it took the shutter about 1/2 second to trigger after I have completely depressed the shutter release. As a result, my shots always looked as if I was a tad too slow to catch the action. In fact all that was hapening was just a speaker on stage giving an opening address and all the action taking place was the occasional bobbing of his head as he bent to look at his notes!

    Hence I usually divorce discussion of shutter lag from focussing speed. Reason is that focussing speed is dependent only on the quality and build of the lens and the quality of the sensor mechanisms on the body and is totally independent of the shutter. If the camera is already focussed, and the shutter takes its own sweet time to trigger, that would be considered shutter lag right? But if the same camera is not pre-focussed, and the shutter triggered, and some time elapses before the shutter fires, then that would be a combination of shutter lag + focussing speed?

    What do you think? Is my interpretation of shutter lag too narrow?

    u r of cos right in the above. Shutter lag most often refers to those found in Digicams with fixed lenese in auto mode where focussing time is taken into the equation.

    e.g, the yashica t5 has a terrible shutter lag too becos it takes time for the lens to forward, focus and then the shutter opens , after ur initial depression of the release button. Cameras like the t5 with no manual controls for focussing cannot be made faster i.e the SL cannot be reduced. ANd the lens speed issue in the case of the t5 is not in the SL equation. It's just how the camera electronics is designed...to be lagging.

    For consumer DCs, to reduce the SL, the only way is to prefocus. That will shorten the focussing time needed in auto mode. But then, most of these non proffesional Dcs won't have that manual focus options, so the SL is dead fixed! Not to mention the time for AE and the electronic signal from shuuter button trigger to shutter gate opening.

    I tink the focussing speeds really depends on the cam body rather than how fast the lens is. Liek the f80 with focus light assist, I can use a slow f4.5 lens but still nails the focus points easily in the dark.

    Modern dslrs or slrs, these SL issues are quite negligible IMO. And some new DCs like the Caplio? is reported to have a minimal SL. SO the technology is closing that gap fast.

    also, leaf shutters in some old RF or MF cams do in fact respond faster than mirror flaps of slrs, manual or auto.
    Last edited by Cash; 16th March 2004 at 03:55 PM.

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    Quote Originally Posted by TME
    Hence I usually divorce discussion of shutter lag from focussing speed. Reason is that focussing speed is dependent only on the quality and build of the lens and the quality of the sensor mechanisms on the body and is totally independent of the shutter. If the camera is already focussed, and the shutter takes its own sweet time to trigger, that would be considered shutter lag right? But if the same camera is not pre-focussed, and the shutter triggered, and some time elapses before the shutter fires, then that would be a combination of shutter lag + focussing speed?

    What do you think? Is my interpretation of shutter lag too narrow?
    I don't think there's a formal definition. Taken loosely, it just mean the time lag between depressing of the shutter button and the actual capturing of the picture.

    Imaging Resource does list three kinds of shutter lag:
    -Shutter lag, full autofocus
    -Shutter lag, manual focus
    -Shutter lag, prefocus

    The three timings are all relevant. e.g. under a unprepared spontaneous scenario, "full AF" shutter lag will be applicable. if there's time to set up the camera, pre-focus or manual focus, the other two timings would be appropriate.

    DP Review doesn't even call it shutter lag. It's simply termed half-press lag, full-press lag, etc.

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    Quote Originally Posted by TME
    I would like to clarify the use of the term "shutter lag" and its meaning to most photographers. Your explanations to ordinaryless questions started by addressing the speed of the shutter's response while towards the end, u focussed on focussing speed of the lens.
    Erm, yeah. And that would be a problem because? Ordinaryless' questions started out asking about shutter lag and then lens speed. So naturally my answers begin with addressing his questions about shutter lag and then move on to dealing with his questions about lens speed.

    Are we talking about how fast the camera's shutter responds to the depression of the shutter release, assuming a pre-focussed frame? Or do we include the focussing speed of the lens as well (from an unfocused state)?

    Both. You have to include the speed of the lens as well. That's why as I explained there is a theoretical maximum (fastest) shutter lag but cameras need not necessarily achieve that figure based on the lens they have attached.

    Or if you're Canon for instance, then you have one shutter lag timing if the lens is used wide open, and one if the lens needs to be stopped down.

    I think Image-Resource does it differently in that they measure the time taken for the camera to focus, then fire the shutter and capture the image from the time the shutter release is depressed without a pre-focussed image to the image capture.

    No, go read it first. They do that, and they also measure with the camera prefocused, and with the camera on manual focus.

    In fact, they also measure time for shutter to trip from the camera being asleep and the camera being active, with both manual focus and full AF.

    But then it begs the question, would Image Resource's method of measuring "shutter lag" be considered indicative of shutter lag?

    Actually, it begs the question if you've read Imaging Resource. And also begs the question about the reason for your post.

    You will find that for a SLR, that lag would differ with different types of lens (primes, internal motor, etc). Then would such a definition be meaningful? Surely shutter lag should be constant, since it is but a mechanical and/or electronic triggering of a mechnical device that prevents like from exposing film or the CCD?

    Yes, it is different, as I have been at pains to point out. It is meaningful because it gives you a very good indication of a camera's responsiveness, ceteris paribus. And as I was also at great pains to explain in my original post, a fast camera is a fast camera with a fast lens attached. A slow camera is a slow camera even with a fast lens attached, although it would be a faster camera than a slow camera with an even slower lens attached.

    My understanding is that shutter lag refers specifically to just that - how long the shutter lags before firing after the shutter release has been depressed.

    No, you are right. Don't try to outthink yourself or outthink me. If you can't grasp beyond that, that sentence will do quite well as a stopgap.

    Hence I usually divorce discussion of shutter lag from focussing speed.

    Strangely enough, I probably do too. Generally. But for completeness. Basically a camera will not trip the shutter if it cannot attain focus (with some exceptions) and hence the shutter won't fire until the lens focuses. So from that regard, autofocus speed is a critical element of shutter lag.

    If the camera is already focussed, and the shutter takes its own sweet time to trigger, that would be considered shutter lag right? But if the same camera is not pre-focussed, and the shutter triggered, and some time elapses before the shutter fires, then that would be a combination of shutter lag + focussing speed?

    Yes and yes. But what in the second scenario, what lag time would you have till the shutter firing? Say, 0.500 seconds. So the lag between the time you press the shutter till the time the shutter fires is still 0.500. What was that definition of shutter lag again?

    Extending the principle. Canon's 1D mk II has a shutter lag of 40ms if the aperture is wide open, and 55ms if the aperture is not wide open. Figures are from memory and might not be accurate. So what exactly is the 1D2's shutter lag then? Those figures and terms come from Canon directly. Have I got a 40ms camera or a 55ms camera? Both...

    Or the Canon 45 point focusing system, only works with 11 points if you have too slow a lens attached. So it's either an 11 point or 45 point camera, depending on lens.

    Another analogy. A car's 0-60 figures. What happens if I need to go up hill (slow lens)? The 0-60 figures are still accurate for that car. But the 0-60 figures of that car uphill at whatever gradient has to be slower, like it would a camera with a slow lens. But both 0-60 figures are still valid.
    Last edited by Jed; 16th March 2004 at 07:32 PM.

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    Quote Originally Posted by mpenza
    DP Review doesn't even call it shutter lag. It's simply termed half-press lag, full-press lag, etc.
    Actually, it's the same thing as Imaging Resource's active, asleep respectively. Just different terminology.

  13. #13

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    Quote Originally Posted by ordinaryless
    Hi all,

    I'm using Canon Powershot A60, something which i realised is there is a significant lag between the moment i press my shutter and the time the picture was captured so here are my questions.

    1)Is this called shutter lag?
    2)Where can we find the shutter lags spects for cameras?(Can't find it on dpreview)
    3) Is this shutter lag thingy only significant in consumer cameras like mine?
    4) For DSLR cameras, is the shutter lags dependable on lens or the body itself?

    I read from many threads about the need to use 'fast lens' in sports photography. Here's another questions:

    5) Does fast lens means it is able to focus on the subject much faster than normal lens, thus we're able to capture the 'moments' we wanted in fast moving subjects'?
    6)Is the speed of focusing in a DSLR only dependable on the lens, is it dependable on the body as well?


    I know there are quite a few questions , please take your time to answer
    Hi TME,

    I apologize if i confused you in anyway. I guess the reason why Jed's reply consist of shutter lag and focusing speed is because i asked 2 questions in the same thread. First questions i asked is about shutter lag, the second part of the questions(italiced, bold and underlined ), i asked about the speed of focusing.

    From my understanding,

    Shutter lag = Difference of time between the moment the image is captured on the camera and the time when you fully depress the shutter.

    I guess speed of focusing is not included in shutter lag and should be dealt with seperately?

    Correct me if i'm wrong.

  14. #14

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    opps, jed answered before me...

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    Ok folks, time for the ole ang moh to wade in.

    The term shutter lag actually dates back to purely mechanical camera days, that is well and truly pre autofocus and was the time delay between pressing the shutter and the activation of the shutter mechanism resulting in the shot being taken.

    In this the original correct context it should be measured in manual focus (pre focused) and manual control mode.

    However as Jed rightly points out with many modern cameras you can't shoot until the AF is locked on focus and this can slow the entire process down considerably, especially with slow lenses, slower AF feedback control, processors etc, as well as low light conditions.

    What is really needed is a manufacturer independent standard set of testing criteria to allow accurate cross evaluation of the system or operational lag of an AF camera.

    Ian
    The Ang Moh from Hell
    Professional Photography - many are called, few are chosen!

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    Quote Originally Posted by Jed
    Erm, yeah. And that would be a problem because? Ordinaryless' questions started out asking about shutter lag and then lens speed. So naturally my answers begin with addressing his questions about shutter lag and then move on to dealing with his questions about lens speed.

    Are we talking about how fast the camera's shutter responds to the depression of the shutter release, assuming a pre-focussed frame? Or do we include the focussing speed of the lens as well (from an unfocused state)?

    Both. You have to include the speed of the lens as well. That's why as I explained there is a theoretical maximum (fastest) shutter lag but cameras need not necessarily achieve that figure based on the lens they have attached.

    Or if you're Canon for instance, then you have one shutter lag timing if the lens is used wide open, and one if the lens needs to be stopped down.

    I think Image-Resource does it differently in that they measure the time taken for the camera to focus, then fire the shutter and capture the image from the time the shutter release is depressed without a pre-focussed image to the image capture.

    No, go read it first. They do that, and they also measure with the camera prefocused, and with the camera on manual focus.

    In fact, they also measure time for shutter to trip from the camera being asleep and the camera being active, with both manual focus and full AF.

    But then it begs the question, would Image Resource's method of measuring "shutter lag" be considered indicative of shutter lag?

    Actually, it begs the question if you've read Imaging Resource. And also begs the question about the reason for your post.

    You will find that for a SLR, that lag would differ with different types of lens (primes, internal motor, etc). Then would such a definition be meaningful? Surely shutter lag should be constant, since it is but a mechanical and/or electronic triggering of a mechnical device that prevents like from exposing film or the CCD?

    Yes, it is different, as I have been at pains to point out. It is meaningful because it gives you a very good indication of a camera's responsiveness, ceteris paribus. And as I was also at great pains to explain in my original post, a fast camera is a fast camera with a fast lens attached. A slow camera is a slow camera even with a fast lens attached, although it would be a faster camera than a slow camera with an even slower lens attached.

    My understanding is that shutter lag refers specifically to just that - how long the shutter lags before firing after the shutter release has been depressed.

    No, you are right. Don't try to outthink yourself or outthink me. If you can't grasp beyond that, that sentence will do quite well as a stopgap.

    Hence I usually divorce discussion of shutter lag from focussing speed.

    Strangely enough, I probably do too. Generally. But for completeness. Basically a camera will not trip the shutter if it cannot attain focus (with some exceptions) and hence the shutter won't fire until the lens focuses. So from that regard, autofocus speed is a critical element of shutter lag.

    If the camera is already focussed, and the shutter takes its own sweet time to trigger, that would be considered shutter lag right? But if the same camera is not pre-focussed, and the shutter triggered, and some time elapses before the shutter fires, then that would be a combination of shutter lag + focussing speed?

    Yes and yes. But what in the second scenario, what lag time would you have till the shutter firing? Say, 0.500 seconds. So the lag between the time you press the shutter till the time the shutter fires is still 0.500. What was that definition of shutter lag again?

    Extending the principle. Canon's 1D mk II has a shutter lag of 40ms if the aperture is wide open, and 55ms if the aperture is not wide open. Figures are from memory and might not be accurate. So what exactly is the 1D2's shutter lag then? Those figures and terms come from Canon directly. Have I got a 40ms camera or a 55ms camera? Both...

    Or the Canon 45 point focusing system, only works with 11 points if you have too slow a lens attached. So it's either an 11 point or 45 point camera, depending on lens.

    Another analogy. A car's 0-60 figures. What happens if I need to go up hill (slow lens)? The 0-60 figures are still accurate for that car. But the 0-60 figures of that car uphill at whatever gradient has to be slower, like it would a camera with a slow lens. But both 0-60 figures are still valid.

    I see thank you. I have read quite a number of Image Resource reviews actually (I was looking for a simple P&S digicam some months back) and the thing that struck me was the timing of the shutter lag that took into account the focussing as well. That stuck (given my own understanding of shutter lag, which seems to be too narrow) and I must have forgotten about the other 2 modes of timing as well... sorry about that...

    And since I obviously missed something here about the relation between shutter lag and speed of the lens... would u be so kind as to explain how the speed of the lens affects the shutter's reponse? I mean if the lens were already pre-focussed, then wouldn't all that is left to do be to trigger the shutter? Also u mention Canon's 1Ds has different timings for different aperatures, care to explain how that is so? It surprises me cos 1) I'm certainly not a pro 2) All along shutter lag to me has been just that, the shutter lagging and the lens having nothing to do with it....

    Hmm.... I'm learning....

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    Quote Originally Posted by Ian
    Ok folks, time for the ole ang moh to wade in.

    The term shutter lag actually dates back to purely mechanical camera days, that is well and truly pre autofocus and was the time delay between pressing the shutter and the activation of the shutter mechanism resulting in the shot being taken.

    In this the original correct context it should be measured in manual focus (pre focused) and manual control mode.

    However as Jed rightly points out with many modern cameras you can't shoot until the AF is locked on focus and this can slow the entire process down considerably, especially with slow lenses, slower AF feedback control, processors etc, as well as low light conditions.

    What is really needed is a manufacturer independent standard set of testing criteria to allow accurate cross evaluation of the system or operational lag of an AF camera.

    Ian
    Thanks for clarifying matters and actually my question pertains to what u have just posted which is what actually I raised to Jed but maybe he didn't get my drift and perhaps I wasn't too clear either...

    Anyway, it seems to me on reading your post that the meaning of shutter lag has changed somewhat since the days of full manual cameras? Bec if I dun understand wrongly, in the bad ole days, shutter lag measured the "time delay between pressing the shutter and the activation of the shutter mechanism resulting in the shot being taken" but now when using modern cameras, the term shutter delay also includes the AF speed.

    First am I right that there is a shift in usage of the term "shutter lag"?
    Then if that is the case, why is there a shift? Why not use the same terms of reference, pre-focussed whether AF or manual?
    If the camera is already pre-focussed, is it this shutter lag different from the shutter lag of old?
    And did the old manual cameras also have different shutter lag timings at different apertures on the same lens and different timings at the same aperture on different lens?

    And of course I have asked Jed what has piqued my curiosity not inconsiderably as to how AF affects shutter lag...

    Sorry ar.... so many questions at one time.... maybe they are one and the same...

    Thanks for your invaluable comments....

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    Quote Originally Posted by TME
    I have read quite a number of Image Resource reviews actually (I was looking for a simple P&S digicam some months back) and the thing that struck me was the timing of the shutter lag that took into account the focussing as well. That stuck (given my own understanding of shutter lag, which seems to be too narrow) and I must have forgotten about the other 2 modes of timing as well... sorry about that...
    I think the issue there is that with P&S digicams, you can't generally not have the lens autofocus, so that cannot be removed from the equation for testing purposes.

    I mean if the lens were already pre-focussed, then wouldn't all that is left to do be to trigger the shutter?

    If all you ever do is prefocus, then yes. But from Imaging Resource you'll see that there's even a difference in lag between prefocusing and manual focusing.

    Also u mention Canon's 1Ds has different timings for different aperatures, care to explain how that is so?

    Not the 1Ds. The 1D mk II. Make sure you read what I write before clarifying my "mistakes". And don't ask me, ask Canon. Basically, Canon can get the "shutter lag" down to 40ms if it doesn't have to also stop the lens aperture blades down. And if it does, then it slows to 55ms. As to why, like I said, you need to ask them.

    Thanks for clarifying matters and actually my question pertains to what u have just posted which is what actually I raised to Jed but maybe he didn't get my drift and perhaps I wasn't too clear either...

    Which is? I still don't get it. Are you trying to say that there is a difference between shutter lag and system lag? If you're being pedantic, then yes. They are different things. But in this day and age, shutter lag = system lag effectively. For instance, if you were being pedantic, you'd be wrong in saying digital P&S cams have shutter lags... nearly none of them have shutters to lag in the first place. Which you have been saying.

    but now when using modern cameras, the term shutter delay also includes the AF speed.

    Ok I'll say it again. Let's call it system lag if it helps you understand the whole thing.

    A modern digital camera has a theoretical shutter lag. Influenced by the following:

    [1] Time taken to get reflex mirror out of the way.
    [2] Time taken to get the shutter curtain out of the way.
    [3] Time taken to stop the lens down to the desired aperture.
    [4] Time to activate the imaging sensor.

    Even in the good old days of manual cameras where shutter lag was apparently ""time delay between pressing the shutter and the activation of the shutter mechanism resulting in the shot being taken" shutter lag still included mirror lag, aperture lag as well as shutter lag. So it really was in a sense system lag as well strictly speaking. So shutter lag was just a term used to describe, as you put it, "time delay between pressing the shutter and the activation of the shutter mechanism resulting in the shot being taken".

    Now with AF cameras, you need to factor in:

    [5] Time for camera to acquire focus.

    Because until [5] is reached, the shutter won't trip, it makes [5] an integral part of the "time delay between pressing the shutter and the activation of the shutter mechanism resulting in the shot being taken"

    First am I right that there is a shift in usage of the term "shutter lag"?

    Not really, you're just splitting non-existent hairs on terminology.
    Last edited by Jed; 16th March 2004 at 08:55 PM.

  19. #19
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    Ah!! I see..... there's a lot more to it than I initially understood... in any case, sorry about the mistake about the Canon model, it was a typo.... didn't check back.... and anyway, I wasn't trying to correct your "mistakes" as u put it. I was just trying to understand what you posted since it seemed at odds with my understanding of shutter lag.... so pardon my ignorance will ya?

    Cool it ok?

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