Micro 4/3 Lens FAQ

This FAQ is divided into several sections, based upon topic. It’s fairly long, so if you have a specific question, your best bet is to search for a specific term or phrase. The sections are:

General Lens Questions

What lenses are made for micro 4/3 cameras?

There is currently a large selection of micro 4/3 lenses available. Please see the lens chart for a listing of all current models and basic specifications.

What are the best micro 4/3 lenses?

This depends entirely on what you are photographing. I do have some recommendations, but remember that lens evaluation is a very subjective art – what appeals to me may not appeal to you!

What are equivalent focal lengths? What is ‘crop factor’?

To compare focal lengths between micro 4/3 and 135 format film or full frame digital cameras, you multiple by 2 (and divide for the reverse comparison). In other words, a 25mm lens on a micro 4/3 camera produces similar framing to a 50mm lens on a full frame camera. 2 is often referred to as the crop factor because if you double the length of the diagonal of a 4/3 format sensor you get something roughly the size of a full-frame sensor.

How about f-stops? Do you also multiply by the crop factor to compare apertures?

Sort of. In terms of light gathering (metering), an f/1.4 lens on one format is the same as on another format. So there’s no conversion there. In terms of matching appearance, you do multiply by 2 to get the same depth-of-field, if you’ve got equivalent framing. In other words, a 25mm f/1.4 lens on a micro 4/3 camera produces the same framing and depth of field as a 50mm f/2.8 lens on a full frame one. Note that a 25mm f/1.4 lens on full frame would have the same depth of field, but offer a much wider angle-of-view.

What aperture do lenses perform best at on micro 4/3?

Most lenses (and micro 4/3 ones are no exception) perform best closed down around 1.5-2 f-stops from their maximum aperture. So if you have a lens with a max. aperture of f/3.5, it will most likely be sharpest between f/5.6 and f/7.1. That said, lenses do vary and if you are picky, it’s best to test yourself, or look at lens test results from a site like photozone.

What is diffraction? When do it occur?

Diffraction is generally used to refer to a softening that occurs at smaller apertures. In practice, stopping down to f/11 and beyond results in significantly less sharp images on m4/3. A smaller degradation can be seen from f/8 to f/11, although with lower quality lenses, it may not be visible. The exact point where this happens depends on the size of the pixels on the sensor (it occurs earlier with smaller pixels).

What is the best aperture to use on micro 4/3 cameras?

It depends. The first concern should always be depth-of-field – is correct part of the image in focus? It is ideal to shoot at a lens’s sharpest aperture, but this isn’t always possible. At the other end, it is also best to avoid smaller apertures and the loss of image quality to diffraction. Do bear in mind though that both diffraction and lens sharpness are in reference to the pixel level of the image – something you simply won’t see if you’re not viewing the image at full-size on your screen or printing very large.

Can I use my Panasonic lens on my Olympus body (or vice versa).

Yes. Any micro 4/3 lens can be used on any micro 4/3 body. You may freely mix and match among manufacturers and basic features work the same.

What is focus-by-wire? When will I use it?

Focus-by-wire means that the focusing ring on the lens is not directly connected to the focusing mechanism of the lens. Instead it connects electronically to the lenses’s focusing motor. Almost all micro 4/3 lenses use focus-by-wire. If you use manual focus with micro 4/3 lenses (or most 4/3 ones), you’ll use focus-by-wire. The main advantage is that it allows finer-control over focus adjustments. The downside is that it makes presetting the focus distance almost impossible on most m4/3 lenses.

What is ‘focus peaking’? Does micro 4/3 offer it?

Focus peaking is a technology developed by Sony where the areas of highest contrast are highlighted. It can be a great aid for manual focusing. Unfortunately, neither Olympus nor Panasonic have incorporated it in any of their cameras yet.

Is there any disadvantage to mixing and matching micro 4/3 lenses and body makes (e.g. Olympus body with Panasonic lens)?

In general, no. In most respects, the lenses behave the same regardless of the body used. Autofocus, aperture control and automatic correction of geometric distortion work the same across all combinations. The only real differences come when using Panasonic lenses on Olympus bodies (vs. on Panasonic bodies). They are:

  • Olympus bodies don’t correct for chromatic aberration on any lenses. Panasonic bodies with panasonic lenses do.
  • OIS (optical image stabilization) is only available on Olympus bodies with Panasonic lenses that have a physical on/off switch for the OIS. On Panasonic bodies, OIS is available with all lenses that have OIS.

What is a polarizer? Is there a particular kind I need for micro 4/3 cameras?

A polarizer blocks light that blocks light of a particular orientation. It is often used to prevent reflections (in water for example) and darken skies (landscapes). There are two types of polarizers – circular and linear. Micro 4/3 works with either one (DSLRs don’t work with linear polarizers).

Image Stabilization

Is there any reason not to leave image stabilization on all the time?

Yes. While generally very useful, stabilization can degrade your images under certain situations:

  • Stabilization should almost always be disabled if the camera is ona tripod.
  • At high shutter speeds, stabilization may introduce a small amount of blurring. As a rule of thumb, if the shutter speed is more than twice the focal length of the lens, I would disable stabilization.

I have an Olympus body and a Panasonic lens that supports OIS. Can I turn on both stabilization in the body (IBIS – in-body image stabilization) and in the lens for even better stabilization?

Don’t do this. The systems operate independently and as such can interfere and actually generate vibrations, rather than reducing them. You should only enable one stabilization option at a time.

Which type of image stabilization is better – in-camera (IBIS) or in-lens (OIS)?

There’s not really a general answer. The effectiveness of IBIS and OIS depends heavily on the specific body and lens. Overall from what I’ve seen, on the Olympus E-M5, the IBIS is usually better, and on the older models, OIS is better on longer focal lengths (150mm+) and IBIS on shorter focal lengths.

Even though I’ve turned OIS off, I can still hear the stabilization motor working. Is this normal?

Yes. The lens elements used for stabilization are essentially free-floating, so the motor must operate to keep them from moving around. If you turn off the camera and turn it over, you may be able to hear a ‘clicking’ sound as the free elements shift.

Which Panasonic lenses can you enable OIS on when using an Olympus body?

As of Sept. 2012, the list is as follows:

  • Panasonic Lumix G Vario X 12-35mm f/2.8 OIS
  • Panasonic Lumix G Vario 14-45mm f/3.5-5.6 OIS
  • Panasonic Lumix G Varios 14-140mm f/4-5.8 OIS
  • Panasonic Lumix G Vario 45-200mm f/4-5.6 OIS
  • Panasonic Lumix G Vario 100-300mm f/4.5-5.6 OIS
  • Panasonic Leica D 45mm f/2.8 OIS

Classic 4/3 Lenses

Can I use 4/3 (non-micro) lenses on my micro 4/3 body?

Yes. You will need a micro-4/3 to 4/3 adapter, and some functionality will be compromised.

Is there a difference between the various 4/3 adapters?

Functionally, no. You will not gain any functionality such as faster autofocus or better compatibility by going with one adapter model over another. The build quality of the original Panasonic and Olympus adapters seems to be a bit more solid than the newer ones. The one functional difference is that the newest Olympus adapter boasts weather-sealing. If you have a sealed lens, and a sealed body, that may be an attraction. Currently the adapter options are:

  • Panasonic DMW-MA1 – the first adapter released
  • Olympus MMF-1 – seemingly discontinued
  • Olympus MMF-2 – less solid construction than the MMF-1
  • Olympus MMF-3 – like the MMF-2 but with two rubber sealing rings, the most expensive by a fair margin
  • Viltrox JY-43F – a third party clone available currently only on eBay, and the least expensive of the lot

What are the drawbacks to using 4/3 lenses on micro 4/3 bodies?

In a word – autofocus. Speed and to a lesser degree accuracy are considerably worse than with native micro 4/3 lenses. Moreover, autofocus is limited to single – there is no tracking or continuous AF ability with these lenses. In terms of speed, there are two classes of 4/3 lenses – those optimized for CDAF (contrast detect autofocus) which take generally 1-2 seconds to AF, and those not optimized for CDAF, which take anywhere from 2-6 seconds.

4/3 lenses that aren’t optimized for CDAF will not autofocus at all on the first generation of Panasonic bodies, the G1, GF1 and GH1. Also, newer bodies (e.g. G3, GH2, E-P3 and E-M5) autofocus a fair amount faster with 4/3 lenses than old ones do (E-P1, E-P2).

Beyond autofocus, there’s also the fact most 4/3 lenses are fairly large, and may not handle comfortably with the smaller micro 4/3 bodies.

Which 4/3 lenses are optimized for CDAF?

    • Olympus ZD 9-18mm f/4-5.6
    • Olympus ZD 14-42mm f/3.5-5.6
    • Olympus ZD 14-54mm f/2.8-3.5 II
    • Olympus ZD 40-150mm f/4.0-5.6
    • Olympus ZD 70-300mm f/4.5-5.6
    • Olympus ZD 25mm f/2.8
    • Panasonic Leica D Vario Elmar 14-50mm f/3.8-5.6
    • Panasonic Leica D Vario Elmar 14-150mm f/3.5-5.6
    • Panasonic Leica D 25mm f/1.4

Adapted (Legacy) Lenses

Can I use my Nikon/Canon/Sonya/Pentax lenses on my micro 4/3 camera?

Yes. Virtually any type of lens can be used on micro 4/3 bodies with an adapter. There are a couple of things to keep in mind:

There is no autofocus. Focus is purely manual. Older lenses tend to have better focusing rings, and thus are better candidates for adapting. Focus by wire lenses are essentially useless.

Aperture is controlled on the lens, not the body. So in terms of shooting mode, you’re generally limited to aperture priority. As a corollary, lenses where the aperture is controlled electronically are a problem as there is no way to set the aperture from the body. Lenses with an aperture ring are best for adapting.

What adapter should I use for my adapted lens?

Most adapters are ‘dumb’ spacers – they have no electronics and their purpose is to ensure that the lens is the correct distance from the sensor. These are fine for lenses with aperture rings.

For lenses that don’t have aperture rings such as Nikon’s G lenses, you’ll need an adapter that lets you control the aperture.

The Canon EF mount is special, as the aperture is controlled electronically. You either have the option of always using the lens at a preset aperture (set by putting the lens on a Canon camera) or buying an adapter with a built-in aperture, or a smart adapter that lets you set the aperture directly (expensive).

While there are several vendors selling high-priced adapters, for most lenses, especially those with built-in aperture rings, an inexpensive adapter off of eBay is more than good enough.

What are the compromises involved in using adapted lenses?

First, as noted above, you lose autofocus. There are various methods for focusing manually, but it is not as convenient nor as fast as modern autofocus. The lack of focus peaking makes it a bit hard as well.

In terms of image quality most older lenses are designed for film, which is significantly less demanding than a digital sensor with small pixels like micro 4/3. As a result, image sharpness is generally not as good as with modern lenses. Very old lenses are not coated or multicoated, meaning they tend to be lower contrast and not deal well with light sources inside the image frame.

Due to the crop factor, adapted lenses also serve different purposes than initially intended. For example, a 24mm lens on 135 format film gives a wide-angle perspective, whereas on micro 4/3 it gives a normal one. There are in fact very few adapted lenses that offer a wide-angle perspective on micro 4/3.

Is image stabilization available with adapted lenses?

Yes, but only on Olympus bodies, using sensor-based stabilization.

I’m using adapted lenses on my Olympus body. What focal length should I input for the stabilization system?

You should input the actual focal length, not the equivalent one. In other words, if you have a 50mm lens, input 50mm, and not 100mm. For zooms lenses, since there’s no option to input a range of focal lengths, you have to choose one. It’s probably best to input the length you use most often.

Specific Lens Issues

My Panasonic 7-14mm f/4.0 has odd color flare spots on my Olympus E-M5.

Unfortunately, there appears to be some sort of interaction between the coating of the E-M5’s sensor and light passing through the lens which results in this odd coloring. Other Olympus bodies and Panasonic bodies do not have this problem.

My Panasonic X 14-42mm f/3.5-5.6 and Panasonic X 45-175mm f/4-5.6 lenses show blurring at certain shutter speeds.

This seems to be a common problem. At intermediate shutter speeds – generally between 1/60 and 1/200 second – at the longer end of both lenses (close to 42mm or 200mm), many users report blurring, regardless of the body used. Early tests comparing these lenses on the Panasonic G5 using both the mechanical shutter and the electronic shutter show the problem is drastically reduced with the electronic shutter, so it seems that the problem may be related to vibrations generated by the shutter. However, enabling stabilization (in body or in lens) does not generally seem to help with the issue.

I see banding in images taken with my Panasonic 20mm f/1.7 lens on the Olympus E-M5.

The AF motor in the 20/1.7 is known to cause interference with the sensor readout, resulting in noise patterns in certain situations. No other lens seems to cause this.

My Olympus E-M5 body sometimes refuses to wake from sleep when the Panasonic 20mm f/1.7 lens is attached to it.

There is a bug with this combination of body and lens. At present, the only way to get the camera out of its locked up state is to remove and then reinsert the camera battery.

My Panasonic 25mm f/1.4 lens makes a rattlesnake-like/chattering noise.

This is primarily a problem with Olympus bodies. The camera rapidly opens and closes the aperture blades in changing light (even if the changes are minimal to nonexistent) in order to keep the amount of light reaching the sensor constant. This is responsible for the noise. It can be fairly loud. Panasonic bodies either do not have this problem at all, or have it to a much lesser degree. A couple of other lenses are reported to cause a milder version of this on Olympus bodies, including the Panasonic 14mm f/2.5 and the Panasonic 20mm f/1.7 although many users also report no problem at all with those lenses.