“Full Frame Equivalence” and Why It Doesn’t Matter

Started Feb 4, 2013 | Discussions thread
sean000 Veteran Member • Posts: 7,348
Re: “Full Frame Equivalence” and Why It Doesn’t Matter

Chez Wimpy wrote:

sean000 wrote:

Chez Wimpy wrote:

sean000 wrote:

Actually I don't mind comparing formats since I shoot two formats, but the thing that chaps my hide is when someone says, "That 45mm f/1.8 is really a 45mm f/3.5." No, it isn't. It's a 45mm f/1.8.

But isn't this a strawman? Where did you see this statement? The "chaps my hide" for most is the "The 45/1.8 is equivalent to 90/1.8 on FF" which is most definitely purported... and leads to The Troubles.

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I've seen it stated both ways numerous times.

Then please post a link. There is a flippant willingness to double focal length and leave apertures untouched, but I have never seen "45/1.8 is really a 45/3.5"

I didn't bookmark them, and I'm not saying that's the typical argument. Probably more common is the argument you are making... that you can't talk about equivalent focal lengths without talking about equivalent depth of field, total light, etc. Why not? For most of us two things matter most when selecting a lens (besides image quality of course): The field of view and the maximum f-stop for the purpose of getting faster shutter speeds in low light. In some threads it makes sense to also discuss equivalent depth of field but for many photos it doesn't matter. Total light is kind of a tricky one unless you're comparing two sensors of different size but the same generation. The fact that more total light hits the sensor of my seven year old Nikon D200 doesn't help it match the image quality of my E-M5. The newer E-M5 is about two stops better in terms of noise.

Most experienced photographers who has selected m4/3 as their primary (or only) format understands the differences between m4/3 and larger sensors. We often discuss FOV equivalency when we say stuff like, "I sold my Nikon 80-200mm f/2.8 and now I use the 35-100mm f/2.8 on m4/3." We don't feel like we have to say, "But I know it's not the same in terms of equivalent aperture." We assume that is known. What matters is that we now have a native fast telephoto zoom for m4/3 that is useful for the same reasons we bought a fast telephoto zoom for a larger sensor: It's useful for portraits and events in low light. No the the DOF won't be as shallow and the backgrounds won't be as blurred. Sometimes that's a bummer, and sometimes it's fantastic.


 sean000's gear list:sean000's gear list
Olympus Stylus XZ-10 Nikon D70 Nikon D200 Panasonic Lumix DMC-GF1 Olympus OM-D E-M5 +14 more
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