sensor size => lo light perf
 

Funny question, but havent found any answer so far. Well i recently read a discussion about low light capabilities of modern digital still cameras, and there is paid attention to anything (like processor type, file format etc) but sensor size. I know that video cameras have very straight dependance of low light quality from pixel phisical size, or sensor area. So i made simple calculation for Pentax DL and Canon S2 IS (both are priced at same level) and found that thier pixel sizes relates as 1:7 !!! Well thats enormous difference. And the question - is the low light performance is that better for dslr's? It should be about 3 exposure steps, isnt it&

Konstantin, is that comparison based on the sensor area or on the linear dimensions of the sensor?

Anyway, I don't know wether the light sensitivity depends linearly on the physical size of the sensor elements. However, there is a clear dependancy. Compact digital cameras with small sensors usually show quite strong noise at the ISO 400 setting while you hardly notice any difference between ISO 100 and ISO 400 on a modern dSLR. And even ISO 800 and ISO 1600 usually show very acceptable results. Most compact digicams don't even have the ISO 800 or ISO 1600 setting, probably because people might be disappointed at the results.

Your assumption, that the difference in light sensitivity between the two cameras you mentioned is about 3 f-stops might be correct.

Constantin

yes the low light performance in still cameras just like with video cameras is in direct relationship to sensor size. Well actually well size which is the size of the light collecting part of each sensel. The more photons it can collect the better the signal to noise ratio.

as you found DSLR's use much larger sensors than compact cameras which allows them to have a much better low light performance

currently the best compact cameras have a somewhat usable ISO 400 wheras the best DSLR's have usable ISO 3200.

The current low light and high ISO king is the Canon 5D closely followed by the 1DIIN and the 30D/20D.

Canon's sensors are unmatched right now for high ISO low light work except for the fuji DSLR sensor but it has other issues and the camera itself is not very good.

We shoot low light stills all the time at ISO 3200 and even often pushed to 6400 or higher and couldnt live without it.

In addition to sensor size though the sensor technology is very important as well

For example if you compare current DSLR's with same sensor size you will find that some have a much better low light capability.

Lots of things play a role here such as the actual size of the well (a lot of the room on the sensor is used for readout circuits), on chip noise reduction, quality of readout circuits and A/D converters as well as amplifiers and last but not least processing in the digital domain as well.

Low Light camcorder
 

Michael,

Thank you for the explanation. It sheds alot of light on questions I've had for a long time.

Do you know the best Low Light camcorder? Thanks.

Sensor size and pixel size are two different issues. Other factors contributing to better low performance include firmware and software in the camera, pixel size, type of sensor (CCD vs CMOS) and other factors such as MTF of the comparison lens etc.

So which one shines in low light? The new Canon D50? (Or is it the 50D?)

I was just reading about this on the Puts shill site. Seems that he's down on Canon even though Canon provided him with a free D5.