Performance of 350D in extremely cold weather

[chenwah_lee]

Photo "1-summer" was taken in a normal summer sunny day with

polarizer and the blue sky was enhanced to my satisfaction. Photo "2-

winter" was taken recently in a minus 30 degrees C sunny day with a

polarizer but the blue sky looks terrible with white dots and uneven

distribution of colors. The two photos were 100% crop from pictures

taken with the same 350D at ISO 100 at full resolution. The same

unpleasant effect of "2-winter" was present in the sky of every

pictures taken in the same morning, either in raw or jpeg formats,

and showed up on the 10x15 Fuji prints too. I thought the sensor was

damaged in the cold. Today I tried to verify if the sensor is

permantly damaged or if it can work perfectly again in normal

temperature so I did a control testing as shown in "3-testing". I

used a red filter to shoot a large light table and the result seems

to show that the sensor is all right again. My questions are: 1) has

anyone experienced the same problems as in "2-winter"? 2) what is

the limit of low temperature below which the sensor will produce

photos like "2-winter"? 3) any possibility that the sensor will be

permantly damaged under even colder temperature?<div></div>

[chenwah_lee]

"2-winter"<div></div>

[chenwah_lee]

"3-testing"<div></div>

[bennyboy]

They both appear to have it to me, just that one image is darker.

[phule]

Astronomers cool sensors with liquid nitrogen. That's at least -320.44 deg F.

 

There is something else going on here. My bet is user error.

[peterlyons]

Chenwah, was the exposure good on all frames to start with? Your winter sky in particular looks like it was shot at high ASA or brightened up from severe underexposure.

[kin_lau]

Looking at the EXIF, winter sky is iso 100, F8 @ 1/125. Summer sky is iso 100, f8 @ 1/400, hence the bluer sky.

 

The sky is probably overexposed.