1.14.2012

Using "legacy" lenses on the G2

One of the really cool capabilities of the micro four thirds (m43) cameras built by Olympus and Panasonic is the ability to use old manual lenses from almost any maker via inexpensive lens adapters.  The design of the m43 cameras makes this possible by removing the traditional optical viewfinder (OVF), mirror, and mirror box found in SLRs and dSLRs.   This makes the cameras smaller.  In the case of the Panasonic G-series and GH-series the removed items have been replaced with an electronic viewfinder (EVF), representing a significant net space savings.

Another result of the m43 design is that the distance between the sensor and the lens-mount is shortened and the cameras are thinner.  By using an adapter ring to "add back" the distance required by old manual lenses, often called "legacy" lenses, we are able to get these old optics to (generally) focus correctly on the new bodies. 

For example, so I can use my old Nikkor lenses, I purchased an adapter ring sold by Cowboy Studios via Amazon for about $20.  EBay is another good source for these inexpensive adapter rings.  The length of the Nikon-to-m43 adapter ring is 25mm (about 1").  It's nothing fancy.  Just a black metal tube with a m43 lens-mount on one end, and a Nikon body-mount on the other. You can find adapter rings for nearly every brand of lens.  Each will be sized little differently.

Nikon-to-m43 adapter from Cowboy Studios

I think the results with my Nikkors are very good, but I have read many reports of soft images, especially with other brands.  It must be remembered that these old lenses were built to be used with film.  They are not optimized for digital.

Some G2 camera features are disabled with the legacy lenses.  Because the lens adapter ring provides no electrical connections between the camera body and the lens, you will need a legacy lens that has an aperture ring.  You will then switch the camera to Aperture-Priority Mode.  After you manually set the aperture using the aperture ring on the lens, the camera's metering system will then pick the speed required to get the "correct" exposure at the ISO you've selected for that image.  The G2 also seems to work well with AutoISO, which I have set to a maximum of 1600.  I notice some underexposing, sometimes 2/3 to 1-stop, in lower light situations when using smaller diameter apertures like F8, so watch the histogram and be prepared to use some EV compensation.

One disadvantage of the G2 (and all Panasonic m43 cameras) is that there is no in-body image stabilization.  Meanwhile, Olympus builds image stabilization right into the m43 body.  This means that any legacy lens you attach to an Olympus will be image stabilized.  On the other hand, Olympus has yet to make a m43 camera with a built-in EVF; though there are rumors of one being announced this year.  If they build one, I'll buy it.

In the meantime, I don't view this Panasonic disadvantage as a big deal, at least for the legacy lenses I own.  My four Nikkor lens have focal lengths of 55mm, 58mm, 85mm and 105mm.  The G2 appears to maintain a minimum speed of 1/125th before bumping up the ISO.  This works for me, as I feel I can satisfactorily hand hold the 55, 56 and 85 at 1/125th.  And since these lenses are used primarily for candids, a speed of 1/125th is about as low as I would want to go, even if I had image stabilization available. 

Panasonic G2 + Cowboy Studios' "Nikon-to-m43" adapter ring + Nikkor 58mm F1.4 circa 1963
The 105mm F2.8 is a different story, but I am still happy with the results.  It is a macro lens (Nikon calls it a "micro").  Theoretically, to get a sharp image I should shoot an unstabilized 105mm lens on a 2x crop factor camera at a shutter speed of 1/200th second.  Coincidentally this is my preferred  lens speed for this lens, and would be my preferred speed even with image stabilization.  That's because I use this primarily for flowers outdoors, and without a flash.  Because even on calm days I believe there is some subject movement, I am happy with this shutter speed even if it requires ISO1600, though admittedly I might follow up such a shot with a shutter speed of 1/125 and lower ISO (1250?), as it's always preferable to use the lowest ISO possible.

A final cool feature that will help you with your manual focusing is the magnified view offered by the EVF.  I don't use it all the time, but when you do need it, just press the thumb dial (it clicks "in" like a button) to get a magnified view of the subject inside the single-point focus box.  As a second step, your magnification can be increased further by turning the thumb dial wheel one click to the right. You can also move the focus box to any other area of the viewfinder using the four-way pad.  When using the LCD you have the added choice of using the touchscreen feature to relocate the focus box. 

For candids, I like to move the focus box so it is centered horizontally and down 1/3rd from the top, because typically the subject's face will be in the 1/3rd  position.  As far as I can tell there are no settings to make this selected position "sticky", not even within one of the Custom Settings modes.  So you will need to reset it every time your turn the camera on... so, if you are not using a tripod, perhaps its will be easier to leave the focus box in the absolute center and just focus and recompose....

In the future, I plan to compare some "old" lenses and some "new" lenses.  Generally, I think the old lenses are fun to use if you already own them.  I'm not sure, however, if it is worth buying old legacy lenses.  It seems that the price of old lenses has increased dramatically as owners of m43 bodies and now Sony NEX bodies have discovered them.

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