One last long exposure question

freeze3kgt

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Cant seem to find the answer im looking for on google thought maybe someone here would know...

the noise created from long exposures seems to be from the sensor heating up.. so if you could keep the sensor cooler like in colder weather would that lower the noise?

found a lot of things on google on how to take shots in the cold, but not this specific question

thanks
 
Essentialy yes it would.
I have read that you can even see a difference (I belive its quite slight) if you compare images taken in the same lighting conditions in polar and tropical regions - because the tropical sensor is going to be a lot hotter to start with than the polar.

Of course there is a limit on how cold you can go before it also starts to affect the sensor - I have no idea where this limit is but suffice to say freezing it won't help matters ;)

You might find more info if you check out/ask around some astrology groups since they often do a lot of long exposure work and might have more tips/advice on this issue in particular.
 
Sure, a cooler sensor will produce less noise than a warm sensor. I simply wonder what it is that you hope to accomplish with this information... In all actuality, the difference is not really worth striving for. For instance, if cooler sensors really performed that much better than warmer sensors, then the top-of-the-line DSLRs out there would have outrageous built-in cooling systems and temperature monitors. The fact of the matter is that such devices haven't been fitted on even the finest DSLRs because, although there is a measurable difference between warm/cold sensor performance, it isn't really so different as to warrant such measures.

Your long exposures... especially low light exposures of more than, say, 3 or 4 seconds, will always be rather noisy in comparison to an exposure made over a tiny fraction of a second. This isn't really avoidable regardless of how warm or cold it is outside, whether you strap an ice pack to your camera or not, whether or not you refrigerate your camera body before leaving the house.

There is only one instance in which I've ever even considered temperature-related sensor performance before. In cold weather conditions, I occasionally keep the battery compartment (and thus the battery itself) a bit warm by using portable, one-use hand warmers. I avoid getting the hand warmers next to the center of the camera body because I don't want the heat packs to jack up the temp on the sensor too high.
 
Of course there is a limit on how cold you can go before it also starts to affect the sensor - I have no idea where this limit is but suffice to say freezing it won't help matters ;)
Astronomers have long used liquid helium (-268.95°) to cool CCD image sensors in telescopes.
 
thanks for all the replys,

and for the person who asked why i wanted to know, well: main reason i was asking, i noticed a lot more noise when i went back out to practice a bridge shot, and the temp from the first time to the 2nd time was about 20 degree's hotter and more humid, i tried using the same settings from the first try attempt at the bridge and noticed a lot more noise on the picture, tried using less time on the exposure and still had a large amount of noise...

went back home in the nice a/c and took a couple of dark room pictures with the same setting and got less noise .. so just got me wondering if the temp. really made that big of a difference, or if i was just getting different noise amounts from my settings being different
 
Film on the other hand has never been known to suffer from heat-induced noise....

And that's one more advantage that film has over digital. My digital camera can only do 4sec exp. My film camera did a 30sec exp. Also, a 35mm ISO100 is equvalent to 96mp. Film prints have higher res.
Ifcourse, I really despised wasting $ on film and development, rewinding the rolls, exposing the insides when removing/inserting film, and having only one original negative, whereas every copy of a digital shot is same as original.
 
If you brighten a dark shot, noise levels increase. Do a test: shoot at say 1/500 or 1/800 f/6.2. Then, try to brighten using PS or whatever. You'll see noise.

I was just in Pittsburgh, in some huge University that looked like a cathedral. Well, got some shots, 1/30 4.5 ISO100. Too dark! I brightened in PS, but too much noise. Using ISO400 would've created noise anyway. So, I guess some conditions are just too dark. Using 2sec or above exposure requires carrying a tripod all over.
 
I generally don't try to make my night shots any brighter in PS i tend to overexpose at night my first few shots because i normally use longer exposures at night to help me with the brightness *had a cc for a night shot i did to try to use bulb mode and i find it helps a lot! amazing the difference between a 30sec and 90sec exposure*
 

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