F65: Venice vs Monstro vs Helium

Couple things to definitely note about these images,

Well for one as Jacek points out the Venice does look zoomed in which is accentuating the noise we see. No explanation on that, not sure anyone has asked Chris. The Venice so far has a native ISO of 500 ISO (as 2nd stage ISO of 2500 is not available yet) and in this shot the Venice was pushed 2 stops to 2000 ISO. I haven't looked at the metadata to see what the RED's were actually pushed to for this exposure, perhaps the same.

The last thing to wonder is if Venice has any stages of built-in NR like the F5/F55 do. It'd be nice to know if NR exists and if it was enabled or not. etc. The guy who shot this owns an F65 so he's not completely Sony inept. :)

So far it seems the Sony is quite a noisy mess at 2000 ISO. Perhaps a bit "worse" than Helium but neither are as clean as the Monstro. Interesting to note that both Helium and Monstro are in fact 8k sensors and seem like they outperform the Sony at 4k sampling.
 
optitek said:
Also Venice looks zoomed in about 20%+
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Well the monstro sensor is almost 15% wider horizontally than Venice.

Also I think maybe the Venice may have been taken at a different time so perhaps the subjet and camera placement isn't exact?
 
The sensor on the Monstro is 40mm (compared to 36mm on the Venice), so it sees a wider field of view with the same lens. The Venice has a taller sensor (24mm compared to 20mm on the Monstro), so it sees a little more vertically than the Monstro will with the same lens.

The native ISO of the Venice is 500, so in this test it was pushed two full stops. Monstro has a native ISO of 1600 (according to Panavision, who have the same sensor in their DXL2) so it was pushed only 1/3 of a stop in this test.

I'd say that explains the discrepancy in noise performance pretty comfortably.

When Venice gets its 2500 native ISO option, I expect it will deliver much more comparable performance to Monstro, as at 2000 ISO you'll actually be OVERexposing the sensor by a 1/3 of a stop.
 
Grug said:
The sensor on the Monstro is 40mm (compared to 36mm on the Venice), so it sees a wider field of view with the same lens. The Venice has a taller sensor (24mm compared to 20mm on the Monstro), so it sees a little more vertically than the Monstro will with the same lens.

The native ISO of the Venice is 500, so in this test it was pushed two full stops. Monstro has a native ISO of 1600 (according to Panavision, who have the same sensor in their DXL2) so it was pushed only 1/3 of a stop in this test.

I'd say that explains the discrepancy in noise performance pretty comfortably.

When Venice gets its 2500 native ISO option, I expect it will deliver much more comparable performance to Monstro, as at 2000 ISO you'll actually be OVERexposing the sensor by a 1/3 of a stop.
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Except it seems like the monstro specifies 7.5 stops over at 1600 vs 6 stops over for Venice at iso 500 so actually it's pretty apples to apples at iso2000. So you're basically looking at a test with them normalized for 8 stops of highlights which most cameras would struggle with. Then again perhaps Venice builds in some highlight rolloff over 6stops that isn't accounted for yet?
 
It's apples to apples at 2000 ISO but Venice has 12db gain applied to its base/native ISO while monstro sits at 0db gain. Hence the noise comparison is definitely not the same.

One solution to account for different base ISO's when you can't change the lighting and don't want to change iris (or can't because you're all the way open) would be through use of ND filters. For example in this case you could put a 2 stop ND filter on the monstro and then shoot the same scene with Venice, then push both in post equally and compare.

BUT - that's not even what this test was about. It was just to show what Venice looked like exposed best it could be for the night shot given right now there is no way to switch it to it's other stage ISO (2500). At that ISO I'm pretty confident Venice will have the same noise quality if not better than Monstro. Well it better, because Venice photosites are bigger. :/
 
starcentral said:
It's apples to apples at 2000 ISO but Venice has 12db gain applied to its base/native ISO while monstro sits at 0db gain. Hence the noise comparison is definitely not the same.

One solution to account for different base ISO's when you can't change the lighting and don't want to change iris (or can't because you're all the way open) would be through use of ND filters. For example in this case you could put a 2 stop ND filter on the monstro and then shoot the same scene with Venice, then push both in post equally and compare.

BUT - that's not even what this test was about. It was just to show what Venice looked like exposed best it could be for the night shot given right now there is no way to switch it to it's other stage ISO (2500). At that ISO I'm pretty confident Venice will have the same noise quality if not better than Monstro. Well it better, because Venice photosites are bigger. :/
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Not sure how you figure those numbers. Both cameras are at 0db gain, the only gain setting available to them at this time as neither seem to support analog gain, only digital EI adjustments. Both cameras are pushed digitally to match in the same lighting and exposure. Both cameras specify about the same white clip point at 0db from what I can tell. Seems about as apples-to-apples as it gets until someone confirms Venice's white clip point and whether perhaps it may be above the 6stop specification that Sony gives for ISO500 as it sounds like there is a chance Sony has added some extra rolloff, but that might just be a LUT/gamma improvement.

If Venice does better with its upcoming additional native ISO setting, it will do so with a loss of highlight range. We don't know if it will do better at the ISO2500 setting, but it will likely lose highlight range to get there.
 
nyvz said:
If Venice does better with its upcoming additional native ISO setting, it will do so with a loss of highlight range. We don't know if it will do better at the ISO2500 setting, but it will likely lose highlight range to get there.
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No, (in theory) it shouldn't lose any highlight latitude at all. That's the entire purpose (and appeal) of the 'dual native' ISOs. You get the added sensitivity, whilst retaining the same spread of latitude at both ISO values.

If the Varicam's results are any indication, the image will be noisier. But no where near as noisy as pulling 500 ISO up to 2500.
 
Grug said:
No, (in theory) it shouldn't lose any highlight latitude at all. That's the entire purpose (and appeal) of the 'dual native' ISOs. You get the added sensitivity, whilst retaining the same spread of latitude at both ISO values.

If the Varicam's results are any indication, the image will be noisier. But no where near as noisy as pulling 500 ISO up to 2500.
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Maybe I wasn't clear in what I meant, as you seem to have misunderstood me. I mean that white clip point will be the same relative to the middle grey value as you are saying, but it will clip 2-1/3 stops earlier compared to at base ISO500. Perhaps the dynamic range will stay the same and the noise won't increase that much, and it may result in a cleaner image than Monstro or at least comparable, but it will still likely have less overall DR than Monstro, and perhaps even than Helium it seems.
 
nyvz said:
Maybe I wasn't clear in what I meant, as you seem to have misunderstood me. I mean that white clip point will be the same relative to the middle grey value as you are saying, but it will clip 2-1/3 stops earlier compared to at base ISO500. Perhaps the dynamic range will stay the same and the noise won't increase that much, and it may result in a cleaner image than Monstro or at least comparable, but it will still likely have less overall DR than Monstro, and perhaps even than Helium it seems.
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No, you were clear Noah. But I think you've got the concept of dual-native ISO a little muddled up. What have you read that makes you think the Venice will lose 2 + 1/3 stops of highlight latitude when it's used in the 'native' 2500 ISO mode?

Do you mean in comparison to shooting in the 500 ISO mode, but rating the camera at 2500 ISO? (in which case you'd underexposing by 2+1/3 stops, and shifting your grey point down, giving yourself 2+1/3 stops more in the highlights compared to the 500 ISO mode shot at 500 ISO).

In that case you'd be correct, but underexposing by 2+1/3 stops for the sake of protecting highlights is pretty extreme.
 
Grug said:
No, you were clear Noah. But I think you've got the concept of dual-native ISO a little muddled up. What have you read that makes you think the Venice will lose 2 + 1/3 stops of highlight latitude when it's used in the 'native' 2500 ISO mode?

Do you mean in comparison to shooting in the 500 ISO mode, but rating the camera at 2500 ISO? (in which case you'd underexposing by 2+1/3 stops, and shifting your grey point down, giving yourself 2+1/3 stops more in the highlights compared to the 500 ISO mode shot at 500 ISO).

In that case you'd be correct, but underexposing by 2+1/3 stops for the sake of protecting highlights is pretty extreme.
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I mean absolute white clip drops accordingly. Sony's highlight spec for base EI is 6 stops over middle grey. In a fixed scene with fixed exposure, highlights will clip 2-1/3 stop sooner at ISO2500 than at ISO500 because middle grey changes by that amount.
 
nyvz said:
I mean absolute white clip drops accordingly. Sony's highlight spec for base EI is 6 stops over middle grey. In a fixed scene with fixed exposure, highlights will clip 2-1/3 stop sooner at ISO2500 than at ISO500 because middle grey changes by that amount.
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Hi Noah,

I think I see your logic where shifting EI also shifts middle grey, reallocating DR? Or are you just saying that no matter what, Sony will have less DR than the latest Reds in any mode? Sorry if I misunderstood you.

In this case, I think Sony is marketing a dual ISO mode where you can be at either ISO mode, without needing to push EI, so grey point and DR remain the same. Perhaps the only thing that changes is the noise floor a bit, similar to the Varicam.
 
hi Noah, my thinking of numbers was that a 2 stop push is equivalent to 12db gain. i.e. 500 to 2000 ISO. Now technically we don't know what RED's monstro base ISO is but yes you are right, if RED is also 500 ISO base then yes both were pushed the same I agree and I see what you mean.

For Venice and regarding DR from low ISO to its high ISO, white papers seem to say that DR is actually increased almost 1/3 or so in the higher ISO mode so I don't think there will be any DR change on the camera. It will just be a way to read the sensor at a different programmed gain and is supposed to give the same performance as the low ISO version.
 
nyvz said:
I mean absolute white clip drops accordingly. Sony's highlight spec for base EI is 6 stops over middle grey. In a fixed scene with fixed exposure, highlights will clip 2-1/3 stop sooner at ISO2500 than at ISO500 because middle grey changes by that amount.
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You've got your concepts wrong Noah. That's neither how Exposure Index or dual-native ISO work.

Shooting in native 500 ISO mode, and rating the camera at 2500 EI, you would GAIN 2+1/3 stops worth of highlight latitude, not lose it. So you'd have 8+1/3 stops over middle grey.

Shooting in native 2500 ISO mode, and rating the camera at 2500 EI, you would get the camera's native split of 6 stops over middle grey.

You would have to be shooting in native 2500 ISO mode, but rating the camera at 500 EI, in order to LOSE 2+1/3 stops of highlight latitude.
 
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