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Ok, I don't like numbers as I've explained before, so maybe that's why I'm asking.

If for example, you have two different cameras set on the same shutter speed, how is one able to shoot at 3fps while the other can do 9fps? Is it all about write speed?

The frames per second rate of film cameras used to be governed by the wind-on motors ability to quickly cycle the shutter, mirror and wind on film. It actually requires a lot of energy to make things happen faster... its a bit like riding a bike.... it actually requires a lot more energy to make things happen faster. It is for this reason why most consumer cameras chug along at two or three frames a second and the professional cameras motor along at 9 frames a second. To gain improved speed you really need a strong battery and a powerful motor ... the write speed is almost a secondary consideration.

As Antsl says, there's quite a lot happening when you're shooting, and when you increase the frame rate, it all has to happen quite a bit faster.

Consider that the camera needs to raise the mirror, open the shutter, meter and expose, close the shutter, lower the mirror, cock the shutter, and clear the sensor of data (to the buffer) in each exposure cycle. That's a lot of work.

Now consider this: let's take a shutter speed of just 1/1000 sec. The shutter needs to open and close 8 times, leaving itself open for just that small amount of time during each such cycle. Consider the acceleration and deceleration speeds of the component parts of the shutter mechanism, likewise the componentry within the mirror box assembly. There's a lot of very small pieces moving around very quickly, but they all need to be able to do that with a very high degree of reliability, and without falling about all over the insides of your camera.

Now consider this: in 14bit mode, there's something close to 20MB data that the sensor is capturing in a D300. At 8FPS, that data has to be capture, and then cleared to the buffer, 8 times every second. Depending on the speed of the card, the D300 this can be done up to 100 times, at that speed. That's a hell of a lot of data to be shifted ...

Cheaper cameras simply aren't built to a standard that can withstand that sort of heavy duty punishment.

Great, just what I was after, thanks for clearing that up lads. Something new everyday..

gstark wrote:Now consider this: in 14bit mode, there's something close to 20MB data that the sensor is capturing in a D300. At 8FPS, that data has to be capture, and then cleared to the buffer, 8 times every second. Depending on the speed of the card, the D300 this can be done up to 100 times, at that speed.

Just a quick clarification here, the D300 cannot do 8fps when working in 14bit mode. In 14-bit mode, it can only do 2.5fps.

Sorry for being pedantic

André

Consider a sedan body car. A Toyota Camry vs a BMW M5. They both are about the same in body size, runs on four wheels, powered by an engine. Starting up both cars to run on the same strip track, who will get there faster? The speed is very obvious and what happens is right under the bonnet.

If that makes more sense without going into the in-depth geeky stuff.

André

radar wrote:Just a quick clarification here, the D300 cannot do 8fps when working in 14bit mode. In 14-bit mode, it can only do 2.5fps.

Sorry for being pedantic

No need to apologise for this. You are quite correct - I just checked - and even with the battery pack, switching to 14 bit pulls the speed down to 2.5 fps.

Thanx for correcting my misunderstanding of this.

You know, we talk about how hard the image processor has to work when we crank up the shooting rate on these cameras but the same used to be true fifteen years ago when you went made with the motor-drive at an event.... long time in darkroom processing...... This is why I prefer to work with the camera in single shot mode most of the time .... every press of the button should be both considered and/or instinctive.

Having said this... some of the best fun I have had a wedding in recent times was when testing the D3 .... at the reception I had friends making mini movies using the D3 set to 9 fps in JPEG mode!

Does make a bit more sense when you put it in car terms

Antsl wrote:This is why I prefer to work with the camera in single shot mode most of the time .... every press of the button should be both considered and/or instinctive.

During the film day yesterday we covered a number of aspects of this.

Stuff like using a bulk film back on a body - the FM/FE/FA series had these available, as did the the various F bodies, although this would be one piece of hardware that I've not had the pleasure to play with.

Ants? Matt?? Chris??? (happy birthday, Chris, btw I hope that you're still celebrating. )

I also explored with the participants the possibility of using a LF camera next time we do a film day, and that was a very warmly received concept. Shooting LF - I'm thinkng 5x4 - of course absolutely impresses your point upon the shooter, about the need for the shot to be seriously considered.

My K20D does 3 FPS at 14.6 Mp or 21 FPS at 1.6Mp.

even though it does the same FPS as my old *istDs that was only 6Mp so the amount of info the K20D has to process is enormous.

gstark wrote: Stuff like using a bulk film back on a body - the FM/FE/FA series had these available, as did the the various F bodies, although this would be one piece of hardware that I've not had the pleasure to play with.

NASA were the biggest users of these bulk film packs, particularly on cameras like the Nikon F3. These backs gave astronauts the opportunity to shoot plenty of film on EVAs without worrying about changing films. These cameras were also popular in remote control cameras in surveillance projects. The actual price of bulk film rolls was actually not that bad.... on the news papers we were using bulk rolls to load our own 36 exposure cassettes from and it worked out at about $1.50 to $2.00 per 36 exp. roll. I would not have liked the challenge of processing a bulk roll though.

I also explored with the participants the possibility of using a LF camera next time we do a film day, and that was a very warmly received concept. Shooting LF - I'm thinkng 5x4 - of course absolutely impresses your point upon the shooter, about the need for the shot to be seriously considered.

What always impresses me is the thought that a 5x4 camera has the equivalent of surface area of about 12 frames of 35mm film... that is why these cameras can capture so much more detail than the smaller formats. The down side is that these cameras require a lot more consideration than most other cameras .... I have used 4 x 5 in my time as a student but these days I prefer to work in medium format if I am getting serious about an image... more chance of changing composition in a hurry if required. I can think of several photos that I would have missed had I been trying to set up the image in 5x4. With a Hasselblad you can recompose and focus in the matter of a few seconds .... with a 5x4 camera it takes at least a couple of minutes... its a beautiful medium but it is not spontaneous. I do hope you get to see one in action with the "Film Day Out" guys though ... they are definitely worth seeing in action (any big gun is isn't it!).

Antsl wrote: I would not have liked the challenge of processing a bulk roll though.

Me either.

It's one thing to process a half dozen rolls of 135/36, and quite another to do 30 meters. I would imagine this has to be in some sort of a continuous process setup, rather than a dip'n'dunk scenario.

The down side is that these cameras require a lot more consideration than most other cameras ....

Is that, really, a downside? Making one think about the images that they're going to make?

I have used 4 x 5 in my time as a student but these days I prefer to work in medium format if I am getting serious about an image... more chance of changing composition in a hurry if required. I can think of several photos that I would have missed had I been trying to set up the image in 5x4.

I don't see the two formats (any LF vs MF) as being comparable in their usage. To me, MF is as usable as 35mm film, or current digital mediums. It's well able to be used for setups, as well as for spontaneous shooting.

I do not see LF as being able to be used for any sort of spontaneous shooting at all; it's far too deliberate a medium for that sort of thing.

While I can readily accept that there may be images that one may miss getting had you needed to set up a LF beforehand, I would argue that this is probably not the forte of LF gear, and I would not be expecting to get a grab shot (or whatever) because that would not be my expected usage for it.

That said, a Speedgraphic loaded with a DDS and using the sports finder can be a usable combo: indeed, before Nikon became the camera de jour of press photographers, that was the usual setup: the Pulitzer Prize winning image of Robert Kennedy lying shot on the floor of the kitchen of an LA hotel was shot with a Speedgraphic. Surely a testament to the viability of this sort of photography.

its a beautiful medium but it is not spontaneous. I do hope you get to see one in action with the "Film Day Out" guys though ... they are definitely worth seeing in action (any big gun is isn't it!).

I know. I've owned one in the past (was sold to Clive Robbo) and I was that close to buying a Toyo 4x5 monorail in HKG last year.

Leigh argued that I would probably never use it. He's probably correct in that assessment, but since when does that matter?

That would have to be a thought .... hanging onto your 5" x 4" camera in the hope that some day a company might bring out a 150 megapixel full frame back for the camera .... with LiveView .... ah, where is my pipe!