Picture Noise and how to Minimize it

[RogerBayford]

In the amazing new Digital world. there are quiet a few references to “Noise” at the higher ISO ratings. I have only been a member for a short while but have never seen a real good explanation of these phenomena. Or better, how to minimize it! (My apologies if there is a previous post on this).

Several years ago I was fortunate enough to work on a new project using a CMOS Sensor and very quickly learned about noise, its causes and effects. I needed to use one at up to 65C Big problems!
Although these CMOS devices have improved drastically. The noise problem still exists and the higher the temperature the more noise you will get.
I wont go in to great technical detail, but take my word for it, shoot an exposure at IS0 3200 at about 5C and then do one at 25 C. You will see the difference! The low temp exposure will show virtually no noise. At the higher temperature noise will be quite evident at the higher magnifications.

When shooting at the higher ISO Ratings in the summer, keep the camera as cool as possible and keep it shaded as much as you can while using it. The black color of the camera soaks up the heat and raises the internal temperature.
Keeping the camera in an air-conditioned car until ready to use helps a lot, just watch out for condensation on the lens in conditions of high humidity.
Ideally keep the camera operating temp. below about 25 C, its not always possible but remember the warmer the camera the more noise. It’s a simple law of Physics.

Oh By the way, I got my D10 back after some focus adjustments and WOW :)
It’s Great! Sharp as a tack. Love it!! And I’m not even using L series.

[polloloco81]

I'm storing my camera in the freezer until I need to use it.

[chris.bailey]

Liquid Nitrogen anyone :lol:

[robertwgross]

Not the freezer.

Five degrees C is more like beer storage temperature, around 40 F.

---Bob Gross---

[Belmondo]

Maybe Canon has this whole thing backwards: perhaps we need black lenses and white camera bodies. Could it be possible that the Drebel is even more of a trend-setter than we'd originally thought?

[drisley]

Shoot "to the right". That is, slightly overexpose without blowing highlights. That keeps noise down. I shot exclusively at ISO1600 this summer in a very hot and humid pool, and the noise was minimal.
I also shot exclusively at ISO800 and ISO1600 on a very hot day in a warm theatre with no air conditioning. Again, noise was minimal. Also, shoot Raw when you can, and use C1 Raw software as it tends to reduce noise....

ISO1600, 100% Crop, C1 Pro, Noise Suppresson OFF
http://www.mts.net/~lftbrain/iso1600crop.jpg

[CyberDyneSystems]

Roger,
Thanks for the insight. In the wonderfull word of microprocessors we have come to understand that "cooler is better" but it had never occured to me (nor have I read elsewhere) that temprature will play a part in a CMOS sensors "noise".

Do I guess correctly that the large medical applications such as those made by Olympus probably contain active cooling?

I guess I'm going to have to see if I can figure a way to "mod" the MkII to fit a "Thermaltake Volcanoe" CPU cooler! :)

... of course, if we get too cool,.. then we start knocking down our battery life :?

Drisley's point and example illustrate another noise phenomenon. The more underexposed the image. the more noise there will be especially at higher ISO. By pushing the exposure "to the right" as far as we can without blowing out the highlights.. we not only get the best exposure in most cases but where High ISO is concerned we get by far the least amount of noise.

Interesting stuff...

:D :D :D Very happy to hear that you got your 10D sorted!!! This is great news. Now you can get down to the serious business of enjoying that fine camera!

:wink:

[Tom W]

The astrophotography folks have taken to cooling their CCD's for the same reason - reducing noise. Of course, they will do all kinds of other tricks like stacking images to cancel the noise and such.

Incidentally, the 10D is starting to make inroads into the astrophotography scene, so we may see some rather creative methods of cooling the camera in the future, given the ingenuity of mankind.

[robertwgross]

Maybe the next Canon model will be water cooled. Maybe not.

---Bob Gross---

[Tom W]

Maybe the next Canon model will be water cooled. Maybe not.

---Bob Gross---

BG-Ed with a radiator? ;)

[CoolToolGuy]

Geez, maybe I can get a good deal on some of those chillers we used to use for the IBM mainframes! :roll:

Of course, then you have to keep the body isolated from the lens to guard against condensation on the lens. :shock:

Seriously, this is good information to have. Thanks, Roger.

Have Fun,

[timmyquest]

hackint software....cooling cmos

buying sutff because it looks cool

we are quikcly becoming more like the computer scene....how soon till we figure out to overclock the cameras

[robertwgross]

Ahh, there's the idea.

Build a Peltier Effect cooler into the grip, and have some heat sink to the underside of the sensor.

The only downside is that it would require enough power that you'd have to hook it up to a heavy battery. You'd have to get the cooling started some minutes before shoot time.

---Bob Gross---

[CoolToolGuy]

Ahh, there's the idea.

Build a Peltier Effect cooler into the grip, and have some heat sink to the underside of the sensor.

The only downside is that it would require enough power that you'd have to hook it up to a heavy battery. You'd have to get the cooling started some minutes before shoot time.

---Bob Gross---

Gee, Bob, think you can fit something like that into the kit that you take trekking into the wild? :roll:

Maybe a freeze-pack/backpack with a battery-powered pump? :shock:

Have Fun,

[robertwgross]

You can get Peltier element heat exchangers pretty small, but they still use some power. It's probably impractical for this application.

However, I manage to drag along a lot of technology when I head into the wilderness. On my last backpacking trip, my general gear amounted to 25 pounds. Then I had 15 pounds worth of photo equipment on top of that.

Solar power is generally practical if you are going to be away from commercial power and fixed at one site, not moving.

---Bob Gross---

[fishboy]

Hi Roger,
Do you have any references where we can read up on the relationship between temperature and noise? I'd be really interested.

Thanks

[Volatile]

we are quikcly becoming more like the computer scene

I'm modding my cam with a plexiglass side window and putting in blue LEDs all over.

I also have an old G3 that I'm taking apart and making a new case out of legos for it. woo woo I r0x0r!

[CyberDyneSystems]

I flashed the bios on the 10D and replaced the OS with with "Tinfoil Hat Linux" ... now i use it to crunch seti... it does one WU every 65 days :wink:

[45R]

If you keep the camera cool enough....the black helicopters wont be able to find you......... :lol:

[theflyingkiwi]

I can image the future of digital cameras, the pro verson will be coloured the as the "L" glasses. so the next model will be 1DMKII L :lol:
but there will be more, on one side there will be a little fan that will keep the air moving around the chip. in the first model it will be placed by the eye piece. as with anything that is new, the fan will only turn on when it is the most annoying time, about to press the shuttler on the best picture of the day :). there will also be no option to turn it off.

This lead some people to think that there is a firmware update to move the fan.

But there will be an upside, the battery will last longer, you will have as a standard option ISO 3200 with little or no noise, unless you are using a shutter speed of a 1sec or slower :roll:

[CoolToolGuy]

I'm seeing Belmondo (and/or others) developing a freeze-pack gel casing for the 1D MKII, followed by versions for the other Canon DSLRs. Like the red 10D, if we are lucky we may be seeing a prototype any day now. :roll: :shock: :) :D :lol:

Have Fun,