CMOS S/N deteriorating with time?

[Piotr Wozniacki]

Thank you guys for the valuable input.

Unfortunately, what Daniel described as the "photon shot noise" looks like it is the case with my camera, as I have tried hard to eliminate all other, obvious factors (also mentioned by Daniel, and in the others' posts).

Of course, I cannot be 100% sure I didn't miss something, but I think that with some 99% certainty, I can see more sensor noise than before.

One thing that may have some relevance here is the Black Balance (or whatever it's called in the menu - in my case of 1.11 firmware, it's grayed-out anyway). I've heard there is no need to execute it manually, as the camera is supposed to do it automatically - who knows, perhaps my EX1 doesn't?

Luckily enough, I extended my Prime Support for an extra year, so will be trying to draw Sony's attention to it...

[Vincent Oliver]

The other thing that hasn't been mentioned is how are you viewing your shots? Have you changed your monitor or have you created a new profile for it recently (a new monitor profile should be created at least once or twice a month).

I too have noticed some noise creeping in, but then I have also been messing about with the EX3 Detail settings. On a recent shoot I noticed some of the shots were soft - but I think this could have been my cameraman (woman actually) didn't hit the mark.

ps. what Detail settings are other users using?

[Tom Bostick]

Originally Posted by Vincent Oliver

On a recent shoot I noticed some of the shots were soft - but I think this could have been my cameraman (woman actually) didn't hit the mark.

ps. what Detail settings are other users using?

you might want to check the back focus

[Vincent Oliver]

Thanks Tom, it was actually the first thing that I did.

The only thing that was different is that I had detail turned OFF, I have now turned it back ON and set it to +4. still can't explain why the shots looked soft on that shoot but they look OK now.

Maybe I should sack the camerawoman - but then I must show some compasion towards her, after all she is Mrs Oliver

[Alister Chapman]

I was noticing some soft shots on my original EX1 and as others have suggested did the usual back focus etc. This made no difference. I checked the shots through the zoom range and there was definitely a discrepancy in the backfocus. No amount of back focussing would make the problem go away and my pictures were all just a little soft. However updating the firmware and the hard reset that this performs restored my backfocus to normality and my pictures were pin sharp again.

I have a very old EX1 (1200 hours) and I recently got a new EX1R, I can't see any difference in noise between the two.

[Vincent Oliver]

Thanks for your advice Alister, I haven't upgraded the firmware on my EX3 (yet) I am in the middle of a production and I know from past experience - don't touch anything until the job is in the can.

At the moment the focus seems to be OK, I am just going to blame Mrs O for the time being, when I discover it is the camera they she will get a bunch of roses :-}

[Bob Grant]

As far as I know the actual photodetectors in CMOS and CCD cameras are the same. I've neither read or seen anything to indicate that photodiodes gradually decay in efficiency.
The noise in most things electronic is a function of temperature, seasonal variations in ambient or even how long the camera was on could account for variations. I should also ask about any filters in front of the lens.

[Chad Johnson]

Maybe you are paying so much attention to noise that you see it in everything? How about just starting with the basics and try shooting on SxS, using the simple Vortex Media PP and see what you get.

[Vincent Oliver]

Many of us are shooting with SxS cards, although I do not see what difference that should make. As good as Doug Jensen profile is, it is not the holy grail of profiles.

I think Bob Grant may have hit the nail on the head with his post.

[John Peterson]

Originally Posted by Vincent Oliver

Maybe I should sack the camerawoman - but then I must show some compasion towards her, after all she is Mrs Oliver

Ha Ha Ha . I love it.

John

[Chad Johnson]

My point Vincent, is that the Nano records detail that does not appear on SxS due to the fact that certain settings in the PP are bypassed (I think) and noise is exposed on Nano recordings. Jensen's PP is not a very extreme change from the factory EX1 settings. I don't get very much noise at all shooting on SxS with the Jensen PP, so if the OP thinks his sensor is going bad and causing noise, he could go back to SxS and a general purpose PP to see if that looks noisy. If it does not, then there is something about his settings that is causing the noise. Either that or he is obsessed with noise (he has been talking about it for months) and sees it all the time now.

[Piotr Wozniacki]

Originally Posted by Chad Johnson

My point Vincent, is that the Nano records detail that does not appear on SxS due to the fact that certain settings in the PP are bypassed (I think) and noise is exposed on Nano recordings. Jensen's PP is not a very extreme change from the factory EX1 settings. I don't get very much noise at all shooting on SxS with the Jensen PP, so if the OP thinks his sensor is going bad and causing noise, he could go back to SxS and a general purpose PP to see if that looks noisy. If it does not, then there is something about his settings that is causing the noise. Either that or he is obsessed with noise (he has been talking about it for months) and sees it all the time now.

None of the PP settings are bypassed when recording the SDI output, Chad. DSP acts between the imagers and SDI out (or own compression to the SxS). Of course this is a simplification, but yo get the idea ...

[Chad Johnson]

Good to know!

[Walter Brokx]

Originally Posted by Chad Johnson

My point Vincent, is that the Nano records detail that does not appear on SxS due to the fact that certain settings in the PP are bypassed (I think) and noise is exposed on Nano recordings. Jensen's PP is not a very extreme change from the factory EX1 settings. I don't get very much noise at all shooting on SxS with the Jensen PP, so if the OP thinks his sensor is going bad and causing noise, he could go back to SxS and a general purpose PP to see if that looks noisy. If it does not, then there is something about his settings that is causing the noise. Either that or he is obsessed with noise (he has been talking about it for months) and sees it all the time now.

Perhaps the difference is caused by difference in compression?
More compression = less info.
A good way to decrease data is a kind of 'blurring/smoothing' which makes almost similair pixels more silimair (this can be done with pixels next to each other, but also with the same pixel over time (from frame to frame). Noise is a distinct difference between pixels (both in location and over time) that 'should' be the 'same' and is caused by the physical properties of the 'lightcapturing-proces'. (Remember: celluloid has grain, which is also the result of that light-capturing-proces.)
= > bypassing compression reveals the noise that was already there but got 'compressed away'.

(If the PP got bypassed in the SDI-signal everything would look like factory-settings)

[Chad Johnson]

Well I'm just wondering if Nano footage looks more grainy as a rule, or under certain conditions, or is it a non issue. I don't want to spend 4 grand getting set up with Nano, only to have to put an unsharp mask filter on all my footage.