The mirrorless digital cameras are really challenging the entry level dSLR market as they offer similar image quality and versatility in a smaller size (and in the case of Micro Four Thirds, much smaller lenses).

Until this generation of Micro Four Thirds cameras, the main complaint has been auto-focus speed – this has now been addressed at least for relatively stationary subjects to the point that Olympus claim their new E-P3 has the FASTEST AF of any camera with 3x kit lens to this point when going from a subject at 1m to a subject at infinity using their new lenses.

Indeed, the many changes Olympus has made with the E-P3 makes it a much more usable camera than any of its PEN predecessors and perhaps the first I personally would consider buying.

I personally own the older Panasonic GH-1 and this has now become my only camera I take on international travels (my Canon 1D Mark III dSLR and its heavy lenses are just too big to carry on flights) and it provides me with all I need. These new cameras have even better image quality and faster AF so should be adequate for most general photography needs if you choose the lenses to suit your needs.

The Micro Four Thirds cameras, although having smaller sensors than other mirrorless cameras such as the Sony NEX and Samsung, have sufficient image quality for most people while allowing smaller lenses, and indeed,have a much wider range of autofocus lenses and camera bodies available to choose from, with significantly better HD video (with the GH-2) and functionality.

The current Micro Four Thirds have a lot in common:

• much higher image quality than point and shoot cameras as their sensors are some 6x larger
• smaller sensors than dSLRs and thus have marginally more noise at high ISO and marginally less dynamic range capability, but the trade off is much smaller lenses and cameras.
• can use almost any lens ever made via adapters in manual focus mode
• do not have optical viewfinders but electronic viewfinders
• are not weather-proofed (hopefully Olympus will be bringing out a Pen Pro weather-proofed version soon)
• have much easier live view and hence manual focus on legacy lenses than dSLRs as there is no need to move a mirror out of the way
• are quieter and smaller than dSLRs
• are not well suited to hand-holding with large, heavy lenses such as a 70-200mm f/2.8
• are best used with either f/3.5-5.6 zoom lenses (as larger aperture zoom lenses are a bit too big at present) or wide aperture prime lenses (eg. 12mm f/2.0, 25mm f/1.4, 45mm f/1.8 and 85mm f/1.4)
• are still not as good as a dSLR for AF tracking of fast moving subjects such as birds in flight.
• they lack pro and some other features such as intervalometer, fast flash sync (only 1/180th sec), GPS, auto-HDR, TTL compatibility with Pocket Wizard Flex TT5 radio flash system, etc
• all use SD-type memory cards
• all can shoot motion jpeg and AVCHD video although GH-2 does it at higher quality

There are some major differences between Panasonic and Olympus cameras:

• Olympus cameras have a built-in image stabiliser which can reduce camera shake with ANY lens – you need to set focal length for legacy lenses
• Panasonic cameras only have IS if the lens has optical IS – and this means only Panasonic OIS lenses
• None of the current Olympus cameras have built-in viewfinder but require an optional one which uses the hotshoe if you want to hold the camera to your eye like I do – I expect Olympus will be bringing out a GH-2-like camera out soon.
• Olympus has far better flash capabilities – good manual output control, remote TTL flash, TTL flash with legacy lenses, I just wish they could get flash sync to 1/300th sec like the pro cams.
• none of the Panasonic cameras support remote TTL flash while the Olympus cameras do (you need the Olympus flashes ending in R for this to work)
• I presume the Panasonic cameras are like my GH-1 and give incorrect exposures in TTL flash mode with legacy lenses – if you use legacy lenses a lot, consider the Olympus cameras as not only you get IS but TTL flash and remote TTL flash.
• Different post-processing “ART” filters or “Film Modes”
• Olympus has iDetect to preferentially AF on a person’s eye
• If you want the best HD video quality or an over-sized sensor for native, uncropped 16:9 images, then the Panasonic GH-2 is the way to go.
• If you primarily want to use small manual focus legacy lenses, then the Olympus cameras may be the better option as you get IS, TTL flash, and remote TTL flash and the E-P3 is better balanced with legacy lenses than is the GF-3, but you do miss out on Panasonic’s picture-in-picture manual focus functionality.
• The smallest are the Panasonic GF-3 and the Olympus E-PM3 which may suit some who just want much better image quality than a point and shoot, but still a small camera, but these lack important features such as a hotshoe, ability to use an EVF, various controls and menu items (eg. no flash exposure compensation on the GF-3), the lack of which may be very annoying for those who want to get a bit more serious or use flash.
• Unlike Olympus E-series dSLRs, none of the current Pens have IR remote control capability, but all except E-PL1 can use the RM-UC1 wired remote cable. The situation appears to be the same for the Panasonic cameras but of course, they have a different wired connector. You can buy 3rd party wired units which allow timer, intervalometer functions as well as radio wireless remote function.

A recent post by Mark Dubovoy on his 1st experience of using a GH-2 on an African safari along with a Leica S2 kit:

• “I was surprised by how well thought out this camera is.  Far superior to anything Canon or Nikon or Sony or Fuji have to offer.  As complicated and feature laden as the camera is, the locations of the controls and the ergonomics (other than the traditional film type shape of the camera which is all wrong, but no manufacturer seems to want to deviate from) are excellent.”
• he does not like an EVF nor the plastic feel but that’s part of the price to pay for this type of camera.
• “The biggest advantage of the camera is that it is so light and small and the autofocus is very fast”
• “Image stabilization is also excellent and seems to be much better than the 35 mm crowd”
• “I have used 35 mm rigs in Africa before, and frankly, I did not miss them.  As I mentioned above, the pro level bodies and lenses have gotten so big and so heavy that they have become quite a chore to use.”
• he mainly used it as a telephoto using 14-140mm and 100-300mm lenses as the longest focal length on his Leica S2 is only 130mm in 35mm terms.

 First a comparison of the new Panasonic cameras:

	Panasonic GH-2	Panasonic G-3	Panasonic GF-3
Price at Amazon.com	$US999 with 14-42mm lens	$US599 body only; $US699 with 14-42mm lens	$US699 with 14mm pancake lens
Weight	442g	336g	264g
Size	124 x 90 x 76mm	115 x 84 x 47mm	108 x 67 x 32mm
EVF	eye sensor auto switching	No eye sensor auto switching	No EVF possible
Touch screen LCD	articulating	articulating	fixed
HD video	1080p 24fps 23Mbps quality and 1080i 60fps; 1/16000th shutter	1080i 60fps derived from 30fps HD video mode,17mbps quality; 1/6000th sec shutter	as for GF-3
Over-sized sensor for native, uncropped 16:9	Yes, 18.3mp giving max. 16.1mp	No; 16.6mp giving 15.8mp	No; 13.1mp giving 12.1mp
Burst rate	5fps; 40fps at 4mp electronic shutter	4fps; 20fps at 4mp electronic shutter	3.8fps
Top panel mode switches	AF mode switch; Drive/self-timer switch	No	No
External mic socket	Yes	No	No, and only mono mic
Rear AF-lock button	Yes	No ?use Fn button	No
Subject tracking AF in HD video	No	Yes	Yes?
Pinpoint AF mode	No	Yes	Yes?
Max.ISO	12,800	6,400	6,400
Max. bulb duration	4min	2min
Hotshoe	Yes	Yes	No
White balance presets	5	5	5
Built-in flash	GN 15.6m	GN 11m	GN 6.3m
Exposure compensation	+/- 5EV	+/- 5EV	+/- 3EV, no flash compensation – a big problem if you want to use flash
AE bracketing	+/- 3EV	+/- 2EV	+/- 2EV
			certain lenses may prevent using tripod plates
			dpreview.com’s review here

And, now the new 3rd generation Olympus Pen cameras:

	Olympus E-P3	Olympus E-PL3 “Lite”	Olympus E-PM3 “Mini”
Price at Amazon.com	$US945 with 14-42mm lens
Weight	369g	313g	263g
Size	122 x 69 x 34mm	110 x 64 x 37mm	110 x 64 x 34mm
EVF	optional via hot shoe	optional via hot shoe	optional via hot shoe
LCD	OLED, 614K dot 3:2 fixed, touch. Usable even in bright sun.	460K dot 16:9 tilting, not touch	460K fixed, not touch
HD video	1080i 60fps; 720p 30/60fps; 17 or 13mbps quality;	as for E-P3	1080i 60fps; 720p 30/60fps
Over-sized sensor for native, uncropped 16:9	No; 13.1mp giving 12.1mp	No; 13.1mp giving 12.1mp	No; 13.1mp giving 12.1mp
Burst rate	3fps	5.5fps with IS turned off	4.1fps or 5.5fps with IS turned off
Top panel mode switches	No	No	No, and no exposure mode dial
External mic socket		No
Rear AF-lock button	5 customisable buttons
Subject tracking AF in HD video	Yes	Yes	?
Pinpoint AF mode	No, but has 35 AF zones, eye-detect AF and front AF lamp	as for E-P3 except 11 points only	No
Max.ISO	12,800	12,800	12,800
Max. bulb duration	4min	2min
Hotshoe	Yes, 1/180th sync	Yes, 1/160th sync	Yes, 1/160th sync
White balance presets	12	8	8
Built-in flash	GN 10m at ISO 200; remote TTL master; manual down to 1/64th output;	None, clip on FL-LM1 included	None,
Exposure compensation	+/- 3EV	+/- 3EV	+/- 3EV
AE bracketing	+/- 3EV	+/- 3EV	+/- 3EV
	level gauge	no level gauge	no level gauge
	10 art filters	6 art filters	6 art filters

Now for some of my favorite Micro Four Thirds autofocus lenses to consider:

The kit zoom lens for outdoors, daylight use:

• this is largely a matter of choice – I love my Lumix 14-140mm OIS 10x zoom as it is great for walk-around documentary work and is optimised for HD video, but it is a little big and heavy.
• Olympus also have a 14-150mm lens but it does not have OIS and OIS comes in handy for video, and if you have a Panasonic camera.
• alternatively, one can get the twin kit lenses for smaller lenses – 14-42mm OIS and 45-200mm Panasonic OIS or the collapsible Olympus 14-42mm
• Panasonic have just announced two new premium, ultra compact 3x zoom lenses – should be available late 2011 – these may be the best option!

Wide aperture prime lenses:

• Olympus 12mm f/2.0 lens – very nice for street photography and low light work as well as landscapes, it even features nice manual focus controls.
• Panasonic 20mm f/1.7 pancake lens – a great compact lens for street work, low light and environmental portraits but AF is a bit slow and noisy.
• Panasonic 25mm f/1.4 – this should be a very nice lens indeed for low light work and environmental portraits – I have the much larger Four Thirds version and love it.
• Olympus 45mm f/1.8 – an affordable portrait lens designed for HD video – I think this will be a must have for most people! $US399 RRP
• Panasonic 45mm f/2.8 macro lens – not my favorite, but until Olympus brings out a wider aperture macro, this is the only AF macro lens – look here for other macro lens options.
• there are a couple of other pancake lenses but I am not sure I would be bothered getting them – Panasonic 14mm f/2.5 and Olympus 17mm f/2.8.

Other AF lenses to consider:

• Olympus 9-18mm – very nice for travel and landscapes
• Panasonic 7-14mm f/4 – very nice lens for creative work but not suited to filters
• Lumix 100-300mm f/4-5.6 OIS or Olympus M.ZD 75-300mm f/4.8-6.7 – having a 600mm hand held telephoto is something most dSLR users can only dream of!
• Lumix 8mm f/3.5 fisheye – well some people just want a fisheye lens.

And a must have manual focus lens for beautiful bokeh and shallow depth of field:

• Rokinon 85mm f/1.4 – you can get this in Nikon or Canon mounts and then buy a cheap adapter from Ebay.

The predecessors of the Olympus E-PL3:

• Olympus E-PL2:
• single core processing engine instead of dual core as with the E-PL3, thus slower AF
• LCD screen is fixed 460K dot, not tilting
• built-in flash
• 3fps burst rate
• no AVCHD video, only 720p motion jpeg at 30fps
• no SDXC memory card support
• heavier at 362g
• Olympus E-PL1:
• as for E-PL2 but LCD screen only 2.7″ 230K dots, min. shutter 1/2000th sec not 1/4000th sec, slower AF, max. ISO 3200 not 6400, no iDetect to AF on a person’s eye, an older version of LiveView and a little lighter at 334g.
• no wired remote possible.
• Olympus E-P2:
• as for E-PL2 but better build, more controls, orientation sensor, 8 art filters instead of 6, but significantly, no built-in flash and no remote TTL flash
• no IR remote but compatible with RM-UC1 wired remote via USB connector.
• Olympus E-P1:
• the 1st digital Pen, as for E-P2 (ie. no flash) but no EVF option, only 5 WB presets not 8
• no IR remote but compatible with RM-UC1 wired remote via USB connector.