On 29/04/2015 14:35, whisky-dave wrote:

8

Perhaps because it's not that important or relivent to film, in the
same way you don't see the grasin size mentioned when talking about
high ISO in DLSRs it's called noise now. I don't remmebr buying HP4
or 5 or kodachrome having a noise rating funny that. Perhasp because
they didn't priduce noise.

Oh, they did.
and they produced different noise on the different layers.
It was caused by interaction in the silver producing bigger grains in
some light conditions than other so the noise would vary across the
image as well as the colour and the exposure time.

Digital doesn't produce the same sort of noise, its just one pixel being
more sensitive to heat than another and you can see it in low light.
Of course if you are going to do low light stuff with digital you could
always go the amateur way and cool the sensor to reduce the noise
effects. You can find youtube videos on how to fit cold fingers to stuff
like D50s if you want to try it.






One thing, that surprises me if you claim to have expert knowledge
in the field,

which I don't, most is common sense and knowing a little bit about
it.


.is one advantage not having a pentaprism and mirror
combination, it unties the hands of lens designers, leading to
simpler and more efficient lenses.

Lens designers have always strived to improve their designs.
pentaprism and mirrors have nothing to do with that.

Of course they do, the mirror makes you space the rear of the lens away
from the sensor, that may not be the best way to design a particular
lens, e.g. wide angles need more elements just to get the focus in the
correct place when there is a 50 mm gap behind the lens. It would be far
easier to make a 12 mm lens if the gap was about 10 mm which means no
mirror.

Its apparent that something is happening with lens designs as camera
manufacturers are removing the filters from the sensors to get better
resolutions, or at least they are doing so on compact system cameras.
If you are still using the old nikon and cnnon lenses designed for film
then you don't want to remove the filter as it hides the poor
performance of the lenses.

most P&S and compact cameras didn;t have pentaprism and mirrors, but
they also didn't have interchangable lenses.