Photophys.com: The Science of Photography

Introduction: These comments concern mainly amateur nature photographers who would like to reduce the size and weight of their gear. I am the happy owner of a Canon 7D that I use primarily for wildlife photography with telephoto lenses. I also use a Canon 60D for landscapes, macrophotography, and night sky photography. When I travel with two camera bodies and a set of lenses including my Canon 100-400mm, my backpack is too heavy. Why not switch to one of the new mFT cameras and cut the weight by a factor of two? The Michael Reichmann’s recent review¹ of the Olympus OM-D on Luminous-landscape.com and the in depth review² of the same camera on Dpreview.com indicate there will be little, if any, loss in image quality relative to APS-C with the smaller format.

Comparison of mFT with APS-C: I was intrigued by the possibility of a lighter and smaller set of equipment so I spent a few days with an Olympus OM-D. That was not enough time for me to learn all of the OM-D’s features, but it did force me to ask the right questions. First I compared the image quality obtained with the M.Zuiko 12-50mm and 40-150mm lenses to that obtained with my Canon 60D equipped with 15-85mm and 70-200mm Canon lenses. I was shooting a book case full of books at about 18 feet, and I compared images with the same field of view, e.g. OM-D at 50mm and 100mm with 60D at 62mm and 125mm, respectively. In every case the OM-D gave images that were at least as good as those obtained with the 60D and in some cases were better. Both cameras used live-view with two second timer. Shutter vibration may still have affected the Canon results. The results showed me that the OM-D is a serious contender, and it merited further consideration.

I think that one’s conclusions will depend on the kind of photography they do and what sort of gear they already have. Street photographers with probably disagree with my conclusions. In any case, here are my reactions. The OM-D is a beautiful little camera. It is very solid and everything indicates high quality. In addition there are high tech features I am not accustomed to. For example there is a touch screen LCD with touch focusing. Also, the 12-50mm lens has remarkable properties. After auto focusing on a subject, simply touching the focus ring gives magnification of the image through the view finder that permits focus tweaking. Also, in the movie mode, a slight twist of the zoom ring gives a smooth automatic zoom. The lens has a manual zoom mode and also a macro mode. Both of the lenses I tried are extremely light and in the package I received they were very inexpensive. The 12-50mm kit lens added $250 to the camera cost and the 40-150mm lens was on sale at $100!

The OM-D is extremely configurable. There are two function buttons and a movie button that can be assigned a variety of functions. There is a learning curve, and the camera is sure to become more valuable with a lot of experience. There are other things to get used to. There is no built-in flash, but a small flash unit is packaged with the camera. The charger is rather standard, but has a plugin cord that adds much to its bulk.

So far everything has been positive, but there were things I was not comfortable with. First of all, the body is a bit too small, and I found some of the buttons are quite tiny. The main weight saving with the mFT system is with the lenses, and the body does need some size to accommodate human hands. I am more comfortable with the Canon Rebel and larger bodies. Having to push a number of function buttons is not that much fun. I admit that practice with this camera would make it more fun, but I use more than one camera type, and I need controls that are more obvious. I get along better with the Q screen on my 60D than with the OM-D super control panel. That may just be experience.

These complaints are quibbles that may not be endorsed by long time OM-D users. But there are more serious problems for me. Am I prepared to start buying a complete set of lenses for the OM-D so that I can use it in place of my APS-C cameras? That would mean fisheye, macro, extreme wide angle, medium and long bright telephoto lenses. Is a good mFT lens set available and is the OM-D able to compete with the 7D in all areas? For nature photographers it is important that the OM-D is not good at tracking moving objects. Also, I could not find fast focusing, high quality, bright telephoto lenses for mFT. There are many FT lenses that can be used on mFT camera with an adaptor, but their focus speed is compromised. There are also lenses from other manufacturers that can be used with adaptors, but they do not autofocus and focusing is not really convenient.

Conclusions: So how does this add up for me:

Pros

1. Light camera and lenses

2. Excellent viewfinder and LCD screen

4. Very good built-in image stabilization

3. Touch screen focusing

4. Convenient focus tweaking through the viewfinder

5. Convenient bracketing

6. Image quality equals the best APS-C cameras

7. Fast focus

8. LCD screen tilts

9. The high pixel density (equiv to 60 Mpixel in Full Frame (FF)) is great for applications such as photography of planetary disks.

Cons

1. Camera buttons are very small and not east to find by touch

2. Fast auto focus is only available for mFT lenses

3. Convenient manual focusing appears to be limited to mFT lenses

4. Focus tracking is not very good

5. Bright, high quality telephoto lenses are not available in mFT lens mount

6. mFT sensors are at a disadvantage compared to larger sensors for image quality (The OM-D sensor is state-of-the-art while some APS-C sensors need to catch up.)

7. LCD tilt is not as convenient as an articulating screen for landscape and astrophotography

Would consideration of Panasonic Lumix cameras have influenced my views. I don’t think so. The Lumix GH2 is acknowledged to be excellent for video work; and its replacement, the GH3, has a sensor similar to that in the OM-D. Its body is somewhat larger and probably handles better. However, the lens set for mFT is still limited. Also, Lumix cameras have no built-in image stabilization and, therefore, cannot take full advantage of the unstabilized Olympus M.Zuiko mFT lenses.

So my answer to the question posed is that APS-C users should consider the mFT systems, but for me at present there are good reasons to stick with my Canon equipment in spite of the size and weight. I do this with the hope that Canon will upgrade their sensors soon to increase both the dynamic range and the resolution (Pixel count). First time users and those who do not emphasize nature photography may well benefit right now from what mFT has to offer. This is especially true for air travelers.

Outlook for mFT, APS-C, and FF: My view of the near term future has been greatly influenced by Peter van den Hamer’s insightful article³ on the DXO Camera Sensor Benchmark and by Nikon’s release of their D800 (FF) and D7100 (APS-C) cameras. To summarize van den Hamer’s conclusions: (1) the image quality depends on the sensor size and, of course, the sensor efficiency; and (2) the pixel count controls the sensor resolution but does not influence the dynamic range. Therefore, Nikon’s use of a 36 Mpixel sensor on their D800 offers very high resolution as well as a high dynamic range.

mFT: The immediate future looks bright. The OM-D and GH3 have state-of-the-art sensors and are expected to be popular. The recent introduction of adaptors with focal length reduction by Metabones⁴ and the Olympus patent along the same lines promises very bright lenses with fields of view similar to that found in FF cameras. What I think Olympus needs to do is to improve the tracking ability of OM-D successors and to introduce bright, high quality telephoto lenses. The limitation of the small sensor size may become more important when FF sensors are less expensive and are available with very large pixel counts.

APS-C: This format will be popular as long as FF sensors are very expensive. With its 1.5 to 1.6 crop factor APS-C provides extra reach for telephoto lenses, and it handles wide angles with special crop factor lenses. I think the recently released Nikon D7100 shows the way forward. First of all it confirms Nikons choice of 24 Mpixels as the standard resolution and, more interestingly, it offers a 1.3 crop factor option. With this option switched on the overall crop from FF is 2x and the pixel count is 16 Mpixel just like the OM-D. That is quite an option!

FF: FF is the new medium format. The image quality with the state-of-the-art sensors offered by Sony is outstanding. As prices come down for FF sensors with high pixel count, cameras with FF sensors can dominate the market. Consider a compact camera with a FF sensor and options for 1.5x and 2x crops. If the sensor has 60 Mpixels, then the 1.5 (APS-C) crop will give a 24 Mpixel sensor and the 2.0 (mFT/FT) crop will give a 16 Mpixel sensor. Wow! Those are just the resolutions we already have for APS-C and mFT/FT, and what will be left for smaller sensors? Will the future play out this way?

Postscript: My friend, John Schwaller, pointed out a couple of links that are relevant to this discussion. The first is by Roger Cicala at LensRentals and concerns the total cost for camera sets for mFT, APS-C, and FF.⁵  The second one is by Scott Bourne, a professional photographer who is using an OM-D now full time. He describes the advantages of mFT and the OM-D in particular for his style of photography.⁶

References/Links:

1. http://www.luminous-landscape.com/reviews/cameras/olympus_om_d_e_m5_review.shtml

2. http://www.dpreview.com/reviews/olympusem5/22

3. http://www.luminous-landscape.com/essays/dxomark_sensor_for_benchmarking_cameras2.shtml

4. http://www.dpreview.com/articles/2667195592/first-impressions-metabones-speed-booster

5. http://www.lensrentals.com/blog/2013/02/roger-buys-a-camera-system-so-whats-this-going-to-cost

6. http://photofocus.com/2013/01/04/olympus-om-d-em-5-micro-four-thirds-long-term-review/

© Charles S. Johnson, Jr. 2013