ARS Loc: Southeast Florida

If I mount a 50mm Nikon ais lens to a m4/3 body with an adapter, will it be a 100mm equivalent or stay at 50mm.

Arnold

GoofyNewfie Loc: Kansas City

The answer is yes.
It will still be a 50 mm lens.
It will be the "full-frame" equivalent of about 100mm.

Architect1776 Loc: In my mind

It stays 50mm.
The format crops the view to look like a 100mm because you just see the small center part of the projected image the lens produces.
Regardless of brand this happens with m4/3 cameras.

ARS Loc: Southeast Florida

Thanks 😊

jcboy3

The focal length of the lens remains the same as long as you are using a straight adapter. But it will be equivalent to 2x the focal length on a full frame body. But that is the same situation as a native m43 lens. Focal length doesn't change.

On the other hand, there are optical adapters (speedboosters) that act like teleconverters in reverse, and make the equivalent focal length shorter. This correction is around a factor of 2/3, which also increases the equivalent aperture by around one stop.

Thus, a 50mm f/1.8 lens on m43 is still 50mm f/1.8 with a straight adapter, but is equivalent to a 100mm f/3.6 lens. With an optical adapter (speedbooster) the 50mm f/1.8 lens is equivalent to a 64mm (or so) f/2.4 lens (or so) lens.

ARS Loc: Southeast Florida

Thank you

epd1947

A lens will never become a different focal length based on the camera to which it is mounted. So your 50mm lens will be nothing other than 50mm. What will change, when mounting the lens to a camera with a smaller sensor, will be the angle of view (compared to that when mounted to a full frame camera) - on a MFT format sensor the angle of view will be equivalent to the angle of view that a 100mm lens would provide on a full frame camera. The 50mm lens puts out the same size image circle (out of the back of the lens) regardless of camera - it’s just that the smaller MFT sensor captures less of it - with quite a bit being outside the sensor boundaries.

burkphoto Loc: High Point, NC

The LENS is always going to remain 50mm. The 2X magnification factor of m43 will give it the field of view similar to a 100mm lens used on a full frame body.

Using Nikon full frame lenses on my Lumix GH4 has been mostly annoying. I have 24, 35, 55, and 135mm Nikkors I can adapt to m43, but:

> The 24mm f/2.8 is one of the worst Nikon lenses I ever owned. Only the 43-86mm zoom from the 1960s was worse. Using it as a 48mm equivalent field of view optic on m43 just magnifies the coma, astigmatism, and other issues of the 24.

> The 35mm f/2.0 was my favorite film lens. But it is mediocre on m43. Contrast is low, oddly, it is prone to flare, and as an unstabilized 70mm equivalent field of view, it is unsteady.

> The 55mm f/3.5 "Micro Nikkor" has a 110mm field of view equivalence on m43, useful for video interviews, macro work and portraits. But its lack of modern coatings leaves it prone to flare.

> The 135mm f/2.8 has a 270mm field of view equivalence on m43, but since it is a manual focus lens and has no stabilization, it is hard to control.

My twins use these lenses on occasion for filmmaking. But we find them all annoying. The adapter is just a mount adapter. There is no automatic diaphragm, no meter coupling, no autofocus, and no lens compensation data to be passed to the firmware, so you're essentially dumped back into the 1950s and the very early days of Exakta SLRs! Plus, they're double the size and weight they need to be for m43 coverage.

I have a 12-35mm f/2.8 II Lumix G X-Vario zoom, a 30mm f/2.8 Lumix Macro lens, a 42.5mm f/1.7 Lumix prime, and a 35-100mm f/2.8 Lumix G X-Vario zoom. All of these have image stabilization (my GH4 does not have IBIS). They also have autofocus, auto diaphragm, and transmit lens aberration and other data to the camera's JPEG engine firmware and to Lightroom Classic for raw file processing. These lenses make very sharp images with lots of contrast.

I highly recommend buying used lenses from KEH, MPB, UsedPhotoPro.com, Adorama, or B&H. Micro 4/3 lenses are a much better match for Micro 4/3 cameras.

wdross Loc: Castle Rock, Colorado

Your full frame 50 mm f(X) lens will act like a 100 mm f(X) lens on a 4/3rds camera. The lens itself will always be a 50 mm lens. It is the sensor size along with the actual lens focal length that determines the angle of view. Although the focal length does not actually change in this case, going from a full frame sensor to a smaller 4/3rds sensor does change the angle of view.

burkphoto Loc: High Point, NC

That light scattering around outside the boundaries of the sensor reflects off of the inside of the camera, back onto the rear element of the lens, causing a bit of contrast reducing flare. That's one of many reasons why using lenses engineered for larger formats on smaller format sensors can be disappointing.

epd1947

I almost never use my Nikkor lenses on my MFT cameras - but I have used both of my 50mm Nikkor primes (and some others as well) on my (APS-C) sensor Sony A6000 with really excellent results - never noticed any issue with flare or reduced contrast - but I can see where that possibility might exist and present an issue from time to time.

burkphoto Loc: High Point, NC

My son recorded a short film on his GH4 a couple of summers ago. He used my Nikkor 35mm f/2 and a Canon FD 28mm f/2.8. Both were soft and flat, even in direct sun. It was as if there were a soft focus filter on them. I thought at first they might have been dirty, but they were spotless.

I cannot duplicate that "look" with Lumix lenses — and I'm glad. Trevor now has a Lumix 12-35mm f/2.8 and won't use the old film lenses.

https://www.m43lenses.com

https://www.four-thirds.org/en/lens/

https://alikgriffin.com/micro-43-lens-buying-guide/

As you can see in the links, there are plenty of options available!

epd1947

I own over a dozen lenses across several platforms- I use the Nikkor lenses (as well as various Sony lenses) on my A6000 because they all work well for me - not for lack of alternatives. I actually don’t own a 50mm Sony lens - I could easily purchase any of those, but I don’t see the point just to have an OEM lens of that focal length.

Canisdirus

The lens never changes...always wonder why the minutia always comes up with micro folks...technicalities.

Lens is a fifty is a fifty...

Your images however...what matters...will be 100mm and DOF will double as well...in the image.

ARS Loc: Southeast Florida

Thank you all for your information. I actually have the Lumix G 12-60 and 45-150. I wanted to be able to use my Nikkors mostly for nostalgic reasons. I hate having them just laying around but I don't have the heart to get rid of them. For the cost of an adapter maybe I just have fun with them.