damage to sensor with higher iso? hello all, being an electrician by trade i know what higher voltages do to electronic equipement that is not rated for it. my question and correct me...

wer224 Loc: Bergen county NewJersey

hello all, being an electrician by trade i know what higher voltages do to electronic equipement that is not rated for it. my question and correct me if i'm wrong my understanding is the way sensors become able to have higher iso values is to increase voltage to them. i'm sure canon,nikon etc. take into consideration for this but i wonder if a lot of higher iso pics you take it degrades the sensor long term so when you use lower iso will there be a reduction in quality in the lower iso pics?? maybe i'm thinking to much!!! thanks for any feelings on this

Apaflo Loc: Anchorage, Alaska

wer224 wrote:

hello all, being an electrician by trade i know what higher voltages do to electronic equipement that is not rated for it. my question and correct me if i'm wrong my understanding is the way sensors become able to have higher iso values is to increase voltage to them.

Not the DC operating voltages.

The sensor itself is not affected at all, in any way, by an increase in ISO.

Generally there is an analog AC amplifier immediately following the sensor. Increasing the gain of the amplifier is the first way that ISO is increased. The output of that amplifier is the input to an Analog to Digital Converter (ADC), which outputs the digital data. The way an ADC works is a sample of the AC input voltage is taken at specified intervals and is compared to a precision DC voltage. The comparison produces the digital output. Hence if the DC voltage and the sample are both 1 VDC all bits are 1's. Newer cameras can also change ISO by changing that precision DC voltage. If it is changed to 0.5 volts, all of the digital bits will be 1's when the AC signal (the amount of light) is only half as much. Hence that is a 1 stop increase in sensitivity.

No voltages are ever raised to any level that could physically damage any of the circuit elements.

wer224 wrote:

i'm sure canon,nikon etc. take into consideration for this but i wonder if a lot of higher iso pics you take it degrades the sensor long term so when you use lower iso will there be a reduction in quality in the lower iso pics?? maybe i'm thinking to much!!! thanks for any feelings on this

That's certainly an interesting idea! Fortunately it doesn't.

wer224 Loc: Bergen county NewJersey

thank you apaflo i'm in industrial and commerical work i deal with a lot of analog equipement inverters plc's etc. i guess like i said before i think to much :) thanks again for the info

singleviking Loc: Lake Sebu Eco Park, Philippines

wer224 wrote:

thank you apaflo i'm in industrial and commerical work i deal with a lot of analog equipement inverters plc's etc. i guess like i said before i think to much :) thanks again for the info

Actually, it's the forward bias voltage that's adjusted to increase or decrease gain or ISO and not the operating voltages. You really need to do some study on transistor theory. CMOS devices are current based and transistor devices are voltage based in operation. Most sensors these days are CMOS devices.

There are no lasting increased noise effects to sensors from increased ISO and no damage to the device. However, when a laser is pointed at your sensor, it can destroy the photo receptor cells of the sensor permanently.

dpullum Loc: Tampa Florida

singleviking wrote:

In Part: ... You really need to do some study on transistor theory. ...

Humm, Life is easier if one accepts some thing on faith ... how wonderful our ever improving cameras are is one of those "on faith" areas.

I grew-up in a tube filament, cathode, grid control world every thing simple, logical, intuitive. When I took a transistor circuit design course in grad-school an electronic engineer buddy helped me have a painfully stressful "way of thinking/visualizing" epiphany!! To an analogue person transistor theory is a whole new way of thought and visualization. On must kill the old god and embrace a new one.

GregWCIL Loc: Illinois

Wow there are a lot of smart people on here. I won't be entering the UHH chess tournament this year.

kavner58 Loc: Portland, Oregon

Apaflo wrote:

That's certainly an interesting idea! Fortunately it doesn't.

Well, there are cases where you can damage the sensor.
When you are in "live view" you raise the mirror and expose the sensor to light for the duration of "live view" time. If you take a video, you are limited to no more than 30 minutes for my Nikon D7100. Otherwise, there is sensor overheating - becoming worse if you do expose the sensor to high light intensities or try to aim it directly into the sun.

Since I an an "analog electrical engineer" and did both analog and digital design both with CCD & CMOS sensors, when you make these work for all pixels under saturation conditions for long time (minutes) you may damage the sensor and deplete your battery very quickly - overall current consumption is high under these conditions.
If you do not use the "live view", I would not expose the sensor to direct sun with exposure of seconds...

Okay, enough with the engineering jargon now...

- AK

singleviking Loc: Lake Sebu Eco Park, Philippines

kavner58 wrote:

Well, there are cases where you can damage the sen... (show quote)

If you did CCD & CMOS designs, then you'd know it's not the photon to electrical device that heats up under continuous operation, but the DSP which is processing that data. I agree that repeated saturation is not good for any photo-electric sensor, but who wants to blow out the photo anyway? The original CCD video phone devices had serious problems with compensating for drastic light changes, but that was decades ago and they used tube encapsulated CCD devices. In modern digital cameras, over exposure can not be recovered from in PP, but the sensor itself is quite robust. After all, it's nothing more than a miniature photo-voltaic array designed in a grid pattern.

wer224 Loc: Bergen county NewJersey

WOW i knew uhh would not let me down with my question thanks all

Apaflo Loc: Anchorage, Alaska

wer224 wrote:

WOW i knew uhh would not let me down with my question thanks all

But now the comments are not about your question regarding voltages and high ISO.

They are about environmental causes of damage. There is no doubt that cameras can be damaged by the sun's extremely bright rays focus on a spot, or that heat buildup is a potential killer. But so is dropping the camera...

kavner58 Loc: Portland, Oregon

singleviking wrote:

If you did CCD & CMOS designs, then you'd know... (show quote)

Well, I think you are wrong. It is not the post processing by the DSP circuits, they will not work "harder" if their input is high or low.
It IS the saturation of the pixels that may cause damage or degradation to specific pixels. The situation can be bad if all pixels are saturated and the pixel (photodiode) current is draining the capacitor.
For your D800E with 36Mpixels, with a pixel saturation current of 50 nano amps [just an example, I do not know the actual sensor's max pixel current] you end up with 1.5 Amps drained from your battery just from the pixel circuits. This causes higher local heat. This is why you will not be able to take long videos when the mirror is always up, or you will try to aim to the sun and fill your entire sensor with high photon flux.
Would you volunteer doing that with your camera? I do not think so.
I have a few papers of my own on sensor design - yes - this was long time ago.

- AK

boberic Loc: Quiet Corner, Connecticut. Ex long Islander

For all of you engineers out there if you want to see the latest engineering data in auto transmissions I suggest that you look of the Turboencabulator in U-tube. When you do, click on the guy in the white lab coat as he gives the clearest discription of this state of the art technology.

Apaflo Loc: Anchorage, Alaska

kavner58 wrote:

It is not the post processing by the DSP circuits, they will not work "harder" if their input is high or low.
It IS the saturation of the pixels that may cause damage or degradation to specific pixels.

I agree with you that the sensor itself generates heat. For long shutter times that causes a temperature rise which results in hot pixels. A well known phenomenon, and not with saturated sensor sites nor necessarily 30 minutes running time for the sensor! Hence we might well expect significantly more heat using Live View.

However, I do question physical damage... The 30 minute limit is due to image quality, and it might take days to extend that to sensor damage.

kavner58 Loc: Portland, Oregon

Apaflo wrote:

I agree with you that the sensor itself generates heat. For long shutter times that causes a temperature rise which results in hot pixels. A well known phenomenon, and not with saturated sensor sites nor necessarily 30 minutes running time for the sensor! Hence we might well expect significantly more heat using Live View.

However, I do question physical damage... The 30 minute limit is due to image quality, and it might take days to extend that to sensor damage.

The damage can be done by extensive time of overheating.
- AK

SonnyE Loc: Communist California, USA

wer224 wrote:

hello all, being an electrician by trade i know wh... (show quote)

I think you think to much.
I'd be much more concerned about the mechanics of the shutter, mirror carriage, moving parts failing, than ISO putting pickles in the fruit salad.
There is a lot of things going on besides the electrons dancing around. ;)