On 29/09/2015 12:05, whisky-dave wrote:
On Monday, 28 September 2015 17:50:29 UTC+1, dennis@home wrote:
On 28/09/2015 12:42, whisky-dave wrote:
On Friday, 25 September 2015 22:49:23 UTC+1, NY wrote:
"dennis@home" wrote in message
eb.com...
On 25/09/2015 16:27, whisky-dave wrote:
Why call it a stop one have such strange stop
numbers....... why does f5.6 let in twice that of f8

f number is a measure of aperture *diameter* relative to lens
focal length.



Its the same as a film camera, where do you think it
differs? Why do you even think it might differ?

My thoughts exactly. I can't work out whether he really doesn't
know or is winding us all up. Film and digital cameras have
more in common that maybe he realises.

They sure do, but there are some important differncies.

You still haven't said what they are, I don't think you know.

if you don't know I'm not listing them for you. We are also talking
about qwhich is best for teaching photography. Teaching photography
adn gettiogn a good picture aren't the same.

There are no differences, if you can't list them i will continue to
state there are no differences. Its up to you to state what you think
they are or stop saying there are differences.




yes the meter is judging this isn't good if you're teaching the
subject.

So you propose not using a light meter while teaching photography.

No I've vere said that. are you sugeswstin we don;t need a light
meter because we have a digital camera ?.

Well its obvious that you can get the exposure by trial and error and
that you can do that trial and error there and then with a decent
digital camera. you will claim that that's too easy which i will ignore.



Why does the image on my LCD look the same irrespected of
the aperature and shutter speed I set.

Because you have a cr@p camera

wrong answer .

It was the polite one.

but still wrong.


and can't set the image to look correct at
a guess. On mine if you stop down, the image darkens when you
do DoF preview just like an old fashioned camera.

does it still darken if you don't do a DoF. ?

Why should it,

cause the f..king sun goes in or it gets dark or night approaches.
you know brightness changes throught they day. Your LCD and eyes
react to changing light levels differntly and to colur differntly.

Your eyes do, the camera doesn't.
You can see what the changes mean on a digital camera after you take a
picture you can only guess with film until you have it processed. Having
such a long delay doesn't aid teaching so digital is best there too.



the diaphragm in the lens doesn't close unless you do a DoF check,

or when taking a photo.

Well there's the obvious.


the same as on a film camera or are you proposing that only manual
lenses are allowed.

if you want to learn about lenses use a manual lens, just like you
would a car.

A manual lens and an auto iris lens produce the same images. Only
preview and metering differ and they differ the same for film and digital.