First this , I am not familier with the C8080 but I like to react on this issue.
You are saying ISO 50 and ISO 200 should have the same noise level.....!
ISO 50 and 1/20 in the example works fine although you need some post processing to get a good picture.
(underexposed picture to lighten up)

ISO 200 and 1/20 does not work because at ISO 200 you also need a higher shutter speed to avoid noise especially with F2.4

Then the example pictures have not the same size.
The picture on the right is enlarged more so noise will be more visible also.
IMO shooting with different ISO settings needs adjustment of the shutter speed also.

I am not a pro but this is what came up in my mind when seeing your picture and explanation.
So if I am wrong please explain and correct me.

Best regards,

PS
this is a good issue for a POL


regards,

Is this more common to the 8080 than other cameras? Also, I would expect a bit more noise, just as a higher ISO film has more grain. However 100 or 200 ISO doesn't seem so high that it would cause big noise problems when compared to similar films.

What program did you use for post-processing. Did it offer adjustable levels of noise reduction?

Udo

Alfred, your test enough is corrected, but I think that in all the digitalcameras you would have approximately the same result. ( Only Nikon D70 start whith more underexposition) I often use to regulate my 8080 to -1 or -2 compensation especially in the concerts and other location whith low light to have more sensitivity and low grain (sometimes 400 iso and compensation -1 or -2 to have 800 or 1600 iso with not bad results and similar or better of same dsrl at 1600 iso).
For Fons: The grai does depend on the aperture or shotter speed but only from the amplification of the signal. Regards

.....pardon " the grain does not depend" ....

Fons van Swaal wrote:
> First this , I am not familier with the C8080 but I like to react on this issue.
> You are saying ISO 50 and ISO 200 should have the same noise level.....!
> ISO 50 and 1/20 in the example works fine although you need some post processing to get a
> good picture.
> (underexposed picture to lighten up)
>
> ISO 200 and 1/20 does not work because at ISO 200 you also need a higher shutter speed to
> avoid noise especially with F2.4
>
> Then the example pictures have not the same size.
> The picture on the right is enlarged more so noise will be more visible also.
> IMO shooting with different ISO settings needs adjustment of the shutter speed also.

Hi Fons,

for some strange reason I did not receive your mail with the comment. Anyway, both images are not enlarged. They have the same size and to the top right you can see how the whole image looks like.

Both images are shot at the same aperture and exposure time. So the ISO 50 image is very dark (underexposed) while the ISO 200 shot is properly exposed.

Then in postprocessing the dark ISO 50 image is brightened up to match the brightness level of the ISO 200 image. In theory there should be no difference in noise levels, but in practice there is.

Alfred

> Hi Fons,
> for some strange reason I did not receive your mail with the comment. Anyway, both images
> are not enlarged. They have the same size and to the top right you can see how the whole image
> looks like.
> Both images are shot at the same aperture and exposure time. So the ISO 50 image is very dark
> (underexposed) while the ISO 200 shot is properly exposed.
> Then in postprocessing the dark ISO 50 image is brightened up to match the brightness level
> of the ISO 200 image. In theory there should be no difference in noise levels, but in practice there is.
> Alfred

Thanks Alfred for explaining again.
I miss understood the whole issue, thanks for explaning again.

Regards