Using Micro Four Thirds lenses on Sony NEX cameras

When the first Micro Four Thirds cameras were launched, they became instantly popular for using old, legacy lenses with adapters. Since the register distance is smaller than most other mounts, it is possible to create adapters for mounting lenses from many other systems to Micro Four Thirds cameras. This makes the most sense with lenses that feature a manual, mechanical focus ring and aperture. Even if there exist adapters for mounting Canon EF lenses on Micro Four Thirds, they do not allow for changing the aperture, hence, they are not very useful. This is because the Canon EF mount is an electro-optical system (EOS), which means that there are no manual rings to control the aperture setting.

As the Sony E mount has an even shorter register distance, though, this is one of the few formats that can not be adapted to the Micro Four Thirds system. Sony NEX lenses have a register distance of 18mm, hence, even if a thin adapter was made for using them on M4/3 cameras, you would not be able to focus to infinity with them. This is because the Micro Four Thirds cameras have a register distance of 20mm, too long for the optical formula of the Sony NEX lenses.

But, the other way around is possible: There are adapters for mounting Micro Four Thirds lenses on Sony NEX cameras. As the difference in the register distance is only 2mm, these adapters are very thin. Note that most Micro Four Thirds lenses are electro-optical, just like the Canon EF lenses, so you will not be able to control the focus or aperture from the camera, rendering most M4/3 lenses useless for this purpose.

The most useful M4/3 lenses for adapting on Sony NEX are those that are fully manual, e.g., the Samyang 7.5mm f/3.5 fisheye, the Olympus 15mm f/8 body cap lens, the Cosina Noktor 17.5mm f/0.95, and so on.

Here is what my adapter looks like:



It does not appear to be the best quality, but works ok. You use it as you would expect: The adapter goes on the Sony NEX camera, and then you can mount a Micro Four Thirds lens to it. Note that the adapter has no electrical contacts: Electronic focus operation and aperture operation is impossible, as is the use of the optical image stabilization (OIS), if the lens has this feature.

Using the Wanderlust Pinwide

Here's the Sony NEX-3N with the Micro Four Thirds to Sony NEX adapter, and the Wanderlust Pinwide:



The Wanderlust Pinwide is not a lens, but a pinhole camera body cap. It is recessed into the camera, for a better wide effect. It corresponds to 11mm focal length, hence, behaves like a 22mm lens on a traditional film camera. Which is very wide indeed.

But when used on the 1.5x crop sensor in the Sony NEX-3N, it becomes like a 17mm lens, i.e., extremely wide. See the difference below:

Used on the GH3	Used on the Sony NEX-3N

The problem is the light falloff outside the centre of the image frame. The extra wideness does not help much, as there is a very significant vignetting. The vignetting is caused mostly by the sensor's sensitivity to the angle of the light hitting it: Light coming from a steep angle does not work well, ideally the light should come perpendicular to the sensor. This appears to affect the green channel the most, giving a purple tint outside the image centre.

Using the Samyang 7.5mm f/3.5 fisheye

The Samyang 7.5mm f/3.5 fisheye is a manual focus lens with a manual aperture ring, hence, very well suited for adapting on a non-Micro Four Thirds camera. See the lens mounted below:



One problem with this setup, though, is that the adapter appears to be too thick, placing the lens too far from the sensor surface. This gives problems focusing to infinity. This is still not a fatal problem: You can still stop down the lens to achieve infinity in focus. I had to set around f/8 to get infinity reasonably in focus.

Here are some example images taken on both a Micro Four Thirds camera, and the Sony NEX-3N:

Used on the GH3	Used on the Sony NEX-3N

In the right image, above, you can see that the left and right sides are black. This is due to the built in lens hood: It keeps out light which would fall outside of the Four Thirds sensor surface, hence, giving black sides. Notice also that the black areas are a bit skewed, because the lens adapter mounts the lenses slightly rotated.

In the corners, you can see parts of the image circle ending. The image circle spans 180° field of view, and where this ends, you can see the black bits in the corners. So one advantage of using the fisheye lens on the Sony NEX camera, is that you can crop the image to several different aspect ratios, and still achieve a 180° diagonal field of view. Using a native Four Thirds sensor, you can only achieve this in the 4:3 aspect ratio. Due to the multi aspect sensor, the Panasonic GH1 and GH2 cameras could achieve this also in 3:2 and 16:9 aspect ratios.

Another comparison example:

Used on the GH3	Used on the Sony NEX-3N

Using the Lumix G 14-42mm f/3.5-5.6 kit zoom lens at 14mm

So, the kit zoom lens is of course an electro-optical lens, and you can only adjust the focus and aperture while having the lens mounted to a native Micro Four Thirds camera. However, there is a small trick. You can mount the lens to a Micro Four Thirds camera, turn on the camera, set the focus and aperture you want, take a long exposure, and then remove the lens during the exposure. The lens then has your desired focus and aperture set.

Using this trick, I used the kit zoom lens at 14mm, infinity focus, f/8 aperture:

Used on the GH3	Used on the Sony NEX-3N

Again, we see the vignetting due to the lens hood. This time, though, I could have removed the hood, but I left it on to illustrate that the lens is mounted slightly rotated when using this adapter. We can also see that the image has a bit of barrel-distortion. This is because the lens needs in camera geometric distortion correction to give rectilinear images. And when using the lens this way, there is no such distortion correction done.

Finally, even when pre-focusing at infinity and setting the aperture to f/8, infinity is not really in focus here. Again, this is due to the adapter being slightly too thick, making it impossible to focus on infinity with most lenses.

Conclusion

Using an adapter, it is possible to mount Micro Four Thirds lenses on Sony NEX cameras. However, my adapter was a bit thick, making infinity focus impossible. Also, most electronic lenses cannot be used at all, since there is no way to operate the focus or change the aperture.

This could be a way to reuse your manual focus Micro Four Thirds lenses on Sony NEX, though, like the Cosina Noktor 17.5mm f/0.95, especially if you don't care about infinity focus. That way, you can use the Sony NEX focus peaking as a manual focus assistance.

Reversed normal lens as macro front lens

There are many ways to achieve macro photography. There is the obvious one, getting a dedicated macro lens. The Panasonic Leica Lumix DG Macro-Elmarit 45mm f/2.8 1:1 Macro lens is a good macro lens, but it is rather expensive.

Another choice is to use a legacy normal lens, some macro rings, and an adaptor. I write about this method here.

Yet another method is to reverse a lens. Using a cheap adaptor, you can mount a basic Lumix G 14-42mm f/3.5-5.6 kit zoom lens for some very close macro capabilities.

In this article, I look into yet another method. This involves getting an adaptor ring with filter threads on each side. This can be bought quite cheaply at various auction sites. I chose the 52mm to 52mm adaptor ring:





This reverser ring can be screwed into the front lens threads of the Lumix G 45-200mm f/4-5.6 tele lens. Other lenses with 52mm front lens threads can be used as well. However, I found that the Lumix G 14-42mm f/3.5-5.6 basic kit lens was useless for this purpose, it gave too much vignetting when mounting the reversed normal lens.

As the normal lens to mount reversed, I chose the Nikkor 50mm f/1.8 AIS. It is a classic manual focus lens, compact and with reasonably good quality. This video shows how to mount it:



It is best to set the normal lens at maximum aperture, to avoid vignetting. I also found that the Lumix G 45-200mm lens should be set to around 150-200mm for the best results.

Here is my test of the magnification rate using this setup.  I photograph a millimeter ruler to find the magification:



And the resulting image shows that 5mm horizontally is reproduced, with a sensor that is 17.3mm wide. This gives a magnification rate of 17.3:5, or 3.5:1. This is also written as 3.5x, and is an extremely large magnification.



I also made an example exposure of the face of a LEGO figure. Here is the setup, with a working distance of around 5cm:



Which produced this image:



I used the very small f/16 aperture on the Lumix G 45-200mm f/4-5.6 tele lens, and still the depth of focus is extremely thin. Only parts of the curved face is in focus.

Using this method, you can still control the aperture from the camera. You can also operate the focus of the lens, although in practice you are limited to a very small fine tuning of the focus, because of the thin depth of focus at this extremely large magnification.

Example image

Here is an example image of the texture from a sock, taken at 3.5x magnification. This was done by setting the Lumix G 45-200mm lens at 200mm, with the normal lens attached to the front. I used f/18 for more depth of focus, but still the focus is very narrow, and it is difficult to get everything you want into focus:



This magnification is of course very impressive, but one could ask: Could you achieve the same details by using the Panasonic Leica 45mm f/2.8 1:1 macro lens, and cropping out the centre of the image? I tried to photograph the same object using the PL45, and this is the maximum magnification I could achieve. I also used f/18 here:



To evaluate the amount of details from either setup, here are 100% crops from the centre of both images. The images have not been sharpened. Click on the images for the full view.

200mm + reversed normal lens, centre crop	PL45, centre crop

Based on this comparison, it is clear that using the reversed normal lens does give a higher resolution than simply using the PL45 macro lens. However, the image quality suffers a bit due to the number of glass elements the light must travel through.

Summary

Here is a summary of various ways to achieve a macro ability:

Method	magnification	working distance	aperture	focus
Using a dedicated macro lens, the PL45	1:1 max	6cm	auto	auto
Macro extension rings, and a legacy normal lens	1.4:1 in my example	6cm	manual, if the lens has an aperture ring	no focus possibilty
Macro reverser ring, with Lumix 14-42mm	2.5:1 - 1.15:1	2-4cm	no control of aperture from camera	no focus possibilty
Olympus ZD 50mm f/2 lens with extra 65mm extension	2:1	3cm	no control of aperture from camera	no focus possibilty
Lumix G 45-200mm with reversed normal lens (this article)	3.5:1	5cm	auto	auto, but only small adjustments

Based on this table, we see fairly easily that this method is in fact preferable, given that we need such an extreme magnification rate. It gives a good working distance, and automatic aperture handling, which is quite useful. There is also some possibility for fine tuning of the focus using the lens' own autofocus system.

Future use of MFT lenses

One of the fun things with the Micro Four Thirds (MFT) format, is the short flange distance (20mm), which enables the possibility of making adapters for a number of formats. There are cheap, abundant adapters for many legacy formats, e.g., Nikon F and Pentax K, to name a few.

When MFT becomes legacy

However, the flip side of the coin is that some day, inevitably, MFT is also going to become a legacy format. What happens with your gorgeous, and expensive, MFT lenses then?

Let's say that the worst case scenario is that, due to competition, the MFT system loses so much volume that it is abandoned by Olympus and Panasonic. It doesn't seem likely now, but stranger things have happened.

You can still use your old cameras and lenses, of course, but at some point you will want a newer camera, due to new features and better image quality. Can you still use your MFT lenses on some camera from another system?

If Samsung NX becomes dominating

The Samsung NX format is one of the competitors in the mirrorless system category. Let's say this format becomes dominating. Can you use your old MFT lenses on this format through an adapter?

In short: No. It's not possible. The Samsung NX format has a longer flange distance (25.50mm), meaning that even if you made a very short adapter, the MFT lenses would not be able to focus to infinity. You could only use them as short focus macro lenses. Which is not very useful.

If Sony E becomes dominating

The Sony E format was introduced for their new NEX series. It has a flange distance which is 2mm shorter than the MFT format. This is good news, because 2mm, while pretty short, is probably enough to make an adapter for using MFT lenses on Sony E. The Sony E format also has a wider flange diameter, which makes it easier to design an adapter.

However, the MFT lenses are pretty useless without the possibility to operate the focus and the aperture. And both are operated electronically, controlled by the camera. So an adapter must have the relevant software to interpret the Sony E signals, and translate them into something that the MFT lenses understand.

This kind of electronic communication might sound easy, however, it is probably far from trivial. And at best, your autofocus would probably be very poor, both the speed, and, possibly, also the accuracy.

For a comparison, let's consider the Canon EF system. There are adapters for using Canon EF lenses on MFT cameras, but none of them can control the aperture or the focus. So the probability of getting future adapters that provide this feature for MFT lenses seems pretty slim, given that there are many magnitudes more Canon EF lenses out there than MFT lenses.

Conclusion

The conclusion is that if the MFT system is abandoned, your lenses are more or less useless.

On the other hand, there are some rumors now that the modular Ricoh GXR system will include a Micro Four Thirds mount/sensor module. If launched, this will enable mounting a MFT lens to the Ricoh GXR camera, with an adapter mount/sensor module.

Update December 2010

Since I wrote this article, an adapter for using MFT lenses on Sony E cameras (NEX) has actually emerged.  However, since it has no electronic contact, it can not control neither the focus nor the aperture.  So you're stuck with a focus around infinity, and the max aperture.  You can, however, use it with the Cosina Nokton 25mm f/0.95, which is a completely manual lens, with a mechanical focus ring, and a mechanical aperture ring.

Attaching a Nikon F AIS lens to Lumix GH1

Nikon F AIS lenses, with an aperture ring, are easy to use on Micro Four Thirds cameras. Adapters are cheap and easy to get. Attaching and removing the adapter and lens is shown in this video, using a Panasonic Lumix GH1 as an example:



The lens shown in this example is a compact Nikon 50mm f/1.8 AIS. It can easily be used for macro photography as well, when using macro extension rings.

Register distance

The register distance, also referred to as the flange focal distance, is the distance between the lens mount, and the film plane. Modern cameras don't use film anymore, so the film plane is in fact the sensor plane.

SLR cameras, with a moving reflex mirror behind the lens mount, need a fairly long register distance. The reason why Micro Four Thirds cameras can be made more compact than SLR cameras, is that they don't need the reflex mirror, and can have a shorter register distance.

A lens mount with a short register distance can be considered a universal mount, since it is possible to create adapters for mounts with longer distance. Micro Four Thirds is such a mount. There are adapters for a number of different formats, e.g., Nikon F and Pentax K.

For comparison, here is the register distance of various formats:

Samsung NX Mini	Very short
Pentax Q	9.20mm
Nikon 1	17.00mm
C mount	17.526mm
Fujifilm X	17.70mm
Sony E (NEX)	18.00mm
Sony FZ	19.00mm
Leica L (T and SL)	19.00mm
Micro Four Thirds	19.25mm
Hasselblad XCD	20.00mm
Samsung NX	25.50mm
Fujifilm G	26.70mm
Leica M	27.80mm
Konica Hexar RF	28.00mm
Olympus Pen F	28.95mm
Contax G	29.00mm
Contax RF	34.85mm
Four Thirds	38.67mm
Konica AR	40.70mm
Canon FD	42.00mm
Minolta MD	43.72mm
Sigma SA	44.00mm
Canon EF	44.00mm
Minolta AF/Sony Alpha	44.00mm
Pentax K	45.46mm
M42 screw	45.46mm
Contax/Yashica	45.50mm
Olympus OM	46.00mm
Nikon F	46.50mm
Leica R	47.00mm
Contax N	47.00mm
Arri PL	52.00mm
Oct-19	61.00mm
Mamiya 645	63.30mm
Pentax 645	70.87mm
Hasselblad 500	74.90mm
Pentax 6x7	84.95mm

The new Samsung mirrorless NX format has a longer register distance than Micro Four Thirds. However, the Samung format still has a shorter distance than most relevant formats, e.g., Leica M, so that it is possible to create adapters just as easily as for Micro Four Thirds.

On the other hand, the Samsung NX has a register distance about 2mm shorter than Leica M, which may be why Novoflex has not yet announced an adapter for it. 2mm may be too short to make a quality adapter.

Pentax PK to Four Thirds adapter

Previously, I've looked at an adapter for Nikon F lenses. Let's continue with a Pentax K-mount lens adapter.

This ring is an adapter for using Pentax K lenses on a Four Thirds mount. It is a crude adapter ring, with no aperture stop down functionality, and no electrical contacts. The adapter adds 7mm of spacing. The packet reads "Olympus 4/3-PK". The adapter can be bought for around US$15 on various auction sites.

Naturally, this adapter is made for use with a Four Thirds mount, so it cannot be put directly on a Micro Four Thirds camera. You will need another adapter stacked between them. I used the Panasonic DMW-MA1 Four Thirds to Micro Four Thirds adapter, but the Olympus MMF1 would have done the same job, since they are functionally similar.

Here are both adapters laid out, with the Pentax 50mm f/1.4 lens behind them.

When stacked together, the adapters allow for mounting Pentax K lenses to a Micro Four Thirds camera. You can see this done in the picture below, with the Pentax 50mm f/1.4 mounted to a Panasonic Lumix GH1.

Note that Pentax K lenses with an aperture ring are most suited for this use. If there is no aperture ring on the lens, then it is impossible to use an aperture smaller than the max, which is f/1.4 in this case. That makes the lens difficult to use. Focusing must be done manually, of course.

There are also adapters for Pentax K lenses to be mounted directly on Micro Four Thirds cameras. They tend to be somewhat more expensive, since they are larger, and also because they were introduced more recently.

The two legacy adapters I have explored so far, Nikon F and Pentax K, represent merely scratching the surface. There are adapters that can be used to mount a wide variety of lenses to Micro Four Thirds cameras. From high end Leica M lenses, to crude surveillance camera lenses.

Macro extension rings

Using macro rings has always been a cheap trick to improve the close focusing distance of a lens. You'll notice that when focusing from infinity to a closer distance, the lens elements usually move away from the camera and the sensor. Some exceptions from this are lenses with internal focusing, or back focusing.

So what happens if you move the lens even further from the camera than what's possible with the focus ring? It turns out that this gives you an even closer focus. So what a macro extension ring simply does, is allow you to mount the lens further from the sensor, translating the focus range of the lens so that it can be used for close up work.

There are no macro rings officially available for the Micro Four Thirds mount yet. However, when using legacy lenses on an adapter, there are a wide range of macro rings to try out. Here is a set of Nikon macro rings from Jessop:

These rings contain some mechanical coupling functions to allow for the aperture information to be transfered to the camera, and for the camera to automatically stop down the lens before taking a picture. However, these functions only work on AIS capable cameras. In today's Nikon lineup, only the top models have retained this functionality.
When using the rings on a crude adapter, you can certainly forget about this functionality. You'll need to focus using a large aperture, and then alter the aperture ring manually prior to pressing the shutter release, if you want to stop down the aperture.
The thickness of the rings are 13mm, 21mm, and 31mm. When stacked in different combinations, they can give these offset distances: 13mm, 21mm, 31mm, 34mm, 41mm, 52mm and 65mm.

Normally, these rings would go between the camera mount and the lens. When using an adapter, however, they go between the adapter and the lens, as in this picture:



A Nikon-Micro Four Thirds adapter (marked with "Nik-M4/3") is mounted to the Panasonic Lumix GH1 camera, and all the macro rings are stacked between the lens and the adapter. The lens is a Nikkor 50mm f/1.8 AIS. Here is a video showing how to attach the adapter and lens to the camera.

When using all the macro rings above, I took this picture of a measure band, to find the largest magnification. It was taken at 4/3 aspect ratio, in which case the active sensor is 18mm wide. Since the photographed item is 13mm wide, this gives an enlargement of 18:13, or 1.4:1. This could also be expressed as 1.4x.



For comparison, the Panasonic Leica DG Macro-Elmarit 45mm f/2.8 macro lens is capable 1:1 enlargement (1x), which means that the largest enlargement possible would have yielded 18mm of the measurement band. The macro rings and Nikkor 50mm lens can be used to make more enlargement than the dedicated Panasonic Leica macro lens.

Using the configuration above, with 65mm extension of the lens, I was able to take this close up picture:


I stopped down the aperture to f/8 for more depth of field.

For comparison, I photographed the same object using the Olympus Zuiko 50mm 1:2 macro lens. This is the closest picture I could take with the Olympus lens, also at f/8, and with an enlargement of approximately 1:2:



Macro rings for legacy mounts can be bought cheaply on various auction sites. There are also extension tubes and bellows, which are functionally similar, but more flexible in use. Another way to achieve closer focusing is to use a reverser ring, essentially a second lens mount to be screwed into the front lens filter thread. Using a reverser ring, the lens can be mounted reversed, in which case it can be used for macro. Lenses with a normal focal length are most commonly used this way.

Please note that macro lenses are special in that the lens formula is designed for close up photography. Using ordinary lenses on extension rings or bellows is not going to give as good results, since those lenses are not designed for close focusing.
Here is another example picture using the full 65mm macro ring extension:



For this picture of a garlic, I used f/22 to achieve enough depth of field. Using such a small aperture is going to give some blurring at pixel level due to diffraction. However, in this case, I valued more depth of field higher than some dullness at the highest magnification. The diffraction effect is barely visible at 100% view.

Nikon to m4/3 adapter

One of the benefits of the Micro Four Thirds format is the short register distance. Since virtually all other formats have a longer register distance, it is possible to make adapters for other lenses to be used on Micro Four Thirds.

Here is one of many adapters available:

It attaches to the camera just as a Micro Four Thirds lens. Here is a video showing how to attach the adapter to the Panasonic Lumix GH1.

It reads "NIK-M4/3", and can be used to mount Nikon F mount lenses to a Micro Four Thirds camera. These kind of adapters are simple, meaning that they only provide a means to mount the lens, and no control over the aperture or focus is possible from the camera. On the positive side, they are rather inexpensive, and can be purchased for around US$30-40.

http://www.amazon.com/gp/product/B002MXFGJI/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B002MXFGJI&linkCode=as2&tag=micr43rdsphot-20&linkId=47SACJR2BVSJUUPV

When using a third party adapter like this, the camera has no electronic confirmation that a lens is actually connected. For the camera to still operate, you need to set the menu item "shoot without lens". This is found under the "Custom" menu, indicated by a "C" with a wrench icon. Here is the menu item from the GH2 camera:

In the picture below, the adapter is used to mount a Nikkor 200mm f/4 AIS tele lens to the Panasonic Lumix GH1. When using this legacy lens on a Four Thirds camera, the field of view becomes equivalent to a 400mm lens. With a long tele like this, using a tripod is a necessity. While you can choose fast shutter speeds and capture an image without blurring due to camera shake, framing the subject is very difficult when handholding this combination. Recording video without a tripod is virtually impossible with such a long lens.



This lens has an aperture ring. Since the camera cannot control the aperture, it needs to be set manually. The presence of an aperture ring makes this operation easier. Some more expensive adapters have a means for controlling the aperture also for lenses without the aperture ring, e.g., the Nikon G mount lenses.

Many newer lenses do not have aperture rings, and require an adapters with a lever to stop the lens down. This goes for both Nikon and Pentax lenses.

Focus confirmation

There is some talk on the internet about adapters that provide focus confirmation for legacy lenses. To my knowledge, such a thing is not possible with Micro Four Thirds cameras. The cameras cannot confirm the focus when using non-compatible lenses. In fact, with the current cameras, the only way for the camera to know that the image is in focus, is to use a Micro Four Thirds lens, or one of the CDAF compatible Four Thirds lenses.

To be able to confirm the focus, the camera must jog the focus back and forth to find the optimum contrast. This is not possible with manual focus lenses, of course, since the camera cannot control the focus at all. So focus confirm adapters for Micro Four Thirds simply make no sense at all.

Size

A fun fact is that the adapter is larger than the Panasonic Lumix 20mm f/1.7 pancake lens. (The lens to the right below.)


Example images

Here are two example pictures taken at f/4:



And an example video:



I have also looked into an adapter for Pentax K lenses.

Manual focus with Lumix GH1

Here is a video that illustrates how manual focusing is done with the Panasonic Lumix GH1 camera. The Olympus 50mm f/2 macro lens is attached to the camera through the Panasonic DMW-MA1 adapter. The adapter is needed since the lens is a Four Thirds standard lens. No autofocus is possible with this combination.



When powering on the camera, it prompts you to switch to manual focus mode. This is not needed. You can leave the camera in autofocus mode, however, no autofocus is possible, of course.

Turning the focus dial will enable the zoomed view. What you see now is a 5x magnification of the centre of the image.

Tapping the shutter release gently brings up the normal full view again.

In the magnified focus assist view, you can use the front dial to switch between 5x and 10x magnification. You can also use the arrow buttons to move the magnified area around, in case you do not want to focus on the centre of the frame.

When you power down the camera, the lens will retract to infinity focus.

It would have been good to have a dedicated button to alter between the magnified focus assist view, and the normal view. While you can bring up the normal view by tapping the shutter release, turning the focus dial, which you may not always want to do. You could also use the focus area button on the rear, and then press OK, which brings up the zoomed view.