E-M5 Firmware update... V 2.0 today..

Started Jan 29, 2014 | Discussions thread
texinwien Veteran Member • Posts: 3,326
The graphs are for JPEGs, not RAW

mchnz wrote:

texinwien wrote:

mchnz wrote:

Sourze wrote:

Whoah! Fantastic news

With access to lower ISO, does this mean we can also expect a slightly higher dynamic range?

It's marked as an "extension" ISO setting - like the very high ones. It's only simulated in firmware to make it easier to use fast lenses in bight daylight. DR will likely be down a bit. The E-P5 does this, so E-P5 users would have a feel for it.

Although it is marked as an extension setting, it is not simulated in firmware like the higher extension settings are.

Rather, at the ISO 200 setting, the E-P5 sensor (and, I believe, the sensors on all of the other most recent Olympus m43 models, including the E-M5 with this update) has an actual ISO of a hair over 100.

The LOW setting simply allows one to set the camera to meter as if ISO 100 was selected, but still has the exact same sensitivity (and DR for RAW shooters) as the ISO 200 file. You'll have to be a little more careful not to clip highlights, but the number of stops of DR does not change.

DPReview was clear about that in their E-P5 review :

The E-P5 offers an ISO 100 equivalent setting with reduced highlight range. This is because the ISO Low and ISO 200 settings are derived from the same sensor amplification setting - ISO 200 images are exposed to less light, protecting highlights, compared to ISO 100. The two settings have different tone curves applied so that both give the same image brightness, despite the difference in exposure.

The upshot of this is that the ISO Low shots include less highlight detail but with 'cleaner' shadows, while the ISO 200 shots strike the opposite balance.

DXO's measurements show the same to be true (for the E-M1, E-P5 and now, presumably, for the E-M5) .

So the firmware is not massaging the data in the same way as high extension ISO's. The firmware shutting off light a bit later in favour of shadows over highlights.

The graphs at the bottom of the dpreview on page 17 do appear to show a narrowing of DR for ISO 100 on the E-P5, more highlights are clipped. Seeming to show that the sensor was built optimally for ISO 200 rather than 100.

Those graphs are showing the result of different exposure plus different tone curves applied to the RAW values by the JPEG engine. They aren't telling us about changes in DR for the RAW file, which is what is more interesting.

Read the text underneath the graph - it says exactly what I did, which is why I linked to that article in my first reply to you.

 texinwien's gear list:texinwien's gear list
Panasonic Lumix DMC-GM5 Olympus E-M5 II Olympus 12-40mm F2.8 OnePlus One Canon EOS 300D +20 more
Post (hide subjects) Posted by
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow