Why are DSLRs faster?

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One of the reasons I bought my D70 nwas because of the lack of "shutter
lag" and the very rapid response after turning the beast on.

I've been enjoying those features and many others.

A recent comparitive review of 8 MP cameras in the New York Times
Circuits page included one DSLR, and the article described it as having
a faster response time than the non-interchangeable lens SLR-style
cameras.

Is there something intrinsic to the basic design of DSLR cameras that
enable their more responsive behavior, or is just that these features
were given priority by the designers?

No: many P&S cameras have fast response now.
Yes.

In article . com,
says...
A recent comparitive review of 8 MP cameras in the New York Times
Circuits page included one DSLR, and the article described it as having
a faster response time than the non-interchangeable lens SLR-style
cameras.

Is there something intrinsic to the basic design of DSLR cameras that
enable their more responsive behavior, or is just that these features
were given priority by the designers?

Well, film SLRs have always had better AF and a shutter response. This
is because the market demanded it. When DSLRs came along, the same
response was expected, so that's why you have it.

In all fairness, a lot of the film point and shoots are really slow to
focus/respond. So it's more a matter of market segment than anything
else.
--
http://www.pbase.com/bcbaird/

Charlie wrote:
X-No-Archive: yes

One of the reasons I bought my D70 nwas because of the lack of "shutter
lag" and the very rapid response after turning the beast on.

I've been enjoying those features and many others.

A recent comparitive review of 8 MP cameras in the New York Times
Circuits page included one DSLR, and the article described it as having
a faster response time than the non-interchangeable lens SLR-style
cameras.

Is there something intrinsic to the basic design of DSLR cameras that
enable their more responsive behavior, or is just that these features
were given priority by the designers?


Basically, because they cost more, the manufacturer can afford to
install a faster processor, and more ram along with a larger sensor.
Then there is also more room for additional specialized chips which can
do some of the work done by the CPU in other, cheaper and smaller, cameras.


--
Ron Hunter

Charlie wrote:
X-No-Archive: yes

One of the reasons I bought my D70 nwas because of the lack of "shutter
lag" and the very rapid response after turning the beast on.

I've been enjoying those features and many others.

A recent comparitive review of 8 MP cameras in the New York Times
Circuits page included one DSLR, and the article described it as having
a faster response time than the non-interchangeable lens SLR-style
cameras.

Is there something intrinsic to the basic design of DSLR cameras that
enable their more responsive behavior, or is just that these features
were given priority by the designers?


You get what you pay for.

Even a DSLR in idiot mode will be slow because it has to take care of
everything, a nice P+S with manual controls can be fast too. Nothing
electronic was as fast as my old film SLR, once I set everything to what I
wanted (f stop, speed, focus) all i had to do was push the button, no lag no
boot up, instant picture taking.

Jean

"Ron Hunter" a écrit dans le message de
...
Charlie wrote:
X-No-Archive: yes

One of the reasons I bought my D70 nwas because of the lack of "shutter
lag" and the very rapid response after turning the beast on.

I've been enjoying those features and many others.

A recent comparitive review of 8 MP cameras in the New York Times
Circuits page included one DSLR, and the article described it as having
a faster response time than the non-interchangeable lens SLR-style
cameras.

Is there something intrinsic to the basic design of DSLR cameras that
enable their more responsive behavior, or is just that these features
were given priority by the designers?


Basically, because they cost more, the manufacturer can afford to
install a faster processor, and more ram along with a larger sensor.
Then there is also more room for additional specialized chips which can
do some of the work done by the CPU in other, cheaper and smaller,
cameras.


--
Ron Hunter

Ron Hunter wrote:
Charlie wrote:
X-No-Archive: yes

One of the reasons I bought my D70 nwas because of the lack
of "shutter lag" and the very rapid response after turning
the beast on.

I've been enjoying those features and many others.

A recent comparitive review of 8 MP cameras in the New York
Times Circuits page included one DSLR, and the article
described it as having a faster response time than the
non-interchangeable lens SLR-style cameras.

Is there something intrinsic to the basic design of DSLR
cameras that enable their more responsive behavior, or is
just that these features were given priority by the
designers?


Basically, because they cost more, the manufacturer can afford
to install a faster processor, and more ram along with a larger
sensor. Then there is also more room for additional
specialized chips which can do some of the work done by the CPU
in other, cheaper and smaller, cameras.

I suspect that's all true. But I wonder if the larger sensor
also helps?

Maybe with a larger sensor that gathers more light per pixel,
the focusing times and exposure calculation times can be reduced.
Maybe also the post processing time needed to reduce noise can be
less because there's less inherent noise. Maybe sharpening can
also be a bit faster because the distinctions between adjacent
pixels are clearer.

That's all just speculation though. I have no idea if any of it
is true.

Alan

jean wrote:
Even a DSLR in idiot mode will be slow because it has to take care of
everything, a nice P+S with manual controls can be fast too. Nothing
electronic was as fast as my old film SLR, once I set everything to what I
wanted (f stop, speed, focus) all i had to do was push the button, no lag no
boot up, instant picture taking.

Jean


Yes, but how long did it take you to set all that stuff up. I would bet
that my $400 P&S can do all that better, and faster, than you can do it
manually. Once I have pushed the button half-way down (the functional
equivalent of your presetting above), there is no perceptible delay on
it either. This wasn't the case with my older digital, however.
Much progress has been made in this respect, both with DSLR and P&S
cameras sold today.



--
Ron Hunter

"Charlie" wrote in message
ups.com...
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Is there something intrinsic to the basic design of DSLR cameras that
enable their more responsive behavior, or is just that these features
were given priority by the designers?
Yes, their intrinsic design makes them go faster - conventional P&S digicams
use the main sensor as their AF sensor. The circuitry analyses the image to
determine if it is sharp (in focus) or blurry (out of focus). It then
readjusts the lens to get focus. Because there is no way of determining if
the object is blurry because it is closer than the focus point or further
away, they have to try adjusting focus in both directions until they get it
right. There is no way of telling if the image is perfectly clear - instead
what it has to do is keep adjusting the lens until it starts becoming blurry
again (overshot the focus point), then pull it back to the point where it
was at it's clearest. This system is quite slow. Because this main sensor is
a video sensor rather than a dedicated still image sensor, when the user
presses the shutter button, the sensor needs to be cleared and charged ready
to take the photo. Modern cameras can do this much faster than the cameras
of only a couple of years ago. After the photo has been taken, most compact
digi's only have one processor to take care of all the functions of the
camera, so while it is processing the image, converting it to JPG, and
saving it on the card, it can't simultaneously be analysing focus and
exposure for the next image, so you can't do anything until the camera
finishes processing the photo you just took.
A DSLR like a film SLR has a separate AF sensor that uses phase detection
techniques to determine focus. This system not only tells the camera how
accurate it is focused, but tells the camera how far and in which direction
it is out of focus. The camera can then start moving the focus motor, and
knows exactly which direction it needs to turn. While the lens is doing
this, the AF sensor continues to monitor how accurate the focus is, and can
slow down the lens motor as it is nearing focus point, so that it stops
right on focus. Because there is no trial-and-error involved, this system is
very fast. Because the main sensor is dedicated to taking the still image
(it's not also trying to do live preview and focussing), the camera can have
it already pre-charged, so that as soon as the shutter button is pressed it
can start recording. Once you have taken the photo, most DSLR's have
multiple processing streams, that allows them to simultaneously convert to
JPG, save the image to the card, and be analysing the data from the AF &
exposure sensors to be ready for the next photo.
If digi compacts used some of the techniques that film compacts use, then
they would be faster. For example most film compacts use infrared or
ultrasonic autofocus systems. While not as fast and accurate as the
phase-detection system used by SLR's, these systems are faster than using
the imaging sensor. Film compacts usually also use light sensors on the body
to judge exposure, whereas most digi's use the imaging sensor for that as
well. If a digi compact was made using an IR or ultrasonic focus system,
and with a separate light sensor on the body, and if the user wasn't using
live preview (or EVF), then then it would be possible for the sensor to be
precharged so that the camera is ready to take the photo as soon as you
press the button. Doing this would of course add to the cost, and since it
is a very price sensitive market, that is usually only compared on
megapixels and zoom, manufacturers would be reluctant to add a feature like
this to the camera, unless it is a premium model.
Actually, my 5 year old Kodak DC3400 has these very features, and when used
with the viewfinder off it is much quicker than the more modern CX7430. The
DC3400 is only a 2MP, 2x zoom camera, and when I bought it cost more than 5
times the price of the current 4MP, 3x Zoom CX7430.

Justin Thyme wrote:


Thank you, at least there is one out of seven who have knowledge in addition
to typing skills.

--
Frode P. Bergsager