E-M5 vs. E-P3: RAW Image Quality

This is a "rewrite" of my previous blog concerning JPEG image quality of these two cameras. It can be found here.

Below I have combined test charts shot with E-M5 and E-P3 at various ISO settings. Settings while shooting:

• Lens Zuiko D. 50mm f/2 Macro @ F4
• Equal aperture and shutter speed settings in both bodies at corresponding ISOs. (These cameras have equal sensitivities)

RAW files were opened in Lightroom 4.1 (Release Candidate 2), normalized and cropped equally. E-M5 crops are 100%. E-P3 crops were enlarged to the same size during Lightroom Export. All images are slightly sharpened and noise reduction applied in Lightroom. I kept the values for these the same for every file.

I chose to enlarge E-P3 files because I am interested in seeing quality in same size prints. This is closest to that situation on screen. Just remember: To see any real difference in sharpness at ISO 200 to 400 you need to print larger than A3. 

In JPEG comparison E-M5 was markedly better in every regard. At higher ISOs E-M5 gained about two stop improvement. I wrote then: This result comes from new sensor with more resolution and better pixel per pixel quality and thinner low pass filter. Now I know better, a lot of it comes also from improved JPEG algorithms. 

With RAW images differencies are not as big in a test target like this. This test target shows now mostly differencies in resolution and noise. E-M5 has a 14% advantage in linear resolution and thinner low pass filter. This is best shown in rhombus structure. Starting from ISO 800 up, E-M5 shows gradually more and more its better sensor. Further tweaking of the relation between sharpening and noise reduction would have benefitted E-M5 more than E-P3. With more demanding subjects E-M5 gives even more headroom for adjustments. I would say that for me the total gain is almost 2 stops in the way I tweak my images in Lightroom. With E-P3 I never went over ISO 1600. Now the limit will be slightly under ISO 6400.

Image below E-M5, M.Zuiko 12mm f/2 (Same image is shown shot as JPEG in previous blog).

• ISO 200, @F6.3
• Adjusted in Lightroom 4.1 (RC2)
• Crops 100% from brightest and darkest area without any modifications

Image below E-M5, Zuiko D. 12-60mm f/2.8-4

• ISO 200, @F5.6, underexposed on purpose.
• First image: opened into Lightroom 4.1 (RC2) at default settings, no adjustments
• Second image: adjusted by +5 stops in Lightroom, full Highlight correction (-100); two simple adjustments just to show the pushability
• Third image is a 100% crop. This radical opening of shadows brings out luminosity noise, as expected. But that´s all. No smearing to mention (grass is always difficult, stone had this mottled surface), relatively sharp details.

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Olympus E-M5: Dynamic Range - RAW

I posted in February a blog on E-M5 dynamic range. At that time it was about jpeg images. Now we have two popular and well known converters supporting E-M5, which enabled me to take another look with raw files. These converters are Lightroom 4.1 (Release Candidate 2) and CaptureOne 6.4.

This graph shows the same E-M5 and E-P3 dynamic ranges (orange and red) for jpeg images as shown in my previous blog. They are actually measured from raw files converted into jpegs in Olympus Viewer 2. This software emulates in camera jpeg process, which means I can tweak the jpegs to show optimal jpeg quality.

Blue and green lines  show what can be achived from E-M5 and E-P3 raw files. I opened raw files into Lightroom and CaptureOne and measured dynamic ranges at various ISOs. Both software showed almost the same numbers for E-M5. With E-P3 there was slight variation at some ISOs but there was no trend in favor of either software. What you can see here is the average performance of these software. The biggest and maybe most important difference was for E-M5 at ISO 200. With Lightroom I was able to read a 12.6 EV dynamic range and with CaptureOne it was 12.0EV.  At ISO 400 they both gave the same 12EV.

When you look at this graph, please do not take exact numbers too seriously. Look at trends E-M5 versus E-P3 and raw versus jpeg. While saying that I think it is no mistake to have E-P3 dynamic range at 10EV, which is the same as DxO Mark result for the same camera. Also two well respected software giving practically same numbers (sans ISO 200) for E-M5 should be no mistake either.

I have now shot a few thousand images with E-M5. Those images show the same trend in real life situations compared to E-P3 as this graph.

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Sigma 30 mm f/2.8 EX DN

The new Sigma 30 mm lens is a well balanced addition for mFT bodies. It is no pancake but its 39 mm length keeps your camera compact. Also its weight is mere 135g. The balance is good for instance with E-P3 body above. All comments in this blog are based on this combination.  

A 30 mm mFT lens corresponds to 60 mm angle of view in full format 35mm. This is a rare angle of view in prime lenses, but on the other hand it would fix the gap for me between 20 mm Lumix and 45 mm M.Zuiko lenses. Physical size would be similar, too. This lens is also available for APS-C size mirrorless cameras. There actual angle of view corresponds to normal focal length. Sigma 30 mm lens has a telecentric optical construction with 7 glass lenses in 5 groups. Two of these lenses are moulded aspherical and one of these has aspherical surface on both sides. The closest focusing distance is 30 cm.

This lens is sold in Europe for under 200 euros, which did not make me to expect for top quality mechanically or optically. My test sample showed some rattling when shaken, which comes (obviously?) from diaphragm blades. This is normal for this lens as I have heard similar comments from others. Diaphragm rattles also while metering light in some circumstances. I did not notice any adverse side effect (like inconsistence in exposures) from these phenomena in images. Internal autofocusing is fast, markedly faster than, say, Lumix 20 mm f/1.7 lens AF. It is not as fast as latest M.Zuikos, though. Focusing is quiet,  if not totally silent. This lens has a linear AF motor just like other latest internally focusing mFT lenses. Linear motor needs less moving parts and helps in quietness. Mechanically the most negative thing for me is focusing ring which jerks when you try to make small focusing adjustments. Focusing ring turns okay in constant move but starting without a jerk is difficult or impossible. Focusing ring is also obviously too thin as pressing fingers makes it lock up. In my opinion this lens should be taken as an AF only lens. During AF operation focusing ring is switched off and has no effect.   

Sigma´s 30 mm lens communicates slowly with camera body when turning camera power on.  It takes longer to get camera ready for the first shot than normally with mFT lenses. 

Test target

I shot my standard test target at apertures from F2.8 to F8. The results were a very positive surprise!

Image center is very good already wide open at F2.8 and reaches its top at F5.6. Edges lag behind at every f-stop, but differencies are not too big to show in normal images except for maybe F2.8 which is not actually bad. I have used Lightroom 4 automatic feature to correct chromatic aberration from these test shots, just like I would do in normal images. Chromatic aberration is not strong and it is removed effectively.

Image Samples and Conclusion

Images below were shot as RAW files with Olympus E-P3 and they were opened into Lightroom 4 and saved as sRGB JPEGs from there. I have done my standard procedure: removed chromatic aberration with LR4 automatic feature, checked and adjusted white balance and tonal range in LR4 Basic window and added slight sharpening in LR4 Detail window. Crops are all 100%.

I think Sigma has produced here a lens, which is optically significantly better than I expected. It gives much compared to its price and is definitely worth considering if this focal lenght is otherwise interesting.

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F2.8 @ ISO 200, 1/1000s.  Nice image quality already wide open. Slight coloring in strong contrast edges might be as much from Lightroom as from lens. 

F2.8 @ ISO 320, 1/80s. Hair detail should be examined while remembering how flat this light is.

F2.8 @ ISO 400, 1/60s.

F2.8 @ ISO 1250, 1/80s.

F2.8. Bokeh - rendering of out of focus areas - depends on contrast of lighting and relative distances between focusing point and background. Diaphgram has seven curved blades, which gives beautiful, almost round out of focus spheres.

F5.6 @ ISO 200, 1/125s. This lens tolerates back light quite well. You can get flare and reddish edges like here, if sky is lighter than everything else by several stops. Generally bright spots are no problem.

F5.6 @ ISO 200, 1/60s.

F5.0 @ IS0 200, 1/500s.

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.

E-M5 vs. E-P3: JPEG Image Quality

Below I have combined test charts shot with E-M5 and E-P3 at various ISO settings. Settings while shooting:

• Lens Zuiko D. 50mm f/2 Macro @ F4
• JPG Large Fine (I saved also RAW files to be compared later) (note: there is no visual difference between files saved at Large Fine or Large Super Fine jpeg compressions at 100%, unless you start to do heavy post processing)
• Picture Mode: 4 Muted @ Contrast -2, Saturation -2, Sharpness -2, Gradation Normal (note: normal means Olympus standard jpeg gamma curve)
• Noise reduction & noise filter: OFF
• Equal aperture and shutter speed settings in both bodies at corresponding ISOs

JPG files were opened in Photoshop, normalized and cropped equally. E-M5 crops are 100%. E-P3 crops were enlarged to same size through Bicubic Smoother interpolation. All images are slightly sharpened. No noise reduction applied. (All test shots have gone through automatic normalization which sets certain amount of lowest values of lowest channel to zero. In E-P3 shots you can see more black outline between white and black than in E-M5 shots. Anything stronger than what I did would lead into losing detail in shadows. I left corrections as they are, and that´s why some E-P3 scales look lighter than the same ones with E-M5. You can copy test charts and tweak them if you want to have another "look".)

I chose to enlarge E-P3 files because I am interested in seeing quality in same size prints. This is closest to that situation on screen. Just remember: To see any real difference in sharpness at ISO 200 to 400 you need to print larger than A3. 

E-M5 is markedly better in every regard: sharpness, signal to noise ratio, dynamic range... . At higher ISOs E-M5 gains about two stop improvement. This result comes from new sensor with more resolution and better pixel per pixel quality, thinner low pass filter and impoved JPG processing.

I will post later more images and compare RAW files.

-p- 

Image below E-M5, M.Zuiko 12mm f/2 

• ISO 200, @F6.3
• JPG Large Fine
• Picture Mode: 4 Muted @ Contrast -2, Saturation -2, Sharpness -2, Gradation Normal
• Noise reduction & noise filter: OFF
• Crops 100% from brightest and darkest area without any modifications

Image below E-M5, M.Zuiko 45mm f/1.8

• ISO 1600, @F2.5
• JPG Large Fine
• Picture Mode: 4 Muted @ Contrast -2, Saturation -2, Sharpness -2, Gradation Normal
• Noise reduction & noise filter: OFF
• Normalization and slight sharpening in Lightroom 3
• Crop 100%, no noise reduction applied