Videos on E-M5 stabilizer and C-AF

I am posting three videos below. They are very raw, just simple tests to see how things work.

The first one is captured looking into E-M5 monitor (camera in my hands at about chest level) while walking. Everything set auto and IS OFF. The second one is captured as similarly as possible with the first one except for having IS 1 ON. The experience is now quite different, smoother, and shows the benefit of IS. 

The third video is shot to see how C-AF and IS work in low light with rapidly changing camera-subject distance and various camera movements. The lens here is M.Zuiko 12mm wide open at F2.0. Continuous AF and IS 1 ON. I am moving on my knees, camera in my hands, bending here and there. The only light is 20W energy saving lamp. TV gives a good indication on light level. I think C-AF does a nice job without hunting and IS dampens my erratic movements quite well. The small size shown here does not show C-AF as it really is.

These videos can be downloaded at full HD size here.

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Untitled from Pekka Potka on Vimeo.

Untitled from Pekka Potka on Vimeo.

Untitled from Pekka Potka on Vimeo.

Olympus E-M5: 5-axis image stabilization

Olympus introduced with E-M5 a new image stabilization system, which has five camera movements stabilized. Present Olympus cameras have different versions of two-axis stabilization.

This picture shows the 2-axis sensor-stabilizator component of E-P3 on the left and the 5-axis component of E-M5 on the right. The sensor floats in the field of electromagnets.

IS test

I have now a pre-production E-M5 body with 1.0 firmware. My first test with it was to see how effective this new image stabilization is. An easy and effective test method is to shoot the ready lights of some electric gadgets in a dark room. 

Here is my test done with E-M5 and Zuiko D. 50mm Macro lens.

I shot a series of 10 images handheld (and standing) at various shutter speeds both with IS off and IS1 on. Then I opened those 10 images from each shutter speed in Photoshop as layers and aligned them so that the lights are as exactly above each other as possible in all images. Layer mode was Lighten. In this way I get a well defined image if every shot is sharp. The more there is blur in images the blurrier the combined image becomes. What I get is kind of cumulative camera shake at every shutter speed. Already one bad shot shows.

The upper row shows what happens when IS is off. This picture shows 100% pixels. I am not steady enough to get sharp images at 1/30s. Actually only at 1/125s I can be sure that there is no blur because of camera shake. At 1/60s I get more sharp images than blurred. This is very well in line with the old adage: you should not use a slower shutter speed than what your focal length says in 35mm eq. millimeters. My shooting technique seems to be quite average. Hmmm...

The lower row shows a similar series with IS1 on. At 1/30s and 1/15s every image is sharp. At 1/8s there are 8 sharp images out of 10 and at 1/4s maybe 2 or 3 out of 10.

I did the same drill twice more and each time the results were consistant. This means, with my shooting technique I gain at least 3 EV values. This of course varies a lot between people depending on your posture, how you hold the camera, press or squeeze the shutter button etc.

Next I checked IS with M.Zuiko 12mm lens. With IS off I can be pretty sure of getting sharp images at 1/15s. With IS1 on I got repeatedly sharp images at 1/4s. Half a second is way too long for me to stay still, my body moves too much and IS can´t compensate for it but only occasionally. So, at this focal length I gain 2(+) EVs from IS. With 12mm lens I had this red LED at the edge of image to see the effect of roll compensation. Looks like I don´t "roll" very much, my body shake is more sideways. 

Many people claim that optical stabilizers are better than in-body stabilizers at longer focal lengths. I was really interested in seeing how effective this new 5-axis IBIS is with a tele lens. To test it, I shot again similar series of images with Zuiko D. 150mm lens plus 1.4X Extender. The total focal length is 210mm, which corresponds to a 420mm lens in Full Frame 35mm camera. Again upper row is without IS and lower with IS1 is on. With IS I was able to stay sharp up to 1/30s. (Blurriness in this image is because of focus. I focused once manually at start and after that my position shifted somewhat between each series of shots.)  That´s at least 4 EV values better than I can do without IBIS. At 1/15s there are more sharp frames than shaken ones. Even at 1/8s there was at least one sharp image in each series of 10 images. Quite astounding!

Conclusion

Olympus claims that their new 5-axis IBIS is effective for up to 5 EV values. It´s based on Olympus´ testing method. Pekka Potka´s testing method gave me again real world knowledge on how far I can trust E-M5 IBIS. I was really surprised to see the benefit at longer focal lenghts. With wide angle lenses like 12mm you really can´t expect to get a 4 EV benefit, as that would mean sharp images at 1 second. Well, maybe some of you can, but at least I wobble way too far over the moving limits of IBIS. 

One huge benefit with already 50mm lens and especially with 150mm lens is E-M5´s stabilized EVF. It´s so calm, you can concentrate on subject and framing without any vibration. EVF image just stays put there solid and clear. It even lacks the snaps and jerks of optical stabilization.

IBIS and video

Olympus new IBIS stabilizes also videoshooting. I will make a separate post on this feature.

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Olympus M.Zuiko 12-50mm f/3.5-6.3 in comparison

During this time of year we have not much light even during daytime and the weather in Southern Finland has been quite cloudy and rainy. Because of that I decided to do a traditional test target shoot to compare the new zoom with some of my other lenses. 

Above is my test setup. I used two targets, one in the center and the other in the right upper corner. I shot the same "subject" (marked here as grey area) with different focal lengths. Of course distance varied accordingly to keep (subject) area the same. I used studio flashes and used their power settings to keep exposure on sensor constant in every picture. Accuracy was 1/10 stop. This way the differencies in lens diaphragm did not affect the results. I also focused center and corner targets separately to compensate for possible curvatures in lenses´focal planes. All test pictures were shot at ISO 200. Camera was Olympus E-P3. RAW images were opened in Lightroom 3.6 and I did a basic normalization of tones, correction of chromatic aberration and added sharpening. Those are the same basic tweaks I would do to real pictures. Possible distortions were not corrected as can be seen in corner shots.

Focal Length 12mm

The first comparison shows the center of 12-50mm zoom at full aperture F3.5 and closed at F5.6. Focal length is widest, 12mm. These are 100% crops, like all other target images here. The image quality gets better with smaller aperture as would be expected here.

 

Olympus´4/3 series zoom lens Zuiko D. 12-60mm f/2.8-4.0 is the perfect comparison lens for any lens having the same focal length range. Here we can see center targets. This result is in line with Olympus´MTF curves below: 12-60mm zoom is a great lens, and especially its resolution (orange curves) is higher than with the new zoom. You can find more of these MTF curves at Olympus web sites. They are good tools when comparing lenses.

 

In upper line of this picture we have the corners of 12-50mm zoom at apertures F3.5 and F5.6. Contrast and resolution gets better with smaller aperture, but radial (sagittal) and tangential (meridional) lines have a very different resolution. It can be also seen in MTF curves, where continuous line is sagittal and dashed line is meridional transfer function. For comparison we have corner shots with 12-60mm zoom at F3.5 and and M.Zuiko 12mm f/2 prime at F4.0. 12mm lens is not too good in corners, but it has this reasonable level all ready from F2.

Focal Length 14mm

 

As a further comparison lens we have M.Zuiko 14-42mm f/3.5-5.6 II kit zoom. Above its results at 14mm focal lenght and apertures F3.5 and F5.6. Left side images are from center and right side images are from corner. Now 12mm and 14mm focal lengths are so different that they should not be compared directly. That´s why I have below a common focal length of about 19mm.

Focal Length about 19mm

 

Here I set the shooting distance with Lumix G 20mm f/1.7 prime. After shooting with it, I shot with those three zooms from the same spot while setting zoom or focal length so that the cropping was always equal. Zoom rings did not show 20mm because Lumix actually has not a 20mm focal length. It is maybe close to 18,5mm. These crops are from center. Lumix 20mm and Olympus 12-60mm zoom show almost identical performance. Wide open 12-50mm zoom has a good resolution but its contrast is not up to 14-42mm zoom.

 

Looking at corners, 12-50mm zoom has again nice resolution but contrast performance is very modest. Thus it is practically a draw with kit zoom. Maybe it comes as a surprise for some people but Lumix 20mm is not much better in the corners. Number one from these lenses is quite obvious.

Closing down to F5.6 makes Lumix 20mm markedly better in the corners than these zooms.

Focal Length 42mm

 

This comparison has on the left centers at full aperture and on the right corners, again at full aperture. 12-50mm zoom gets better all the time as focal length grows. 14-42mm zoom on the other hand sees especially contrast dropping at its longest focal length.

Focal Length 50mm

 

Uppermost, on the left, we have 12-50mm zoom´s center at full aperture. All the other crops are from the corner. 12-50mm zoom shows just slightly better contrast in corners when closed to F8. Still contrast performance is lower than resolution. As new lenses I included M.Zuiko 45mm f/1.8 at the same aperture F4 as earlier were Lumix 20mm and M.Zuiko 12mm. 50mm is 4/3 series Zuiko D. 50mm f/2 Macro. 

Macro setting

 

As close up test I did a watch image. At macro setting 12-50mm has a 43mm focal length. It can not be changed as zoom ring does not move when macro setting is engaged. Largest aperture is F6.0. Here we have the closest focusing distance of 200mm.

I tried apertures F8 and F11. The smaller aperture shows already effects of diffractions but on he other hand the better depth of field can be a bigger benefit. How ever, the 12-50mm lens is capable of very nice images with close up subjects. This is a 100% crop.

For comparison once more on the left the new 12-50mm zoom and on the right Zuiko D. 50mm f/2 Macro. Aperture is F8. Focusing differs between these images, please look for the sharpest details in both images. 

Conclusion

Zuiko D. 12-60mm f/2.8-4 is one heck of a lens. I guess that´s old news. The images should tell quite clearly the differencies. However, we must remember that this kind of very precisely made test target comparison is a lot harsher than any normal shooting. The differencies in normal shooting would not be in the same league, there are too many disturbing factors. Even slight differencies in exposure, focus or camera shake could obscure a lot. But, yes this is what you get when everything is optimized.

M. Zuiko 12-50mm f/3.5-6.3 is a very reasonable lens for photography with its longer focal length and especially for close up shooting. Otherwise it fits better for video because of its silent and fast focusing and silent power-zoom. For video it has plenty of quality. You can check this by scaling test shots into 50%. Then they correspond to Full HD quality. 

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My New Rig

I have used Olympus PEN-system since summer of 2009. With E-P3 and new Olympus 12 and 45mm lenses it has grown into a matured level for me. Image on the left has everything I need for over 90% of my images. 

I have travelled a road from 35mm film system cameras to medium and large format cameras, from there  to best digital backs and 35mm size digital system cameras. As smaller cameras I have tried all kinds of point and shoot cameras (both film and digital) and APS-C size digital system cameras. This does not mean constantly leaping from camera or system to another but owning tools according to needs.

Every camera is a compromise. You get something and lose something. During my professional career sheer quality with the best workflow was the prime qoal. Issues like portability, weight or size were not very important for most of time. 

Now I do photography to express other things and need a tool to suit my way of doing it. I want to be able to print with no compromises in quality in A3 and A2 sizes and high quality up to A1 or A0. But I want also portability. I always want to use a viewfinder, keep looking through it without any need to chimp or because of camera. I need a camera that can be controlled without looking at buttons.

I was very interested in Olympus PEN -system since the beginning in 2009, used it and learned to get every drop of quality out of it. E-P1 and E-P2 felt like my system even though lack of prime lenses and restricted software support (LR2 conversion was horrible) plus slow autofocus have been frustrating at times. But now the pieces have fallen into their places. Olympus E-P3 with high quality, fast prime lenses fills my needs, finally. Now, after a month´s usage I have really grown together with E-P3 and it is now configured just the way I want. E-P3 is the ultimate ETTR (expose to the right) machine. With it and in body stabilisation I can shoot perfectly exposed, sharp RAW images in most available light conditions. Lightroom 3.5 seems to do a very good RAW conversion from E-P3 files.

I have other lenses and equipment for this system of course, actually a lot - and I have full frame 35mm and medium format digital back systems alsoas well as P&S. But the big ones are for specific planned needs. For those 10% of situations.

Of course I am not claiming that my new rig is perfect and final. It never has been. I am happy to get all the improvements that future will bring. But I could just as well keep shooting with this body, viewfinder and those three lenses if this was the final level of optics and engineering.

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A full frame 35mm DSLR is an overkill in size and weight unless there is a specific use where it gives noticeably better final in-use image quality or other benefits compared to E-P3. These uses seem to arise less and less. My two D3xes live mostly a very relaxed life. In contrast my 5D2s with lots of lenses do mostly music videos - by my son. 

I have always used black cameras since metal OM-1s. For a change I wanted to go back to that style. They only call these silver now...

Olympus M.Zuiko 45mm 1:1.8

Image below shows the new 45mm lens attached to an E-P3 body. Lens is quite small and light. It is not as exquisitely made as 12mm 1:2.0 lens sitting next to it. Construction is now plastic and it misses the brilliant distance scale of 12mm lens. How ever it is well made and its price (299 €) is under half of 12mm lens price.

 

Because of missing Lightroom RAW conversion for E-P3 I did my first evaluation of 45mm lens only with JPG files. It is no problem for me anymore like it was while testing 12mm lens. I have worked around the issues I had earlier with E-P3 JPGs.

Like said 45mm 1:1.8 is small and light (116g). Actually I would have liked it to have the same 46mm filter thread as 12mm lens and Lumix 20mm lens instead of the miniscule 37mm. Now it´s on the thin side for me. Although construction is plastic, I don´t see any problems with that as because of internal focusing the only moving exterior part is focusing ring. 

Above we have 45mm lens (left) compared to Olympus m4/3 series zoom lenses at same focal length. Second from left is kit zoom 14-42mm, third 50-150mm and fourth 14-150mm. In it´s collapsed position kit zoom is practically as long as the new lens but a little fatter. They have the same filter thread at 37mm. 

Above from the left we have the new lens and 4/3 series lenses 50mm 1:2.0 Macro and 12-60mm 1:2.8-4.0 zoom with their m4/3-adapters. 

Optically I found very little to say against this lens. Technically it has 9 lenses in 8 groups. Two lenses are of extra high refractive glass. All apertures from 1.8 up to 8 (or 11-16 depending on when you think diffraction starts to soften images too much) are quite usable for me. The sweet point is from 2.8 to 5.6. Contrast and sharpness are very good. Shooting JPGs I didn´t notice any need to worry about distortion, vignetting or chromatic aberrations. Lens has problems with flare only with sun hitting front lens against or nearly against the light. Even so I recommend a good lens hood (Olympus has LH-40B as an accessory) to prevent loss of contrast as this lens does not have a nano coating. Typical for many fast short teles is (green-magenta) color fringing at (almost) sharp highlight edges. This lens makes no exception. Wide open and with slightly smaller apertures 45mm gives lots of opportunities for shallow depth of field and separation of subject from background. The nature of out focus areas, bokeh, can be nice and soft when background is soft enough. Circular diaphragm has 7 blades. In some other instances I would call bokeh busy and restless when background is more contrasty.

As a retired advertising photographer I have used the very best short tele lenses there are. Against that background I think M.Zuiko 45mm 1:1.8 is a good, solid performer. It is optically a lot better lens than its price tag says. With M.Zuiko 12mm 1:2.0, Lumix 20mm 1:1.7 this lens forms an excellent set of prime lenses for any m4/3 shooter.

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Comparison between lenses 45mm 1:1.8 (left) and 4/3 system 50mm 1:2.0 Macro, both at f/2.0. All images 100% crops. Traffic sign is half way to left from image center. Lenses are nearly equal. But 50mm lens has a nicer bokeh. 

40-150mm zoom (left, f/4.1, @45mm) has no chance aginst 45mm lens (f/4.0). Both images 100% crops from left upper corner.

45mm lens at f/2.0 (ISO 200). Contrast and detail hold very well against white sky, also when out of focus.

45mm lens at f/2.0 (1/500s, ISO 200). Crops 100%.  

Inside parking carage, f/1.8, 1/100s, ISO 400.  

f/1.8, 1/100s, ISO 500.  

f/2.0, 1/200s, ISO 200. Below 100% crop.