Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Jul 31, 2007, 7:59 PM   #81
Senior Member
 
Join Date: Feb 2007
Location: Wisconsin
Posts: 1,241
Default

Keoeeit wrote:
Quote:
Keoeeit wrote:
Quote:
Raise the temperature of any CCD or CMOS chip and you will get more noise in the image. Painting a camera body black will increase the amount of thermal radiation absorbed by the camera from its surrounding environment as well as insulate it from dissipating that heat. This isn't a deeply held electronics secret. Nearly everyone on earth with the least bit of experience knows this. Commonly referred to as "thermal noise" in imaging fields. Why do you think astro-photographers use Peltier Junction, water-cooled, or even liquid-nitrogen cooled heat-sinks to try to cool their CCD chips for long exposures?
You are absolutely correct about the black camera absorbing heat faster.

You are absolutely INCORRECT about it insulating and keeping heat inside. Black absorbs heat faster and it releases heat faster.

Now to the sensor temperature part. What sensor is going to be warmer. A DSLR sensor thatis in stand-by mode until the fraction of a second the exposure requires of it, or the digicam which is functioning full time providing data for the EVF and a back-lit LCD. Olympus had to address this to try to get live view functional on their E410/E510 DSLR cameras.
Quote:
fldspringer wrote:
Quote:
You are absolutely correct about the black camera absorbing heat faster.

You are absolutely INCORRECT about it insulating and keeping heat inside. Black absorbs heat faster and it releases heat faster.
Great, just what I want. A camera that absorbs heat faster transmitting it deeper into the camera and causes more noise in the images, but if I wait around for it to dissipate that heat it'll cool off faster. I don't care to sit around waiting for my camera to cool off before I take another shot.

Now if you'll excuse me again, I'll be returning to where people can actually think and reason with an iota of intelligence and worthwhile common-sense.

You take a month and a half to reply and that's the best you can come up with?

In reply to your questioning my intelligence, I have a physics degree and graduated with honors. I also spent a considerable amount of time working in the observatory and pardon me if I'm not impressed with your grasp of the subject matter which you refer.

Common sense aside, if you would like to understand the subject better, do a search of "Blackbody Radiation" and you may begin to understand why the radiator of your car is black and not silver.

Not that it has a thing to do with a manufacturer's choice of color in constructing a camera. More to do with marketing than anything else.

Best of luck and have fun taking pics,

Greg





fldspringer is offline   Reply With Quote
Old Aug 1, 2007, 12:51 AM   #82
Senior Member
 
Corpsy's Avatar
 
Join Date: Dec 2005
Posts: 879
Default

Greg, far be it for me to be defending Keoeeit here, his comments about black body cameras vs silver ones was way off topic, and in his tirade against DSLRs in general it appeared to be a grasp at straws, but I'm not really understanding your point about black bodies.

Yes, black bodies absorb more light and therefore generate more heat, and yes they dissipate heat faster (being that it's in the nature of heat energy to maintain equilibrium with the energy surrounding it), but it certainly isn't going to dissipate it in the general direction from whence it came. The heat will be redistributed to all adjacent matter of lower temperature, whether it be the air on the outside of the camera, the air on the inside, or the mechanisms inside. Everything inside the camera will continue to heat up until it reaches equilibrium with the temperature of the black surface, and not until then will it cease to heat up the interior. Therefore, if a black camera is out in the sun and the surface of the body reaches a temperature of 150 degrees Fahrenheit, the interior will heat up until it is the same unless the camera has some kind of ventilation system.

In any case it was a pretty flimsy argument against DSLRs. I have yet to see the thread where someone complains about how their DSLR is especially noisy when taking photos in sunlight, and I haven't heard of anyone having their camera break down from heat build-up, and people in this forum aren't generally very shy when it comes to complaining. I know I'm no exception.
Corpsy is offline   Reply With Quote
Old Aug 1, 2007, 5:49 AM   #83
Senior Member
 
Join Date: Feb 2007
Location: Wisconsin
Posts: 1,241
Default

Corpsy wrote:
Quote:
Greg, far be it for me to be defending Keoeeit here, his comments about black body cameras vs silver ones was way off topic, and in his tirade against DSLRs in general it appeared to be a grasp at straws, but I'm not really understanding your point about black bodies.

Yes, black bodies absorb more light and therefore generate more heat, and yes they dissipate heat faster (being that it's in the nature of heat energy to maintain equilibrium with the energy surrounding it), but it certainly isn't going to dissipate it in the general direction from whence it came. The heat will be redistributed to all adjacent matter of lower temperature, whether it be the air on the outside of the camera, the air on the inside, or the mechanisms inside. Everything inside the camera will continue to heat up until it reaches equilibrium with the temperature of the black surface, and not until then will it cease to heat up the interior. Therefore, if a black camera is out in the sun and the surface of the body reaches a temperature of 150 degrees Fahrenheit, the interior will heat up until it is the same unless the camera has some kind of ventilation system.

In any case it was a pretty flimsy argument against DSLRs. I have yet to see the thread where someone complains about how their DSLR is especially noisy when taking photos in sunlight, and I haven't heard of anyone having their camera break down from heat build-up, and people in this forum aren't generally very shy when it comes to complaining. I know I'm no exception.
I agree with everything you said here.




fldspringer is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 4:31 AM.