The Q is almost 1-stop brighter than the Q2

[dancook]

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It's close to 0.79 of a stop, the difference is significant.

I've noticed it in other testing, but this is a more controlled comparison

Fixed settings - 1/500th, F4, ISO 6400

Using artificial lighting to rule out external light variants

Q1

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Q1 1/500 ISO 6400 F4 by Daniel Cook, on Flickr

Q2

Q2 1/500 ISO 6400 F4 by Daniel Cook, on Flickr

Then if I bring down the Q1 by exactly 1-stop

Q2 1/500 ISO 6400 F4 - 1EV by Daniel Cook, on Flickr

Edited March 9, 2019 by dancook

[dancook]

This means at the same aperture and shutter settings the Q2 would need a higher ISO than the Q1 to get a similar exposure.

Edited March 9, 2019 by dancook

[Chaemono]

That sucks.

Edit - try a scene with extreme Highlights and dark Shadows and see which sensor handles it better. I bet the Q2’s. 

Edited March 9, 2019 by Chaemono

[frame-it]

49 minutes ago, dancook said:

This means at the same aperture and shutter settings the Q2 would need a higher ISO than the Q1 to get a similar exposure.

and what could be the reason for this fairly extreme difference?

[dancook]

6 minutes ago, frame-it said:

and what could be the reason for this fairly extreme difference?

Perhaps it's fixed this way to make the ISO handling look better/comparable for side-by-side comparison, but it's not like-for-like when the Q has a 0.79 of a stop advantage. (tweaked histogram to match)

Edited March 9, 2019 by dancook

[frame-it]

2 minutes ago, dancook said:

Perhaps it makes the ISO handling look better/comparable for side-by-side comparison, but it's not like-for-like when the Q has a 0.79 of a stop advantage. (tweaked histogram to match)

less visible banding on the ISO25000 shots with the q2 in your other post.

 

perhaps RAWdigger would give a accurate idea of whats happening

[dancook]

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Just now, frame-it said:

less visible banding on the ISO25000 shots with the q2 in your other post.

 

perhaps RAWdigger would give a accurate idea of whats happening

But we should probably compare Q at 16000 ISO versus Q2 at 25000 ISO (guessing at comparable figures based on exposure difference)

[Chaemono]

We’ll see when the sensor is compared to the SL, α7R III, and Z7 all with the same lens. I think your conclusion is wrong. 

[dancook]

1 minute ago, Chaemono said:

We’ll see when the sensor is compared to the SL, α7R III, and Z7 all with the same lens. I think your conclusion is wrong. 

The conclusion that Leica rigged it?  perhaps a little cynical of me

Edited March 9, 2019 by dancook

[frame-it]

almost looks like leica toned the exposure down to avoid banding.

[LocalHero1953]

There have been discussions elsewhere about similar behaviour in the M10. The most favourable explanation I have seen is that, because digital sensors are vulnerable to blown highlights but amenable to recovering shadows, Leica has implemented a strategy of setting its metering to under expose. I have no idea if this is true or not!

[Chaemono]

I bet Q blows Highlights more easily and Q2 files are more malleable.

[M11 for me]

An explanatin that I remember is the following: Necessary iSO settings to produce a defined brightness are measured on the sensor level, But depending a camera 2 diferent sensors might have different layers of additional glass on top ofthe sensor that take away a bit of light. That is why pictures taken with same settings and resulting same brightness might require different ISO settings (or aperture or shutter speed).

[Chaemono]

This could be it. Leica may have just put too much glass in front of the Q2 sensor which means users will just have to crank up the ISO and all will be fine. Or, dial the aperture ring all the way to 1.4. It is a Summilux after all. 

[Fedro]

1.7

[Chaemono]

I’m not sure. There could be 1.4 hidden somewhere on the dial. Maybe it requires firmware upgrade to unlock it. 

[jaapv]

This topic has been done to death in many threads on this forum. 

Digital ISO is basically whatever the camera designer says it is The ISO norm allows at least three definitions which all render different results and are moving targets. The only thing to do is determine the value for each camera type or trust the internal exposure meter. Not too different from film, really. The film speed is related to the development. 

The point is that the sensor output is a constant determined by the amount of light and sensor architecture (for most of the time and cases) and the so-called ISO is the way the camera software handles  the signal. 

[LocalHero1953]

Just a thought, @dancook - and I have never used a Q - can you set the exposure from the histogram in the EVF? If you use this, and set it identically in Q and Q2, rather than the simple exposure over/under scale, do you get similarly exposed images? 

[dancook]

7 minutes ago, LocalHero1953 said:

Just a thought, @dancook - and I have never used a Q - can you set the exposure from the histogram in the EVF? If you use this, and set it identically in Q and Q2, rather than the simple exposure over/under scale, do you get similarly exposed images? 

When i took my next test images, see the colour comparison thread

I did under expose the Q1 by 2/3rds a stop to get a more similar exposure - which led to ISO 5000 vs ISO 8000

Edited March 9, 2019 by dancook

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Hallo,

Look here: Leica Q

[jaapv]

Which is the correct way to do it.