Crop Factor, Low Light and Aperture with m4/3 lenses?

Started Jun 15, 2014 | Discussions thread
Anders W Forum Pro • Posts: 21,468
Re: Very simple:

Just another Canon shooter wrote:

Anders W wrote:

FF has the same noise for equivalent images only if the sensors are equally efficient. But as a rule they are not. Smaller sensors tend to be more efficient than larger. See here:

http://www.dpreview.com/forums/post/53189207

Not true. QE of newer sensors is about 53%, see sensorgen, from m43 to APS-C to FF.

Sensorgen doesn't have data for many of the sensors in my sample and are based on fitting curves to numbers that results from previous curve fitting. Further, QE is an indirect measure that doesn't take certain facts into account (e.g., fixed pattern noise and read noise). My more direct measures are not subject to any of these problems.

What you are talking about is read noise at higher ISOs (affecting mostly the deep shadows), where the current m43 sensors are better by about a stop.

Please read the post I linked to (including references to other posts). I am not talking about read noise at higher ISOs only. I used four different indicators, two for lower and two for higher ISO, and two indexing DR and the other two indexing max SNR.

But for that, you need, say, f/1.4 vs. f/2.8, and the sensor would not be able to register at least 1/2 stop of that light, you get a noticeably lower resolution, etc.

I would need f/1.4 vs f/2.8 only if the sensors were equally efficient. My point is that they are not.

As to the rest, please elaborate/substantiate what you have in mind.

What FF can do is to take non-equivalent images, as simple as that.

Yes. Nobody disputes that. What I disputed was your claim that it can take equivalent images just as well as smaller sensors as far as noise is concerned. Since smaller sensors tend to be more efficient than larger, that's not the case.

When you must take equivalent images, there is still a resolution advantage,

See my request for elaboration/substantiation above.

but there is no IS (sometimes) disadvantage and the lower DR you mentioned, with the current sensors.

Yes. DR is part of the efficiency of the sensor.

 Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Olympus E-M1 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH +28 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow