Anybody that thinks the D70 is not *fast*..

Not sure exactly what you're saying here. Where do you come up with 1/250?

Nikon's site says:

flash synchronization at up to 1/500 second

Tom
"E. Magnuson" wrote in message
. ..
On 2004-07-16, Mark M wrote:

"E. Magnuson" wrote in message
om...
Do you happen to have a link to more info on this?

Nikon specifies that it's a combined electronic/mechanical shutter. If
you think about it, this is pretty much how it has to work. (Well, you
could always use the electronic shutter if you always fire the
mechanical shutter for a tiny bit longer than the actual exposure time.)
It works just like flash sync.

Here is a site that repeats what I said:
http://www.jjmehta.com/indepth/nikon_d70_04.htm

Thom mentions this in his review (http://www.bythom.com/D70REVIEW.HTM)
but puts the boundary at 1/250. I think he's wrong because a
mechanical shutter that can sync at 1/250 is a more expensive part
than Nikon used in the D100 -- which was only 1/180. And there is no
reason at all for a faster mechanical shutter for a 3FPS camera with
an electronic shutter.

I'm not saying it isn't so, but I find it interesting and would like to
look
further.

There were some writeups on the original Canon 1D which also has a
combined mechanical/electronic shutter, nothing realy detailed.

--
Erik

On 2004-07-16, Jeremy Nixon wrote:

Right -- I'm thinking of a mode that finds the highlights and puts them just
under the point where they would be blown out,

The problem with this is that you would need an exposure sensor that
is exactly the same size (and maybe resolution) as the imaging sensor.

Well, you say, why not use the sensor itself? You can (and that's how
a lot non-SLR cameras work -- well for speed reasons they almost
always read only a limited subset of the pixels). The main problem is
that for a CCD, reading a cell's charge value is destructive. If you
read it out and decide it's not long enough, you can't put the charge
"back". You could read a scene, make an estimate of when it might
blow out what you've seen so far, and then make the exposure, but all
that reading/estimating is one of the reasons for the long
"pre-shutter" lag on these cameras. (The CCD is also used for
focusing.)

--
Erik

In article ,
E. Magnuson wrote:
On 2004-07-16, Jeremy Nixon wrote:

Right -- I'm thinking of a mode that finds the highlights and puts them just
under the point where they would be blown out,

The problem with this is that you would need an exposure sensor that
is exactly the same size (and maybe resolution) as the imaging sensor.

Only if you're being utterly pedantic about every last pixel. I for one
would be happy for this sort of algorithm to be applied to the output from
existing matrix metering systems. As it is, the way they actually decide
what the exposure is going to be is not easilly derived from what they're
seeing, and this makes them useless if you're trying to meter for the
highlights.

In article ,
E. Magnuson wrote:
On 2004-07-16, Jeremy Nixon wrote:

Right -- I'm thinking of a mode that finds the highlights and puts them just
under the point where they would be blown out,

The problem with this is that you would need an exposure sensor that
is exactly the same size (and maybe resolution) as the imaging sensor.

Only if you're being utterly pedantic about every last pixel. I for one
would be happy for this sort of algorithm to be applied to the output from
existing matrix metering systems. As it is, the way they actually decide
what the exposure is going to be is not easilly derived from what they're
seeing, and this makes them useless if you're trying to meter for the
highlights.

On 2004-07-17, Tom Scales wrote:
Not sure exactly what you're saying here. Where do you come up with 1/250?

Let me try again:

The D70 has a hybrid mechanical/CCD electronic shutter. Slow shutter
speeds are controlled by the mechanical two-curtain focal plane
shutter (just like almost every other SLR). Fast shutter speeds are
controlled by the CCD. However, just as with electronic flash, you
must open the mechanical shutter such that it completely exposes the
entire CCD before you can use it's shuttering capability. (At fast
speeds, the mechanical shutter releases the second curtain before the
1st has completed - thus the exposure is via a moving slit.)

So the question is what is the fastest mechanical shutter speed where
the CCD is completely exposed? On the D100 it was 1/180th. On a N75
film body, it's 1/90th. Generally speaking, a faster (mechanical) sync
speed is more expensive.

The question I was attempting to answer was about the speed that
the mechanical shutter operates on the D70.

(BTW, adding to the confusion, note that sometimes an electronically
timed mechanical shutter is called an "electronic" shutter - as
opposed to a purely mechanical clockwork controlled shutter. These
days almost all SLR shutters are electronically timed.)

Nikon's site says:

flash synchronization at up to 1/500 second

Yes. This is achieved via the CCD electronic shutter.
In theory this number could be even higher. However, many
flashes have a maximum flash duration of about 1/700th of
a second. If your shutter speed is higher than your flash
duration, you will loose flash brightness.

--
Erik

On 2004-07-17, Tom Scales wrote:
Not sure exactly what you're saying here. Where do you come up with 1/250?

Let me try again:

The D70 has a hybrid mechanical/CCD electronic shutter. Slow shutter
speeds are controlled by the mechanical two-curtain focal plane
shutter (just like almost every other SLR). Fast shutter speeds are
controlled by the CCD. However, just as with electronic flash, you
must open the mechanical shutter such that it completely exposes the
entire CCD before you can use it's shuttering capability. (At fast
speeds, the mechanical shutter releases the second curtain before the
1st has completed - thus the exposure is via a moving slit.)

So the question is what is the fastest mechanical shutter speed where
the CCD is completely exposed? On the D100 it was 1/180th. On a N75
film body, it's 1/90th. Generally speaking, a faster (mechanical) sync
speed is more expensive.

The question I was attempting to answer was about the speed that
the mechanical shutter operates on the D70.

(BTW, adding to the confusion, note that sometimes an electronically
timed mechanical shutter is called an "electronic" shutter - as
opposed to a purely mechanical clockwork controlled shutter. These
days almost all SLR shutters are electronically timed.)

Nikon's site says:

flash synchronization at up to 1/500 second

Yes. This is achieved via the CCD electronic shutter.
In theory this number could be even higher. However, many
flashes have a maximum flash duration of about 1/700th of
a second. If your shutter speed is higher than your flash
duration, you will loose flash brightness.

--
Erik