LX7 - does its IQ compete with e.g. Sony RX100?

Started Apr 6, 2013 | Discussions thread
areichow Senior Member • Posts: 1,586
Re: LX7 - does its IQ compete with e.g. Sony RX100?

kkardster wrote:

ultimitsu wrote:

kkardster wrote:

The sensor specs favor the RX100 but the brighter and sharper LX7 lens often makes up for its lesser sensor.

This is a common misconception.

LX7 does not have a faster lens.

LX7's lens is 4.7mm F1.4, aperture is 3.6mm in diameter, actual opening is 10.2mm2

RX100's lens is 10mm F1.8, aperture is 5.6mm in diameter, actual opening is 24.6mm2

RX100's lens lets in 150% more light. it is much much brighter.

It appears to me that you have the misconception here.  Basic photography has taught us that f/1.4 is faster than f/1.8, period - it's a basic photographic quality.

It is not period. F numnber is a ratio, you need to understand it is what  over what.

I don't have the time nor specs to challenge your calculations, so I'll take them at face value.

That is why you are wrong.

However, I find that your equations are incomplete, leaving out the fact that the larger RX100 opening needs to feed its additional light across a larger sensor area.

And precisely because it has a larger sensor and a larger opening, its image gets more light overall and thus better IQ. in other words. to get the same IQ, it can afford faster shutter speed than LX7.

I'm shocked that this debate is still going on. I'm at a loss for words.

I had this misconception for a while myself. Then I played with my RX100, P300, and a borrowed T3i side by side. Given the same aperture and ISO, the exposures were the same, other than some minor metering differences.

The larger sensor of the RX100 means it can achieve higher IQ and less nose at higher ISOs than the LX7 it has nothing to do with shutter speeds as you imagine. These can be confusing concepts, please read about them before playing forum expert.

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