5 hours ago
|
Re: Intermediate ISOs and the E-30/E-620, and noise ...
In reply to WhyNot,
3 months ago
|
WhyNot wrote:
veroman wrote:
WhyNot wrote:
There was an article on Digital ISO a while back in Digital Photo Pro Magazine and you can read it here . What I took from the article was that ISO is raised in a digital system by increasing the gain on the sensor. However, the increasing gain is not a continuous function but a step function so that if the base ISO is 100 it changes 100, 200, 400, … Intermediate values are then computed from one of these steps.
As I recall, one of the things we can never know about a DSLR (or any other digital, I guess) is exactly what that base ISO is. I believe it's proprietary for each manufacturer. Tests I've done with all of my Olympus E-cameras suggests that their base ISO is anything BUT ISO 200. ISO 100 is more like it. ISO 200 on everything except my E-30 shows a dip in dynamic range. My old Olympus C-5060 was at its very best at ISO 80 ... the lowest it could go.
--
SteveG
'When love and skill work together, expect a masterpiece.'
— Found in a Chinese Fortune Cookie
www.stephenmichaelgarey.com
I believe the article that I provide a link to calls "base" ISO the "native" ISO and agrees that the manufactures never specify it. ... If your comment is about my statement then I only specified a hypothetical base ISO and had no intention of claiming 100 as a universal base. The only point was about the step gain....????
Yes, I understood that. I was just adding my own 2 cents to the discussion of intermediate settings.
--
SteveG
'When love and skill work together, expect a masterpiece.'
— Found in a Chinese Fortune Cookie
www.stephenmichaelgarey.com
| Post (hide subjects) | Posted by | When | |
|---|---|---|---|
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | 1 | ||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago | |||
| 3 months ago |
   |
|
Connect with dpreview
|
