Panasonic GH4 vs GH3 What's the difference ?

 

The recently released GH4  looks the same and mostly works the same as the GH3, Panasonic's previous, and still available, top tier pro level, hybrid stills/video camera.

So, is it worth the cost to upgrade from the GH3 to the GH4 ?  Let's see the differences between them.

* Top of the list is the very well advertised 4K video which comes to a consumer camera for the first time in the GH4. So heavily has this feature been promoted that the prospective buyer might be inclined to think the GH4 is for motion pictures and little else.

I think of the GH4 as two extremely sophisticated capture device in one body,  one for motion picture the other for stills.  

I use the GH4 exclusively for still photos. So this post compares the two cameras for still photo capture. There is a great abundance of commentary available elsewhere about motion picture capabilities. 

* Next comes the electronic viewfinder. The EVF is the feature of the GH3 that drew the most criticism. The GH4 has a completely new EVF and optics which answers all the criticisms of the previous one. It is a delight to use. I posted about it recently on this blog.

* The GH4 has much improved continuous autofocus capability. With the right lens, for instance the 35-100mm, 12-35mm or 14-140mm f3.5-5.6, the GH4 delivers almost twice the frame rate, a noticeably reduced EVF blackout time and a substantially higher rate of sharply in focus frames when follow focussing on moving subjects. I have posted about it recently.

Specifications and features    In no particular order here follows a list of features of the GH4, most but not all of which represent an upgrade from the GH3.

* Auto ISO in Manual Exposure Mode.  At last, after many requests by users, Panasonic has finally offered this capability. I use it frequently. For instance if I am shooting with the 100-300mm lens at the long end, I want the shutter speed at 1/1600sec for sharp pix hand held (1/600sec is definitely not fast enough and even 1/1000sec gets me some unsharp frames) and f8 for best image quality. So I set those two exposure parameters and the camera adjusts ISO to ensure correct exposure.

* Peaking is now available in Manual Focus Mode. This is another  feature frequently requested by users. On the GH4 it is well implemented with numerous options and it works very well.

* Extended ISO now goes down to 1/100sec, was previously 1/125sec.

* Highlight/shadow/tone curve adjustment is available in the EVF or monitor, prior to capture.

* Face detect adds eye detect and puts cross lines on the selected eye, usually the nearest.

* E-Shutter scans the sensor in 1/15 sec which is faster than the GH3's 1/10 sec. This should offer less rolling shutter effect (distortion of subjects moving in relation to the camera). In addition the highest ISO setting available with E-Shutter has increased from 1600 to 3200.

There is a possible downside to the increased scanning speed. One blogger has reported that with E Shutter the GH4 captures at 10 bits instead of the usual 12 bits available on M43 cameras and the GH4 with mechanical shutter.

* There are many improvements to the manual focus and autofocus capabilities of the GH4. I have posted about this here.

23 Area AF on the GH3 becomes 49 Area on the GH4. 1 Area AF can be set anywhere in the frame.

* There is an extra position on the Drive Mode dial for time lapse.

* Still, you cannot set AEB +Timer delay. They are occupy separate positions on the Drive Mode dial. There is no position which combines both. Furthermore there is still no facility to actuate the shutter mechanism once and have all 3 or 5 AEB frames fire automatically. So as with the GH3 you still need a wired remote shutter cable or smartphone app.

* There is an item in the Setup Menu called [Live View Mode] which is a bit confusing. It is said to refresh the "Live View Screen" but doesn't clarify if that is the EVF or monitor or both, at 30 or 60 fps. The 60fps setting is supposed to provide smoother panning at the expense of greater power use.  I tried both and had difficulty convincing myself there was a difference.

* Part of the AF/MF upgrade is about being able to seamlessly integrate AF with MF. On the GH3 you can focus manually while in an Autofocus Mode. Now with the GH4 this is still available but you can also autofocus with the AFL/AEL button while in Manual Focus Mode. This is handy to get quickly to the desired focus point ready for manual fine tuning.

* AF area size can now be adjusted in large steps with the rear dial and smaller steps with the front dial. This might be considered overkill but it does allow almost any AF area size and position to be quickly set.

* Pinpoint AF has additional options for screen magnification, also using the front and rear dials.

* Zoom level in MF Assist can also be adjusted with the front and rear dials, also using the rear dial>large steps, front dial>small steps feature which operates on several functions on the GH4.

*Silent Mode is available on the GH3 as a firmware update. It is built into the GH4.

* Flash shutter speed has increased from 1/160sec to 1/250sec.

* Top shutter speed is up from 1/4000sec to 1/8000sec. This could be useful in bright light if a wide lens aperture is used. Shutter longevity rating has increased from 100000 to 200000 cycles.

* The GH4 has extensive options for in camera playback of images including RAW processing and image editing.

* Wi Fi is available and compatible with NFC on the GH4.  There is extensive coverage of Wi Fi features in the owners manual.

* The Owners Manual has increased to a massive 420 pages. The full version is still available only as a PDF.   However it is better designed than before. In particular navigating the PDF is more coherent and streamlined than before.  The GH4 owners manual is the first one from Panasonic that I feel reasonably confident of being able to use without having to print the whole thing out.

* The list of items assignable to the Q menu has increased from 24 to 35. However the maximum which can be carried on the Q Menu is 15 of which only 5 are visible without scrolling.

* The list of items assignable to a Function button has increased from 39 to 54. In addition the GH4 has more soft Fn buttons if you want to use the touch screen feature. Just for fun I worked out that if you used all the hard and soft Fn buttons the total number of possible combinations of Fn button functions would be  86839771950000000, or something like that.

I will post a series on "setting up the GH4" soon to help new and maybe some not so new owners manage the hyper configurable environment of an upper spec Panasonic camera. There is a logical approach to it, which makes the task considerably less daunting than might appear initially.

* There appears to have been a backwards step with the auto ISO upper limit setting. On the GH3 you can change ISO with one dial and auto ISO upper limit with the other dial. But on the GH4 the auto ISO upper limit can only be set in the Rec Menu. I was unable to find any other way to do it. So I just set 25800 as the upper limit and leave it at that.

* There also appears to have been a backwards step with flash exposure compensation. On the GH3 you can change exposure compensation with one dial and flash exposure compensation with the other dial, while looking at the same screen. But on the GH4 the quickest access to flash exposure compensation appears to be the Q menu, to which this can be allocated.

Summary  The GH4 is the most highly specified camera I have ever encountered. Panasonic has included almost every conceivable feature, specification, option and capability in the one amazingly capable device. Other manufacturers hold features back from some models forcing buyers to change models or buy several bodies to access different capabilities. Some have touch screen some do not. Some have a fully articulated monitor, some do not.  Some have high grade video some do not.   The list goes on....

But the GH4 has the lot. A novice could pick up the camera, set iA Mode  and use it as a point and shoot device. Yet it can function as a professional video or stills camera or both at once if desired.

The user can choose which of the camera's myriad functions he or she wishes to utilise. These choices can be altered at any time without having to invest in a different camera body.

What about image quality ?  You will notice I did not mention picture quality in the list of features above. Adobe Camera Raw 8.5 final has only just become available as I write this so I have not done systematic picture quality comparisons yet. However the GH4 has a DXO Mark score only 3 points greater than the GH3  so I do not expect much difference to emerge from real world testing. My subjective impression is that the GH4 performs better at high ISO settings but we shall see.

Is the GH4  worth the upgrade cost from a GH3 ? 

For still photos I would say yes if: 

* You regard EVF quality as an important part of the user experience.

* You want the GH4's superior burst rate and follow focus performance with moving subjects.

Otherwise keep your GH3 or buy one new at the current discounted price or get one second hand.

Just a word about used GH3s. Mine is in the repair shop at the moment with a superficially scratched EVF eyepiece lens, resulting from normal cleaning. I have read reports by users that others have had this problem, so be alert. Presumably the eyepiece glass is soft. In addition some of them have developed looseness in the articulated monitor joint.

I do not do video, never use a touch screen, never set iA and  never use Creative Control Mode. I have no interest in Wi-Fi and never want to perform image editing in camera. But I will be keeping my GH4 and selling the GH3 which is still an excellent camera, by the way. I do regard EVF quality as important and I do want the superior burst/AF-C performance.

I doubt whether many owners would care to use all the possible functions of the GH4. But they are there for those who want them and each individual will have his or her own ideas about that.

The GH4 is like Photoshop to me. I run Photoshop in preference to Lightroom. I don't  use or even remotely understand many of Photoshop's more advanced features but I don't care because it has Bridge which I do want and  I often use functions of Photoshop which Lightroom does not have.

 

 

 

Panasonic GH4 User review Part 5, 100-300mm lens compatibility problems

GH4 with 100-300mm , hand held.  f8, 1/1600 sec. It was a hazy warm day, not really good for long distance photography however the 100-300mm lens has handled the conditions well. The buildings in the foreground and the old crane which is being dismantled by the men from Marrs are about 1.5 kilometres from the camera. The buildings in the background are about 3 k away.

 

The Panasonic Lumix 100-300mm lens was announced in September 2010 along with the GH2 camera body. Since then Panasonic has introduced the G3, 5, and 6, then the GH3 and now the GH4. With each new model comes an increase in performance especially when using burst Mode and AF-C for follow focus on moving subjects.

Unfortunately the performance capability of the 100-300mm lens has not been able to keep up with the camera bodies. The GH4's frame rate in Burst Mode M (7fps) is almost double that of the GH3 (4fps).  Even on the GH3 the 100-300mm lens was unable to run at 4 fps, giving on average about 3 fps.  Unfortunately the 100-300mm lens is not able to match the performance of the GH4 at all.

This is a particular problem because in the GH4 we have for the first time a Panasonic Lumix camera which can genuinely claim to be usable for follow focus on sport/action/wildlife with a high frame rate and on my tests with the 35-100mm lens a very high rate of frames in sharp focus.

For many sports, action, wildlife and similar subjects the 100-300mm lens has the ideal focal length range and is very good optically.

But many users reporting on forums are expressing frustration that the 100-300mm lens does not allow the GH4 to express it's potential.  I have had the same problem.

Crop of the top photo. It appears the Navy has parked a ship in the middle of the city, which it has, more or less.  The 100-300mm is great for single shot photos, when it focusses correctly which is about 90% of the time.

Timings

I ran some timings on the 100-300mm lens mounted on the GH4. I used a SanDisk Extreme Pro 95 MB/sec card, Burst Mode M (which allows AF, AE and live view on each frame), 1 Area center AF Mode, AF-C and AF-S  Focus Mode, RAW capture. I timed bursts of 40 frames. The GH4 will deliver 48 RAW frames before the frame rate slows due to the buffer filling.

At f4: AF-S gave 7fps,  AF-C gave 4 fps.

At f8:  AF-S gave 3fps,  AF-C gave 2.3 fps.

When the lens did not have to focus or close down the aperture diaphragm for each shot it ran at 7fps which is the same rate as the 35-100mm lens.

Forcing the lens to focus on each frame slowed it considerably. Forcing it in addition to close the aperture diaphragm made the lens slow even further.

In addition I found that when using the lens on moving subjects in AF-C the hit rate of sharply focussed frames was significantly less (variable but about 70%) than that delivered by the 35-100mm (around 95% with many types of subject).

Other issues  I have been using the 100-300mm a lot lately and have found two other problems on the GH4.

* Even in AF-S Focus Mode, the hit rate of perfectly focussed frames is lower than I get with most other lenses. With the 12-35mm, 35-100mm and 14-140mm which are the lenses I most often use, I see about 1% of frames not in perfect focus provided I use the camera thoughtfully,  don't expect the impossible and don't expect the camera to read my mind.

But with the 100-300mm I am seeing 5-10% of frames not quite in perfect focus. Furthermore I can see no particular reason why the slightly off focus  frames should be so.

* The last one is that the EVF on my GH4 flickers intermittently when the 100-300mm is mounted.  At first I thought I had a faulty camera but it appears to work fine with other lenses. I think the problem is one of partial incompatibility between the GH4 and the 100-300mm lens.

I would very much like Panasonic to update this lens very soon as it has become  obvious that it is not a good match for the GH4 camera body and is holding back the performance capability of the GH4 for sport/action/wildlife photography.

 

Panasonic GH4 User Review Part 4 Shutter Shock

Mechanical shutter 1/80sec

E-Shutter 1/80sec

All Micro Four thirds cameras to date have a mechanical shutter.  All of those which I have tested to date can produce unsharpness with or without double imaging with some lenses at some shutter speeds. 

In order to  prevent the occurrence of this nasty little problem recent Panasonic cameras have an Electronic shutter and recent Olympus cameras have an "Antishock 0" setting, which has been reported to utilise an electronic first curtain.  

On my testing Panasonic E-Shutter completely eliminates blurring due to shutter shock. I have not tested Olympus Antishock 0 but it is also reported to be effective.

I have no idea why Panasonic does not offer electronic first curtain shutter operation. Several other manufacturers do and it is reported to eliminate the shutter shock problem with no adverse effects as far as I am aware.

The benefits of Panasonic E-Shutter are the result of there being no mechanical parts thus allowing

* Silent operation, with or without beeps as set in the Custom Mode.

* No vibration and therefore no blurring due to shutter shock.

The disadvantages of E-Shutter are largely due to the fact that the process of scanning the sensor electronically takes 1/15 second. The GH3 E-shutter takes 1/10 second.

* Incompatible with electronic flash.

* ISO limited to 3200. (1600 in the GH3).

* Longest shutter speed available is 1 second. For vibration free exposures longer than 1 second set Shutter Delay page 4/7 in the Rec Menu.

* Subjects moving in relation to the camera may be distorted in shape.

* There have been reports that E-Shutter on the GH4 may provide only 10 bit capture. Panasonic M43 cameras have 12 bit capture with the mechanical shutter. The trade  off  for the faster scanning speed on the GH4 may be a lower bit rate.

The Panasonic GH4 has a faster mechanical shutter than the GH3 which allows a faster  shutter speed to be used with flash (1/250 sec vs 1/160 sec) and a faster top speed (1/8000 vs 1/4000) which can be useful in bright light when a wide lens aperture is desired.  I was wondering if it also causes more problems with shutter shock than the GH3 and other Panasonic M43 cameras.

So I ran my usual test procedure which is:

* Select camera body, lens, focal length for testing.
* Set up a suitable test target. I use classified adverts from a newspaper as this provides clear differentiation between sharp and unsharp frames and readily shows any double imaging if present.
* Mount the camera on a sturdy tripod. This is to eliminate camera movement as a source of any unsharpness.
* Use remote shutter release, wired or wireless, for the same reason.
* Switch OIS or IBIS off. This is recommended by the manufacturers for tripod use.
* Set Shutter Priority auto exposure and auto ISO.
* Focus with AF or MF. Run some preliminary tests to ensure your equipment is focussing accurately.
* Make a series of exposures from 1/4 sec to 1/500 sec. Use the mechanical shutter for the first run then the E-Shutter (or Olympus Antishock 0) for the second run.
* Look at the results at 100% on screen. Any unsharpness or double imaging will be clearly evident.    

On this occasion I used the Panasonic 14-140mm lens set at 140 mm. I had previously determined that this lens at this focal length is affected by unsharpness due to shutter shock with the GH3 and G6 camera bodies.

Results  I got essentially the same results with the GH3 and GH4. With the mechanical shutter, speeds of 1/15 sec or lower were no problem. From 1/20s to 1/50s there was some blurring visible. From 1/60s to 1/200s there was blurring with double imaging. 1/250s and 1/320s were slightly soft.  1/400s and faster were sharp.

When using the E-Shutter all the frames were sharp.

Recommendations for use  With the 14-140mm lens I always use the E-Shutter for general photography and have no problems at all. 

If I want to use a shutter speed of 1/500 sec or faster which is usually for moving subjects, sport/action and the like, I set E-Shutter OFF which causes the camera to revert to the mechanical shutter.

If I need to use a shutter speed longer than 1 second, with the camera on a tripod, I set Shutter Delay to ON. If I am firing the shutter remotely a delay of 2 seconds is plenty. If I press the shutter button it can take longer for the camera to settle down so I use 4 seconds.

The only problem with these usage strategies is that you have to keep an eye on the shutter speed and remember when to switch the E-Shutter on or off.

Some in the camera commentariat have proclaimed the E-Shutter to be "useless" because of it's limitations. But I use it all the time with no problems at all. One just has to be aware of the limitations and work around them as described above.

 

Panasonic GH4 User review Part 3.4 Continuous autofocus

GH4, 35-100mm f2.8 lens

 

In the previous post  I commented that GH4 single shot AF  is not much better than  the GH3 largely because the GH3 is already excellent and difficult to improve.

But continuous AF   is another story altogether. Since the first MILCs appeared in 2008 they have lagged behind the best DSLRs in follow focus performance, using AF Continuous and Burst Mode to photograph subjects moving towards or away from the camera or moving unpredictably. 

The GH4 changes all that.  The GH4 is both faster and more accurate than the GH3 in Burst Mode using  AF-C. Even better the GH4's EVF blackout time after each frame  is substantially less than that of the GH3. Together these improvements make for a much improved user experience and much better results.

Recommended Setup  In the Rec Menu, page 2/7 set the Burst Rate to M. This is the fastest rate which provides AF and live view on each frame and is therefore the optimum rate for sport/action.

In the Autofocus Menu set 1 Area, not tracking.  Set the active AF area  usually to center position and the second or third smallest (not the very smallest) size.  AFC works with the AF area anywhere in the frame. I recommend placing it in the center for most situations as keeping the subject in frame is usually easiest that way.

Preparing for Continuous AF   The GH4 allows very quick shifting from  single shot settings for general photography to follow focus settings for sport/action.

1. Move the Drive Mode Dial to Burst.

2. Flick the Focus Mode Lever to AFC.

3. Move the Main Mode Dial to S (shutter priority AE) having pre set the shutter to a speed suitable for the lens in use. I use about 1/500 with the 35-100mm lens at 100mm and about 1/650 second with the 14-140mm at 140mm.

4. Set ISO to Auto ISO if it was not there already.

5. Check that OIS is On.

6. You can use E-Shutter or the mechanical shutter. I prefer the mechanical shutter provided the shutter speed is faster than the upper limit of the observed shutter shock zone, which is about 1/400 sec. Distortion of subject elements moving within the frame is quite likely with the E-Shutter.

Lenses matter  With the GH4 Panasonic has introduced some new AF technology which means that optimum performance is achieved only with certain Panasonic M43 lenses and not with lenses from other brands even though they are dedicated M43 models.

I  have not yet used many lenses with the GH4 in Burst Mode but I have determined that the Panasonic 35-100mm f2.8 and the  Panasonic 14-140mm f3.5-5.6 allow the GH4 to produce it's full  performance. The Panasonic 100-300mm does not. This lens is good optically but delivers about half the frame rate of the other two lenses together with a much lower success rate expressed as percentage of frames in sharp focus. The operational deficiencies of this lens have become glaringly obvious now the GH4 has arrived. I would like Panasonic to upgrade this lens tout suite.

Memory cards matter  For the results reported here I used a San Disk Extreme Pro UHS 3, 280MB/s card. However I also noticed and others have reported there is little or no loss of performance using a San Disk Extreme Pro UHS 1, 95MB/s card.  Any slower card is not recommended.

Technique  There is nothing arcane here. Zoom to frame your subject, place the active AF area over the part of the subject you want to be in focus, press and hold the shutter button.  Follow the action by panning as required. I have found it is not good practice to zoom while capturing a burst of exposures. Zooming seems to unsettle the AF function. My practice is to zoom between capture bursts.

Results  It is early days yet and I have many more tests to run but my initial results are worth reporting.  Remember these results are all obtained using Burst M and 1Area AF Mode setting.

Frame rate  JPG capture gives 7 fps.  RAW capture starts at 7 fps then  after about 15 frames slows slightly to about 6 fps.

Frames to slowdown  When the buffer is full the frame rate slows suddenly. This point is reached after 48 RAW files in 8 seconds. With JPG capture the camera was still ripping along at 7fps after 100 frames in 14 seconds at which point I stopped recording. Presumably capture will continue at that rate until the card is full.

Recovery after burst  (time to clear the buffer)  This was 23 seconds after 48 RAW files and 7 seconds after 100 JPG files. The camera continues to operate while the buffer is clearing, allowing adjustments to be made and photos to be taken.

Percentage of sharp frames  This is the big test. There is not much point having a camera which runs fast unless it is also accurate. I found that the  GH4 is indeed remarkably accurate, on easy and difficult subjects alike.

Easy subjects:  Cars moving towards and away from the camera and people walking or running towards or away from the camera. Just two model generations ago this would have been a difficult test but now it is no problem for the GH4 at all. On  all my tests in bright light or dull, overcast conditions the GH4 with 35-100mm lens scored 95% or better of frames in sharp focus. The only frames not in sharp focus have been those produced by holding the shutter down until the subject came impossibly close such that I doubt any camera could hold focus.

A more difficult subject:  As it happens three days after picking up my new GH4 I had the opportunity to photograph one of my grandsons playing indoor basketball. The occasion was a grand final so the 11 year olds were running as fast as they could and made very good game of it.   Lighting was mediocre, consisting of a few small skylights and a few high banks of fluorescent tubes. I set the shutter speed to 1/500 sec and Auto ISO selected ISO 6400-12800.

To my surprise and delight 95% of  the 200 frames of boys running were in sharp focus at the active focus area position. This means I didn't always get the right boy in focus but that was a framing issue not a focus problem.  Sometimes I didn't get any of the players in the middle of the frame. The camera simply focussed on the background on that frame then jumped back to the player on the next frame. The remarkable thing is this all happened at 7 fps.

Summary The GH4 represents a big improvement over the GH3 in follow focus performance using AF-C on fast moving subjects. The frame rates are impressive and  the number of sharp frames even more so. The main former advantage of the DSLR over MILC type cameras is held  no longer.

Footnote about technology  Over the last few years most camera makers already had beneath the mirror box (DSLR) or incorporated onto the imaging sensor (some Canon models and several MILCs)  the capability for phase detect autofocus. Many in the camera commentariat opined this was necessary for good follow focus performance. The only holdout using contrast detect AF exclusively is Panasonic which with the GH4 appears to have produced the current champion for AF-C among MILCs, with a performance equal to or better than many DSLRs.    Go figure.  It appears the commentariat was wrong. No doubt other manufacturers will catch up soon, using a variety of technologies. Us camera users are the beneficiaries.

There is a curious irony afoot right now. Camera sales are falling steeply across all categories but the actual cameras being offered are better than ever and improving with each new model.  Happy days for those of us who still like to use a real camera to make photos.   

 

Panasonic GH4 User Review Part 3.3 Single Shot Autofocus

GH4, 100-300mm lens

 

The GH4 is reallytwo cameras in one body, a high performance stills camera and a highly capable 4K video camera.

This post is about  autofocus for still photos. There is extensive information about AF for video elsewhere.

Panasonic M43 cameras  have delivered very good single shot AF right from the G1 of 2008. Successive models have improved AF speed and added features and capability. The GH4 has the best AF Single of any camera I have ever used.

Newcomers to  the Panasonic AF user interface might be a bit overwhelmed at first by the number and variety of AF options and features available. Careful perusal of the owners manual is definitely recommended.  Fortunately the GH4 manual is well designed and easy to use but with 420 pages it's no light read.  I hope this and other posts in the current series will be useful for new GH4 owners.

Recommended Setup  In the Custom Menu, set Direct Focus Area On, AF+MF On, MF Assist On (Focus ring on lens), MF Guide On, Peaking On, AF/AE Lock button to AF On, Shutter AF On, Half Press Release Off, Quick AF Off,  Eye Sensor AF Off, AF assist lamp Off (not required:  the AF works just fine in very low light without the assist lamp), Focus/Release Priority FOCUS, .  In the Rec Menu set AFS/AFF to AFS. (page 1/7)

Allocate Autofocus Mode to the Fn3 button (this is the default setting so you can just leave it there).

General caveats about AF  All AF systems will fail in certain situations. Some of these are due to the inherent nature of AF technology, others are due to the inability of the camera to read your mind. Examples:

* A smooth subject with no lines or exclusively horizontal lines or no  texture provides nothing for the AF system to read.

* A dark/small foreground subject which you want in focus in front of a bright/contrasty background. The AF system will be attracted to the bright lights and focus there. You need to set an AF area smaller than the subject and make sure the AF area does not stray outside the edge of the subject.

* Lights on Xmas tree or any other subject with multiple bright light sources in frame will tend to confuse AF systems. The lights produce multiple small flare sources making it difficult for the AF system to figure out which are in focus and which are not quite in focus.

* A forest of little branches is another type of subject which the AF system can't resolve. No matter where the lens is focussed, some branches are in focus and some are out of focus. I switch to manual focus in this situation.

Hints about technique  Achieving accurate AF is not a passive process which you leave to the camera's automatic functions. It needs active guidance from the user.

* If time is not of the essence, half press the shutter button or press the AF/AE Lock button, wait for the AF square to go green and hear the double beep, check that the part of the subject which you want to be in focus actually is, then fully depress the shutter button.

* Adjust the size and position of the active AF area so it lies exactly over and is smaller than the part of the subject you want to be in focus. With the GH4 you can be very precise about this.

Settings  Set the Drive Mode dial to Single Shot. (single rectangle icon).  Set the Focus Mode Lever to AFS/AFF.

Activating AF  As usual with a high end Panasonic camera you get several options. You can activate AF with a half press of the shutter button or by pressing the AF/AE Lock button (back button AF start). However if you set Quick AF in the Custom Menu to On, the camera will continuously try to focus. If you set Eye Sensor AF in the Custom Menu On, the camera will focus when you bring the viewfinder to the eye. I find these last two options distracting so I switch them off. Some users might like them on although they do drain the battery somewhat.

But wait, there's more. The GH4 has a capacitive touch screen. This can be used to select and activate AF, change AF area position and size and fire the shutter. I mostly use the EVF for viewing so I find the touch screen functions not useful for me. Even with monitor viewing I find operating the touch screen awkward. Some reviewers and users report they like the touch screen. Anyway it's there if you want it.

There is also a function called Touch Pad AF which enables the user to move AF area with the touch screen while eye level viewing. Some users have reported they like this function but I found it very awkward as you have to push a finger between the screen and your face. I find moving AF area with the Control Dial much more satisfactory.

Autofocus Mode  The GH4 has a very comprehensive Autofocus Mode which enables the user to manage virtually every conceivable contingency. The price for this is a learning curve to manage the complexity. The AF Mode options are:

Face detect, Tracking, 49 Area, Custom Multi, 1-Area, Pinpoint.

Face Detect does what it says and I find it works well most of the time. The face detect system is quite sophisticated. It will identify a face then locate the eyes and indicate which eye will be selected, usually the closest.   If the system cannot identify a face it defaults to 49 area with auto selection. You may or may not like this as auto selection assigns selection of AF area(s) to the camera.

Tracking  This has been a feature of Panasonic AF from the G1 but I never use it as I am not convinced it works for my requirements. The function identifies the part of the subject in the center of the frame when the shutter button is half pressed then endeavours to keep that part in focus if it moves laterally (left/right, up/down) within the frame. I think this could possibly be useful for video or some types of slow subject movement across the frame. Unfortunately many reviewers and users set tracking when they want the camera to follow focus on a subject moving towards or away from the camera as in sport/action. This is not a good idea, see 1 Area below. Unfortunately the owners manual does not clarify which situations are best served by tracking and which are best managed by another AF function.

49 Area  This covers a box about 3/4 linear size of the whole frame. You can let the camera decide which of the 49 areas to select using it's inscrutable electronic brain, or you can select any subgroup of  9 contiguous areas. I never use the 49 area option as it does not give me enough control over the position and size of the active AF area.

Custom Multi  This is a new AF mode for the GH4 designated by the [Free] icon in the AF Mode submenu. I have to confess this looks to me like the answer to a question nobody asked.  It is a variant of the 49 area Mode which allows you to create an AF area of any size or shape provided it is built up from any of  the 49 areas, which don't even need to be contiguous.  It also allows you to save three of these shapes as Custom AF areas.  

1 Area  I find this to be the most useful AF Mode for most types of photography. It gives the user full control of  AF area position and size. It also works best for AF-C, see the next post.

You can set the active AF area anywhere in the frame. The size can vary from a very small to a very large box.

Activate control of the AF area by pressing the Control Dial anywhere on it's rim (Pre select Direct Focus Area in Custom Mode)  and directly move AF area position by press and hold or repeated presses of the Control Dial. Change AF area size in big jumps with the rear dial or smaller intermediate steps with the front dial.  Return the AF area to center by pressing the Disp button while AF area is active (yellow with bounding arrows).  Half press shutter button to resume normal operation.

With practice this is much quicker to do than read about. I change AF area position and size very frequently as it is so easy to do.

The GH4 offers both smaller and larger options for AF area box size than the GH3. As a result I now find few situations where Pinpoint is required.

Pinpoint  This does what it says. Focus is confined to a very small pinpoint in the frame. Position of the point can be moved within a box smaller than that available for manual focus. Use the Control Dial as for 1 Area above. When the shutter button is pressed half way or the AF/AE Lock button is pressed focus is initiated and the monitor or EVF shows a magnified view of the in focus area as a box within a box. The time for  which this displays can be adjusted in the Custom Menu> Pinpoint AF time> Long/Mid/Short.  The Mid setting gives about one second which is usually plenty.

Pinpoint can be useful for situations like the bird in a tree subject where you want to focus precisely on the bird without catching  all the branches and leaves around it.  I don't use pinpoint very often but when I have used it focus appears to have been very accurate.

Results  You can see from the description above that the GH4 offers the user an astounding plethora of autofocus modes, functions and options. But does it all work ?

In a word, Yes. In a few more words, I have found the GH4 to have the most effective AF system of any camera which I have ever used.  In general use, with a variety of lenses in a range of conditions from very bright to so dark I can hardly see, the AF system nails correct focus almost every time. I have to put that "almost" in there because on my count about 0.5% of the 2000 or so photos I have made with the GH4 to date are not quite in sharp focus, for no apparent reason. The system is just ever so slightly less than perfect.

Panasonic claims that the camera will focus down to EV minus 4 which seems about right to me. In very low light levels the system shifts gears to Low Light mode in which the sensor is sampled at a slower than normal. This slows down AF acquisition but maintains accuracy.

In the early days of MILCs there was much discussion about the relative AF speeds of various camera types and models.  Recent model MILCs from many makers are now so fast at acquiring single AF that the process is almost instantaneous and too fast to measure effectively. The question "has camera A got the fastest AF" has become largely irrelevant as most of them are so fast it hardly matters. In the case of the GH3/4 the only exception to this is that some single focal length lenses, for instance the 20mm f1.7 are noticeably slower to AF than newer primes and zooms.

When comparing the GH4 with the GH3 it is hard to see much improvement in single shot AF as the GH3 was already so capable. Some reviewers have opined the GH4 is a bit faster, maybe that is so but the difference must be quite small. The big improvement in focus capability delivered by the GH4  lies in AF Continuous which is the subject of the next post.

 

 

 

 

 

Panasonic GH4 User Review Part 3.2 Manual Focus

GH4 with 100-300mm lens

 

The Panasonic GH4   has a very sophisticated and effective focus system. This post is about manual focus.  The user who has never before encountered a recent model Panasonic M43 camera might find the number of options and functions for manual focus a bit daunting at first. Fear not, with help from the owners manual and a bit of practice the process of camera work will become second nature.

The GH4 has several technologies and features to make the user experience enjoyable and the results of manual focus very effective.

Focus on the imaging sensor  All focus determination is carried out right on the imaging sensor. As a result focus is both precise (repeated measurement gives the same result) and accurate (that result is the correct one).

Focus looks and works  the same in EVF view or monitor view.

Setup for focussing  I use and recommend the following settings in the Custom Menu:

* Direct Focus Area On

* AF+MF  On

* MF Assist On, set focus ring on lens.

* MF guide  On

* Peaking  On,  Detect level High, select a color, I use cyan.

* Leave Fn3 with default function which is Autofocus Mode.

To enter manual focus   push the Focus Mode lever around the AF/AE Lock button to MF.

To move the active MF area  Press Fn3. This brings up the manual focus rectangle with bounding arrows in a box within a box display. Note MF uses a rectangle,  AF uses a square so you can tell at a glance which focus function is active.

Move active MF area with the Control Dial. Recenter by pressing Disp. The MF area can be set anywhere in a box about 3/4 the linear size of the whole frame.

To change the size of the MF area use the rear dial for big steps and/or the front dial for small steps.

To activate MF  turn the focus ring on the lens. This brings up a box within a box showing the preview image magnified at the position of the MF area.

Move the box around the screen with the Control dial.

Change the zoom level with the rear dial for big steps and/or front dial for small steps.

Peaking  if set to On in the Custom Menu will activate automatically. The implementation of peaking in the GH4 is very good  and a genuine aid to focus speed and accuracy. The only exception I would make is that in very low light levels peaking is less effective and AF works better.

AF in MF  Set the function of the AF/AE Lock button in the Custom Menu to AF On. Now you can press the AF/AE button in Manual Focus and the camera will quickly autofocus on the active area, so you only have to fine tune with the focus ring on the lens.

MF in AF  If you set AF+MF On in the Custom Menu you can MF while in AF. Just turn the focus ring on the lens while half pressing the shutter button or holding down the AF/AE Lock button.  This brings up the MF box in a box with peaking.  This allows you to fine tune focus manually while in AF focus mode.

Summary  The GH4 provides a very comprehensive and effective suite of Manual focus functions and options. It readily enables the practiced user to find precise and accurate manual focus in all conditions except the very lowest light levels when AF appears to be more effective.

The new GH4 owner will find perusal of the owners manual and some practice using the manual focus functions pays dividends with more confident camera handling  leading to more effective MF operation.

 

 

 

Panasonic GH4 User Review Part 3.1 Focus Technologies

GH4 with 100-300mm lens

 

From 1989 to 2009  my main cameras were Canon SLRs then DSLRs.  In many respects these were decent cameras with good image quality and performance. But every one of them suffered from inconsistent autofocus accuracy.

Then in 2009 I bought a Panasonic G1, the first mirrorless interchangeable lens camera (MILC) with EVF.  Compared to DSLRs of the time, this camera had second best image quality, performance and ergonomics. But it focussed accurately. First time, every time, all the time. This was a revelation. In single shot use the G1 hardly ever missed focus.  The G1 and all subsequent Panasonic MILCs used a different type of focus technology which clearly delivered a big advantage in accuracy. 

For several years camera reviewers kept asking the wrong question: "how fast does it focus" ? when they should have been asking "how accurately does it focus" ?

In the event Panasonic brought it's MILC AF speed up to match and now surpass that of DSLRs, while maintaining a clear advantage in accuracy and consistency.

 

DSLR focus  systems  Refer to the DSLR schematic.

A standard flipping mirror DSLR has three separate focus systems.   

For manual focus with eye level view the image coming through the lens reflects off the main mirror and is focussed onto  the focussing screen which lies beneath the pentaprism.  The user turns the focus ring on the lens back and forth until the image appears at it's sharpest.  In  manual SLRs of yesteryear this was the only way (apart from setting a distance by scale on the lens) to focus.  On my 50 years old Pentax Spotmatic this actually works quite well with a fast prime lens feeding plenty of light through the optical pathway.  Fast forward to the autofocus era with zoom lenses of smaller aperture and manual focus becomes very difficult at the wide end of a kit zoom. In the digital era sensor size reduced to the 28mm diagonal and pentaprisms gave way to pentamirror design. Manual focus became even more difficult.

For autofocus using the optical viewfinder (OVF)  some light from the lens passes through the main mirror, reflects off a submirror and proceeds to an autofocus module at the bottom of the mirror box. This module uses mirrors, lenses and sensors to tell the main lens which way it should turn to bring a specific part of the image into focus. There are multiple potential sources of inaccuracy in this system. It uses phase detect AF which is inherently both imprecise and inaccurate. It also depends on all the optical and mechanical components in the focussing chain being precisely aligned in the correct position. This is frequently not the case leading to further inaccuracies.

For autofocus in live (monitor) view a completely different focus system is used.  In this case, focus is assessed directly on the imaging sensor. Some cameras use a phase detect array built right into the sensor, many use a contrast detect system like most MILCs.  This has the potential to be more precise and accurate than the PDAF module in the bottom of the mirror box.  Whether it actually is or not depends on the implementation of the technology in each case.

 

Panasonic MILC focus system  Refer to the MILC schematic.

Focus arrangements in Panasonic MILCs are conceptually much more simple. No doubt the actual technology involved is very sophisticated and complex but in principle the ideas behind it are straight forward. 

There is just one focus system. It works by contrast detection (CD) directly on the imaging sensor. This works the same for eye level or monitor view. It is also the same for manual focus except that the contrast detect function is carried out by the operator's eye and the lens is focussed by hand.

Panasonic is one of the few makers to rely entirely on contrast detect focus technology. In the past this meant good single shot AF performance but sub standard follow focus capability using AF continuous on a moving subject. However as I will describe in a subsequent post, Panasonic has  been able to achieve excellent follow focus capability with the GH4 while staying with CDAF.  

In  the next three posts I will describe how the GH4 works and performs with manual focus, single shot autofocus and continuous autofocus on moving subjects. As you will read I have found it to perform exceptionally well in all three focus modalities. In fact the GH4 has the best focus performance of any camera used by me, ever. It is a big step up from the GH3  particularly in AF Continuous on moving subjects.     

Panasonic GH4 User Review Part 2 EVF

GH4, 100-300mm lens, hand held

 

Problems reported with the GH3  

The feature of the GH3 which has drawn most criticism is  the EVF.  This is  prone to a "smearing" appearance towards the edges of the frame if the eye is not held exactly centered and/or the diopter adjustment is a bit off. In addition there have been  various minor complaints about color balance. My GH3 is in for repairs right now in fact for fine superficial scuffing and loss of clarity on the surface of the viewfinder eyepiece caused by normal cleaning. There have been reports on user forums about this. Apparently the glass is too soft or has not been hard coated.  In addition the preview/review image in the GH3 EVF is not really sharp, making accurate focus determination before or after capture a bit more difficult than it needs to be.

From the earliest days of  EVF technology, refresh rate and blackout time have been  impediments to widespread acceptance of the EVF as an alternative to the established optical viewfinder (OVF). The blackout time is a particular problem when shooting in Burst mode, using AF Continuous when following a moving subject as in sport/action/birds in flight etc. 

But EVF's are improving with each new model and the one in the GH4 is no exception. 

The GH4

* Externally the eyepiece lens of the GH4 looks the same as that of the GH3 so I hope they got the surface hardness right this time round.

The EVF can be set to DSLR style view with camera data on a black strip beneath the preview (my choice) or monitor style with camera data superimposed over the preview image. Brightness, contrast and color balance are all adjustable. The EVF can be configured to look exactly the same as the monitor so the segue from one to the other is seamless.

EVF<>Monitor  switching can be triggered by the eyepiece proximity sensor, a button or by folding the monitor in/out. The system is highly versatile and can be configured to suit the individual user.

EVF refresh rate, mysteriously referred to as Live View Mode in the Setup Menu can be set to 30 or 60 fps.  The higher speed is said to provide smoother panning but I found little difference between the two settings in practice. On that subject the EVF pans smoothly in good light, becoming jerky in very low light. It remains perfectly usable however even when ISO 25600 is required, providing a clear well defined preview image. In these conditions you would see hardly anything through the OVF of a mid range DSLR. I was photographing junior indoor basketball a few days ago in rather dull light requiring ISO 10000. The EVF remained sharp and clear with smooth panning even on fast action.

* I am pleased to report the smearing problem has gone.

* Overall the EVF is excellent even at default adjustment settings.  I have set the contrast down one notch to improve highlight/shadow detail and calm down a bit of slightly over exuberant color saturation.  I also lifted brightness one step which suits my eyes.

With my right eye looking through the viewfinder and my left eye looking at the same scene simultaneously, both views look extremely similar. Via the EVF color saturation and accuracy are very good and the preview has a very natural appearance. The direct eye view reveals a bit more highlight and shadow detail in scenes with high subject brightness range but apart from that the EVF provides a very natural looking preview.

* Some reviewers have praised other cameras (for instance the Fuji X-E1)  for providing a more magnified EVF view as if that were a self evident benefit. However the very large view cannot be taken in all at once so there are advantages to the slightly smaller but still plenty large enough approach taken by Panasonic.

* EVF sharpness is clearly improved, making evaluation of image sharpness/focus accuracy easier even with peaking switched off.

* Fortunately the GH4 does have focus peaking which on my initial tests appears to work very well.  I have it set to the "High" position for greater accuracy.

* In burst mode and AF continuous, EVF blackout time is noticeably less, making it considerably easier to follow a moving subject and keep it in frame. I do not have a way to accurately measure the amount but my subjective impression is this:

I guesstimate a good  DSLR  as having about  20%  blackout when shooting continuously. That is, the user spends about 20% of the total capture time looking at a black viewfinder. Again subjectively I guesstimate the blackout time for the GH3 in Burst M Mode to be about 60%. This is so high it makes birds in flight or other unpredictably moving subjects very difficult to hold in the frame.

I put the blackout time for the GH4 at about 30-40% in Burst Mode M at 6 (RAW) to 7 (JPG) frames per second.  This is still significant but subjectively is a big improvement over the GH3. It makes the operator's task of keeping the subject in frame substantially easier.

Summary  Apart from the rubber eyecup which I think they haven't quite got right yet all the problems and issues with the GH3 EVF have been fixed or markedly improved in the GH4.  The overall improvement is so great that in my first few days of use the EVF has "disappeared" in the sense that I am not aware of it's intervention between myself and the subject.  And that is how it should be.

 

 

 

 

 

Panasonic GH4 User Review Part 1 Exterior and first impressions

GH4, Panasonic 100-300mm lens, hand held

 

The GH4  is the latest iteration of Panasonic's top of the line GH series combining a high level of stills and video capability in one compact unit.

My GH4 has finally landed in the household. It will be my main camera, replacing the GH3. I will be reporting my owner/user experience with the GH4 over the next few months.  Most reviews of the GH4 have concentrated on it's amazing video capability. But I don't do video so I will be reporting on it purely as a stills camera.

First impressions  It looks like a GH3, it works like a GH3.  That's a good thing. The camera has good ergonomics and is a pleasure to use. It uses the same battery and other accessories as the GH3. So users stepping up from the GH3 will feel right at home. 

It is, at 920 grams one of the  largest and heaviest mirrorless interchangeable lens cameras (MILC) with standard 12-35mm f2.8 kit lens fitted.  Even the full frame Sony Alpha 7/7R/7S MILC's with the 24-70mm mounted are about the same weight although the lens is larger and only f4.

The GH4 is also, at AUD2500-2700  retail in Australia for the single lens kit one of the higher priced MILCs, although the Sony Alpha 7 cameras and lenses are considerably more costly as are the Leicas.

Some people might think that buying a camera like this purely for stills use is a poor allocation of financial resources and they might be right.  On the other hand in all the excitement about the GH4's remarkable motion picture performance I think the message about it's stills performance is not getting much of a hearing.  So you can read about it here over the coming months.

Exterior appearance and feel  Differences between the GH3 and GH4 are minor.

* There is a little  lip running down the inside of the handle on the GH4, providing a slightly better grip for the finger tips, not that there was any problem with the GH3 grip.

* There are two little nipples on the ISO button, so it is easier to locate by feel.

* The rubber eyecup is wider. I am not enthused by this. I think that if they wanted to improve the eyecup it should have gone deeper, with a thicker, softer feel to the rubber and a more ergonomic shape to better fit the orbital curve in both landscape and portrait orientation. I tried the GH3 eyecup  (it fits) but decided I didn't much care for either of them.

* The Drive Mode dial has an extra position for direct access to the interval timer.

* The Main Mode dial is taller, presumably to make it easier to operate, not that I ever had any difficulty with the one on the GH3, and is fitted with a push/push locking button. This can be set so the dial is locked or unlocked. I never had a problem with the dial moving unintentionally on the GH3 so I will leave it unlocked. The dial itself is a bit stiffer than that on the GH3 and clunks into each setting in a slightly more positive fashion.

* The memory card cover feels a bit tighter, requiring a bit more force to open. Several users had complained about this cover opening inadvertently on the GH3 and I also had this happen occasionally.

* A minor irritation, there is no plastic cover or even a little ziplok bag for the battery, GH3 style. I will look for a small ziplok bag at the supermarket tomorrow.

The really significant upgrades are all inside the camera. Most improvements relate to the EVF, the imaging sensor, autofocus performance and especially continuous AF and of course the video about which you can read elsewhere.