Any ringlights work TTL with the D70?

Archived from groups: rec.photo.digital.slr-systems (More info?)

I surfed the Nikon website the other day and found out that Nikon's own
SB-29 only works with the D70 in the "manual" mode. Does any other
manufacturer's equipment work TTL yet?

BTW, the website provided an explanation of why older flash units don't work
TTL. The Nikon flash-TTL design (as does the implementation of [almost]
every other manufacturer) relies on the light reflected from the film
surface to measure the amount of (integrated) flash light from the strobe.
Since the D70 -- and AFAIK --- every other Nikon DSLR obviously doesn't use
film, there's no way this scheme works. Apparently the newest units
(SB-600/800) have sufficient electronics to do the job for the body. My
question is, since Nikon was designing the CCD sensor anyway, couldn't they
have arranged it so that there was enough light reflected off of it to make
the older TTL flash units work as well?

Norm

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <d84d6d$j4r$1@inews.gazeta.pl>,
Alan Browne <alan.browne@FreelunchVideotron.ca> wrote:
>Norm Dresner wrote:
>
>
>> (SB-600/800) have sufficient electronics to do the job for the body.

In combination with using the metering sensors in the viewfinder
with the pre-flash. It is even more interesting when you have a stable
of the SB-600s and at least one SB-800, and are using the camera in
commander mode, or letting the SB-800 on the hot shoe be the commander.
(This is a bit beyond my setup so far -- I have just the one SB-800 and
the built-in flash -- plus the SB-28 for the NC2000e/c (N90s).

>> My
>> question is, since Nikon was designing the CCD sensor anyway, couldn't they
>> have arranged it so that there was enough light reflected off of it to make
>> the older TTL flash units work as well?

That would have reduced the sensitivity of the sensor, and
probably image detail at the same time, since the surface would have to
produce diffuse reflections, not specular ones.

>There are no OTF-TTL sensor implementations on any DSLR's that I know
>of.

Well ... it depends on what you allow as a DSLR. Consider the
NC2000e/c, made by Kodak converting a Nikon N90s with a replacement
back. The sensors are still there for OTF flash metering (as is the
motor drive for winding the film), but it does not work properly as long
as the Kodak back is in place with the digital sensor. Swap back to a
film back, and the SB-28's TTL flash metering will work.

> I suppose that the implementation of sensor cover, filters and the
>sensor itself render such a weak, or over directional reflection as to
>make the OTF sensors useless.

I believe the latter. The sensor and filters would produce
specular reflection (like a mirror), while the film produces a diffuse
reflection -- from the halide salts in the emulsion. The film backing
would probably be nearly as bad as the sensor for specular reflection.

>They could have implemented flash sensors around the edge of the imaging
>sensor, but this would not have been effective for center weighted flash
>metering.

Or -- flash sensors around the inside of the lens mount, looking
back at the imaging sensor. But this would leave it free to be confused
by the specular reflections off of the various highlights which happened
to be in just the right place -- or heavily black image areas as well.

And, as you can imagine, you still could not mount a sensor in
the center of the lens area to see the specular reflection from the
center of the image.

Oh yes -- the sensor ring would also have to be multiple
concentric rings to handle the different angles of illumination from
different lens focal lengths.

>As it is, pre-flash seems to work well in most cases. (Requires
>appropriate flash).

Indeed so.

As for the ring flash in the "Subject: " header, I can testify
that the one built into the antique 200mm Medical Nikkor works well.
Not as an auto exposure setup, but rather with the aperture ring, a
magnification ratio ring, and an ASA (now ISO) ring making an exposure
calculator for the camera/lens combination. Obviously, it is best for
really close-up things -- though you do need a ND filter to reduce the
sensitivity a bit, since 200 ISO is a bit too high. Since I have not
yet acquired the ND filter, I have not been able to use it at its
closest on the D70.

It *does* need the AS-15 adaptor (or some other one) to convert
the hot shoe to a PC contact. For other ring flashes, with manual
exposure, you might need a hot shoe adaptor which also reduces the
voltage applied to the flash sync controller in the camera. Some
produce too high a voltage for the solid-state switching element.

Enjoy,
DoN.

--
Email: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Archived from groups: rec.photo.digital.slr-systems (More info?)

"Frederick" <nomailplease@nomail.com> wrote in message
news:1118179676.117141@ftpsrv1...
> Norm Dresner wrote:
>
> > I surfed the Nikon website the other day and found out that Nikon's own
> > SB-29 only works with the D70 in the "manual" mode. Does any other
> > manufacturer's equipment work TTL yet?
> >
> > BTW, the website provided an explanation of why older flash units don't
work
> > TTL. The Nikon flash-TTL design (as does the implementation of [almost]
> > every other manufacturer) relies on the light reflected from the film
> > surface to measure the amount of (integrated) flash light from the
strobe.
> > Since the D70 -- and AFAIK --- every other Nikon DSLR obviously doesn't
use
> > film, there's no way this scheme works. Apparently the newest units
> > (SB-600/800) have sufficient electronics to do the job for the body. My
> > question is, since Nikon was designing the CCD sensor anyway, couldn't
they
> > have arranged it so that there was enough light reflected off of it to
make
> > the older TTL flash units work as well?
> >
> > Norm
> >
>
> Sigma:
> http://www.dpreview.com/news/0409/ [...] gflash.asp
> Supposed to work with i-TTL / Nikon.

Yeah. For $360 (street). For now, I'll just handhold my SB-600 with a
diffuser at the end of a SC-17 cord -- the results I've gotten with it so
far indicate that it's probably not worth it for me to invest in the
additional equipment. Now if it had been $150 or less ...

Norm

Archived from groups: rec.photo.digital.slr-systems (More info?)

Father Kodak wrote:

> On Tue, 07 Jun 2005 11:06:52 -0400, Alan Browne
> <alan.browne@FreelunchVideotron.ca> wrote:
>
>
>>Norm Dresner wrote:
>>
>>
>>
>>>(SB-600/800) have sufficient electronics to do the job for the body. My
>>>question is, since Nikon was designing the CCD sensor anyway, couldn't they
>>>have arranged it so that there was enough light reflected off of it to make
>>>the older TTL flash units work as well?
>>
>>There are no OTF-TTL sensor implementations on any DSLR's that I know
>>of. I suppose that the implementation of sensor cover, filters and the
>>sensor itself render such a weak, or over directional reflection as to
>>make the OTF sensors useless.
>
>
> I guess I'm missing something here. I'm going to guess that the OTF
> sensor output is directed back to the flash. And when the flash sees
> that the sensor output has reached a certain level, it cuts off the
> remainder of the flash exposure.

I don't think so - but I might be wrong.
>
> My confusion arises because the DSLRs must also have some kind of
> sensor whose output is fed into the SB-600/800. So how difficult
> could have been to include an "OTF flash" compatibility mode into the
> D70, D1 and D2 series,etc?
>
> Whatever this i-TTL DSLR measurement method, how different can it be
> from the OTF method? In principle both are measuring the same thing,
> which is the exposure from the Nikon speedlight?
>
> Kodak, Pere
>
I wish that there was a concise explanation of this somewhere. I read
on one hand how great the Nikon i-ttl system is, but it would be nice to
know how it works - to get some better understanding of how to use it.

I thought that measuring of a preflash (while the mirror is still down)
was used to set the level of the full flash exposure. It seems to work
pretty well for the built in flash - which is better than any others I
have used.

Prices seem to have come down quite a bit here (NZ) for SB600/800 -
thanks to grey market importers. Although I seldom use flash, it is
starting to look almost affordable.

Archived from groups: rec.photo.digital.slr-systems (More info?)

dnichols@d-and-d.com (DoN. Nichols) wrote:

>Perhaps bring back the Pelex design of Cannon, eliminate the
>mirror movement, and use the sensors in the focusing screen, since that
>will still be getting flash illumination. What killed the Pelex,
>anyway? It was mechanically simpler, with no mirror motion to deal
>with.


Did you mean the Canon Pellix? Some references:

http://www.mir.com.my/rb/photograp [...] es/pellix/

http://www.cosmonet.org/camera/canon_fx_e.html

Archived from groups: rec.photo.digital.slr-systems (More info?)

DoN. Nichols wrote:
> The only way to meter during the flash would be
> to install a bunch of sensors mixed in with the pixels used for the
> imaging.

No. You could do like P&S cameras, and flash twice - once to meter the
flash (and read selected [or random] pixels of the sensor), the second
(metered based on the previous image) to actually take the image. Most P&S
digitals meter flash this way, and it happens so fast most people don't
realize the flash fires twice.

Austin