Hotpixel test of Canon 300D

[tony723]

Here is the sample photos taken to test hotpixel. Sorry that my service provider cropped the photo to 1024 pixel due to photo size limit.

http://www.fotop.net/hktraveller/300D_hotpixel

I found that there are 4 red spots using 4" F5.6 ISO1600 (same positions for several shots).

However the red spots disappear when using 1/800 F5.6 ISO1600.

I also tested under ISO 100, 30", F5.6 condition, no hotpixel can be found.

Is it normal? Should I replace the camera? Should I use slow shutter speed or fast shutter speed to test hotpixel?

Thanks!

[Guillermo Freige]

This is normal, and indeed you are VERY lucky to have only 4 hot pixels at a ISO 1600 / 4sec exposure !!!
Check in DPreview the 10D night shots to see a lot of hot pixels. Probably is a good idea to replicate that test (I think it was a 5min ISO 100 exposure) to compare.
Hot pixels appears at very long exposures in low ISO and in medium to long in high ones. If only appears in that cases (as in your camera), don't worry.

[bnpndxtr]

Hot pixel tests at higher than ISO 100 are not very meaningful because it is hard to tell the difference between noise and hot pixels. You can repeat your test at ISO 100, 10 seconds if you want- that would be more reasonable. But with what you see at ISO 800, you probably don't have much to worry about.

[tony723]

Guillermo Freige wrote:
This is normal, and indeed you are VERY lucky to have only 4 hot pixels at a ISO 1600 / 4sec exposure !!!
Check in DPreview the 10D night shots to see a lot of hot pixels. Probably is a good idea to replicate that test (I think it was a 5min ISO 100 exposure) to compare.
Hot pixels appears at very long exposures in low ISO and in medium to long in high ones. If only appears in that cases (as in your camera), don't worry.


I will try again and post some 100% cropped photos with different settings say 1 min, 5 mins, 10 mins with ISO 100/200/400 which is more common in daily use.
ISO 800/1600 may not be too good for long exposure.

[Guillermo Freige]

Don't expect too much from more than 5min exposures even at ISO 100. And forget to use high ISO (800-1600) for more than a 30sec exposure (and probably only at ISO 800. ISO 1600 is really noisy for long exposures).
This is a bad thing? I don't think so. After all, the whole idea of use high ISO settings is to shoot handheld in situations where a tripod is needed at ISO 100 (because of low light, or the need to use a small aperture), so if you will be using a tripod, why not to use ISO 100 and very long exposures if needed? You will get a more clean picture. Check the dpreview.com 300d review for different ISO/speed combinations of the same night shot, and see how much cleaner is the ISO 100 and 200 shots and how awful the 4sec ISO1600 shot look.

[tony723]

I retest the case and found that 300D is very good at ISO 100, hotpixel appears after 5 mins exposure.

http://www.fotop.net/hktraveller/300D_hotpixel

[Guillermo Freige]

Nice 21min exposure!!! I've expected much more noise for such a long exposure. But it's a 10D picture, have you tried the same with the 300d? How bad it look at 100%? Can you post a 100% crop of the sky and another one of a house?

[tony723]

Guillermo Freige wrote:
Nice 21min exposure!!! I've expected much more noise for such a long exposure. But it's a 10D picture, have you tried the same with the 300d? How bad it look at 100%? Can you post a 100% crop of the sky and another one of a house?

You may see the photo of ISO 100, 718", F5.6 and ISO 100, 214", F5.6 which is taken by 300D. You can see lots of hotpixels. So my best guess of the maximum exposure is about 5 mins without hotpixels.