Panasonic GX1 Lens choice?

Started Nov 21, 2011 | Discussions thread
Detail Man
Detail Man Forum Pro • Posts: 16,688
Re: Panasonic GX1 Lens choice?

bzanchet wrote:

My only worry is that thos new 14-42 x power lenses comes with a f3.5. Isn't that a little high for night shots? I'm afraid that even with the much larger sensor, the low light pics will look like my point and shoot...

The minimum F-Number of 3.5 is no different than that of the 14-42mm and the 14-45mm (the 14-140mm is F=4.0).

That is 3.063 times less light (on a linear scale) than (say ) a LX3/LX5 at F=2.0. But the G3 image-sensor that is said to exist in the GX1 can be operated at around ISO=640, and achieve the same SNR (18%) as that of the LX3/LX5 at ISO=100. So you would still be ahead by around a factor two increase in "light-sensitivity" at the same SNR.

The problems arise if you want to achieve the same DOF of focus between the two camera-types. My analysis of the GH2 at ISO=640 compared to the LX3/LX5 at ISO=100 indicates that the LX3/LX5 would be have a slightly better SNR (18%) than the GH2 (or the G3 or GX1) when the DOF is equalized between camera-systems.

... should I get a 20mm f1.7 lens also? I've seen that this 20mm is 40mm equivalent, also a little worried about this, what do you guys think?

With 17.33mm active vertical width GX1 image-sensor, and a 20mm Focal Length, it looks like that would give you a 46.86 Degree Angle of View (aka FOV) referenced to the horizontal dimension .

See: http://www.bobatkins.com/photography/technical/field_of_view.html

... Oh, and this pancake lens don't have image stabilization ...

Depending on how much one is believer in the effectiveness of Power OIS, it could, conceivably make up the difference (between F=1.7 and F=3.5). The effectiveness of OIS, however, is a statistical figure (whereas shot-shot mileage "would not vary" in the case of a "faster" lens-system).

However, if a deeper (rather than a shallower) amount of DOF is desired, the F=1.7 of the "pancake" lens would be a profound disappointment (compared to the DOF the LX3/LX5).

Another consideration is the minimum Focus Distance of the MFT lenses. 20cm (around 8 Inches) is about as good as it gets (compared to 1cm in the case of the LX3/LX5).

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