Thursday, 4 May 2017

GH5 IBIS is as good as Olympus

The Lumix GH5 is the first GH series camera to have IBIS, in body image stabilization. This means that even prime lenses without any OIS feature can be stabilized, in both photos and videos. But how does it compare with the Olympus E-M5 Mark II, which made waves in this area almost a couple of years ago, with a fantastic video image stabilization?

In this article, I put them head to head. To avoid any possible advantage of using the same brand name lens as camera body, I have used the third party Sigma 30mm f/2.8 Art lenses, which I like a lot:


Both cameras are mounted to a Desmond stereo bracket here. They are both recording in 1080p resolution, with 60FPS framerate. I have both set to f/2.8 aperture, and using continuous autofocus. Here is the comparison:



A note about the autofocus speed of the Lumix GH5. In this video, I set both the AF sliders to max, "AF Speed" and "AF Sensitivity". Without this change, the GH5 would have been hopelessly slower to focus than the Olympus camera in this comparison.


However, in real life use, I don't think I would have set them this high. After all, it is seldom you need the AF to react this fast in real life usage.

My analysis of the outcome, is that the Lumix GH5 is just as good as the Olympus camera when it comes to stabilizing the video stream. So it shows that Panasonic have come a long way with IBIS!

Tuesday, 25 April 2017

GH5 e-shutter is slower!

The Lumix GH3 introduced a new concept in 2012: Electronic shutter. Meaning that you no longer had to rely on a mechanical curtain shutter in front of the sensor to start and stop the exposure, this could now be done purely electronically by the sensor itself.

The benefits are obvious: Less wear on the shutter if you want to make a time-lapse, for example. And a perfectly silent camera.

However, there was also a big downside: The sensor was scanned vertically during electronic shutter usage, and this scan was slow, taking a total of 1/10s. If you moved the camera, or the subject moved in this time, you would get skewed lines and weird effects. And can you hold the camera steady for 1/10s? No, that is impossible.

So the usefulness was rather limited. Future implementations increased the e-shutter scan speed, however, at the expense of the bit depth. Using only 10 bits rather than 12 bits normally, that would increase the scanning speed, but reduce the dynamic range capabilities. This was done, e.g., in the Lumix GH4, angering some users. And the scan speed was still quite slow, way slower than cameras from the Nikon 1 series, for example, with a 1/80s scan speed.

With this backdrop, the big question is: What about the Lumix GH5? What is the electronic shutter scanning speed and bit depth? Does it finally make the electronic shutter useful? That is what I will answer here, by comparing with two similar cameras:


Back: Lumix GH5 (left) and Lumix GH4 (right), and Lumix G85 in the front. Despite these cameras appearing to be the same size, they are in fact significantly different, with the GH5 being largest, and the G85 being smallest.

Speed of E-shutter readout


The Lumix GH3 electronic shutter had a readout speed of 1/10s, which is very slow. This leads to significant rolling shutter artifacts, that you can read about here. How do the cameras above compare?

One way to test the speed of the electronic shutter is to take a photo at a fast shutter speed in artificial light. For about a century or so, people have been using incandescent light bulbs for electronic indoor lightning. Even when used on alternating current (AC), the light is stable. Since the filament is heated, it emits light also when the alternating current is at zero.

However, traditional incandescent light bulbs are now being replaced with the energy saving fluorescent light bulbs. They tend to flicker at 100Hz (in Europe) or at 120Hz (in the US). The lights don't flicker at 50Hz and 60Hz, as you might expect. This is since during each period, the electrical current reaches two peaks, see the illustration below:



Here are images taken at ISO 3200, 1/400s with the three cameras:

Lumix GH5Lumix GH4Lumix G85

Each yellow row represents 1/100s of scan time, and the more rows, the slower. So there is your answer, the Lumix GH5 has the slowest e-shutter scan speed of the three. Who would have guessed?

By counting the lines more thoroughly, I get these approximate scan speeds:

Lumix GH5Lumix GH4Lumix G85
1/22s1/30s1/25s

Bit depth


Having answered the first question, what about the second? Do you lose some bit depth, and, hence, dynamic range, when using the electronic shutter?

To find out, I took the same picture using the three cameras, and I underexposed by two stops. Then I increased the exposure by three stops in a RAW editing program. That reveals how much details are left in the shadows. I used ISO 200, the base ISO, in all the cases.

Here are the pictures, after adjusting the exposure by +3 in post processing, using the RAW file:

Lumix GH5Lumix GH4Lumix G85
Mechanical shutter
Electronic shutter

They look quite similar on first look, but some crops at 100% reveals the difference. The top crops are from the mechanical shutter, while the lower are from the electronic shutter:


What we see here is that the Lumix GH5 has the same image quality using both the mechanical and electronic shutters. The other cameras, on the other hand, lose some details in the shadows in electronic shutter mode, indicating a lower bit depth.

So the Lumix GH5 prioritizes image quality over scan speed, which is why it is the slowest in my above test. Also, it has a higher resolution at 20MP, which slows down the sensor scan.

Keep in mind that these images were underexposed significantly, and then raised in post processing. So the image quality you see here is much worse than what you would get with normal use. In real life use, you would probably not see any difference at all between the electronic shutter and mechanical shutter images, using the Lumix GH4 or G85.

Also, when using a higher ISO, the lower bits are probably mostly noise anyway, meaning that there is little to benefit from the extra bits in the GH5 rendering.

Conclusion


The Lumix GH5 prioritizes image quality over scanning speed in electronic shutter mode. While this will make many fans happy, there is a downside: A slower sensor scan which leads to rolling shutter effects.

Here are some examples taken using the electronic shutter with the GH5. In the first, I pan the camera following the bird, which skews the building in the background:


In the second, a passing car is skewed, due to the speed:


The shutter speed is not relevant for these effects. Even if you set a very fast shutter speed, you would still get the skewing. It is the scan speed which creates these effects, and it cannot be changed. The only solution is to use the mechanical shutter.

But there is good news! If you use the 6K photo mode, then the camera is able to scan the sensor surface much faster, which should help avoiding the rolling shutter effects. It probably caps some bit depth, but as you don't get any RAW file anyway, I guess it doesn't matter much.

Here is the Joker picture taken with 6K photo mode, indicating a scan speed of 1/60s, quite impressive:


Lumix GH5Lumix GH4Lumix G85
Electronic shutter scan speed1/22s1/30s1/25s
Electronic shutter bit depth121010
6K Photo scan speed1/60sNANA
6K Photo bit depth10?NANA

So my conclusion is: If you want to use the electronic shutter and get the best image quality, make sure to keep your camera stable and use the ordinary electronic shutter mode.

If you are going to do actions shots, use the 6K photo mode, which does the same, but with a faster scanning, and without the RAW file output.

The really positive news here is that with the Lumix GH5, Panasonic gives us this choice.

Electronic shutter6K Photo
ProsBest image qualityLess rolling shutter effects, better for sports, animals, etc
ConsCan give skewed effects due to rolling shutterNo RAW output, however, the JPEG image is actually quite good. Be sure to get the exposure and white balance correct when taking the images

Out of the three cameras, I would recommend the Lumix GH5 if you can justify the investment, otherwise, get the Lumix G85. The Lumix GH4 is good for those who must have the V-Log functionality, but want the cheaper option.


Sunday, 8 January 2017

G85 IBIS makes mirror tele lens usable

There are some third party mirror tele lenses available, e.g., the Tokina 300mm f/6.3 seen below:


The big advantage with the is that they are relatively cheap, and, not least, very compact. The lens here is surprisingly short for a 300mm tele lens.

On the other hand, there are drawbacks, for example, manual focus only, fixed aperture, no zoom, and loss of contrast when you have a bright background. Read more about this in my review.

Another drawback is the lack of image stabilization, which makes it near impossible to use the lens without a tripod. Even focusing correctly or framing is hard without a tripod. And this is where a newer camera like the Lumix G85 comes handy: It has built in In-Body Image Stabilization (IBIS) which makes this lens much more usable. See the sensor movement demonstrated here.

Notice that the lens above has electrical contacts, which is unusual for a manual focus lens without any aperture mechanism or image stabilization. However, it is still useful because it tells the camera the right focal length, so that you don't need to input it manually for the IBIS to work well.

Also, it signals to the camera when you operate the manual focus, so that it can show you a magnified view, if you have setup the camera to show this.

To illustrate how much easier it is to use on the Lumix G85, compared with the Lumix GH4, which does not have IBIS, consider this comparison video:



As you see, with the Lumix GH4, which lacks IBIS, it is impossible to focus or frame the lens, even if I support the camera and lens with both hands, and support both elbows on a windowsill. With the Lumix G85, though, the lens becomes usable, even without a tripod.

Note that Olympus cameras can also stabilize this lens. However, due to the way Olympus cameras operate, they only stabilize the viewfinder while you half press the shutter button. And half pressing the shutter removes the magnified view. So with Olympus, you can only get the focus aid stabilized for a split second at a time, which is quite frustrating. Not so with Lumix G85: Using the lens becomes fun!

Here is an example image taken handheld at 1/25s, f/6.3, ISO 3200:


Note that the focus is not perfect here, and there is some blur. But keep in mind that 1/25s is way below safe handholding speed for a 300mm lens, in fact, it is five stops below. You'll notice the typical out of focus donuts in the background, due to the mirror design of the lens.

If you just want an inexpensive, very long lens, then get the Lumix G 100-300mm f/4-5.6. It is a good lens at a good price, and will give you much better pictures than the mirror lens. The mirror lens is more of a fun novelty item, in my opinion.

In the picture below, you can see the Lumix G 100-300mm at 300mm (left), compared with the Tokina 300mm f/6.3 (right):


The picture clearly shows the size advantage of the catadioptric mirror design of the Tokina lens, making it remarkably short.

Sunday, 18 December 2016

Lumix G 12-60mm f/3.5-5.6 review

Some have questioned why Panasonic have churned out so many different kit zoom lenses in the M4/3 format so far. However, one lens which is not going to be questioned in the same way, I think, is the new Lumix G 12-60mm f/3.5-5.6.

It is shown below, in the fully zoomed position at 60mm, on the Lumix G85 camera it comes in a kit with:


It is not just a new kit zoom lens, it also has some good features:

  • A proper wide angle end, starting at 24mm equivalent. This is not only good news in itself, it is also good for 4k video use. All Lumix cameras so far record 4k video using a crop factor only, meaning that a 14mm lens becomes around 18mm in 4k mode. Hence, starting at a focal length of 12mm is good news.

    Not many Lumix zoom lenses start at 12mm so far, making this a lens to look for. There is the Lumix G 12-32mm f/3.5-5.6, which I think is great, but is has a somewhat short reach, see my review.
  • More reach in the long end, at 120mm equivalent.
  • Weather protected: It is the least expensive Panasonic lens so far with weather protection, meaning that you can use it even when there is a risk for some rain and splashes. There is no guarantee against water damage, so you should still be careful, but hopefully, the lens will be more safe to use in wet or dusty environments.

But how does the lens perform? That is what I'll look into here.

Specifications


The lens is sized as you can expect, between the Lumix G 14-42mm II and the Lumix G 14-140mm II:

From left to right Lumix G 12-32mm f/3.5-5.6, Lumix G 14-42mm f/3.5-5.6 II, Lumix G 12-60mm f/3.5-5.6 and Lumix G 14-140mm f/3.5-5.6 II

Looking into the specifications, you'll see that here as well, it is placed between them:

LensLumix G 12-32mm f/3.5-5.6Lumix G 14-42mm f/3.5-5.6 IILumix G 12-60mm f/3.5-5.6Lumix G 14-140mm f/3.5-5.6 II
AnnouncedOct 17th, 2013Jan 29th, 2013Feb 24th, 2016Apr 24th, 2013
Lens elements/groups8/79/811/914/12
Minimum focus0.2m0.2m0.2m0.3m
Weight70g110g210g265g
Diameter56mm56mm66mm67mm
Length24mm49mm71mm75mm
Filter thread37mm46mm58mm58mm
Weather protectedNoNoYesNo
Hood suppliedNoYesYesYes

You can note that the 10x superzoom Lumix G 14-140mm f/3.5-5.6 II is only slightly larger and heavier. So in terms of bulk, there is not that much reason to choose the 12-60mm lens. The 14-140mm is also one of my favorite lenses, see my review here. So it remains to be seen if the 12-60mm lens can compete.

Saturday, 19 November 2016

G85 video stabilization vs Olymous E-M5 Mark II

I recently showed that the Lumix G85 is way superior to the GH4 when it comes to video image stabilization, using the newer in-body image stabilization (IBIS). However, the focus speed was not as good in 4k mode, probably due to less processing power in the Lumix G85.

But how does it compare with the Olympus E-M5 Mark II, which made waves in this area almost a couple of years ago, with a fantastic video image stabilization?

In this article, I put them head to head. To avoid any possible advantage of using the same brand name lens as camera body, I have used the third party Sigma 30mm f/2.8 Art lenses, which I like a lot:

Both cameras are mounted to a Desmond stereo bracket here. They are both recording in 1080p resolution, with 60FPS framerate. I have both set to f/2.8 aperture, and using continuous autofocus. Here is the comparison:



Based on this comparison, it looks like the Olympus E-M5 Mark II is still a bit better when it comes to image stabilization, however, this was a quite extreme test, with some careless walking around.

In terms of autofocus, no single camera is consistently the best here, but I think both do quite well.

The Lumix G85 has the newest firmware, 1.1, designed to fix the panning jerkiness.

Given the capabilities of the two cameras, my choice is clear. The Lumix G85 is by far the most usable. I also like its ergonomics much better. With the Olympus E-M5 Mark II I often get annoyed trying to find the feature I want in the menus. I will still keep it for when I want to try the high resolution mode.

Monday, 14 November 2016

G85: Awesome video image stabilization in 4k

The recently announced Lumix G85 breaks new ground with the in-body image stabilization (IBIS) trickling down into more camera models. It also helps giving very good stabilization of video recordings. See a demonstration of how the sensor moves here.

To further illustrate the effectiveness of the image stabilization, I have compared it with the Lumix GH4. In the comparison, I used two pairs of lenses: The classic Lumix G 20mm f/1.7 pancake prime, and the Lumix G 14-42mm II basic kit zoom lens. I had both cameras mounted to a Desmond stereo bracket for the comparison:


Both cameras were recording 4k video at 30FPS, at maximum aperture. On the Lumix G85 I had the in-body image stabilization enabled, but not the additional E-stabilization. Both cameras were set to continuously autofocus during the video recording. Here are the results:

Saturday, 12 November 2016

Lumix G85 IBIS sensor shift demo

While Olympus have relied on in-body image stabilization (IBIS) since the start of Micro Four Thirds, Panasonic have taken another route: Optical Image Stabilization (OIS), i.e., lens elements moving to offset camera shake. The disadvantage of OIS is that it needs to be implemented in every lens. And many Panasonic prime lenses do not have OIS built in.

Hence, Panasonic have started to use IBIS: First in the premium rangefinder style GX series: GX7, GX8, and the more reasonably priced Lumix GX85. Starting this autumn, the technique has also trickled into the SLR styled G series with the Lumix G85. At the same time, we see the quality and the usability of the IBIS implementation improve.

To demonstrate how this works, I have mounted the Lumix G85 on a Desmond stereo bracket, facing the Lumix GH4 with a Samyang 7.5mm f/3.5 fisheye lens:


The lens was set to the closest possible focus distance, and f/4.5. By powering on the Lumix G85 camera without a lens mounted, it is possible to see how the sensor moves around inside it:

Sunday, 6 November 2016

Mirrorless or DSLR camera?

If you are in the market for a system camera, i.e., one with interchangeable lenses, there are basically two choices: A mirrorless system like Micro Four Thirds, or a more traditional DSLR system. So how are they different?

To illustrate, here are two enthusiast cameras in the categories: Olympus OM-D E-M5 Mark II and Nikon D7200:


One difference between them, which is not easily visible in the picture, is that the register distance is much shorter for the mirrorless camera on the left: 20mm vs 46.5mm for the Nikon F mount on the right. This allows for making smaller cameras, obviously, but it also allow the designers make smaller wide angle lenses.

This is illustrated with the Samyang fisheye lenses pictured: They are functionally the same, but the fisheye lens for the mirrorless camera can be made much smaller due to the smaller register distance. For longer tele lenses, there is not so much difference for the same focal lengths, though.

Sunday, 9 October 2016

News: Even better enthusiast cameras

The Photokina trade fair is recently over, and we have had some more announcements in the time after that. In summary, I think this was the most exciting Photokina for Micro Four Thirds users, ever.

Both Panasonic and Olympus announced their new high end models, the Lumix GH5, and Olympus OM-D E-M1 Mark II. On top of that, we also got a lot of new lens options.

Looking at recently announced compact mirrorless cameras for enthusiast users, I think it is fair to say that there has been a revolution in terms of features. The image quality has probably not changed much, but a lot of useful features have been added. More cameras get articulated touch screens, and we get better video options and better image stabilization.

Here is a summary of some important models:

CameraSize, weightPriceCropArticulated screenVideoIBISLayoutWeather protected
Lumix G80/G81/G85128 x 89 x 74mm, 505gUS$9002xYes, touch4k30pYesSLR styleYes
Lumix GH5133 x 93 x 84mm?, ~600g?US$2000??2xYes, touch4k60p @ 8 bit, 4k30p @ 10 bitYesSLR styleYes
Olympus E-M1 Mark II134 x 91 x 67mm, 574gUS$20002xYes, touch4k30pYesSLR styleYes
Fujifilm X-T2133 x 92 x 49mm, 507gUS$16001.5xTilt only4k30pNoSLR styleYes
Sony A6300120 x 67 x 49mm, 404gUS$10001.5xTilt only4k30pNoRangefinder styleNo
Sony A6500120 x 67 x 53mm, 453gUS$14001.5xTilt only, touch4k30pYesRangefinder styleNo
Canon EOS M5116 x 89 x 61mm, 427gUS$10001.6xTilt only, touch1080 60pNoSLR styleNo