how quiet is the GF1 shutter?

[Abbazz]

BTW, I am not aware of any digital cam that uses a mechanical shutter. Those hand cranked gizmos are history.

Epson RD1/RD1S.

Cheers!

Abbazz

 

[Vivek]

Still an electro-mechanical shutter. That historic camera also had a "film rewind" knob.

 

[ChrisJ]

All stills digital cameras require a mechanical shutter the D70 is no different.

Quote from the spec sheet.

"Shutter

Combined mechanical and CCD electronic shutter,30 to 1/8000 s in steps of 1/3 or 1/2 EV, bulb"

To get a fast shutter speed with a large sensor you have to have a mechanical shutter even cheap 'point and shoot' cameras have them.

The limit to electronic shutters is the sensor themselves, to get the data to stream out of a sensor takes time, in electonic terms sensors are slow devices, video only needs low resolution compared to still and slow frame rates.

A good measure of how fast a camera can clear the sensor of data to the buffer is to look at the frame rate in continuous shooting mode. In a G1 it's 3 frames a second the same as your D70 (and that's only a 6Mp sensor). This spec is always optomised by manufacturers as they know it's important to photographers, it will always be as fast as the sensor can reliably operate.

Chris

 

[Vivek]

The D70 could flash sync as high as the highest shutter speed when a suitable flash is used (none of the iTTL/TTL flsahes would work). The reason for that was the electronic shutter working. The electro-mechanical shutter would only sync up to 1/250s.

Search for high speed flash and the D70 instead of what the spec sheet says.

 

[pellicle]

as far as I have seen all digital cameras have shutters. They may have between the lens iris shutters, which allow shutter speeds to be greater than focal plane shutters do meaning faster flash sync.

focal plane shutters (which have to move a long way) have a moving window of exposure to effect the higher shutter speeds. Flash is typically 1/5000th of a second or shorter duration so the full sensor must be exposed for the flash to expose it ... thus we have 100th or 125th (or rarely 250th) shutter speeds for focal plane cameras.

some exceptions (like OM-4) operate by pulsing the flash during the exposure and thus have reduced flash GN for a given system.

 

[Vivek]

Pellicle, The Nikon SB-24, for example can do >1/10,000 s flash at its lowest power. BTW, with the D70, at high speeds, the whole sensor is exposed. No clippings occur.

There are others that can do even higher.

 

[pellicle]

Pellicle, The Nikon SB-24, for example can do >1/10,000 s flash at its lowest power. BTW, with the D70, at high speeds, the whole sensor is exposed. No clippings occur.

There are others that can do even higher.

I understand that ... but I think you'll find that in the time that the shutter plane is moving along that it has to pulse a few times on a single charge ... this causes the GN to be revised down ... did you not read what I explained? If you have an alternative mechanism to explain it I would be interested to read it, but to my knowledge it works as I explained.

 

[ChrisJ]

Pellicle, The Nikon SB-24, for example can do >1/10,000 s flash at its lowest power. BTW, with the D70, at high speeds, the whole sensor is exposed. No clippings occur.

There are others that can do even higher.

Not true Vivek. focal plane shutters get their fast shutter speeds by releasing the second curtain before the first curtain has travelled to the bottom of the sensor, a stip of light travels down the sensor. For faster shutter speeds the strip of light is narrower for slower ones it's wider.

Flash normally operates when the sensor is fully exposed, the fastest speed where this happens is usually around 1/160th of a second for most shutter mecanisms. (all camera manufacturers tend to use the same shutter mechanisms from Seiko, who are experts in the field).

In high speed flash the flash strobes the light as the shutter travels down the sensor at the faster shutter speeds so every strip of light is exposed to the flash, they can only do this at the expense of GN value, in other words they use a limited output on every flash.

The only way you can get all the sensor to be exposed at high speeds is to use a copal shutter built into the lens, this is impractical on any camera that can change the lens hence the use of focal plane shutters on DSLR's.

Chris

 

[pellicle]

in the words of someone else:

This is where High Speed Sync comes into play and why it is so important to TriCoast’s wireless flash technique. When you have your High Speed Sync button set on your flash and you click the shutter to take an image, everything works the same with the curtains, however now the flash fires for a longer period of time and keeps firing as the stripe between the two curtains runs across the chip or sensor. So even though the shutter was never completely all the way open, all of the chip or sensor gets the light of the flash on it. However there are drawbacks to this technique in that the faster the shutter speed is the less time the flash can “fire” on the chip or sensor. The end result will be less light on your image. Due to this effect your light source needs to be closer to your subject the faster the shutter speeds are to get more light on them

 

[pellicle]

The only way you can get all the sensor to be exposed at high speeds is to use a copal shutter built into the lens, this is impractical on any camera that can change the lens hence the use of focal plane shutters on DSLR's.

or use the system pioneered by Olympus (iirc) which essentially high frequency pulses the flash for the duration of the shutter operation....

 

[pellicle]

about the OM-4

from this link

This is what gives Olympus engineers their clue. Instead of just one flash emission per discharge, the F280 produces thousands of pulses, perfectly timed so that the level of illumination remains constant from start of finish.

one of the few advantages of being old is that I lived through this ... so I actually remember it rather than need to research it.

 

[ChrisJ]

or use the system pioneered by Olympus (iirc) which essentially high frequency pulses the flash for the duration of the shutter operation....

Then we are back to the limited GN of the flash.

I have an old Yashica Minster rangefinder camera with a fixed lens and copal shutter. It's fastest shutter speed is 1/2000th of a second and I can use the flash, at full power, at that speed. Combined with my old Metz flashgun I could effectively floodlight a whole building in one frame. Mind you, it did take a full fifteen seconds to re-charge LOL.

Chris

 

[pellicle]

Then we are back to the limited GN of the flash

yep remember the old GE flashbulbs?

When used with ISO100 B&W film, they give a guide number of about 200 at 1/100s shutter speed.

GN 200 ... man ... stick that in your pipe and smoke it ;-)

http://graflex.org/flash/ge-5.html

http://www.darklightimagery.net/flashbulbs.html


watching this video was enough to make me sigh ..

http://www.youtube.com/watch?v=x9Pn8AUwmHQ

just how dumb are some people?

 

[ChrisJ]

yep remember the old GE flashbulbs?



GN 200 ... man ... stick that in your pipe and smoke it ;-)

http://graflex.org/flash/ge-5.html

http://www.darklightimagery.net/flashbulbs.html


watching this video was enough to make me sigh ..

http://www.youtube.com/watch?v=x9Pn8AUwmHQ

just how dumb are some people?

He has a smoke detector in his workshop, good to see He's safety minded!!!

He didn't even check for the blue spot, remember how if it changed to red the bulb could (and did) explode, ah memories.

I think we are a little off topic here pellicle, it's very interesting though, the kind of thing I love, but I think we have left a few posters behind here.

Chris

 

[Ranger 9]

Geez, I'm gone for one day and all this stuff breaks out...

-- Vivek's right about the Nikon D70/D70s being a special case for high-speed flash sync. It used its mechanically-operated (but electronically timed) shutter blades to time slow exposures. However, at its high speeds (up to 1/8000) it timed exposures electronically by turning the sensor on and off, and this allowed electronic flash sync at all those speeds since there was no shutter slit traveling across the film.

The drawback of this was artifacts; as Nikon-guide author Thom Hogan wrote: "...the electronic shutter speeds (1/500 to 1/8000) seem to produce curious grid-like patterns in plain tonal areas in bright light."

Presumably this is why nobody, not even Nikon, has used this system in subsequent cameras. That makes me doubt the contention that µ4/3 cameras would be better off eliminating the mechanical shutter for timing and relying entirely on this system.

-- I believe it's correct that Olympus was the first to offer a dedicated flash system that achieved higher sync speeds with a mechanical slit shutter by dividing the flash energy into a series of short pulses that could be stretched out over a longer duration (although the idea actually may have come from Minolta, as with off-the-film flash metering, which they licensed to Olympus in some kind of patent swap.) Now every DSLR manufacturer that offers a high-speed-sync option in a camera with a conventional focal-plane shutter uses the same system. (As noted above, the Nikon D70 was a special case.)

That's why your Nikon SB-800's range plummets when you use CLS flash in its HSS (high-speed sync) mode, for example; if you take a full "bucket" of energy and divide it into a lot of little drips, each of which lights just one narrow slit of the full sensor, each drip isn't going to be very powerful. At slower shutter speeds, with no moving slit, you can throw the whole "bucket" of energy at the sensor all at once.

-- While this approach gets around the sync limits of a traveling-slit shutter, the disadvantage (other than a huge loss of flash power) is that it only works with dedicated flash units; you can't get high-speed sync with any old flash, the way you can with a camera that uses a leaf shutter (such as ChrisJ's old Yashica Minister.) But I don't think most of us would put up with the size and cost disadvantages of including a leaf shutter in every lens of a µ4/3-format camera!

 

[Vivek]

Not true Vivek.
Chris

Chris, Search p.net for Frank Skomial's posts. AFAIK, he is the one who found this feature and expounded on it. He also knows a thing or two about flashes and flash sync and such.

I have tried it myself (so have others). It is prudent to check the facts before saying "not true" based on hypothetical, broad brush explanations.

 

[ChrisJ]

Thanks for that Vivek I wasn't fully aware of the unusual way the D70 used it's sensor, using the four separate channels on the sensor this way, they did get the headline figure of 1/500th of a second sync speed (not 1/4000th of a second which, as I understand it, is the flash duration) at the cost of a lot of IQ issues highlighted in the article you referred me to, which were never resolved.

Trying to use the sensors control circuitry is currently really a non starter it's just too slow. Even CCD sensors use Cmos for the control circuitry due mainly to it's very modest current requirements, Cmos is a capacitor coupled device, delays at every stage are measured in milliseconds, not the microseconds required for what you suggest and what Nikon tried.

It will change as sensor technology moves on, but currently we are stuck with the electro mechanical means of controlling the exposure for the higher shutter speeds and using electronics in the camera to control the flash (which can be switched in the Mhz region if required) for high speed flash. It's revealing that Nikon have not tried this again in the 4 years since the D70.

Chris

 

[pellicle]

Vivek

Search p.net for Frank Skomial's posts. AFAIK, he is the one who found this feature and expounded on it.

real interesting ... reading Edward Ingolds discussion on the only thread I could find much detail on he says:

The D70 has a CCD sensor with an electronic (gate) shutter that supplements the mechanical shutter. It appears that the mecanical shutter is fully open at all shutter speeds, and does not exceed 1/250 second. The electronic shutter takes over above 1/250 second and affects the entire image area at one time. Therefore, you can use an SB-800 at any shutter speed if you sync from a PC port rather than from the hot shoe. You may find an adapter you can place between the SB-800 and the hot shoe to either eliminate the "TTL" connections or provide a PC port. If necessary to prevent shorting, insulate the foot (or accessory shoe) of the SB-800 with Scotch Magic Tape.

I'm not entirely across the system, although Frank says in this post:

This requires to place FP flashes very close to the subject, - (due to FP/HSS loss of power/or rather spread of power over longer time - thus making it "thin"),

its interesting that they apply an electronic gating method, but it seems that the flash operation is more or less as described above (pulsing).

However getting back to the electronic shutter it seems that it has at least one instance ... I didn't know of any digital cameras taking advantage of this technology, but its interesting to the flash system come up again.

thanks for the information

PS ... further searching found this interesting post:

To prove that I was right with D70 and SB800 FP operation at 1/4000 and my understanding was correct about this sharade, I performed test with D70 set in manual at 1/4000. On purpose I used a non-FP flash, notably great flash Sunpak 555, and expected partially exposed frames.

Using non-FP flash at 1/4000 I expected to obtain partially exposed frames, but to my surprise ! entire frames were exposed correctly, end the recorded picture data stated 1/4000 shutter speed. I just could not believe my eyes. The only explanation is that Sunpak 555 flash slowest duration is 1/200 and that is certainly long enough to cover narrow shutter slot (1/4000) travelling across the sensor that only needs 1/500 sec to complete the journey.

The bottom line is that D70 shutter speed faster than 1/500 can be used with FP flash, or any flash with longer duration than 1/500 sec, but results are not quaranteed by anyone. You are responsible for setting appropriate flash output level to obtain correct exposure.

which kind of implies that the shutter is open less than 250th ... hmmm

 

[pellicle]

an interesting question on this is could the MOS technology of the G1 work with the system employed by the D70 which is CCD (and I understand faster electronic operation)